PowerShell/src/System.Management.Automation/engine/serialization.cs

// Copyright (c) Microsoft Corporation.
// Licensed under the MIT License.

using System;
using System.Collections;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Diagnostics.CodeAnalysis;
using System.Globalization;
using System.IO;
using System.Linq;
using System.Management.Automation.Internal;
using System.Management.Automation.Language;
using System.Management.Automation.Remoting;
using System.Management.Automation.Runspaces;
using System.Management.Automation.Tracing;
using System.Net.Mail;
using System.Reflection;
using System.Runtime.CompilerServices;
using System.Security;
using System.Text;
using System.Xml;

using Microsoft.Management.Infrastructure;
using Microsoft.Management.Infrastructure.Serialization;
using Microsoft.PowerShell.Commands;

using Dbg = System.Management.Automation.Diagnostics;

namespace System.Management.Automation
{
    [Flags]
    internal enum SerializationOptions
    {
        None = 0,
        UseDepthFromTypes = 1,
        NoRootElement = 2,
        NoNamespace = 4,
        NoObjectRefIds = 8,
        PreserveSerializationSettingOfOriginal = 16,

        RemotingOptions = UseDepthFromTypes | NoRootElement | NoNamespace | PreserveSerializationSettingOfOriginal,
    }

    internal class SerializationContext
    {
        private const int DefaultSerializationDepth = 2;

        internal SerializationContext()
            : this(DefaultSerializationDepth, true)
        {
        }

        internal SerializationContext(int depth, bool useDepthFromTypes)
            : this(
                    depth,
                    (useDepthFromTypes ? SerializationOptions.UseDepthFromTypes : SerializationOptions.None) |
                       SerializationOptions.PreserveSerializationSettingOfOriginal,
                    null)
        {
        }

        internal SerializationContext(int depth, SerializationOptions options, PSRemotingCryptoHelper cryptoHelper)
        {
            if (depth < 1)
            {
                throw PSTraceSource.NewArgumentException("writer", Serialization.DepthOfOneRequired);
            }

            this.depth = depth;
            this.options = options;
            this.cryptoHelper = cryptoHelper;
        }

        internal readonly int depth;
        internal readonly SerializationOptions options;
        internal readonly PSRemotingCryptoHelper cryptoHelper;

        internal readonly CimClassSerializationCache<CimClassSerializationId> cimClassSerializationIdCache = new CimClassSerializationCache<CimClassSerializationId>();
    }

    /// <summary>
    /// This class provides public functionality for serializing a PSObject.
    /// </summary>
    public class PSSerializer
    {
        internal PSSerializer() { }

        /// <summary>
        /// Serializes an object into PowerShell CliXml.
        /// </summary>
        /// <param name="source">The input object to serialize. Serializes to a default depth of 1.</param>
        /// <returns>The serialized object, as CliXml.</returns>
        public static string Serialize(object source)
        {
            return Serialize(source, s_mshDefaultSerializationDepth);
        }

        /// <summary>
        /// Serializes an object into PowerShell CliXml.
        /// </summary>
        /// <param name="source">The input object to serialize.</param>
        /// <param name="depth">The depth of the members to serialize.</param>
        /// <returns>The serialized object, as CliXml.</returns>
        public static string Serialize(object source, int depth)
        {
            // Create an xml writer
            StringBuilder sb = new StringBuilder();
            XmlWriterSettings xmlSettings = new XmlWriterSettings();
            xmlSettings.CloseOutput = true;
            xmlSettings.Encoding = System.Text.Encoding.Unicode;
            xmlSettings.Indent = true;
            xmlSettings.OmitXmlDeclaration = true;
            XmlWriter xw = XmlWriter.Create(sb, xmlSettings);

            // Serialize the objects
            Serializer serializer = new Serializer(xw, depth, true);
            serializer.Serialize(source);
            serializer.Done();
            serializer = null;

            // Return the output
            return sb.ToString();
        }

        /// <summary>
        /// Deserializes PowerShell CliXml into an object.
        /// </summary>
        /// <param name="source">The CliXml the represents the object to deserialize.</param>
        /// <returns>An object that represents the serialized content.</returns>
        public static object Deserialize(string source)
        {
            object[] results = DeserializeAsList(source);

            // Return the results
            if (results.Length == 0)
            {
                return null;
            }
            else if (results.Length == 1)
            {
                return results[0];
            }
            else
            {
                return results;
            }
        }

        /// <summary>
        /// Deserializes PowerShell CliXml into a list of objects.
        /// </summary>
        /// <param name="source">The CliXml the represents the object to deserialize.</param>
        /// <returns>An object array represents the serialized content.</returns>
        public static object[] DeserializeAsList(string source)
        {
            List<object> results = new List<object>();

            // Create the text reader to hold the content
            TextReader textReader = new StringReader(source);
            XmlReader xmlReader = XmlReader.Create(textReader, InternalDeserializer.XmlReaderSettingsForCliXml);

            // Deserialize the content
            Deserializer deserializer = new Deserializer(xmlReader);
            while (!deserializer.Done())
            {
                object result = deserializer.Deserialize();
                results.Add(result);
            }

            return results.ToArray();
        }

        /// <summary>
        /// Default depth of serialization.
        /// </summary>
        private static readonly int s_mshDefaultSerializationDepth = 1;
    }

    /// <summary>
    /// This class provides functionality for serializing a PSObject.
    /// </summary>
    internal class Serializer
    {
        #region constructor

        private readonly InternalSerializer _serializer;

        /// <summary>
        /// Creates a Serializer using default serialization context.
        /// </summary>
        /// <param name="writer">Writer to be used for serialization.</param>
        internal Serializer(XmlWriter writer)
            : this(writer, new SerializationContext())
        {
        }

        /// <summary>
        /// Creates a Serializer using specified serialization context.
        /// </summary>
        /// <param name="writer">Writer to be used for serialization.</param>
        /// <param name="depth">Depth of serialization.</param>
        /// <param name="useDepthFromTypes">
        /// if <see langword="true"/> then types.ps1xml can override depth
        /// for a particular types (using SerializationDepth property)
        /// </param>
        internal Serializer(XmlWriter writer, int depth, bool useDepthFromTypes)
            : this(writer, new SerializationContext(depth, useDepthFromTypes))
        {
        }

        /// <summary>
        /// Creates a Serializer using specified serialization context.
        /// </summary>
        /// <param name="writer">Writer to be used for serialization.</param>
        /// <param name="context">Serialization context.</param>
        internal Serializer(XmlWriter writer, SerializationContext context)
        {
            if (writer == null)
            {
                throw PSTraceSource.NewArgumentException(nameof(writer));
            }

            if (context == null)
            {
                throw PSTraceSource.NewArgumentException(nameof(context));
            }

            _serializer = new InternalSerializer(writer, context);
            _serializer.Start();
        }

        #endregion constructor

        #region public methods / properties

        /// <summary>
        /// Used by Remoting infrastructure. This TypeTable instance
        /// will be used by Serializer if ExecutionContext is not
        /// available (to get the ExecutionContext's TypeTable)
        /// </summary>
        internal TypeTable TypeTable
        {
            get { return _serializer.TypeTable; }

            set { _serializer.TypeTable = value; }
        }

        /// <summary>
        /// Serializes the object.
        /// </summary>
        /// <param name="source">Object to be serialized.</param>
        /// <remarks>
        /// Please note that this method shouldn't throw any exceptions.
        /// If it throws - please open a bug.
        /// </remarks>
        internal void Serialize(object source)
        {
            Serialize(source, null);
        }

        /// <summary>
        /// Serializes passed in object.
        /// </summary>
        /// <param name="source">
        /// object to be serialized
        /// </param>
        /// <param name="streamName">
        /// Stream to which this object belong. Ex: Output, Error etc.
        /// </param>
        /// <remarks>
        /// Please note that this method shouldn't throw any exceptions.
        /// If it throws - please open a bug.
        /// </remarks>
        internal void Serialize(object source, string streamName)
        {
            _serializer.WriteOneTopLevelObject(source, streamName);
        }

        /// <summary>
        /// Write the end of root element.
        /// </summary>
        internal void Done()
        {
            _serializer.End();
        }

        internal void Stop()
        {
            _serializer.Stop();
        }

        #endregion
    }

    [Flags]
    internal enum DeserializationOptions
    {
        None = 0,
        NoRootElement = 256,            // I start at 256 to try not to overlap
        NoNamespace = 512,              // with SerializationOptions and to catch bugs early
        DeserializeScriptBlocks = 1024,

        RemotingOptions = NoRootElement | NoNamespace,
    }

    internal class DeserializationContext
    {
        internal DeserializationContext()
            : this(DeserializationOptions.None, null)
        {
        }

        internal DeserializationContext(DeserializationOptions options, PSRemotingCryptoHelper cryptoHelper)
        {
            this.options = options;
            this.cryptoHelper = cryptoHelper;
        }

        /// <summary>
        /// Limits the total data processed by the deserialization context. Deserialization context
        /// is used by PriorityReceivedDataCollection (remoting) to process incoming data from the
        /// remote end. A value of Null means that the max memory is unlimited.
        /// </summary>
        internal int? MaximumAllowedMemory { get; set; }

        /// <summary>
        /// Logs that memory used by deserialized objects is not related to the size of input xml.
        /// Used mainly to account for memory usage of cloned TypeNames when calculating memory quota usage.
        /// </summary>
        /// <param name="amountOfExtraMemory"></param>
        internal void LogExtraMemoryUsage(int amountOfExtraMemory)
        {
            if (amountOfExtraMemory < 0)
            {
                return;
            }

            if (MaximumAllowedMemory.HasValue)
            {
                if (amountOfExtraMemory > (MaximumAllowedMemory.Value - _totalDataProcessedSoFar))
                {
                    string message = StringUtil.Format(Serialization.DeserializationMemoryQuota, ((double)MaximumAllowedMemory.Value) / (1 << 20),
                                                       ConfigurationDataFromXML.MAXRCVDOBJSIZETOKEN_CamelCase,
                                                       ConfigurationDataFromXML.MAXRCVDCMDSIZETOKEN_CamelCase);
                    throw new XmlException(message);
                }

                _totalDataProcessedSoFar += amountOfExtraMemory;
            }
        }

        private int _totalDataProcessedSoFar;

        internal readonly DeserializationOptions options;
        internal readonly PSRemotingCryptoHelper cryptoHelper;

        internal static readonly int MaxItemsInCimClassCache = 100;
        internal readonly CimClassDeserializationCache<CimClassSerializationId> cimClassSerializationIdCache = new CimClassDeserializationCache<CimClassSerializationId>();
    }

    internal class CimClassDeserializationCache<TKey>
    {
        private readonly Dictionary<TKey, CimClass> _cimClassIdToClass = new Dictionary<TKey, CimClass>();

        internal void AddCimClassToCache(TKey key, CimClass cimClass)
        {
            if (_cimClassIdToClass.Count >= DeserializationContext.MaxItemsInCimClassCache)
            {
                _cimClassIdToClass.Clear();
            }

            _cimClassIdToClass.Add(key, cimClass);

            /* PRINTF DEBUG
            Console.WriteLine("Contents of deserialization cache (after a call to AddCimClassToCache ({0})):", key);
            Console.WriteLine("  Count = {0}", this._cimClassIdToClass.Count);
            foreach (var t in this._cimClassIdToClass.Keys)
            {
                Console.WriteLine("  {0}", t);
            }
             */
        }

        internal CimClass GetCimClassFromCache(TKey key)
        {
            CimClass cimClass;
            if (_cimClassIdToClass.TryGetValue(key, out cimClass))
            {
                /* PRINTF DEBUG
                Console.WriteLine("GetCimClassFromCache - class found: {0}", key);
                 */

                return cimClass;
            }

            /* PRINTF DEBUG
            Console.WriteLine("GetCimClassFromCache - class NOT found: {0}", key);
             */

            return null;
        }
    }

    internal class CimClassSerializationCache<TKey>
    {
        private readonly HashSet<TKey> _cimClassesHeldByDeserializer = new HashSet<TKey>(EqualityComparer<TKey>.Default);

        internal bool DoesDeserializerAlreadyHaveCimClass(TKey key)
        {
            return _cimClassesHeldByDeserializer.Contains(key);
        }

        internal void AddClassToCache(TKey key)
        {
            Dbg.Assert(!_cimClassesHeldByDeserializer.Contains(key), "This method should not be called for classes already in the cache");

            if (_cimClassesHeldByDeserializer.Count >= DeserializationContext.MaxItemsInCimClassCache)
            {
                _cimClassesHeldByDeserializer.Clear();
            }

            _cimClassesHeldByDeserializer.Add(key);

            /* PRINTF DEBUG
            Console.WriteLine("Contents of serialization cache (after adding {0}):", key);
            Console.WriteLine("  Count = {0}", this._cimClassesHeldByDeserializer.Count);
            foreach (var t in _cimClassesHeldByDeserializer)
            {
                Console.WriteLine("  {0}", t);
            }
             */
        }
    }

    internal class CimClassSerializationId : Tuple<string, string, string, int>
    {
        public CimClassSerializationId(string className, string namespaceName, string computerName, int hashCode)
            : base(className, namespaceName, computerName, hashCode)
        {
        }

        public string ClassName { get { return this.Item1; } }

        public string NamespaceName { get { return this.Item2; } }

        public string ComputerName { get { return this.Item3; } }

        public int ClassHashCode { get { return this.Item4; } }
    }

    /// <summary>
    /// This class provides functionality for deserializing a PSObject.
    /// </summary>
    internal class Deserializer
    {
        #region constructor

        private readonly XmlReader _reader;
        private readonly InternalDeserializer _deserializer;
        private readonly DeserializationContext _context;

        /// <summary>
        /// Creates a Deserializer using default deserialization context.
        /// </summary>
        /// <param name="reader">Reader to be used for deserialization.</param>
        /// <exception cref="XmlException">
        /// Thrown when the xml is in an incorrect format
        /// </exception>
        internal Deserializer(XmlReader reader)
            : this(reader, new DeserializationContext())
        {
        }

        /// <summary>
        /// Creates a Deserializer using specified serialization context.
        /// </summary>
        /// <param name="reader">Reader to be used for deserialization.</param>
        /// <param name="context">Serialization context.</param>
        /// <exception cref="XmlException">
        /// Thrown when the xml is in an incorrect format
        /// </exception>
        internal Deserializer(XmlReader reader, DeserializationContext context)
        {
            if (reader == null)
            {
                throw PSTraceSource.NewArgumentNullException(nameof(reader));
            }

            _reader = reader;
            _context = context;
            _deserializer = new InternalDeserializer(_reader, _context);

            try
            {
                Start();
            }
            catch (XmlException exception)
            {
                ReportExceptionForETW(exception);
                throw;
            }
        }

        #endregion constructor

        #region public method / properties

        private static void ReportExceptionForETW(XmlException exception)
        {
            PSEtwLog.LogAnalyticError(
                PSEventId.Serializer_XmlExceptionWhenDeserializing, PSOpcode.Exception, PSTask.Serialization,
                PSKeyword.Serializer | PSKeyword.UseAlwaysAnalytic,
                exception.LineNumber, exception.LinePosition, exception.ToString());
        }

        private bool _done = false;

        /// <summary>
        /// Used by Remoting infrastructure. This TypeTable instance
        /// will be used by Deserializer if ExecutionContext is not
        /// available (to get the ExecutionContext's TypeTable)
        /// </summary>
        internal TypeTable TypeTable
        {
            get { return _deserializer.TypeTable; }

            set { _deserializer.TypeTable = value; }
        }

        /// <summary>
        /// Read the root element tag and set the cursor to start tag of
        /// first object.
        /// </summary>
        private void Start()
        {
            Dbg.Assert(_reader.ReadState == ReadState.Initial, "When deserialization starts we should have XmlReader.ReadState == Initial");
            Dbg.Assert(_reader.NodeType == XmlNodeType.None, "When deserialization starts we should have XmlReader.NodeType == None");
            _reader.Read();

            // If version is not provided, we assume it is the default
            string version = InternalSerializer.DefaultVersion;
            if ((_context.options & DeserializationOptions.NoRootElement) == DeserializationOptions.NoRootElement)
            {
                _done = _reader.EOF;
            }
            else
            {
                // Make sure the reader is positioned on the root ( <Objs> ) element (not on XmlDeclaration for example)
                _reader.MoveToContent();
                Dbg.Assert(_reader.EOF || (_reader.NodeType == XmlNodeType.Element), "When deserialization starts reading we should have XmlReader.NodeType == Element");

                // Read version attribute and validate it.
                string versionAttribute = _reader.GetAttribute(SerializationStrings.VersionAttribute);
                if (versionAttribute != null)
                {
                    version = versionAttribute;
                }

                // If the root element tag is empty, there are no objects to read.
                if (!_deserializer.ReadStartElementAndHandleEmpty(SerializationStrings.RootElementTag))
                {
                    _done = true;
                }
            }

            _deserializer.ValidateVersion(version);
        }

        internal bool Done()
        {
            if (!_done)
            {
                if ((_context.options & DeserializationOptions.NoRootElement) == DeserializationOptions.NoRootElement)
                {
                    _done = _reader.EOF;
                }
                else
                {
                    if (_reader.NodeType == XmlNodeType.EndElement)
                    {
                        try
                        {
                            _reader.ReadEndElement();
                        }
                        catch (XmlException exception)
                        {
                            ReportExceptionForETW(exception);
                            throw;
                        }

                        _done = true;
                    }
                }
            }

            return _done;
        }

        internal void Stop()
        {
            _deserializer.Stop();
        }

        /// <summary>
        /// Deserializes next object.
        /// </summary>
        /// <exception cref="XmlException">
        /// Thrown when the xml is in an incorrect format
        /// </exception>
        internal object Deserialize()
        {
            string ignore;
            return Deserialize(out ignore);
        }

        /// <summary>
        /// Deserializes next object.
        /// </summary>
        /// <param name="streamName">Stream the object belongs to (i.e. "Error", "Output", etc.).</param>
        /// <exception cref="XmlException">
        /// Thrown when the xml is in an incorrect format
        /// </exception>
        internal object Deserialize(out string streamName)
        {
            if (Done())
            {
                throw PSTraceSource.NewInvalidOperationException(Serialization.ReadCalledAfterDone);
            }

            try
            {
                return _deserializer.ReadOneObject(out streamName);
            }
            catch (XmlException exception)
            {
                ReportExceptionForETW(exception);
                throw;
            }
        }

        #endregion public methods

        #region Helper methods for dealing with "Deserialized." prefix

        /// <summary>
        /// Adds "Deserialized." prefix to passed in argument if not already present.
        /// </summary>
        /// <param name="type"></param>
        internal static void AddDeserializationPrefix(ref string type)
        {
            Dbg.Assert(type != null, "caller should validate the parameter");
            if (!type.StartsWith(Deserializer.DeserializationTypeNamePrefix, StringComparison.OrdinalIgnoreCase))
            {
                type = type.Insert(0, Deserializer.DeserializationTypeNamePrefix);
            }
        }

        /// <summary>
        /// Checks if an object <paramref name="o"/> is either a live or deserialized instance of class <paramref name="type"/> or one of its subclasses.
        /// </summary>
        /// <param name="o"></param>
        /// <param name="type"></param>
        /// <returns><see langword="true"/> if <paramref name="o"/> is either a live or deserialized instance of class <paramref name="type"/> or one of its subclasses;  <see langword="false"/> otherwise.</returns>
        internal static bool IsInstanceOfType(object o, Type type)
        {
            if (type == null)
            {
                throw PSTraceSource.NewArgumentNullException(nameof(type));
            }

            if (o == null)
            {
                return false;
            }

            return type.IsInstanceOfType(PSObject.Base(o)) || IsDeserializedInstanceOfType(o, type);
        }

        /// <summary>
        /// Checks if an object <paramref name="o"/> is a deserialized instance of class <paramref name="type"/> or one of its subclasses.
        /// </summary>
        /// <param name="o"></param>
        /// <param name="type"></param>
        /// <returns><see langword="true"/> if <paramref name="o"/> is a deserialized instance of class <paramref name="type"/> or one of its subclasses;  <see langword="false"/> otherwise.</returns>
        internal static bool IsDeserializedInstanceOfType(object o, Type type)
        {
            if (type == null)
            {
                throw PSTraceSource.NewArgumentNullException(nameof(type));
            }

            if (o == null)
            {
                return false;
            }

            PSObject pso = o as PSObject;
            if (pso != null)
            {
                IEnumerable<string> typeNames = pso.InternalTypeNames;
                if (typeNames != null)
                {
                    foreach (string typeName in typeNames)
                    {
                        if (typeName.Length == Deserializer.DeserializationTypeNamePrefix.Length + type.FullName.Length &&
                            typeName.StartsWith(Deserializer.DeserializationTypeNamePrefix, StringComparison.OrdinalIgnoreCase) &&
                            typeName.EndsWith(type.FullName, StringComparison.OrdinalIgnoreCase))
                        {
                            return true;
                        }
                    }
                }
            }

            // not the right type
            return false;
        }

        internal static string MaskDeserializationPrefix(string typeName)
        {
            if (typeName == null)
            {
                return null;
            }

            if (typeName.StartsWith(Deserializer.DeserializationTypeNamePrefix, StringComparison.OrdinalIgnoreCase))
            {
                typeName = typeName.Substring(Deserializer.DeserializationTypeNamePrefix.Length);
            }

            return typeName;
        }

        /// <summary>
        /// Gets a new collection of typenames without "Deserialization." prefix
        /// in the typename. This will allow to map type info/format info of the orignal type
        /// for deserialized objects.
        /// </summary>
        /// <param name="typeNames"></param>
        /// <returns>
        /// Null if no type with "Deserialized." prefix is found.
        /// Otherwise <paramref name="typeNames"/> with the prefix removed if any.
        /// </returns>
        internal static Collection<string> MaskDeserializationPrefix(Collection<string> typeNames)
        {
            Dbg.Assert(typeNames != null, "typeNames cannot be null");

            bool atleastOneDeserializedTypeFound = false;

            Collection<string> typesWithoutPrefix = new Collection<string>();
            foreach (string type in typeNames)
            {
                if (type.StartsWith(Deserializer.DeserializationTypeNamePrefix,
                    StringComparison.OrdinalIgnoreCase))
                {
                    atleastOneDeserializedTypeFound = true;
                    // remove *only* the prefix
                    typesWithoutPrefix.Add(type.Substring(Deserializer.DeserializationTypeNamePrefix.Length));
                }
                else
                {
                    typesWithoutPrefix.Add(type);
                }
            }

            if (atleastOneDeserializedTypeFound)
            {
                return typesWithoutPrefix;
            }

            return null;
        }

        /// <summary>
        /// Used to prefix a typename for deserialization.
        /// </summary>
        private const string DeserializationTypeNamePrefix = "Deserialized.";

        #endregion
    }

    /// <summary>
    /// Types of known type container supported by monad.
    /// </summary>
    internal enum ContainerType
    {
        Dictionary,
        Queue,
        Stack,
        List,
        Enumerable,
        None
    }

    /// <summary>
    /// This internal helper class provides methods for serializing mshObject.
    /// </summary>
    internal class InternalSerializer
    {
        #region constructor

        internal const string DefaultVersion = "1.1.0.1";

        /// <summary>
        /// Xml writer to be used.
        /// </summary>
        private readonly XmlWriter _writer;

        /// <summary>
        /// Serialization context.
        /// </summary>
        private readonly SerializationContext _context;

        /// Used by Remoting infrastructure. This TypeTable instance
        /// will be used by Serializer if ExecutionContext is not
        /// available (to get the ExecutionContext's TypeTable)
        private TypeTable _typeTable;

        /// <summary>
        /// Depth below top level - used to prevent infinitely deep serialization
        /// (without this protection it would be possible i.e. with SerializationDepth and recursion)
        /// </summary>
        private int _depthBelowTopLevel;

        private const int MaxDepthBelowTopLevel = 50;

        private readonly ReferenceIdHandlerForSerializer<object> _objectRefIdHandler;
        private readonly ReferenceIdHandlerForSerializer<ConsolidatedString> _typeRefIdHandler;

        internal InternalSerializer(XmlWriter writer, SerializationContext context)
        {
            Dbg.Assert(writer != null, "caller should validate the parameter");
            Dbg.Assert(context != null, "caller should validate the parameter");
            _writer = writer;
            _context = context;

            IDictionary<object, ulong> objectRefIdDictionary = null;
            if ((_context.options & SerializationOptions.NoObjectRefIds) == 0)
            {
                objectRefIdDictionary = new WeakReferenceDictionary<UInt64>();
            }

            _objectRefIdHandler = new ReferenceIdHandlerForSerializer<object>(objectRefIdDictionary);

            _typeRefIdHandler = new ReferenceIdHandlerForSerializer<ConsolidatedString>(
                new Dictionary<ConsolidatedString, UInt64>(ConsolidatedString.EqualityComparer));
        }

        #endregion

        /// <summary>
        /// Used by Remoting infrastructure. This TypeTable instance
        /// will be used by Serializer if ExecutionContext is not
        /// available (to get the ExecutionContext's TypeTable)
        /// </summary>
        internal TypeTable TypeTable
        {
            get { return _typeTable; }

            set { _typeTable = value; }
        }

        /// <summary>
        /// Writes the start of root element.
        /// </summary>
        internal void Start()
        {
            if ((_context.options & SerializationOptions.NoRootElement) != SerializationOptions.NoRootElement)
            {
                this.WriteStartElement(SerializationStrings.RootElementTag);
                this.WriteAttribute(SerializationStrings.VersionAttribute, InternalSerializer.DefaultVersion);
            }
        }

        /// <summary>
        /// Writes the end of root element.
        /// </summary>
        internal void End()
        {
            if ((_context.options & SerializationOptions.NoRootElement) != SerializationOptions.NoRootElement)
            {
                _writer.WriteEndElement();
            }

            _writer.Flush();
        }

        private bool _isStopping = false;

        /// <summary>
        /// Called from a separate thread will stop the serialization process.
        /// </summary>
        internal void Stop()
        {
            _isStopping = true;
        }

        private void CheckIfStopping()
        {
            if (_isStopping)
            {
                throw PSTraceSource.NewInvalidOperationException(Serialization.Stopping);
            }
        }

        internal static bool IsPrimitiveKnownType(Type input)
        {
            // Check if source is of primitive known type
            TypeSerializationInfo pktInfo = KnownTypes.GetTypeSerializationInfo(input);
            return (pktInfo != null);
        }

        /// <summary>
        /// This writes one object.
        /// </summary>
        /// <param name="source">
        /// source to be serialized.
        /// </param>
        /// <param name="streamName">
        /// Stream to which source belongs
        /// </param>
        internal void WriteOneTopLevelObject
        (
            object source,
            string streamName
        )
        {
            Dbg.Assert(_depthBelowTopLevel == 0, "InternalSerializer.depthBelowTopLevel should be 0 at top-level");
            WriteOneObject(source, streamName, null, _context.depth);
        }

        private void WriteOneObject
        (
            object source,
            string streamName,
            string property,
            int depth
        )
        {
            Dbg.Assert(depth >= 0, "depth should always be greater or equal to zero");
            this.CheckIfStopping();

            if (source == null)
            {
                WriteNull(streamName, property);
                return;
            }

            try
            {
                _depthBelowTopLevel++;
                Dbg.Assert(_depthBelowTopLevel <= MaxDepthBelowTopLevel, "depthBelowTopLevel should be <= MaxDepthBelowTopLevel");
                if (HandleMaxDepth(source, streamName, property))
                {
                    return;
                }

                depth = GetDepthOfSerialization(source, depth);

                if (HandlePrimitiveKnownTypeByConvertingToPSObject(source, streamName, property, depth))
                {
                    return;
                }

                // Object is not of primitive known type. Check if this has
                // already been serialized.
                string refId = _objectRefIdHandler.GetRefId(source);
                if (refId != null)
                {
                    WritePSObjectReference(streamName, property, refId);
                    return;
                }

                if (HandlePrimitiveKnownTypePSObject(source, streamName, property, depth))
                {
                    return;
                }

                // Note: We do not use containers in depth calculation. i.e even if the
                // current depth is zero, we serialize the container. All contained items will
                // get serialized with depth zero.
                if (HandleKnownContainerTypes(source, streamName, property, depth))
                {
                    return;
                }

                PSObject mshSource = PSObject.AsPSObject(source);
                // If depth is zero, complex type should be serialized as string.
                if (depth == 0 || SerializeAsString(mshSource))
                {
                    HandlePSObjectAsString(mshSource, streamName, property, depth);
                    return;
                }

                HandleComplexTypePSObject(source, streamName, property, depth);
                return;
            }
            finally
            {
                _depthBelowTopLevel--;
                Dbg.Assert(_depthBelowTopLevel >= 0, "depthBelowTopLevel should be >= 0");
            }
        }

        private bool HandleMaxDepth(object source, string streamName, string property)
        {
            if (_depthBelowTopLevel == MaxDepthBelowTopLevel)
            {
                // assert commented out because of clashes with Wei's tests
                // Dbg.Assert(false, "We should never reach MaxDepthBelowTopLevel with non-malicious input");

                PSEtwLog.LogAnalyticError(PSEventId.Serializer_MaxDepthWhenSerializing, PSOpcode.Exception,
                    PSTask.Serialization, PSKeyword.Serializer, source.GetType().AssemblyQualifiedName, property, _depthBelowTopLevel);

                string content = Serialization.DeserializationTooDeep;
                HandlePrimitiveKnownType(content, streamName, property);
                return true;
            }
            else
            {
                return false;
            }
        }

        /// <summary>
        /// Serializes Primitive Known Types.
        /// </summary>
        /// <returns>
        /// true if source is handled, else false.
        /// </returns>
        private bool HandlePrimitiveKnownType
        (
            object source,
            string streamName,
            string property
        )
        {
            Dbg.Assert(source != null, "caller should validate the parameter");

            // Check if source is of primitive known type
            TypeSerializationInfo pktInfo = KnownTypes.GetTypeSerializationInfo(source.GetType());
            if (pktInfo != null)
            {
                WriteOnePrimitiveKnownType(this, streamName, property, source, pktInfo);
                return true;
            }

            return false;
        }

        /// <summary>
        /// Handles primitive known type by first converting it to a PSObject.In W8, extended
        /// property data is stored external to PSObject. By converting to PSObject, we will
        /// be able to retrieve and serialize the extended properties. This is tracked by
        /// Win8: 414042.
        /// </summary>
        /// <param name="source"></param>
        /// <param name="streamName"></param>
        /// <param name="property"></param>
        /// <param name="depth"></param>
        /// <returns></returns>
        private bool HandlePrimitiveKnownTypeByConvertingToPSObject(
            object source,
            string streamName,
            string property,
            int depth
        )
        {
            Dbg.Assert(source != null, "caller should validate the parameter");
            // Check if source is of primitive known type
            TypeSerializationInfo pktInfo = KnownTypes.GetTypeSerializationInfo(source.GetType());
            if (pktInfo != null)
            {
                PSObject pktInfoPSObject = PSObject.AsPSObject(source);
                return HandlePrimitiveKnownTypePSObject(pktInfoPSObject, streamName, property, depth);
            }

            return false;
        }

        /// <summary>
        /// </summary>
        /// <param name="source"></param>
        /// <param name="streamName"></param>
        /// <param name="property"></param>
        /// <returns></returns>
        private bool HandleSecureString(object source, string streamName, string property)
        {
            Dbg.Assert(source != null, "caller should validate the parameter");

            SecureString secureString = null;
            secureString = source as SecureString;
            PSObject moSource;

            if (secureString != null)
            {
                moSource = PSObject.AsPSObject(secureString);
            }
            else
            {
                moSource = source as PSObject;
            }

            if (moSource != null && !moSource.ImmediateBaseObjectIsEmpty)
            {
                // check if source is of type secure string
                secureString = moSource.ImmediateBaseObject as SecureString;
                if (secureString != null)
                {
                    // the principle used in serialization is that serialization
                    // never throws, and if something can't be serialized nothing
                    // is written. So we write the elements only if encryption succeeds.
                    // However, in the case for non-Windows where secure string encryption
                    // is not yet supported, a PSCryptoException will be thrown.
                    string encryptedString;
                    if (_context.cryptoHelper != null)
                    {
                        encryptedString = _context.cryptoHelper.EncryptSecureString(secureString);
                    }
                    else
                    {
                        encryptedString = Microsoft.PowerShell.SecureStringHelper.Protect(secureString);
                    }

                    if (property != null)
                    {
                        WriteStartElement(SerializationStrings.SecureStringTag);
                        WriteNameAttribute(property);
                    }
                    else
                    {
                        WriteStartElement(SerializationStrings.SecureStringTag);
                    }

                    if (streamName != null)
                    {
                        WriteAttribute(SerializationStrings.StreamNameAttribute, streamName);
                    }

                    // Note: We do not use WriteRaw for serializing secure string. WriteString
                    // does necessary escaping which may be needed for certain
                    // characters.
                    _writer.WriteString(encryptedString);

                    _writer.WriteEndElement();

                    return true;
                }
            }

            return false;
        }

        /// <summary>
        /// Serializes PSObject whose base objects are of primitive known type.
        /// </summary>
        /// <param name="source"></param>
        /// <param name="streamName"></param>
        /// <param name="property"></param>
        /// <param name="depth"></param>
        /// <returns>
        /// true if source is handled, else false.
        /// </returns>
        private bool HandlePrimitiveKnownTypePSObject
        (
            object source,
            string streamName,
            string property,
            int depth
        )
        {
            Dbg.Assert(source != null, "caller should validate the parameter");

            bool sourceHandled = false;
            PSObject moSource = source as PSObject;
            if (moSource != null && !moSource.ImmediateBaseObjectIsEmpty)
            {
                // Check if baseObject is primitive known type
                object baseObject = moSource.ImmediateBaseObject;
                TypeSerializationInfo pktInfo = KnownTypes.GetTypeSerializationInfo(baseObject.GetType());
                if (pktInfo != null)
                {
                    WritePrimitiveTypePSObject(moSource, baseObject, pktInfo, streamName, property, depth);
                    sourceHandled = true;
                }
            }

            return sourceHandled;
        }

        private bool HandleKnownContainerTypes
        (
            object source,
            string streamName,
            string property,
            int depth
        )
        {
            Dbg.Assert(source != null, "caller should validate the parameter");

            ContainerType ct = ContainerType.None;
            PSObject mshSource = source as PSObject;
            IEnumerable enumerable = null;
            IDictionary dictionary = null;

            // If passed in object is PSObject with no baseobject, return false.
            if (mshSource != null && mshSource.ImmediateBaseObjectIsEmpty)
            {
                return false;
            }

            // Check if source (or baseobject in mshSource) is known container type
            SerializationUtilities.GetKnownContainerTypeInfo(mshSource != null ? mshSource.ImmediateBaseObject : source, out ct,
                                      out dictionary, out enumerable);

            if (ct == ContainerType.None)
                return false;

            string refId = _objectRefIdHandler.SetRefId(source);
            WriteStartOfPSObject(
                mshSource ?? PSObject.AsPSObject(source),
                streamName,
                property,
                refId,
                true, // always write TypeNames information for known container types
                null); // never write ToString information for known container types

            switch (ct)
            {
                case ContainerType.Dictionary:
                    WriteDictionary(dictionary, SerializationStrings.DictionaryTag, depth);
                    break;
                case ContainerType.Stack:
                    WriteEnumerable(enumerable, SerializationStrings.StackTag, depth);
                    break;
                case ContainerType.Queue:
                    WriteEnumerable(enumerable, SerializationStrings.QueueTag, depth);
                    break;
                case ContainerType.List:
                    WriteEnumerable(enumerable, SerializationStrings.ListTag, depth);
                    break;
                case ContainerType.Enumerable:
                    WriteEnumerable(enumerable, SerializationStrings.CollectionTag, depth);
                    break;
                default:
                    Dbg.Assert(false, "All containers should be handled in the switch");
                    break;
            }

            if (depth != 0)
            {
                // An object which is original enumerable becomes an PSObject with ArrayList on deserialization.
                // So on roundtrip it will show up as List.
                // We serialize properties of enumerable and on deserialization mark the object as Deserialized.
                // So if object is marked deserialized, we should write properties.
                if (ct == ContainerType.Enumerable || (mshSource != null && mshSource.IsDeserialized))
                {
                    PSObject sourceAsPSObject = PSObject.AsPSObject(source);
                    PSMemberInfoInternalCollection<PSPropertyInfo> specificPropertiesToSerialize = SerializationUtilities.GetSpecificPropertiesToSerialize(sourceAsPSObject, AllPropertiesCollection, _typeTable);
                    WritePSObjectProperties(sourceAsPSObject, depth, specificPropertiesToSerialize);
                    SerializeExtendedProperties(sourceAsPSObject, depth, specificPropertiesToSerialize);
                }
                // always serialize instance properties if there are any
                else if (mshSource != null)
                {
                    SerializeInstanceProperties(mshSource, depth);
                }
            }

            _writer.WriteEndElement();

            return true;
        }

        #region Write PSObject

        /// <summary>
        /// Writes PSObject Reference Element.
        /// </summary>
        private void WritePSObjectReference
        (
            string streamName,
            string property,
            string refId
        )
        {
            Dbg.Assert(!string.IsNullOrEmpty(refId), "caller should validate the parameter");

            WriteStartElement(SerializationStrings.ReferenceTag);
            if (streamName != null)
            {
                WriteAttribute(SerializationStrings.StreamNameAttribute, streamName);
            }

            if (property != null)
            {
                WriteNameAttribute(property);
            }

            WriteAttribute(SerializationStrings.ReferenceIdAttribute, refId);
            _writer.WriteEndElement();
        }

        private static bool PSObjectHasModifiedTypesCollection(PSObject pso)
        {
            ConsolidatedString currentTypes = pso.InternalTypeNames;
            Collection<string> originalTypes = pso.InternalAdapter.BaseGetTypeNameHierarchy(pso.ImmediateBaseObject);

            if (currentTypes.Count != originalTypes.Count)
            {
                return true;
            }

            IEnumerator<string> currentEnumerator = currentTypes.GetEnumerator();
            IEnumerator<string> originalEnumerator = originalTypes.GetEnumerator();
            while (currentEnumerator.MoveNext() && originalEnumerator.MoveNext())
            {
                if (!currentEnumerator.Current.Equals(originalEnumerator.Current, StringComparison.OrdinalIgnoreCase))
                {
                    return true;
                }
            }

            return false;
        }

        /// <summary>
        /// Serializes an PSObject whose baseobject is of primitive type.
        /// </summary>
        /// <param name="source">
        /// source from which notes are written
        /// </param>
        /// <param name="primitive">
        /// primitive object which is written as base object. In most cases it
        /// is same source.ImmediateBaseObject. When PSObject is serialized as string,
        /// it can be different. <see cref="HandlePSObjectAsString"/> for more info.
        /// </param>
        /// <param name="pktInfo">
        /// TypeSerializationInfo for the primitive.
        /// </param>
        /// <param name="streamName"></param>
        /// <param name="property"></param>
        /// <param name="depth"></param>
        private void WritePrimitiveTypePSObject
        (
            PSObject source,
            object primitive,
            TypeSerializationInfo pktInfo,
            string streamName,
            string property,
            int depth
        )
        {
            Dbg.Assert(source != null, "Caller should validate source != null");

            string toStringValue = SerializationUtilities.GetToStringForPrimitiveObject(source);
            bool hasModifiedTypesCollection = PSObjectHasModifiedTypesCollection(source);
            bool hasNotes = PSObjectHasNotes(source);
            bool hasModifiedToString = (toStringValue != null);

            if (hasNotes || hasModifiedTypesCollection || hasModifiedToString)
            {
                WritePrimitiveTypePSObjectWithNotes(
                    source,
                    primitive,
                    hasModifiedTypesCollection,
                    toStringValue,
                    pktInfo,
                    streamName,
                    property,
                    depth);
                return;
            }
            else
            {
                if (primitive != null)
                {
                    WriteOnePrimitiveKnownType(this, streamName, property, primitive, pktInfo);
                    return;
                }
                else
                {
                    WriteNull(streamName, property);
                    return;
                }
            }
        }

        /// <summary>
        /// Serializes an PSObject whose baseobject is of primitive type
        /// and which has notes.
        /// </summary>
        /// <param name="source">
        /// source from which notes are written
        /// </param>
        /// <param name="primitive">
        /// primitive object which is written as base object. In most cases it
        /// is same source.ImmediateBaseObject. When PSObject is serialized as string,
        /// it can be different. <see cref="HandlePSObjectAsString"/> for more info.
        /// </param>
        /// <param name="hasModifiedTypesCollection"></param>
        /// <param name="toStringValue"></param>
        /// <param name="pktInfo">
        /// TypeSerializationInfo for the primitive.
        /// </param>
        /// <param name="streamName"></param>
        /// <param name="property"></param>
        /// <param name="depth"></param>
        private void WritePrimitiveTypePSObjectWithNotes
        (
            PSObject source,
            object primitive,
            bool hasModifiedTypesCollection,
            string toStringValue,
            TypeSerializationInfo pktInfo,
            string streamName,
            string property,
            int depth
        )
        {
            Dbg.Assert(source != null, "caller should validate the parameter");
            Dbg.Assert(pktInfo != null, "Caller should validate pktInfo != null");

            string refId = _objectRefIdHandler.SetRefId(source);
            WriteStartOfPSObject(
                source,
                streamName,
                property,
                refId,
                hasModifiedTypesCollection, // preserve TypeNames information if different from the primitive type
                toStringValue); // preserve ToString information only if got it from deserialization or overridden by PSObject
                                // (example where preservation of TypeNames and ToString is needed: enums serialized as ints, help string with custom type names (HelpInfoShort))

            if (pktInfo != null)
            {
                WriteOnePrimitiveKnownType(this, streamName, null, primitive, pktInfo);
            }

            // serialize only instance properties - members from type table are
            // always going to be available for known primitive types
            SerializeInstanceProperties(source, depth);

            _writer.WriteEndElement();
        }

        private void HandleComplexTypePSObject
        (
            object source,
            string streamName,
            string property,
            int depth
        )
        {
            Dbg.Assert(source != null, "caller should validate the parameter");
            PSObject mshSource = PSObject.AsPSObject(source);

            // Figure out what kind of object we are dealing with
            bool isErrorRecord = false;
            bool isInformationalRecord = false;
            bool isEnum = false;
            bool isPSObject = false;
            bool isCimInstance = false;

            if (!mshSource.ImmediateBaseObjectIsEmpty)
            {
                do // false loop
                {
                    CimInstance cimInstance = mshSource.ImmediateBaseObject as CimInstance;
                    if (cimInstance != null)
                    {
                        isCimInstance = true;
                        break;
                    }

                    ErrorRecord errorRecord = mshSource.ImmediateBaseObject as ErrorRecord;
                    if (errorRecord != null)
                    {
                        errorRecord.ToPSObjectForRemoting(mshSource);
                        isErrorRecord = true;
                        break;
                    }

                    InformationalRecord informationalRecord = mshSource.ImmediateBaseObject as InformationalRecord;
                    if (informationalRecord != null)
                    {
                        informationalRecord.ToPSObjectForRemoting(mshSource);
                        isInformationalRecord = true;
                        break;
                    }

                    isEnum = mshSource.ImmediateBaseObject is Enum;
                    isPSObject = mshSource.ImmediateBaseObject is PSObject;
                } while (false);
            }

            bool writeToString = true;
            if (mshSource.ToStringFromDeserialization == null) // continue to write ToString from deserialized objects, but...
            {
                if (mshSource.ImmediateBaseObjectIsEmpty) // ... don't write ToString for property bags
                {
                    writeToString = false;
                }
            }

            string refId = _objectRefIdHandler.SetRefId(source);
            WriteStartOfPSObject(
                mshSource,
                streamName,
                property,
                refId,
                true, // always write TypeNames for complex objects
                writeToString ? SerializationUtilities.GetToString(mshSource) : null);

            PSMemberInfoInternalCollection<PSPropertyInfo> specificPropertiesToSerialize = SerializationUtilities.GetSpecificPropertiesToSerialize(mshSource, AllPropertiesCollection, _typeTable);

            if (isEnum)
            {
                object baseObject = mshSource.ImmediateBaseObject;
                WriteOneObject(System.Convert.ChangeType(baseObject, Enum.GetUnderlyingType(baseObject.GetType()), System.Globalization.CultureInfo.InvariantCulture), null, null, depth);
            }
            else if (isPSObject)
            {
                WriteOneObject(mshSource.ImmediateBaseObject, null, null, depth);
            }
            else if (isErrorRecord || isInformationalRecord)
            {
                // nothing to do
            }
            else
            {
                WritePSObjectProperties(mshSource, depth, specificPropertiesToSerialize);
            }

            if (isCimInstance)
            {
                CimInstance cimInstance = mshSource.ImmediateBaseObject as CimInstance;
                PrepareCimInstanceForSerialization(mshSource, cimInstance);
            }

            SerializeExtendedProperties(mshSource, depth, specificPropertiesToSerialize);

            _writer.WriteEndElement();
        }

        private static readonly Lazy<CimSerializer> s_cimSerializer = new Lazy<CimSerializer>(CimSerializer.Create);

        private void PrepareCimInstanceForSerialization(PSObject psObject, CimInstance cimInstance)
        {
            Queue<CimClassSerializationId> serializedClasses = new Queue<CimClassSerializationId>();

            //
            // CREATE SERIALIZED FORM OF THE CLASS METADATA
            //
            ArrayList psoClasses = new ArrayList();
            for (CimClass cimClass = cimInstance.CimClass; cimClass != null; cimClass = cimClass.CimSuperClass)
            {
                PSObject psoClass = new PSObject();
                psoClass.TypeNames.Clear();
                psoClasses.Add(psoClass);

                psoClass.Properties.Add(new PSNoteProperty(InternalDeserializer.CimClassNameProperty, cimClass.CimSystemProperties.ClassName));
                psoClass.Properties.Add(new PSNoteProperty(InternalDeserializer.CimNamespaceProperty, cimClass.CimSystemProperties.Namespace));
                psoClass.Properties.Add(new PSNoteProperty(InternalDeserializer.CimServerNameProperty, cimClass.CimSystemProperties.ServerName));
                psoClass.Properties.Add(new PSNoteProperty(InternalDeserializer.CimHashCodeProperty, cimClass.GetHashCode()));

                CimClassSerializationId cimClassSerializationId = new CimClassSerializationId(
                    cimClass.CimSystemProperties.ClassName,
                    cimClass.CimSystemProperties.Namespace,
                    cimClass.CimSystemProperties.ServerName,
                    cimClass.GetHashCode());
                if (_context.cimClassSerializationIdCache.DoesDeserializerAlreadyHaveCimClass(cimClassSerializationId))
                {
                    break;
                }

                serializedClasses.Enqueue(cimClassSerializationId);
                byte[] miXmlBytes = s_cimSerializer.Value.Serialize(cimClass, ClassSerializationOptions.None);
                string miXmlString = Encoding.Unicode.GetString(miXmlBytes, 0, miXmlBytes.Length);
                psoClass.Properties.Add(new PSNoteProperty(InternalDeserializer.CimMiXmlProperty, miXmlString));
            }

            psoClasses.Reverse();

            //
            // UPDATE CLASSDECL CACHE
            //
            foreach (CimClassSerializationId serializedClassId in serializedClasses)
            {
                _context.cimClassSerializationIdCache.AddClassToCache(serializedClassId);
            }

            //
            // ATTACH CLASS METADATA TO THE OBJECT BEING SERIALIZED
            //
            PSPropertyInfo classMetadataProperty = psObject.Properties[InternalDeserializer.CimClassMetadataProperty];
            if (classMetadataProperty != null)
            {
                classMetadataProperty.Value = psoClasses;
            }
            else
            {
                PSNoteProperty classMetadataNote = new PSNoteProperty(
                    InternalDeserializer.CimClassMetadataProperty,
                    psoClasses);
                classMetadataNote.IsHidden = true;
                psObject.Properties.Add(classMetadataNote);
            }

            // ATTACH INSTANCE METADATA TO THE OBJECT BEING SERIALIZED
            List<string> namesOfModifiedProperties = cimInstance
                .CimInstanceProperties
                .Where(static p => p.IsValueModified)
                .Select(static p => p.Name)
                .ToList();
            if (namesOfModifiedProperties.Count != 0)
            {
                PSObject instanceMetadata = new PSObject();
                PSPropertyInfo instanceMetadataProperty = psObject.Properties[InternalDeserializer.CimInstanceMetadataProperty];
                if (instanceMetadataProperty != null)
                {
                    instanceMetadataProperty.Value = instanceMetadata;
                }
                else
                {
                    PSNoteProperty instanceMetadataNote = new PSNoteProperty(InternalDeserializer.CimInstanceMetadataProperty, instanceMetadata);
                    instanceMetadataNote.IsHidden = true;
                    psObject.Properties.Add(instanceMetadataNote);
                }

                instanceMetadata.InternalTypeNames = ConsolidatedString.Empty;

                instanceMetadata.Properties.Add(
                    new PSNoteProperty(
                        InternalDeserializer.CimModifiedProperties,
                        string.Join(" ", namesOfModifiedProperties)));
            }
        }

        /// <summary>
        /// Writes start element, attributes and typeNames for PSObject.
        /// </summary>
        /// <param name="mshObject"></param>
        /// <param name="streamName"></param>
        /// <param name="property"></param>
        /// <param name="refId"></param>
        /// <param name="writeTypeNames">If true, TypeName information is written, else not.</param>
        /// <param name="toStringValue">If not null then ToString information is written.</param>
        private void WriteStartOfPSObject
        (
            PSObject mshObject,
            string streamName,
            string property,
            string refId,
            bool writeTypeNames,
            string toStringValue
        )
        {
            Dbg.Assert(mshObject != null, "caller should validate the parameter");

            // Write PSObject start element.
            WriteStartElement(SerializationStrings.PSObjectTag);

            if (streamName != null)
            {
                WriteAttribute(SerializationStrings.StreamNameAttribute, streamName);
            }

            if (property != null)
            {
                WriteNameAttribute(property);
            }

            if (refId != null)
            {
                WriteAttribute(SerializationStrings.ReferenceIdAttribute, refId);
            }

            if (writeTypeNames)
            {
                // Write TypeNames
                ConsolidatedString typeNames = mshObject.InternalTypeNames;
                if (typeNames.Count > 0)
                {
                    string typeNameHierarchyReferenceId = _typeRefIdHandler.GetRefId(typeNames);
                    if (typeNameHierarchyReferenceId == null)
                    {
                        WriteStartElement(SerializationStrings.TypeNamesTag);

                        // Create a new refId and write it as attribute
                        string tnRefId = _typeRefIdHandler.SetRefId(typeNames);
                        Dbg.Assert(tnRefId != null, "SetRefId should always succeed for strings");
                        WriteAttribute(SerializationStrings.ReferenceIdAttribute, tnRefId);

                        foreach (string type in typeNames)
                        {
                            WriteEncodedElementString(SerializationStrings.TypeNamesItemTag, type);
                        }

                        _writer.WriteEndElement();
                    }
                    else
                    {
                        WriteStartElement(SerializationStrings.TypeNamesReferenceTag);
                        WriteAttribute(SerializationStrings.ReferenceIdAttribute, typeNameHierarchyReferenceId);
                        _writer.WriteEndElement();
                    }
                }
            }

            if (toStringValue != null)
            {
                WriteEncodedElementString(SerializationStrings.ToStringElementTag, toStringValue);
            }
        }

        #region membersets

        /// <summary>
        /// Returns true if PSObject has notes.
        /// </summary>
        /// <param name="source"></param>
        /// <returns>
        /// </returns>
        private static bool PSObjectHasNotes(PSObject source)
        {
            Dbg.Assert(source != null, "Caller should validate the parameter");
            if (source.InstanceMembers != null && source.InstanceMembers.Count > 0)
            {
                return true;
            }

            return false;
        }

        private bool? _canUseDefaultRunspaceInThreadSafeManner;

        private bool CanUseDefaultRunspaceInThreadSafeManner
        {
            get
            {
                if (!_canUseDefaultRunspaceInThreadSafeManner.HasValue)
                {
                    _canUseDefaultRunspaceInThreadSafeManner = Runspace.CanUseDefaultRunspace;
                }

                return _canUseDefaultRunspaceInThreadSafeManner.Value;
            }
        }

        /// <summary>
        /// Serialize member set. This method serializes without writing
        /// enclosing tags and attributes.
        /// </summary>
        /// <param name="me">
        /// enumerable containing members
        /// </param>
        /// <param name="depth"></param>
        /// <param name="writeEnclosingMemberSetElementTag">
        /// if this is true, write an enclosing "<memberset></memberset>" tag.
        /// </param>
        /// <returns></returns>
        private void WriteMemberInfoCollection
        (
            IEnumerable<PSMemberInfo> me,
            int depth,
            bool writeEnclosingMemberSetElementTag
        )
        {
            Dbg.Assert(me != null, "caller should validate the parameter");

            bool enclosingTagWritten = false;
            foreach (PSMemberInfo info in me)
            {
                if (!info.ShouldSerialize)
                {
                    continue;
                }

                int depthOfMember = info.IsInstance ? depth : depth - 1;

                if (info.MemberType == (info.MemberType & PSMemberTypes.Properties))
                {
                    bool gotValue;
                    object value = SerializationUtilities.GetPropertyValueInThreadSafeManner((PSPropertyInfo)info, this.CanUseDefaultRunspaceInThreadSafeManner, out gotValue);
                    if (gotValue)
                    {
                        if (writeEnclosingMemberSetElementTag && !enclosingTagWritten)
                        {
                            enclosingTagWritten = true;
                            WriteStartElement(SerializationStrings.MemberSet);
                        }

                        WriteOneObject(value, null, info.Name, depthOfMember);
                    }
                }
                else if (info.MemberType == PSMemberTypes.MemberSet)
                {
                    if (writeEnclosingMemberSetElementTag && !enclosingTagWritten)
                    {
                        enclosingTagWritten = true;
                        WriteStartElement(SerializationStrings.MemberSet);
                    }

                    WriteMemberSet((PSMemberSet)info, depthOfMember);
                }
            }

            if (enclosingTagWritten)
            {
                _writer.WriteEndElement();
            }
        }

        /// <summary>
        /// Serializes MemberSet.
        /// </summary>
        private void WriteMemberSet
        (
            PSMemberSet set,
            int depth
        )
        {
            Dbg.Assert(set != null, "Caller should validate the parameter");

            if (!set.ShouldSerialize)
            {
                return;
            }

            WriteStartElement(SerializationStrings.MemberSet);
            WriteNameAttribute(set.Name);
            WriteMemberInfoCollection(set.Members, depth, false);
            _writer.WriteEndElement();
        }

        #endregion membersets

        #region properties

        /// <summary>
        /// Serializes properties of PSObject.
        /// </summary>
        private void WritePSObjectProperties
        (
            PSObject source,
            int depth,
            IEnumerable<PSPropertyInfo> specificPropertiesToSerialize
        )
        {
            Dbg.Assert(source != null, "caller should validate the information");

            // Depth available for each property is one less
            --depth;
            Dbg.Assert(depth >= 0, "depth should be greater or equal to zero");

            if (specificPropertiesToSerialize != null)
            {
                SerializeProperties(specificPropertiesToSerialize, SerializationStrings.AdapterProperties, depth);
            }
            else
            {
                if (source.ShouldSerializeAdapter())
                {
                    IEnumerable<PSPropertyInfo> adapterCollection = null;
                    adapterCollection = source.GetAdaptedProperties();
                    if (adapterCollection != null)
                    {
                        SerializeProperties(adapterCollection, SerializationStrings.AdapterProperties, depth);
                    }
                }
            }
        }

        private void SerializeInstanceProperties
        (
            PSObject source,
            int depth
        )
        {
            // Serialize instanceMembers
            Dbg.Assert(source != null, "caller should validate the information");
            PSMemberInfoCollection<PSMemberInfo> instanceMembers = source.InstanceMembers;
            if (instanceMembers != null)
            {
                WriteMemberInfoCollection(instanceMembers, depth, true);
            }
        }

        private Collection<CollectionEntry<PSMemberInfo>> _extendedMembersCollection;

        private Collection<CollectionEntry<PSMemberInfo>> ExtendedMembersCollection
        {
            get
            {
                return _extendedMembersCollection ??=
                    PSObject.GetMemberCollection(PSMemberViewTypes.Extended, _typeTable);
            }
        }

        private Collection<CollectionEntry<PSPropertyInfo>> _allPropertiesCollection;

        private Collection<CollectionEntry<PSPropertyInfo>> AllPropertiesCollection
        {
            get
            {
                return _allPropertiesCollection ??= PSObject.GetPropertyCollection(PSMemberViewTypes.All, _typeTable);
            }
        }

        private void SerializeExtendedProperties
        (
            PSObject source,
            int depth,
            IEnumerable<PSPropertyInfo> specificPropertiesToSerialize
        )
        {
            Dbg.Assert(source != null, "caller should validate the information");

            IEnumerable<PSMemberInfo> extendedMembersEnumerable = null;
            if (specificPropertiesToSerialize == null)
            {
                // Get only extended members including hidden members from the psobect source.
                PSMemberInfoIntegratingCollection<PSMemberInfo> membersToSearch =
                    new PSMemberInfoIntegratingCollection<PSMemberInfo>(source, ExtendedMembersCollection);
                extendedMembersEnumerable = membersToSearch.Match(
                        "*",
                        PSMemberTypes.Properties | PSMemberTypes.PropertySet | PSMemberTypes.MemberSet,
                        MshMemberMatchOptions.IncludeHidden | MshMemberMatchOptions.OnlySerializable);
            }
            else
            {
                List<PSMemberInfo> extendedMembersList = new List<PSMemberInfo>(source.InstanceMembers);
                extendedMembersEnumerable = extendedMembersList;

                foreach (PSMemberInfo member in specificPropertiesToSerialize)
                {
                    if (member.IsInstance)
                    {
                        continue;
                    }

                    if (member is PSProperty)
                    {
                        continue;
                    }

                    extendedMembersList.Add(member);
                }
            }

            if (extendedMembersEnumerable != null)
            {
                WriteMemberInfoCollection(extendedMembersEnumerable, depth, true);
            }
        }

        /// <summary>
        /// Serializes properties from collection.
        /// </summary>
        /// <param name="propertyCollection">
        /// Collection of properties to serialize
        /// </param>
        /// <param name="name">
        /// Name for enclosing element tag
        /// </param>
        /// <param name="depth">
        /// depth to which each property should be
        /// serialized
        /// </param>
        private void SerializeProperties
        (
            IEnumerable<PSPropertyInfo> propertyCollection,
            string name,
            int depth
        )
        {
            Dbg.Assert(propertyCollection != null, "caller should validate the parameter");
            bool startElementWritten = false;

            foreach (PSMemberInfo info in propertyCollection)
            {
                if (!(info is PSProperty prop))
                {
                    continue;
                }

                if (!startElementWritten)
                {
                    WriteStartElement(name);
                    startElementWritten = true;
                }

                bool success;
                object value = SerializationUtilities.GetPropertyValueInThreadSafeManner(prop, this.CanUseDefaultRunspaceInThreadSafeManner, out success);
                if (success)
                {
                    WriteOneObject(value, null, prop.Name, depth);
                }
            }

            if (startElementWritten)
            {
                _writer.WriteEndElement();
            }
        }

        #endregion base properties

        #endregion WritePSObject

        #region enumerable and dictionary

        /// <summary>
        /// Serializes IEnumerable.
        /// </summary>
        /// <param name="enumerable">
        /// enumerable which is serialized
        /// </param>
        /// <param name="tag">
        /// </param>
        /// <param name="depth"></param>
        private void WriteEnumerable
        (
            IEnumerable enumerable,
            string tag,
            int depth
        )
        {
            Dbg.Assert(enumerable != null, "caller should validate the parameter");
            Dbg.Assert(!string.IsNullOrEmpty(tag), "caller should validate the parameter");

            // Start element
            WriteStartElement(tag);

            IEnumerator enumerator = null;
            try
            {
                enumerator = enumerable.GetEnumerator();
                try
                {
                    enumerator.Reset();
                }
                catch (System.NotSupportedException)
                {
                    // ignore exceptions thrown when the enumerator doesn't support Reset() method as in win8:948569
                }
            }
            catch (Exception exception)
            {
                // Catch-all OK. This is a third-party call-out.
                PSEtwLog.LogAnalyticWarning(
                    PSEventId.Serializer_EnumerationFailed, PSOpcode.Exception, PSTask.Serialization,
                    PSKeyword.Serializer | PSKeyword.UseAlwaysAnalytic,
                    enumerable.GetType().AssemblyQualifiedName,
                    exception.ToString());

                enumerator = null;
            }

            // AD has incorrect implementation of IEnumerable where they returned null
            // for GetEnumerator instead of empty enumerator
            if (enumerator != null)
            {
                while (true)
                {
                    object item = null;
                    try
                    {
                        if (!enumerator.MoveNext())
                        {
                            break;
                        }
                        else
                        {
                            item = enumerator.Current;
                        }
                    }
                    catch (Exception exception)
                    {
                        // Catch-all OK. This is a third-party call-out.
                        PSEtwLog.LogAnalyticWarning(
                            PSEventId.Serializer_EnumerationFailed, PSOpcode.Exception, PSTask.Serialization,
                            PSKeyword.Serializer | PSKeyword.UseAlwaysAnalytic,
                            enumerable.GetType().AssemblyQualifiedName,
                            exception.ToString());

                        break;
                    }

                    WriteOneObject(item, null, null, depth);
                }
            }
            // End element
            _writer.WriteEndElement();
        }

        /// <summary>
        /// Serializes IDictionary.
        /// </summary>
        /// <param name="dictionary">Dictionary which is serialized.</param>
        /// <param name="tag"></param>
        /// <param name="depth"></param>
        private void WriteDictionary
        (
            IDictionary dictionary,
            string tag,
            int depth
        )
        {
            Dbg.Assert(dictionary != null, "caller should validate the parameter");
            Dbg.Assert(!string.IsNullOrEmpty(tag), "caller should validate the parameter");

            // Start element
            WriteStartElement(tag);

            IDictionaryEnumerator dictionaryEnum = null;
            try
            {
                dictionaryEnum = dictionary.GetEnumerator();
            }
            catch (Exception exception) // ignore non-severe exceptions
            {
                // Catch-all OK. This is a third-party call-out.
                PSEtwLog.LogAnalyticWarning(
                    PSEventId.Serializer_EnumerationFailed, PSOpcode.Exception, PSTask.Serialization,
                    PSKeyword.Serializer | PSKeyword.UseAlwaysAnalytic,
                    dictionary.GetType().AssemblyQualifiedName,
                    exception.ToString());
            }

            if (dictionaryEnum != null)
            {
                while (true)
                {
                    object key = null;
                    object value = null;
                    try
                    {
                        if (!dictionaryEnum.MoveNext())
                        {
                            break;
                        }
                        else
                        {
                            key = dictionaryEnum.Key;
                            value = dictionaryEnum.Value;
                        }
                    }
                    catch (Exception exception)
                    {
                        // Catch-all OK. This is a third-party call-out.
                        PSEtwLog.LogAnalyticWarning(
                            PSEventId.Serializer_EnumerationFailed, PSOpcode.Exception, PSTask.Serialization,
                            PSKeyword.Serializer | PSKeyword.UseAlwaysAnalytic,
                            dictionary.GetType().AssemblyQualifiedName,
                            exception.ToString());

                        break;
                    }

                    Dbg.Assert(key != null, "Dictionary keys should never be null");
                    if (key == null) break;

                    WriteStartElement(SerializationStrings.DictionaryEntryTag);
                    WriteOneObject(key, null, SerializationStrings.DictionaryKey, depth);
                    WriteOneObject(value, null, SerializationStrings.DictionaryValue, depth);
                    _writer.WriteEndElement();
                }
            }

            // End element
            _writer.WriteEndElement();
        }

        #endregion enumerable and dictionary

        #region serialize as string

        private void HandlePSObjectAsString(
            PSObject source,
            string streamName,
            string property,
            int depth)
        {
            Dbg.Assert(source != null, "caller should validate the information");

            string value = GetSerializationString(source);

            TypeSerializationInfo pktInfo = null;
            if (value != null)
            {
                pktInfo = KnownTypes.GetTypeSerializationInfo(value.GetType());
            }

            WritePrimitiveTypePSObject(source, value, pktInfo, streamName, property, depth);
        }

        /// <summary>
        /// Gets the string from PSObject using the information from
        /// types.ps1xml.
        /// This string is used for serializing the PSObject at depth 0
        /// or when pso.SerializationMethod == SerializationMethod.String.
        /// </summary>
        /// <param name="source">
        /// PSObject to be converted to string
        /// </param>
        /// <returns>
        /// string value to use for serializing this PSObject.
        /// </returns>
        private string GetSerializationString(PSObject source)
        {
            Dbg.Assert(source != null, "caller should have validated the information");

            PSPropertyInfo serializationProperty = null;
            try
            {
                serializationProperty = source.GetStringSerializationSource(_typeTable);
            }
            catch (ExtendedTypeSystemException e)
            {
                PSEtwLog.LogAnalyticWarning(
                    PSEventId.Serializer_ToStringFailed, PSOpcode.Exception, PSTask.Serialization,
                    PSKeyword.Serializer | PSKeyword.UseAlwaysAnalytic,
                    source.GetType().AssemblyQualifiedName,
                    e.InnerException != null ? e.InnerException.ToString() : e.ToString());
            }

            string result = null;
            if (serializationProperty != null)
            {
                bool success;
                object val = SerializationUtilities.GetPropertyValueInThreadSafeManner(serializationProperty, this.CanUseDefaultRunspaceInThreadSafeManner, out success);
                if (success && (val != null))
                {
                    result = SerializationUtilities.GetToString(val);
                }
            }
            else
            {
                result = SerializationUtilities.GetToString(source);
            }

            return result;
        }

        /// <summary>
        /// Reads the information the PSObject
        /// and returns true if this object should be serialized as
        /// string.
        /// </summary>
        /// <param name="source">PSObject to be serialized.</param>
        /// <returns>True if the object needs to be serialized as a string.</returns>
        private bool SerializeAsString(PSObject source)
        {
            SerializationMethod method = source.GetSerializationMethod(_typeTable);
            if (method == SerializationMethod.String)
            {
                PSEtwLog.LogAnalyticVerbose(
                    PSEventId.Serializer_ModeOverride, PSOpcode.SerializationSettings, PSTask.Serialization,
                    PSKeyword.Serializer | PSKeyword.UseAlwaysAnalytic,
                    source.InternalTypeNames.Key,
                    (UInt32)(SerializationMethod.String));

                return true;
            }
            else
            {
                return false;
            }
        }

        #endregion serialize as string

        /// <summary>
        /// Compute the serialization depth for an PSObject instance subtree.
        /// </summary>
        /// <param name="source">PSObject whose serialization depth has to be computed.</param>
        /// <param name="depth">Current depth.</param>
        /// <returns></returns>
        private int GetDepthOfSerialization(object source, int depth)
        {
            Dbg.Assert(source != null, "Caller should verify source != null");

            PSObject pso = PSObject.AsPSObject(source);
            if (pso == null)
            {
                return depth;
            }

            if (pso.BaseObject is CimInstance)
            {
                return 1;
            }

            if (pso.BaseObject is PSCredential)
            {
                return 1;
            }

            if (pso.BaseObject is PSSenderInfo)
            {
                return 4;
            }

            if (pso.BaseObject is SwitchParameter)
            {
                return 1;
            }

            if ((_context.options & SerializationOptions.UseDepthFromTypes) != 0)
            {
                // get the depth from the PSObject
                // NOTE: we assume that the depth out of the PSObject is > 0
                // else we consider it not set in types.ps1xml
                int typesPs1xmlDepth = pso.GetSerializationDepth(_typeTable);
                if (typesPs1xmlDepth > 0)
                {
                    if (typesPs1xmlDepth != depth)
                    {
                        PSEtwLog.LogAnalyticVerbose(
                            PSEventId.Serializer_DepthOverride, PSOpcode.SerializationSettings, PSTask.Serialization,
                            PSKeyword.Serializer | PSKeyword.UseAlwaysAnalytic,
                            pso.InternalTypeNames.Key, depth, typesPs1xmlDepth, _depthBelowTopLevel);

                        return typesPs1xmlDepth;
                    }
                }
            }

            if ((_context.options & SerializationOptions.PreserveSerializationSettingOfOriginal) != 0)
            {
                if ((pso.IsDeserialized) && (depth <= 0))
                {
                    return 1;
                }
            }

            return depth;
        }

        /// <summary>
        /// Writes null.
        /// </summary>
        /// <param name="streamName"></param>
        /// <param name="property"></param>
        private void WriteNull(string streamName, string property)
        {
            WriteStartElement(SerializationStrings.NilTag);

            if (streamName != null)
            {
                WriteAttribute(SerializationStrings.StreamNameAttribute, streamName);
            }

            if (property != null)
            {
                WriteNameAttribute(property);
            }

            _writer.WriteEndElement();
        }

        #region known type serialization

        /// <summary>
        /// Writes raw string as item or property in Monad namespace.
        /// </summary>
        /// <param name="serializer">The serializer to which the object is serialized.</param>
        /// <param name="streamName">Name of the stream to write. Do not write if null.</param>
        /// <param name="property">Name of property. Pass null for item.</param>
        /// <param name="raw">String to write.</param>
        /// <param name="entry">Serialization information.</param>
        private static void WriteRawString
        (
            InternalSerializer serializer,
            string streamName,
            string property,
            string raw,
            TypeSerializationInfo entry
        )
        {
            Dbg.Assert(serializer != null, "caller should have validated the information");
            Dbg.Assert(raw != null, "caller should have validated the information");
            Dbg.Assert(entry != null, "caller should have validated the information");

            if (property != null)
            {
                serializer.WriteStartElement(entry.PropertyTag);
                serializer.WriteNameAttribute(property);
            }
            else
            {
                serializer.WriteStartElement(entry.ItemTag);
            }

            if (streamName != null)
            {
                serializer.WriteAttribute(SerializationStrings.StreamNameAttribute, streamName);
            }

            serializer._writer.WriteRaw(raw);
            serializer._writer.WriteEndElement();
        }

        /// <summary>
        /// Writes an item or property in Monad namespace.
        /// </summary>
        /// <param name="serializer">The serializer to which the object is serialized.</param>
        /// <param name="streamName"></param>
        /// <param name="property">Name of property. Pass null for item.</param>
        /// <param name="source">Object to be written.</param>
        /// <param name="entry">Serialization information about source.</param>
        private static void WriteOnePrimitiveKnownType
        (
            InternalSerializer serializer,
            string streamName,
            string property,
            object source,
            TypeSerializationInfo entry
        )
        {
            Dbg.Assert(serializer != null, "caller should have validated the information");
            Dbg.Assert(source != null, "caller should have validated the information");
            Dbg.Assert(entry != null, "caller should have validated the information");

            if (entry.Serializer == null)
            {
                // we are not using GetToString, because we assume that
                // ToString() for primitive types never throws
                string value = Convert.ToString(source, CultureInfo.InvariantCulture);
                Dbg.Assert(value != null, "ToString shouldn't return null for primitive types");
                WriteRawString(serializer, streamName, property, value, entry);
            }
            else
            {
                entry.Serializer(serializer, streamName, property, source, entry);
            }
        }

        /// <summary>
        /// Writes DateTime as item or property.
        /// </summary>
        /// <param name="serializer">The serializer to which the object is serialized.</param>
        /// <param name="streamName"></param>
        /// <param name="property">Name of property. pass null for item.</param>
        /// <param name="source">DateTime to write.</param>
        /// <param name="entry">Serialization information about source.</param>
        internal static void WriteDateTime(InternalSerializer serializer, string streamName, string property, object source, TypeSerializationInfo entry)
        {
            Dbg.Assert(serializer != null, "caller should have validated the information");
            Dbg.Assert(source != null, "caller should have validated the information");
            Dbg.Assert(entry != null, "caller should have validated the information");

            WriteRawString(serializer, streamName, property, XmlConvert.ToString((DateTime)source, XmlDateTimeSerializationMode.RoundtripKind), entry);
        }

        /// <summary>
        /// Writes Version.
        /// </summary>
        /// <param name="serializer">The serializer to which the object is serialized.</param>
        /// <param name="streamName"></param>
        /// <param name="property">Name of property. pass null for item.</param>
        /// <param name="source">Version to write.</param>
        /// <param name="entry">Serialization information about source.</param>
        internal static void WriteVersion(InternalSerializer serializer, string streamName, string property, object source, TypeSerializationInfo entry)
        {
            Dbg.Assert(serializer != null, "caller should have validated the information");
            Dbg.Assert(source != null, "caller should have validated the information");
            Dbg.Assert(source is Version, "Caller should verify that typeof(source) is Version");
            Dbg.Assert(entry != null, "caller should have validated the information");

            WriteRawString(serializer, streamName, property, Convert.ToString(source, CultureInfo.InvariantCulture), entry);
        }

        /// <summary>
        /// Writes SemanticVersion.
        /// </summary>
        /// <param name="serializer">The serializer to which the object is serialized.</param>
        /// <param name="streamName"></param>
        /// <param name="property">Name of property. pass null for item.</param>
        /// <param name="source">Version to write.</param>
        /// <param name="entry">Serialization information about source.</param>
        internal static void WriteSemanticVersion(InternalSerializer serializer, string streamName, string property, object source, TypeSerializationInfo entry)
        {
            Dbg.Assert(serializer != null, "caller should have validated the information");
            Dbg.Assert(source != null, "caller should have validated the information");
            Dbg.Assert(source is SemanticVersion, "Caller should verify that typeof(source) is Version");
            Dbg.Assert(entry != null, "caller should have validated the information");

            WriteRawString(serializer, streamName, property, Convert.ToString(source, CultureInfo.InvariantCulture), entry);
        }

        /// <summary>
        /// Serialize scriptblock as item or property.
        /// </summary>
        /// <param name="serializer">The serializer to which the object is serialized.</param>
        /// <param name="streamName"></param>
        /// <param name="property">Name of property. pass null for item.</param>
        /// <param name="source">Scriptblock to write.</param>
        /// <param name="entry">Serialization information about source.</param>
        internal static void WriteScriptBlock(InternalSerializer serializer, string streamName, string property, object source, TypeSerializationInfo entry)
        {
            Dbg.Assert(serializer != null, "caller should have validated the information");
            Dbg.Assert(source != null, "caller should have validated the information");
            Dbg.Assert(source is ScriptBlock, "Caller should verify that typeof(source) is ScriptBlock");
            Dbg.Assert(entry != null, "caller should have validated the information");

            WriteEncodedString(serializer, streamName, property, Convert.ToString(source, CultureInfo.InvariantCulture), entry);
        }

        /// <summary>
        /// Serialize URI as item or property.
        /// </summary>
        /// <param name="serializer">The serializer to which the object is serialized.</param>
        /// <param name="streamName"></param>
        /// <param name="property">Name of property. pass null for item.</param>
        /// <param name="source">URI to write.</param>
        /// <param name="entry">Serialization information about source.</param>
        internal static void WriteUri(InternalSerializer serializer, string streamName, string property, object source, TypeSerializationInfo entry)
        {
            Dbg.Assert(serializer != null, "caller should have validated the information");
            Dbg.Assert(source != null, "caller should have validated the information");
            Dbg.Assert(source is Uri, "Caller should verify that typeof(source) is Uri");
            Dbg.Assert(entry != null, "caller should have validated the information");

            WriteEncodedString(serializer, streamName, property, Convert.ToString(source, CultureInfo.InvariantCulture), entry);
        }

        /// <summary>
        /// Serialize string as item or property.
        /// </summary>
        /// <param name="serializer">The serializer to which the object is serialized.</param>
        /// <param name="streamName"></param>
        /// <param name="property">Name of property. pass null for item.</param>
        /// <param name="source">String to write.</param>
        /// <param name="entry">Serialization information about source.</param>
        internal static void WriteEncodedString(InternalSerializer serializer, string streamName, string property, object source, TypeSerializationInfo entry)
        {
            Dbg.Assert(serializer != null, "caller should have validated the information");
            Dbg.Assert(source != null, "caller should have validated the information");
            Dbg.Assert(source is string, "caller should have validated the information");
            Dbg.Assert(entry != null, "caller should have validated the information");

            if (property != null)
            {
                serializer.WriteStartElement(entry.PropertyTag);
                serializer.WriteNameAttribute(property);
            }
            else
            {
                serializer.WriteStartElement(entry.ItemTag);
            }

            if (streamName != null)
            {
                serializer.WriteAttribute(SerializationStrings.StreamNameAttribute, streamName);
            }

            // Note: We do not use WriteRaw for serializing string. WriteString
            // does necessary escaping which may be needed for certain
            // characters.
            Dbg.Assert(source is string, "Caller should verify that typeof(source) is String");
            string s = (string)source;
            string encoded = EncodeString(s);
            serializer._writer.WriteString(encoded);

            serializer._writer.WriteEndElement();
        }

        /// <summary>
        /// Writes Double as item or property.
        /// </summary>
        /// <param name="serializer">The serializer to which the object is serialized.</param>
        /// <param name="streamName"></param>
        /// <param name="property">Name of property. pass null for item.</param>
        /// <param name="source">Double to write.</param>
        /// <param name="entry">Serialization information about source.</param>
        internal static void WriteDouble(InternalSerializer serializer, string streamName, string property, object source, TypeSerializationInfo entry)
        {
            Dbg.Assert(serializer != null, "caller should have validated the information");
            Dbg.Assert(source != null, "caller should have validated the information");
            Dbg.Assert(entry != null, "caller should have validated the information");

            WriteRawString(serializer, streamName, property, XmlConvert.ToString((double)source), entry);
        }

        /// <summary>
        /// Writes Char as item or property.
        /// </summary>
        /// <param name="serializer">The serializer to which the object is serialized.</param>
        /// <param name="streamName"></param>
        /// <param name="property">Name of property. pass null for item.</param>
        /// <param name="source">Char to write.</param>
        /// <param name="entry">Serialization information about source.</param>
        internal static void WriteChar(InternalSerializer serializer, string streamName, string property, object source, TypeSerializationInfo entry)
        {
            Dbg.Assert(serializer != null, "caller should have validated the information");
            Dbg.Assert(source != null, "caller should have validated the information");
            Dbg.Assert(entry != null, "caller should have validated the information");

            // Char is defined as unsigned short in schema
            WriteRawString(serializer, streamName, property, XmlConvert.ToString((UInt16)(char)source), entry);
        }

        /// <summary>
        /// Writes Boolean as item or property.
        /// </summary>
        /// <param name="serializer">The serializer to which the object is serialized.</param>
        /// <param name="streamName"></param>
        /// <param name="property">Name of property. pass null for item.</param>
        /// <param name="source">Boolean to write.</param>
        /// <param name="entry">Serialization information about source.</param>
        internal static void WriteBoolean(InternalSerializer serializer, string streamName, string property, object source, TypeSerializationInfo entry)
        {
            Dbg.Assert(serializer != null, "caller should have validated the information");
            Dbg.Assert(source != null, "caller should have validated the information");
            Dbg.Assert(entry != null, "caller should have validated the information");

            WriteRawString(serializer, streamName, property, XmlConvert.ToString((bool)source), entry);
        }

        /// <summary>
        /// Writes Single as item or property.
        /// </summary>
        /// <param name="serializer">The serializer to which the object is serialized.</param>
        /// <param name="streamName"></param>
        /// <param name="property">Name of property. pass null for item.</param>
        /// <param name="source">Single to write.</param>
        /// <param name="entry">Serialization information about source.</param>
        internal static void WriteSingle(InternalSerializer serializer, string streamName, string property, object source, TypeSerializationInfo entry)
        {
            Dbg.Assert(serializer != null, "caller should have validated the information");
            Dbg.Assert(source != null, "caller should have validated the information");
            Dbg.Assert(entry != null, "caller should have validated the information");

            WriteRawString(serializer, streamName, property, XmlConvert.ToString((Single)source), entry);
        }

        /// <summary>
        /// Writes TimeSpan as item or property.
        /// </summary>
        /// <param name="serializer">The serializer to which the object is serialized.</param>
        /// <param name="streamName"></param>
        /// <param name="property">Name of property. pass null for item.</param>
        /// <param name="source">DateTime to write.</param>
        /// <param name="entry">Serialization information about source.</param>
        internal static void WriteTimeSpan(InternalSerializer serializer, string streamName, string property, object source, TypeSerializationInfo entry)
        {
            Dbg.Assert(serializer != null, "caller should have validated the information");
            Dbg.Assert(source != null, "caller should have validated the information");
            Dbg.Assert(entry != null, "caller should have validated the information");

            WriteRawString(serializer, streamName, property, XmlConvert.ToString((TimeSpan)source), entry);
        }

        /// <summary>
        /// Writes Single as item or property.
        /// </summary>
        /// <param name="serializer">The serializer to which the object is serialized.</param>
        /// <param name="streamName"></param>
        /// <param name="property">Name of property. pass null for item.</param>
        /// <param name="source">Bytearray to write.</param>
        /// <param name="entry">Serialization information about source.</param>
        internal static void WriteByteArray(InternalSerializer serializer, string streamName, string property, object source, TypeSerializationInfo entry)
        {
            Dbg.Assert(serializer != null, "caller should have validated the information");
            Dbg.Assert(source != null, "caller should have validated the information");
            Dbg.Assert(entry != null, "caller should have validated the information");

            byte[] bytes = (byte[])source;
            if (property != null)
            {
                serializer.WriteStartElement(entry.PropertyTag);
                serializer.WriteNameAttribute(property);
            }
            else
            {
                serializer.WriteStartElement(entry.ItemTag);
            }

            if (streamName != null)
            {
                serializer.WriteAttribute(SerializationStrings.StreamNameAttribute, streamName);
            }

            serializer._writer.WriteBase64(bytes, 0, bytes.Length);
            serializer._writer.WriteEndElement();
        }

        internal static void WriteXmlDocument(InternalSerializer serializer, string streamName, string property, object source, TypeSerializationInfo entry)
        {
            Dbg.Assert(serializer != null, "caller should have validated the information");
            Dbg.Assert(source != null, "caller should have validated the information");
            Dbg.Assert(entry != null, "caller should have validated the information");

            string xml = ((XmlDocument)source).OuterXml;
            WriteEncodedString(serializer, streamName, property, xml, entry);
        }

        internal static void WriteProgressRecord(InternalSerializer serializer, string streamName, string property, object source, TypeSerializationInfo entry)
        {
            Dbg.Assert(serializer != null, "caller should have validated the information");
            Dbg.Assert(source != null, "caller should have validated the information");
            Dbg.Assert(entry != null, "caller should have validated the information");

            ProgressRecord rec = (ProgressRecord)source;
            serializer.WriteStartElement(entry.PropertyTag);
            if (property != null)
            {
                serializer.WriteNameAttribute(property);
            }

            if (streamName != null)
            {
                serializer.WriteAttribute(SerializationStrings.StreamNameAttribute, streamName);
            }

            serializer.WriteEncodedElementString(SerializationStrings.ProgressRecordActivity, rec.Activity);
            serializer.WriteEncodedElementString(SerializationStrings.ProgressRecordActivityId, rec.ActivityId.ToString(CultureInfo.InvariantCulture));
            serializer.WriteOneObject(rec.CurrentOperation, null, null, 1);
            serializer.WriteEncodedElementString(SerializationStrings.ProgressRecordParentActivityId, rec.ParentActivityId.ToString(CultureInfo.InvariantCulture));
            serializer.WriteEncodedElementString(SerializationStrings.ProgressRecordPercentComplete, rec.PercentComplete.ToString(CultureInfo.InvariantCulture));
            serializer.WriteEncodedElementString(SerializationStrings.ProgressRecordType, rec.RecordType.ToString());
            serializer.WriteEncodedElementString(SerializationStrings.ProgressRecordSecondsRemaining, rec.SecondsRemaining.ToString(CultureInfo.InvariantCulture));
            serializer.WriteEncodedElementString(SerializationStrings.ProgressRecordStatusDescription, rec.StatusDescription);

            serializer._writer.WriteEndElement();
        }

        internal static void WriteSecureString(InternalSerializer serializer, string streamName, string property, object source, TypeSerializationInfo entry)
        {
            Dbg.Assert(serializer != null, "caller should have validated the information");
            Dbg.Assert(source != null, "caller should have validated the information");
            Dbg.Assert(entry != null, "caller should have validated the information");

            serializer.HandleSecureString(source, streamName, property);
        }

        #endregion known type serialization

        #region misc

        /// <summary>
        /// Writes start element in Monad namespace.
        /// </summary>
        /// <param name="elementTag">Tag of element.</param>
        private void WriteStartElement(string elementTag)
        {
            Dbg.Assert(!string.IsNullOrEmpty(elementTag), "Caller should validate the parameter");
            if ((_context.options & SerializationOptions.NoNamespace) == SerializationOptions.NoNamespace)
            {
                _writer.WriteStartElement(elementTag);
            }
            else
            {
                _writer.WriteStartElement(elementTag, SerializationStrings.MonadNamespace);
            }
        }

        /// <summary>
        /// Writes attribute in monad namespace.
        /// </summary>
        /// <param name="name">Name of attribute.</param>
        /// <param name="value">Value of attribute.</param>
        private void WriteAttribute(string name, string value)
        {
            Dbg.Assert(!string.IsNullOrEmpty(name), "Caller should validate the parameter");
            Dbg.Assert(value != null, "Caller should validate the parameter");
            _writer.WriteAttributeString(name, value);
        }

        private void WriteNameAttribute(string value)
        {
            Dbg.Assert(!string.IsNullOrEmpty(value), "Caller should validate the parameter");
            WriteAttribute(
                SerializationStrings.NameAttribute,
                EncodeString(value));
        }

        /// <summary>
        /// Encodes the string to escape characters which would make XmlWriter.WriteString throw an exception.
        /// </summary>
        /// <param name="s">String to encode.</param>
        /// <returns>Encoded string.</returns>
        /// <remarks>
        /// Output from this method can be reverted using XmlConvert.DecodeName method
        /// (or InternalDeserializer.DecodeString).
        /// This method has been introduced to produce shorter output than XmlConvert.EncodeName
        /// (which escapes everything that can't be part of an xml name - whitespace, punctuation).
        ///
        /// This method has been split into 2 parts to optimize its performance:
        /// 1) part1 (this method) checks if there are any encodable characters and
        ///    if there aren't it simply (and efficiently) returns the original string
        /// 2) part2 (EncodeString(string, int)) picks up when part1 detects the first encodable
        ///    character.  It avoids looking at the characters already verified by part1
        ///    and copies those already verified characters and then starts encoding
        ///    the rest of the string.
        /// </remarks>
        internal static string EncodeString(string s)
        {
            Dbg.Assert(s != null, "Caller should validate the parameter");

            int slen = s.Length;
            for (int i = 0; i < slen; ++i)
            {
                char c = s[i];
                // A control character is in ranges 0x00-0x1F or 0x7F-0x9F
                // The escape character is 0x5F ('_') if followed by an 'x'
                // A surrogate character is in range 0xD800-0xDFFF
                if (c <= 0x1F
                        || (c >= 0x7F && c <= 0x9F)
                        || (c >= 0xD800 && c <= 0xDFFF)
                        || (c == 0x5F && (i + 1 < slen) &&
                            ((s[i + 1] == 'x') || (s[i + 1] == 'X'))
                            ))
                {
                    return EncodeString(s, i);
                }
            }
            // No encodable characters were found above - simply return the original string
            return s;
        }

        private static readonly char[] s_hexlookup = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F' };

        /// <summary>
        /// This is the real workhorse that encodes strings.
        /// See <see cref="EncodeString(string)"/> for more information.
        /// </summary>
        /// <param name="s">String to encode.</param>
        /// <param name="indexOfFirstEncodableCharacter">IndexOfFirstEncodableCharacter.</param>
        /// <returns>Encoded string.</returns>
        private static string EncodeString(string s, int indexOfFirstEncodableCharacter)
        {
            Dbg.Assert(s != null, "Caller should validate the 's' parameter");
            Dbg.Assert(indexOfFirstEncodableCharacter >= 0, "Caller should verify validity of indexOfFirstEncodableCharacter");
            Dbg.Assert(indexOfFirstEncodableCharacter < s.Length, "Caller should verify validity of indexOfFirstEncodableCharacter");

            int slen = s.Length;
            char[] result = new char[indexOfFirstEncodableCharacter + (slen - indexOfFirstEncodableCharacter) * 7];

            s.CopyTo(0, result, 0, indexOfFirstEncodableCharacter);
            int rlen = indexOfFirstEncodableCharacter;

            for (int i = indexOfFirstEncodableCharacter; i < slen; ++i)
            {
                char c = s[i];
                // A control character is in ranges 0x00-0x1F or 0x7F-0x9F
                // The escape character is 0x5F ('_') if followed by an 'x'
                // A surrogate character is in range 0xD800-0xDFFF
                if (c > 0x1F
                        && (c < 0x7F || c > 0x9F)
                        && (c < 0xD800 || c > 0xDFFF)
                        && (c != 0x5F || ((i + 1 >= slen) ||
                            ((s[i + 1] != 'x') && (s[i + 1] != 'X'))
                            )))
                {
                    result[rlen++] = c;
                }
                else if (c == 0x5F)
                {
                    // Special case the escape character, encode _
                    result[rlen + 0] = '_';
                    result[rlen + 1] = 'x';
                    result[rlen + 2] = '0';
                    result[rlen + 3] = '0';
                    result[rlen + 4] = '5';
                    result[rlen + 5] = 'F';
                    result[rlen + 6] = '_';
                    rlen += 7;
                }
                else
                {
                    // It is a control character or a unicode surrogate
                    result[rlen + 0] = '_';
                    result[rlen + 1] = 'x';

                    result[rlen + 2 + 3] = s_hexlookup[c & 0x0F];
                    c >>= 4;
                    result[rlen + 2 + 2] = s_hexlookup[c & 0x0F];
                    c >>= 4;
                    result[rlen + 2 + 1] = s_hexlookup[c & 0x0F];
                    c >>= 4;
                    result[rlen + 2 + 0] = s_hexlookup[c & 0x0F];

                    result[rlen + 6] = '_';

                    rlen += 7;
                }
            }

            return new string(result, 0, rlen);
        }

        /// <summary>
        /// Writes element string in monad namespace.
        /// </summary>
        /// <param name="name"></param>
        /// <param name="value"></param>
        private void WriteEncodedElementString(string name, string value)
        {
            Dbg.Assert(!string.IsNullOrEmpty(name), "Caller should validate the parameter");
            Dbg.Assert(value != null, "Caller should validate the parameter");
            this.CheckIfStopping();

            value = EncodeString(value);

            if ((_context.options & SerializationOptions.NoNamespace) == SerializationOptions.NoNamespace)
            {
                _writer.WriteElementString(name, value);
            }
            else
            {
                _writer.WriteElementString(name, SerializationStrings.MonadNamespace, value);
            }
        }

        #endregion misc
    }

    /// <summary>
    /// This internal class provides methods for de-serializing mshObject.
    /// </summary>
    internal class InternalDeserializer
    {
        #region constructor

        /// <summary>
        /// XmlReader from which object is deserialized.
        /// </summary>
        private readonly XmlReader _reader;

        /// <summary>
        /// Deserialization context.
        /// </summary>
        private readonly DeserializationContext _context;

        /// Used by Remoting infrastructure. This TypeTable instance
        /// will be used by Serializer if ExecutionContext is not
        /// available (to get the ExecutionContext's TypeTable)
        private TypeTable _typeTable;

        /// <summary>
        /// If true, unknowntags are allowed inside PSObject.
        /// </summary>
        private bool UnknownTagsAllowed
        {
            get
            {
                Dbg.Assert(_version.Major <= 1, "Deserializer assumes clixml version is <= 1.1");
                // If minor version is greater than 1, it means that there can be
                // some unknown tags in xml. Deserialization should ignore such element.
                return (_version.Minor > 1);
            }
        }

        [SuppressMessage(
            "Performance",
            "CA1822:Mark members as static",
            Justification = "Accesses instance members in preprocessor branch.")]
        private bool DuplicateRefIdsAllowed
        {
            get
            {
#if DEBUG
                Dbg.Assert(_version.Major <= 1, "Deserializer assumes clixml version is <= 1.1");
                Version boundaryVersion = new Version(1, 1, 0, 1);
                return (_version < boundaryVersion);
#else
                return true; // handle v1 stuff gracefully
#endif
            }
        }

        /// <summary>
        /// Depth below top level - used to prevent stack overflow during deserialization.
        /// </summary>
        private int _depthBelowTopLevel;

        /// <summary>
        /// Version declared by the clixml being read.
        /// </summary>
        private Version _version;

        private const int MaxDepthBelowTopLevel = 50;

        private readonly ReferenceIdHandlerForDeserializer<object> _objectRefIdHandler;
        private readonly ReferenceIdHandlerForDeserializer<ConsolidatedString> _typeRefIdHandler;

        /// <summary>
        /// </summary>
        /// <param name="reader"></param>
        /// <param name="context"></param>
        internal InternalDeserializer(XmlReader reader, DeserializationContext context)
        {
            Dbg.Assert(reader != null, "caller should validate the parameter");

            _reader = reader;
            _context = context;

            _objectRefIdHandler = new ReferenceIdHandlerForDeserializer<object>();
            _typeRefIdHandler = new ReferenceIdHandlerForDeserializer<ConsolidatedString>();
        }

        #endregion constructor

        #region Known CIMTypes

        private static readonly Lazy<HashSet<Type>> s_knownCimArrayTypes = new Lazy<HashSet<Type>>(
            () =>
                new HashSet<Type>
                {
                    typeof(bool),
                    typeof(byte),
                    typeof(char),
                    typeof(DateTime),
                    typeof(decimal),
                    typeof(double),
                    typeof(Int16),
                    typeof(Int32),
                    typeof(Int64),
                    typeof(sbyte),
                    typeof(Single),
                    typeof(string),
                    typeof(TimeSpan),
                    typeof(UInt16),
                    typeof(UInt32),
                    typeof(UInt64),
                    typeof(object),
                    typeof(CimInstance)
                }
            );

        #endregion

        #region deserialization
        /// <summary>
        /// Used by Remoting infrastructure. This TypeTable instance
        /// will be used by Deserializer if ExecutionContext is not
        /// available (to get the ExecutionContext's TypeTable)
        /// </summary>
        internal TypeTable TypeTable
        {
            get { return _typeTable; }

            set { _typeTable = value; }
        }

        /// <summary>
        /// Validates the version for correctness. Also validates that deserializer
        /// can deserialize this version.
        /// </summary>
        /// <param name="version">
        /// version in string format
        /// </param>
        internal void ValidateVersion(string version)
        {
            Dbg.Assert(version != null, "Caller should validate the parameter");

            _version = null;
            Exception exceptionToRethrow = null;
            try
            {
                _version = new Version(version);
            }
            catch (ArgumentException e)
            {
                exceptionToRethrow = e;
            }
            catch (FormatException e)
            {
                exceptionToRethrow = e;
            }

            if (exceptionToRethrow != null)
            {
                throw NewXmlException(Serialization.InvalidVersion, exceptionToRethrow);
            }

            // Versioning Note:Future version of serialization can add new known types.
            // This version will ignore those known types, if they are base object.
            // It is expected that future version will still put information in base
            // and adapter properties which this serializer can read and use.
            // For example, assume the version 2 serialization engine supports a new known
            // type IPAddress. The version 1 deserializer doesn't know IPAddress as known
            // type and it must retrieve it as an PSObject. The version 2 serializer
            // can serialize this as follows:
            // <PSObject Version=1.2 Was=Deserialized.IPAddress >
            //  <TypeNames>...</TypeNames>
            //  <BaseObject>
            //      <IPAddress>120.23.35.53</IPAddress>
            //  </BaseObject>
            //  <Properties>
            //      <string name=Address>120.23.34.53</string>
            //      <string name=class>A</string>
            //  </Properties>
            // </PSObject>
            // In above example, V1 serializer will ignore <IPAddress> element and read
            // properties from <Properties>
            // V2 serializer can read <IPAddress> tag and ignore properties.
            // Read serialization note doc for information.

            // Now validate the major version number is 1
            if (_version.Major != 1)
            {
                throw NewXmlException(Serialization.UnexpectedVersion, null, _version.Major);
            }
        }

        private object ReadOneDeserializedObject(out string streamName, out bool isKnownPrimitiveType)
        {
            if (_reader.NodeType != XmlNodeType.Element)
            {
                throw NewXmlException(Serialization.InvalidNodeType, null,
                                       _reader.NodeType.ToString(), nameof(XmlNodeType.Element));
            }

            s_trace.WriteLine("Processing start node {0}", _reader.LocalName);

            streamName = _reader.GetAttribute(SerializationStrings.StreamNameAttribute);
            isKnownPrimitiveType = false;

            // handle nil node
            if (IsNextElement(SerializationStrings.NilTag))
            {
                Skip();
                return null;
            }

            // Handle reference to previous deserialized object.
            if (IsNextElement(SerializationStrings.ReferenceTag))
            {
                string refId = _reader.GetAttribute(SerializationStrings.ReferenceIdAttribute);

                if (refId == null)
                {
                    throw NewXmlException(Serialization.AttributeExpected, null, SerializationStrings.ReferenceIdAttribute);
                }

                object duplicate = _objectRefIdHandler.GetReferencedObject(refId);
                if (duplicate == null)
                {
                    throw NewXmlException(Serialization.InvalidReferenceId, null, refId);
                }

                Skip();
                return duplicate;
            }

            // Handle primitive known types
            TypeSerializationInfo pktInfo = KnownTypes.GetTypeSerializationInfoFromItemTag(_reader.LocalName);
            if (pktInfo != null)
            {
                s_trace.WriteLine("Primitive Knowntype Element {0}", pktInfo.ItemTag);
                isKnownPrimitiveType = true;
                return ReadPrimaryKnownType(pktInfo);
            }

            // Handle PSObject
            if (IsNextElement(SerializationStrings.PSObjectTag))
            {
                s_trace.WriteLine("PSObject Element");
                return ReadPSObject();
            }

            // If we are here, we have an unknown node. Unknown nodes may
            // be allowed inside PSObject. We do not allow them at top level.

            s_trace.TraceError("Invalid element {0} tag found", _reader.LocalName);
            throw NewXmlException(Serialization.InvalidElementTag, null, _reader.LocalName);
        }

        private bool _isStopping = false;

        /// <summary>
        /// Called from a separate thread will stop the serialization process.
        /// </summary>
        internal void Stop()
        {
            _isStopping = true;
        }

        private void CheckIfStopping()
        {
            if (_isStopping)
            {
                throw PSTraceSource.NewInvalidOperationException(Serialization.Stopping);
            }
        }

        internal const string CimInstanceMetadataProperty = "__InstanceMetadata";
        internal const string CimModifiedProperties = "Modified";
        internal const string CimClassMetadataProperty = "__ClassMetadata";
        internal const string CimClassNameProperty = "ClassName";
        internal const string CimNamespaceProperty = "Namespace";
        internal const string CimServerNameProperty = "ServerName";
        internal const string CimHashCodeProperty = "Hash";
        internal const string CimMiXmlProperty = "MiXml";

        private static bool RehydrateCimInstanceProperty(
            CimInstance cimInstance,
            PSPropertyInfo deserializedProperty,
            HashSet<string> namesOfModifiedProperties)
        {
            Dbg.Assert(cimInstance != null, "Caller should make sure cimInstance != null");
            Dbg.Assert(deserializedProperty != null, "Caller should make sure deserializedProperty != null");

            if (deserializedProperty.Name.Equals(RemotingConstants.ComputerNameNoteProperty, StringComparison.OrdinalIgnoreCase))
            {
                string psComputerNameValue = deserializedProperty.Value as string;
                if (psComputerNameValue != null)
                {
                    cimInstance.SetCimSessionComputerName(psComputerNameValue);
                }

                return true;
            }

            CimProperty cimProperty = cimInstance.CimInstanceProperties[deserializedProperty.Name];
            if (cimProperty == null)
            {
                return false;
            }

            // TODO/FIXME - think if it is possible to do the array handling in a more efficient way
            object propertyValue = deserializedProperty.Value;
            if (propertyValue != null)
            {
                PSObject psoPropertyValue = PSObject.AsPSObject(propertyValue);
                if (psoPropertyValue.BaseObject is ArrayList)
                {
                    if ((psoPropertyValue.InternalTypeNames == null) || (psoPropertyValue.InternalTypeNames.Count == 0))
                    {
                        return false;
                    }

                    string originalArrayTypeName = Deserializer.MaskDeserializationPrefix(psoPropertyValue.InternalTypeNames[0]);
                    if (originalArrayTypeName == null)
                    {
                        return false;
                    }

                    Type originalArrayType;
                    if (!LanguagePrimitives.TryConvertTo(originalArrayTypeName, CultureInfo.InvariantCulture, out originalArrayType))
                    {
                        return false;
                    }

                    if (!originalArrayType.IsArray || !s_knownCimArrayTypes.Value.Contains(originalArrayType.GetElementType()))
                    {
                        return false;
                    }

                    object newPropertyValue;
                    if (!LanguagePrimitives.TryConvertTo(propertyValue, originalArrayType, CultureInfo.InvariantCulture, out newPropertyValue))
                    {
                        return false;
                    }

                    psoPropertyValue = PSObject.AsPSObject(newPropertyValue);
                }

                propertyValue = psoPropertyValue.BaseObject;
            }

            try
            {
                cimProperty.Value = propertyValue;

                if (!namesOfModifiedProperties.Contains(deserializedProperty.Name))
                {
                    cimProperty.IsValueModified = false;
                }
#if DEBUG
                else
                {
                    Dbg.Assert(cimProperty.IsValueModified, "Deserialized CIM properties should by default be marked as 'modified' ");
                }
#endif
            }
            catch (FormatException)
            {
                return false;
            }
            catch (InvalidCastException)
            {
                return false;
            }
            catch (ArgumentException)
            {
                return false;
            }
            catch (CimException)
            {
                return false;
            }

            return true;
        }

        private static readonly Lazy<CimDeserializer> s_cimDeserializer = new Lazy<CimDeserializer>(CimDeserializer.Create);

        private CimClass RehydrateCimClass(PSPropertyInfo classMetadataProperty)
        {
            if ((classMetadataProperty == null) || (classMetadataProperty.Value == null))
            {
                return null;
            }

            IEnumerable deserializedClasses = LanguagePrimitives.GetEnumerable(classMetadataProperty.Value);
            if (deserializedClasses == null)
            {
                return null;
            }

            Stack<KeyValuePair<CimClassSerializationId, CimClass>> cimClassesToAddToCache = new Stack<KeyValuePair<CimClassSerializationId, CimClass>>();

            //
            // REHYDRATE CLASS METADATA
            //
            CimClass parentClass = null;
            CimClass currentClass = null;
            foreach (var deserializedClass in deserializedClasses)
            {
                parentClass = currentClass;

                if (deserializedClass == null)
                {
                    return null;
                }

                PSObject psoDeserializedClass = PSObject.AsPSObject(deserializedClass);

                if (!(psoDeserializedClass.InstanceMembers[InternalDeserializer.CimNamespaceProperty] is PSPropertyInfo namespaceProperty))
                {
                    return null;
                }

                string cimNamespace = namespaceProperty.Value as string;

                if (!(psoDeserializedClass.InstanceMembers[InternalDeserializer.CimClassNameProperty] is PSPropertyInfo classNameProperty))
                {
                    return null;
                }

                string cimClassName = classNameProperty.Value as string;

                if (!(psoDeserializedClass.InstanceMembers[InternalDeserializer.CimServerNameProperty] is PSPropertyInfo computerNameProperty))
                {
                    return null;
                }

                string computerName = computerNameProperty.Value as string;

                if (!(psoDeserializedClass.InstanceMembers[InternalDeserializer.CimHashCodeProperty] is PSPropertyInfo hashCodeProperty))
                {
                    return null;
                }

                var hashCodeObject = hashCodeProperty.Value;
                if (hashCodeObject == null)
                {
                    return null;
                }

                if (hashCodeObject is PSObject)
                {
                    hashCodeObject = ((PSObject)hashCodeObject).BaseObject;
                }

                if (hashCodeObject is not int)
                {
                    return null;
                }

                int hashCode = (int)hashCodeObject;

                CimClassSerializationId cimClassSerializationId = new CimClassSerializationId(cimClassName, cimNamespace, computerName, hashCode);
                currentClass = _context.cimClassSerializationIdCache.GetCimClassFromCache(cimClassSerializationId);
                if (currentClass != null)
                {
                    continue;
                }

                PSPropertyInfo miXmlProperty = psoDeserializedClass.InstanceMembers[InternalDeserializer.CimMiXmlProperty] as PSPropertyInfo;
                if ((miXmlProperty == null) || (miXmlProperty.Value == null))
                {
                    return null;
                }

                string miXmlString = miXmlProperty.Value.ToString();
                byte[] miXmlBytes = Encoding.Unicode.GetBytes(miXmlString);
                uint offset = 0;
                try
                {
                    currentClass = s_cimDeserializer.Value.DeserializeClass(
                        miXmlBytes,
                        ref offset,
                        parentClass,
                        computerName: computerName,
                        namespaceName: cimNamespace);
                    cimClassesToAddToCache.Push(new KeyValuePair<CimClassSerializationId, CimClass>(cimClassSerializationId, currentClass));
                }
                catch (CimException)
                {
                    return null;
                }
            }

            //
            // UPDATE CLASSDECL DACHE
            //
            foreach (var cacheEntry in cimClassesToAddToCache)
            {
                _context.cimClassSerializationIdCache.AddCimClassToCache(cacheEntry.Key, cacheEntry.Value);
            }

            return currentClass;
        }

        // NOTE: Win7 change for refid-s that span multiple xml documents: ADMIN: changelist #226414

        private PSObject RehydrateCimInstance(PSObject deserializedObject)
        {
            if (deserializedObject.BaseObject is not PSCustomObject)
            {
                return deserializedObject;
            }

            PSPropertyInfo classMetadataProperty = deserializedObject.InstanceMembers[CimClassMetadataProperty] as PSPropertyInfo;
            CimClass cimClass = RehydrateCimClass(classMetadataProperty);
            if (cimClass == null)
            {
                return deserializedObject;
            }

            CimInstance cimInstance;
            try
            {
                cimInstance = new CimInstance(cimClass);
            }
            catch (CimException)
            {
                return deserializedObject;
            }

            PSObject psoCimInstance = PSObject.AsPSObject(cimInstance);

            // process __InstanceMetadata
            HashSet<string> namesOfModifiedProperties = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
            PSPropertyInfo instanceMetadataProperty = deserializedObject.InstanceMembers[CimInstanceMetadataProperty] as PSPropertyInfo;
            if ((instanceMetadataProperty != null) && (instanceMetadataProperty.Value != null))
            {
                PSObject instanceMetadata = PSObject.AsPSObject(instanceMetadataProperty.Value);

                PSPropertyInfo modifiedPropertiesProperty = instanceMetadata.InstanceMembers[CimModifiedProperties] as PSPropertyInfo;
                if ((modifiedPropertiesProperty != null) && (modifiedPropertiesProperty.Value != null))
                {
                    string modifiedPropertiesString = modifiedPropertiesProperty.Value.ToString();
                    foreach (string nameOfModifiedProperty in modifiedPropertiesString.Split(Utils.Separators.Space))
                    {
                        namesOfModifiedProperties.Add(nameOfModifiedProperty);
                    }
                }
            }

            // process properties that were originally "adapted" properties
            if (deserializedObject.AdaptedMembers != null)
            {
                foreach (PSMemberInfo deserializedMemberInfo in deserializedObject.AdaptedMembers)
                {
                    if (!(deserializedMemberInfo is PSPropertyInfo deserializedProperty))
                    {
                        continue;
                    }

                    bool propertyHandledSuccessfully = RehydrateCimInstanceProperty(
                        cimInstance,
                        deserializedProperty,
                        namesOfModifiedProperties);

                    if (!propertyHandledSuccessfully)
                    {
                        return deserializedObject;
                    }
                }
            }

            // process properties that were originally "extended" properties
            foreach (PSMemberInfo deserializedMemberInfo in deserializedObject.InstanceMembers)
            {
                if (!(deserializedMemberInfo is PSPropertyInfo deserializedProperty))
                {
                    continue;
                }

                // skip adapted properties
                if ((deserializedObject.AdaptedMembers != null) && (deserializedObject.AdaptedMembers[deserializedProperty.Name] != null))
                {
                    continue;
                }

                // skip metadata introduced by CliXml/CimInstance serialization
                if (deserializedProperty.Name.Equals(CimClassMetadataProperty, StringComparison.OrdinalIgnoreCase))
                {
                    continue;
                }

                // skip properties re-added by the client (i.e. through types.ps1xml)
                if (psoCimInstance.Properties[deserializedProperty.Name] != null)
                {
                    continue;
                }

                PSNoteProperty noteProperty = new PSNoteProperty(deserializedProperty.Name, deserializedProperty.Value);
                psoCimInstance.Properties.Add(noteProperty);
            }

            return psoCimInstance;
        }

        /// <summary>
        /// Reads one object. At this point reader should be positioned
        /// at the start tag of object.
        /// </summary>
        /// <returns>
        /// Deserialized Object.
        /// </returns>
        internal object ReadOneObject(out string streamName)
        {
            this.CheckIfStopping();

            try
            {
                _depthBelowTopLevel++;

                Dbg.Assert(_depthBelowTopLevel <= MaxDepthBelowTopLevel, "depthBelowTopLevel should be <= MaxDepthBelowTopLevel");
                if (_depthBelowTopLevel == MaxDepthBelowTopLevel)
                {
                    throw NewXmlException(Serialization.DeserializationTooDeep, null);
                }

                bool isKnownPrimitiveType;
                object result = ReadOneDeserializedObject(out streamName, out isKnownPrimitiveType);
                if (result == null)
                {
                    return null;
                }

                if (!isKnownPrimitiveType)
                {
                    PSObject mshSource = PSObject.AsPSObject(result);
                    if (Deserializer.IsDeserializedInstanceOfType(mshSource, typeof(CimInstance)))
                    {
                        return RehydrateCimInstance(mshSource);
                    }

                    // Convert deserialized object to a user-defined type (specified in a types.ps1xml file)
                    Type targetType = mshSource.GetTargetTypeForDeserialization(_typeTable);
                    if (targetType != null)
                    {
                        Exception rehydrationException = null;
                        try
                        {
                            object rehydratedResult = LanguagePrimitives.ConvertTo(
                                result, targetType, true /* recurse */, CultureInfo.InvariantCulture, _typeTable);

                            PSEtwLog.LogAnalyticVerbose(PSEventId.Serializer_RehydrationSuccess,
                                                        PSOpcode.Rehydration, PSTask.Serialization, PSKeyword.Serializer,
                                                        mshSource.InternalTypeNames.Key, targetType.FullName,
                                                        rehydratedResult.GetType().FullName);

                            return rehydratedResult;
                        }
                        catch (InvalidCastException e)
                        {
                            rehydrationException = e;
                        }
                        catch (ArgumentException e)
                        {
                            rehydrationException = e;
                        }

                        Dbg.Assert(rehydrationException != null,
                                   "The only way to get here is with rehydrationException != null");

                        PSEtwLog.LogAnalyticError(PSEventId.Serializer_RehydrationFailure,
                                                  PSOpcode.Rehydration, PSTask.Serialization, PSKeyword.Serializer,
                                                  mshSource.InternalTypeNames.Key,
                                                  targetType.FullName,
                                                  rehydrationException.ToString(),
                                                  rehydrationException.InnerException == null
                                                      ? string.Empty
                                                      : rehydrationException.InnerException.ToString());
                    }
                }

                return result;
            }
            finally
            {
                _depthBelowTopLevel--;
                Dbg.Assert(_depthBelowTopLevel >= 0, "depthBelowTopLevel should be >= 0");
            }
        }

        private object ReadOneObject()
        {
            string ignore;
            return ReadOneObject(out ignore);
        }

        // Reads one PSObject
        private PSObject ReadPSObject()
        {
            PSObject dso = ReadAttributeAndCreatePSObject();

            // Read start element tag
            if (!ReadStartElementAndHandleEmpty(SerializationStrings.PSObjectTag))
            {
                // Empty element.
                return dso;
            }

            bool overrideTypeInfo = true;
            // Process all the child nodes
            while (_reader.NodeType == XmlNodeType.Element)
            {
                if (IsNextElement(SerializationStrings.TypeNamesTag) ||
                    IsNextElement(SerializationStrings.TypeNamesReferenceTag))
                {
                    ReadTypeNames(dso);
                    overrideTypeInfo = false;
                }
                else if (IsNextElement(SerializationStrings.AdapterProperties))
                {
                    ReadProperties(dso);
                }
                else if (IsNextElement(SerializationStrings.MemberSet))
                {
                    ReadMemberSet(dso.InstanceMembers);
                }
                else if (IsNextElement(SerializationStrings.ToStringElementTag))
                {
                    dso.ToStringFromDeserialization = ReadDecodedElementString(SerializationStrings.ToStringElementTag);
                    dso.InstanceMembers.Add(PSObject.DotNetInstanceAdapter.GetDotNetMethod<PSMemberInfo>(dso, "ToString"));
                    PSGetMemberBinder.SetHasInstanceMember("ToString");
                    // Fix for Win8:75437
                    // The TokenText property is used in type conversion and it is not being populated during deserialization
                    // As a result, parameter binding fails in the following case on a remote session
                    // register-psssessionconfiguration -Name foo -psversion 3.0
                    // The value "3.0" is treated as a double and since the TokenText property holds null, the type converter tries to convert
                    // from System.Double to System.Version using Parse method of System.Version and fails
                    dso.TokenText = dso.ToStringFromDeserialization;
                }
                else
                {
                    // Handle BaseObject
                    object baseObject = null;
                    ContainerType ct = ContainerType.None;

                    // Check if tag is PrimaryKnownType.
                    TypeSerializationInfo pktInfo = KnownTypes.GetTypeSerializationInfoFromItemTag(_reader.LocalName);
                    if (pktInfo != null)
                    {
                        s_trace.WriteLine("Primitive Knowntype Element {0}", pktInfo.ItemTag);
                        baseObject = ReadPrimaryKnownType(pktInfo);
                    }
                    else if (IsKnownContainerTag(out ct))
                    {
                        s_trace.WriteLine("Found container node {0}", ct);
                        baseObject = ReadKnownContainer(ct);
                    }
                    else if (IsNextElement(SerializationStrings.PSObjectTag))
                    {
                        s_trace.WriteLine("Found PSObject node");
                        baseObject = ReadOneObject();
                    }
                    else
                    {
                        // We have an unknown tag
                        s_trace.WriteLine("Unknown tag {0} encountered", _reader.LocalName);
                        if (UnknownTagsAllowed)
                        {
                            Skip();
                        }
                        else
                        {
                            throw NewXmlException(Serialization.InvalidElementTag, null, _reader.LocalName);
                        }
                    }

                    if (baseObject != null)
                    {
                        dso.SetCoreOnDeserialization(baseObject, overrideTypeInfo);
                    }
                }
            }

            ReadEndElement();

            PSObject immediateBasePso = dso.ImmediateBaseObject as PSObject;
            if (immediateBasePso != null)
            {
                PSObject.CopyDeserializerFields(source: immediateBasePso, target: dso);
            }

            return dso;
        }

        /// <summary>
        /// This function reads the refId attribute and creates a
        /// mshObject for that attribute.
        /// </summary>
        /// <returns>MshObject which is created for refId.</returns>
        private PSObject ReadAttributeAndCreatePSObject()
        {
            string refId = _reader.GetAttribute(SerializationStrings.ReferenceIdAttribute);
            PSObject sh = new PSObject();

            // RefId is not mandatory attribute
            if (refId != null)
            {
                s_trace.WriteLine("Read PSObject with refId: {0}", refId);
                _objectRefIdHandler.SetRefId(sh, refId, this.DuplicateRefIdsAllowed);
            }

            return sh;
        }

        /// <summary>
        /// Read type names.
        /// </summary>
        /// <param name="dso">
        /// PSObject to which TypeNames are added
        /// </param>
        private void ReadTypeNames(PSObject dso)
        {
            Dbg.Assert(dso != null, "caller should validate the parameter");
            Dbg.Assert(_reader.NodeType == XmlNodeType.Element, "NodeType should be Element");

            if (IsNextElement(SerializationStrings.TypeNamesTag))
            {
                Collection<string> typeNames = new Collection<string>();

                // Read refId attribute if available
                string refId = _reader.GetAttribute(SerializationStrings.ReferenceIdAttribute);

                s_trace.WriteLine("Processing TypeNamesTag with refId {0}", refId);

                if (ReadStartElementAndHandleEmpty(SerializationStrings.TypeNamesTag))
                {
                    while (_reader.NodeType == XmlNodeType.Element)
                    {
                        if (IsNextElement(SerializationStrings.TypeNamesItemTag))
                        {
                            string item = ReadDecodedElementString(SerializationStrings.TypeNamesItemTag);
                            if (!string.IsNullOrEmpty(item))
                            {
                                Deserializer.AddDeserializationPrefix(ref item);
                                typeNames.Add(item);
                            }
                        }
                        else
                        {
                            throw NewXmlException(Serialization.InvalidElementTag, null, _reader.LocalName);
                        }
                    }

                    ReadEndElement();
                }

                dso.InternalTypeNames = new ConsolidatedString(typeNames);

                if (refId != null)
                {
                    _typeRefIdHandler.SetRefId(dso.InternalTypeNames, refId, this.DuplicateRefIdsAllowed);
                }
            }
            else if (IsNextElement(SerializationStrings.TypeNamesReferenceTag))
            {
                string refId = _reader.GetAttribute(SerializationStrings.ReferenceIdAttribute);
                s_trace.WriteLine("Processing TypeNamesReferenceTag with refId {0}", refId);
                if (refId == null)
                {
                    throw NewXmlException(Serialization.AttributeExpected, null, SerializationStrings.ReferenceIdAttribute);
                }

                ConsolidatedString typeNames = _typeRefIdHandler.GetReferencedObject(refId);
                if (typeNames == null)
                {
                    throw NewXmlException(Serialization.InvalidTypeHierarchyReferenceId, null, refId);
                }

                // At this point we know that we will clone the ConsolidatedString object, so we might end up
                // allocating much more memory than the length of the xml string
                // We have to account for that to limit that to remoting quota and protect against OOM.
                _context.LogExtraMemoryUsage(
                    typeNames.Key.Length * sizeof(char) // Key is shared among the cloned and original object
                                                        // but the list of strings isn't.  The expression to the left
                                                        // is roughly the size of memory the list of strings occupies
                    - 29 // size of <Obj><TNRef RefId="0"/></Obj> in UTF8 encoding
                    );
                dso.InternalTypeNames = new ConsolidatedString(typeNames);

                // Skip the node
                Skip();
            }
            else
            {
                Dbg.Assert(false, "caller should validate that we do no reach here");
            }
        }

        /// <summary>
        /// Read properties.
        /// </summary>
        private void ReadProperties(PSObject dso)
        {
            Dbg.Assert(dso != null, "caller should validate the parameter");
            Dbg.Assert(_reader.NodeType == XmlNodeType.Element, "NodeType should be Element");

            // Since we are adding baseobject properties as propertybag,
            // mark the object as deserialized.
            dso.IsDeserialized = true;
            dso.AdaptedMembers = new PSMemberInfoInternalCollection<PSPropertyInfo>();

            // Add the GetType method to the instance members, so that it works on deserialized psobjects
            dso.InstanceMembers.Add(PSObject.DotNetInstanceAdapter.GetDotNetMethod<PSMemberInfo>(dso, "GetType"));
            PSGetMemberBinder.SetHasInstanceMember("GetType");

            // Set Clr members to a collection which is empty
            dso.ClrMembers = new PSMemberInfoInternalCollection<PSPropertyInfo>();

            if (ReadStartElementAndHandleEmpty(SerializationStrings.AdapterProperties))
            {
                // Read one or more property elements
                while (_reader.NodeType == XmlNodeType.Element)
                {
                    string property = ReadNameAttribute();
                    object value = ReadOneObject();
                    PSProperty prop = new PSProperty(property, value);
                    dso.AdaptedMembers.Add(prop);
                }

                ReadEndElement();
            }
        }

        #region memberset

        /// <summary>
        /// Read memberset.
        /// </summary>
        /// <param name="collection">
        /// collection to which members are added
        /// </param>
        private void ReadMemberSet(PSMemberInfoCollection<PSMemberInfo> collection)
        {
            Dbg.Assert(collection != null, "caller should validate the value");

            if (ReadStartElementAndHandleEmpty(SerializationStrings.MemberSet))
            {
                while (_reader.NodeType == XmlNodeType.Element)
                {
                    if (IsNextElement(SerializationStrings.MemberSet))
                    {
                        string name = ReadNameAttribute();
                        PSMemberSet set = new PSMemberSet(name);
                        collection.Add(set);
                        ReadMemberSet(set.Members);

                        PSGetMemberBinder.SetHasInstanceMember(name);
                    }
                    else
                    {
                        PSNoteProperty note = ReadNoteProperty();
                        collection.Add(note);

                        PSGetMemberBinder.SetHasInstanceMember(note.Name);
                    }
                }

                ReadEndElement();
            }
        }

        /// <summary>
        /// Read note.
        /// </summary>
        /// <returns></returns>
        private PSNoteProperty ReadNoteProperty()
        {
            string name = ReadNameAttribute();
            object value = ReadOneObject();
            PSNoteProperty note = new PSNoteProperty(name, value);
            return note;
        }

        #endregion memberset

        #region known container

        private bool IsKnownContainerTag(out ContainerType ct)
        {
            Dbg.Assert(_reader.NodeType == XmlNodeType.Element, "Expected node type is element");

            if (IsNextElement(SerializationStrings.DictionaryTag))
            {
                ct = ContainerType.Dictionary;
            }
            else if (IsNextElement(SerializationStrings.QueueTag))
            {
                ct = ContainerType.Queue;
            }
            else if (IsNextElement(SerializationStrings.StackTag))
            {
                ct = ContainerType.Stack;
            }
            else if (IsNextElement(SerializationStrings.ListTag))
            {
                ct = ContainerType.List;
            }
            else if (IsNextElement(SerializationStrings.CollectionTag))
            {
                ct = ContainerType.Enumerable;
            }
            else
            {
                ct = ContainerType.None;
            }

            return ct != ContainerType.None;
        }

        private object ReadKnownContainer(ContainerType ct)
        {
            switch (ct)
            {
                case ContainerType.Dictionary:
                    return ReadDictionary(ct);

                case ContainerType.Enumerable:
                case ContainerType.List:
                case ContainerType.Queue:
                case ContainerType.Stack:
                    return ReadListContainer(ct);

                default:
                    Dbg.Assert(false, "Unrecognized ContainerType enum");
                    return null;
            }
        }

        /// <summary>
        /// Read List Containers.
        /// </summary>
        /// <returns></returns>
        private object ReadListContainer(ContainerType ct)
        {
            Dbg.Assert(ct == ContainerType.Enumerable ||
                       ct == ContainerType.List ||
                       ct == ContainerType.Queue ||
                       ct == ContainerType.Stack, "ct should be queue, stack, enumerable or list");

            ArrayList list = new ArrayList();
            if (ReadStartElementAndHandleEmpty(_reader.LocalName))
            {
                while (_reader.NodeType == XmlNodeType.Element)
                {
                    list.Add(ReadOneObject());
                }

                ReadEndElement();
            }

            if (ct == ContainerType.Stack)
            {
                list.Reverse();
                return new Stack(list);
            }
            else if (ct == ContainerType.Queue)
            {
                return new Queue(list);
            }

            return list;
        }

        /// <summary>
        /// Deserialize Dictionary.
        /// </summary>
        /// <returns></returns>
        private object ReadDictionary(ContainerType ct)
        {
            Dbg.Assert(ct == ContainerType.Dictionary, "Unrecognized ContainerType enum");

            // We assume the hash table is a PowerShell hash table and hence uses
            // a case insensitive string comparer.  If we discover a key collision,
            // we'll revert back to the default comparer.
            Hashtable table = new Hashtable(StringComparer.CurrentCultureIgnoreCase);
            int keyClashFoundIteration = 0;
            if (ReadStartElementAndHandleEmpty(SerializationStrings.DictionaryTag))
            {
                while (_reader.NodeType == XmlNodeType.Element)
                {
                    ReadStartElement(SerializationStrings.DictionaryEntryTag);

                    // Read Key
                    if (_reader.NodeType != XmlNodeType.Element)
                    {
                        throw NewXmlException(Serialization.DictionaryKeyNotSpecified, null);
                    }

                    string name = ReadNameAttribute();
                    if (!string.Equals(name, SerializationStrings.DictionaryKey, StringComparison.OrdinalIgnoreCase))
                    {
                        throw NewXmlException(Serialization.InvalidDictionaryKeyName, null);
                    }

                    object key = ReadOneObject();

                    if (key == null)
                    {
                        throw NewXmlException(Serialization.NullAsDictionaryKey, null);
                    }
                    // Read Value
                    if (_reader.NodeType != XmlNodeType.Element)
                    {
                        throw NewXmlException(Serialization.DictionaryValueNotSpecified, null);
                    }

                    name = ReadNameAttribute();
                    if (!string.Equals(name, SerializationStrings.DictionaryValue, StringComparison.OrdinalIgnoreCase))
                    {
                        throw NewXmlException(Serialization.InvalidDictionaryValueName, null);
                    }

                    object value = ReadOneObject();

                    // On the first collision, copy the hash table to one that uses the default comparer.
                    if (table.ContainsKey(key) && (keyClashFoundIteration == 0))
                    {
                        keyClashFoundIteration++;
                        Hashtable newHashTable = new Hashtable();
                        foreach (DictionaryEntry entry in table)
                        {
                            newHashTable.Add(entry.Key, entry.Value);
                        }

                        table = newHashTable;
                    }

                    // win8: 389060. If there are still collisions even with case-sensitive default comparer,
                    // use an IEqualityComparer that does object ref equality.
                    if (table.ContainsKey(key) && (keyClashFoundIteration == 1))
                    {
                        keyClashFoundIteration++;
                        IEqualityComparer equalityComparer = new ReferenceEqualityComparer();
                        Hashtable newHashTable = new Hashtable(equalityComparer);
                        foreach (DictionaryEntry entry in table)
                        {
                            newHashTable.Add(entry.Key, entry.Value);
                        }

                        table = newHashTable;
                    }

                    try
                    {
                        // Add entry to hashtable
                        table.Add(key, value);
                    }
                    catch (ArgumentException e)
                    {
                        throw this.NewXmlException(Serialization.InvalidPrimitiveType, e, typeof(Hashtable));
                    }

                    ReadEndElement();
                }

                ReadEndElement();
            }

            return table;
        }

        #endregion known containers

        #endregion deserialization

        #region Getting XmlReaderSettings

        internal static XmlReaderSettings XmlReaderSettingsForCliXml { get; } = GetXmlReaderSettingsForCliXml();

        private static XmlReaderSettings GetXmlReaderSettingsForCliXml()
        {
            XmlReaderSettings xrs = new XmlReaderSettings();

            xrs.CheckCharacters = false;
            xrs.CloseInput = false;

            // The XML data needs to be in conformance to the rules for a well-formed XML 1.0 document.
            xrs.ConformanceLevel = ConformanceLevel.Document;
            xrs.IgnoreComments = true;
            xrs.IgnoreProcessingInstructions = true;
            xrs.IgnoreWhitespace = false;
            xrs.MaxCharactersFromEntities = 1024;
            xrs.XmlResolver = null;
            xrs.DtdProcessing = DtdProcessing.Prohibit;
            xrs.Schemas = null;
            xrs.ValidationFlags = System.Xml.Schema.XmlSchemaValidationFlags.None;
            xrs.ValidationType = ValidationType.None;
            return xrs;
        }

        internal static XmlReaderSettings XmlReaderSettingsForUntrustedXmlDocument { get; } = GetXmlReaderSettingsForUntrustedXmlDocument();

        private static XmlReaderSettings GetXmlReaderSettingsForUntrustedXmlDocument()
        {
            XmlReaderSettings settings = new XmlReaderSettings();

            settings.CheckCharacters = false;
            settings.ConformanceLevel = ConformanceLevel.Auto;
            settings.IgnoreComments = true;
            settings.IgnoreProcessingInstructions = true;
            settings.IgnoreWhitespace = true;
            settings.MaxCharactersFromEntities = 1024;
            settings.MaxCharactersInDocument = 512 * 1024 * 1024; // 512M characters = 1GB
            settings.XmlResolver = null;
            settings.DtdProcessing = DtdProcessing.Parse;   // Allowing DTD parsing with limits of MaxCharactersFromEntities/MaxCharactersInDocument
            settings.ValidationFlags = System.Xml.Schema.XmlSchemaValidationFlags.None;
            settings.ValidationType = ValidationType.None;
            return settings;
        }

        #endregion

        #region known type deserialization

        internal static object DeserializeBoolean(InternalDeserializer deserializer)
        {
            Dbg.Assert(deserializer != null, "Caller should validate the parameter");
            try
            {
                return XmlConvert.ToBoolean(deserializer._reader.ReadElementContentAsString());
            }
            catch (FormatException e)
            {
                throw deserializer.NewXmlException(Serialization.InvalidPrimitiveType, e, typeof(bool).FullName);
            }
        }

        internal static object DeserializeByte(InternalDeserializer deserializer)
        {
            Dbg.Assert(deserializer != null, "Caller should validate the parameter");
            Exception recognizedException = null;
            try
            {
                return XmlConvert.ToByte(deserializer._reader.ReadElementContentAsString());
            }
            catch (FormatException e)
            {
                recognizedException = e;
            }
            catch (OverflowException e)
            {
                recognizedException = e;
            }

            throw deserializer.NewXmlException(Serialization.InvalidPrimitiveType, recognizedException, typeof(byte).FullName);
        }

        internal static object DeserializeChar(InternalDeserializer deserializer)
        {
            Dbg.Assert(deserializer != null, "Caller should validate the parameter");
            Exception recognizedException = null;
            try
            {
                return (char)XmlConvert.ToUInt16(deserializer._reader.ReadElementContentAsString());
            }
            catch (FormatException e)
            {
                recognizedException = e;
            }
            catch (OverflowException e)
            {
                recognizedException = e;
            }

            throw deserializer.NewXmlException(Serialization.InvalidPrimitiveType, recognizedException, typeof(char).FullName);
        }

        internal static object DeserializeDateTime(InternalDeserializer deserializer)
        {
            Dbg.Assert(deserializer != null, "Caller should validate the parameter");
            try
            {
                return XmlConvert.ToDateTime(deserializer._reader.ReadElementContentAsString(), XmlDateTimeSerializationMode.RoundtripKind);
            }
            catch (FormatException e)
            {
                throw deserializer.NewXmlException(Serialization.InvalidPrimitiveType, e, typeof(DateTime).FullName);
            }
        }

        internal static object DeserializeDecimal(InternalDeserializer deserializer)
        {
            Dbg.Assert(deserializer != null, "Caller should validate the parameter");
            Exception recognizedException = null;
            try
            {
                return XmlConvert.ToDecimal(deserializer._reader.ReadElementContentAsString());
            }
            catch (FormatException e)
            {
                recognizedException = e;
            }
            catch (OverflowException e)
            {
                recognizedException = e;
            }

            throw deserializer.NewXmlException(Serialization.InvalidPrimitiveType, recognizedException, typeof(decimal).FullName);
        }

        internal static object DeserializeDouble(InternalDeserializer deserializer)
        {
            Dbg.Assert(deserializer != null, "Caller should validate the parameter");
            Exception recognizedException = null;
            try
            {
                return XmlConvert.ToDouble(deserializer._reader.ReadElementContentAsString());
            }
            catch (FormatException e)
            {
                recognizedException = e;
            }
            catch (OverflowException e)
            {
                recognizedException = e;
            }

            throw deserializer.NewXmlException(Serialization.InvalidPrimitiveType, recognizedException, typeof(double).FullName);
        }

        internal static object DeserializeGuid(InternalDeserializer deserializer)
        {
            Dbg.Assert(deserializer != null, "Caller should validate the parameter");
            Exception recognizedException = null;
            try
            {
                return XmlConvert.ToGuid(deserializer._reader.ReadElementContentAsString());
            }
            // MSDN for XmlConvert.ToGuid doesn't list any exceptions, but
            // Reflector shows that this just calls to new Guid(string)
            // which MSDN documents can throw Format/OverflowException
            catch (FormatException e)
            {
                recognizedException = e;
            }
            catch (OverflowException e)
            {
                recognizedException = e;
            }

            throw deserializer.NewXmlException(Serialization.InvalidPrimitiveType, recognizedException, typeof(Guid).FullName);
        }

        internal static object DeserializeVersion(InternalDeserializer deserializer)
        {
            Dbg.Assert(deserializer != null, "Caller should validate the parameter");
            Exception recognizedException = null;
            try
            {
                return new Version(deserializer._reader.ReadElementContentAsString());
            }
            catch (ArgumentException e)
            {
                recognizedException = e;
            }
            catch (FormatException e)
            {
                recognizedException = e;
            }
            catch (OverflowException e)
            {
                recognizedException = e;
            }

            throw deserializer.NewXmlException(Serialization.InvalidPrimitiveType, recognizedException, typeof(Version).FullName);
        }

        internal static object DeserializeSemanticVersion(InternalDeserializer deserializer)
        {
            Dbg.Assert(deserializer != null, "Caller should validate the parameter");
            Exception recognizedException = null;
            try
            {
                return new SemanticVersion(deserializer._reader.ReadElementContentAsString());
            }
            catch (ArgumentException e)
            {
                recognizedException = e;
            }
            catch (FormatException e)
            {
                recognizedException = e;
            }
            catch (OverflowException e)
            {
                recognizedException = e;
            }

            throw deserializer.NewXmlException(Serialization.InvalidPrimitiveType, recognizedException, typeof(Version).FullName);
        }

        internal static object DeserializeInt16(InternalDeserializer deserializer)
        {
            Dbg.Assert(deserializer != null, "Caller should validate the parameter");
            Exception recognizedException = null;
            try
            {
                return XmlConvert.ToInt16(deserializer._reader.ReadElementContentAsString());
            }
            catch (FormatException e)
            {
                recognizedException = e;
            }
            catch (OverflowException e)
            {
                recognizedException = e;
            }

            throw deserializer.NewXmlException(Serialization.InvalidPrimitiveType, recognizedException, typeof(Int16).FullName);
        }

        internal static object DeserializeInt32(InternalDeserializer deserializer)
        {
            Dbg.Assert(deserializer != null, "Caller should validate the parameter");
            Exception recognizedException = null;
            try
            {
                return XmlConvert.ToInt32(deserializer._reader.ReadElementContentAsString());
            }
            catch (FormatException e)
            {
                recognizedException = e;
            }
            catch (OverflowException e)
            {
                recognizedException = e;
            }

            throw deserializer.NewXmlException(Serialization.InvalidPrimitiveType, recognizedException, typeof(Int32).FullName);
        }

        internal static object DeserializeInt64(InternalDeserializer deserializer)
        {
            Dbg.Assert(deserializer != null, "Caller should validate the parameter");
            Exception recognizedException = null;
            try
            {
                return XmlConvert.ToInt64(deserializer._reader.ReadElementContentAsString());
            }
            catch (FormatException e)
            {
                recognizedException = e;
            }
            catch (OverflowException e)
            {
                recognizedException = e;
            }

            throw deserializer.NewXmlException(Serialization.InvalidPrimitiveType, recognizedException, typeof(Int64).FullName);
        }

        internal static object DeserializeSByte(InternalDeserializer deserializer)
        {
            Dbg.Assert(deserializer != null, "Caller should validate the parameter");
            Exception recognizedException = null;
            try
            {
                return XmlConvert.ToSByte(deserializer._reader.ReadElementContentAsString());
            }
            catch (FormatException e)
            {
                recognizedException = e;
            }
            catch (OverflowException e)
            {
                recognizedException = e;
            }

            throw deserializer.NewXmlException(Serialization.InvalidPrimitiveType, recognizedException, typeof(sbyte).FullName);
        }

        internal static object DeserializeSingle(InternalDeserializer deserializer)
        {
            Dbg.Assert(deserializer != null, "Caller should validate the parameter");
            Exception recognizedException = null;
            try
            {
                return XmlConvert.ToSingle(deserializer._reader.ReadElementContentAsString());
            }
            catch (FormatException e)
            {
                recognizedException = e;
            }
            catch (OverflowException e)
            {
                recognizedException = e;
            }

            throw deserializer.NewXmlException(Serialization.InvalidPrimitiveType, recognizedException, typeof(float).FullName);
        }

        internal static object DeserializeScriptBlock(InternalDeserializer deserializer)
        {
            Dbg.Assert(deserializer != null, "Caller should validate the parameter");
            string scriptBlockBody = deserializer.ReadDecodedElementString(SerializationStrings.ScriptBlockTag);
            if ((deserializer._context.options & DeserializationOptions.DeserializeScriptBlocks) == DeserializationOptions.DeserializeScriptBlocks)
            {
                return ScriptBlock.Create(scriptBlockBody);
            }
            else
            {
                // Scriptblock is deserialized as string
                return scriptBlockBody;
            }
        }

        internal static object DeserializeString(InternalDeserializer deserializer)
        {
            Dbg.Assert(deserializer != null, "Caller should validate the parameter");
            return deserializer.ReadDecodedElementString(SerializationStrings.StringTag);
        }

        internal static object DeserializeTimeSpan(InternalDeserializer deserializer)
        {
            Dbg.Assert(deserializer != null, "Caller should validate the parameter");
            try
            {
                return XmlConvert.ToTimeSpan(deserializer._reader.ReadElementContentAsString());
            }
            catch (FormatException e)
            {
                throw deserializer.NewXmlException(Serialization.InvalidPrimitiveType, e, typeof(TimeSpan).FullName);
            }
        }

        internal static object DeserializeUInt16(InternalDeserializer deserializer)
        {
            Dbg.Assert(deserializer != null, "Caller should validate the parameter");
            Exception recognizedException = null;
            try
            {
                return XmlConvert.ToUInt16(deserializer._reader.ReadElementContentAsString());
            }
            catch (FormatException e)
            {
                recognizedException = e;
            }
            catch (OverflowException e)
            {
                recognizedException = e;
            }

            throw deserializer.NewXmlException(Serialization.InvalidPrimitiveType, recognizedException, typeof(UInt16).FullName);
        }

        internal static object DeserializeUInt32(InternalDeserializer deserializer)
        {
            Dbg.Assert(deserializer != null, "Caller should validate the parameter");
            Exception recognizedException = null;
            try
            {
                return XmlConvert.ToUInt32(deserializer._reader.ReadElementContentAsString());
            }
            catch (FormatException e)
            {
                recognizedException = e;
            }
            catch (OverflowException e)
            {
                recognizedException = e;
            }

            throw deserializer.NewXmlException(Serialization.InvalidPrimitiveType, recognizedException, typeof(UInt32).FullName);
        }

        internal static object DeserializeUInt64(InternalDeserializer deserializer)
        {
            Dbg.Assert(deserializer != null, "Caller should validate the parameter");
            Exception recognizedException = null;
            try
            {
                return XmlConvert.ToUInt64(deserializer._reader.ReadElementContentAsString());
            }
            catch (FormatException e)
            {
                recognizedException = e;
            }
            catch (OverflowException e)
            {
                recognizedException = e;
            }

            throw deserializer.NewXmlException(Serialization.InvalidPrimitiveType, recognizedException, typeof(UInt64).FullName);
        }

        internal static object DeserializeUri(InternalDeserializer deserializer)
        {
            Dbg.Assert(deserializer != null, "Caller should validate the parameter");
            try
            {
                string uriString = deserializer.ReadDecodedElementString(SerializationStrings.AnyUriTag);
                return new Uri(uriString, UriKind.RelativeOrAbsolute);
            }
            catch (UriFormatException e)
            {
                throw deserializer.NewXmlException(Serialization.InvalidPrimitiveType, e, typeof(Uri).FullName);
            }
        }

        internal static object DeserializeByteArray(InternalDeserializer deserializer)
        {
            Dbg.Assert(deserializer != null, "Caller should validate the parameter");
            try
            {
                return Convert.FromBase64String(deserializer._reader.ReadElementContentAsString());
            }
            catch (FormatException e)
            {
                throw deserializer.NewXmlException(Serialization.InvalidPrimitiveType, e, typeof(byte[]).FullName);
            }
        }

        /// <exception cref="System.Xml.XmlException"></exception>
        internal static XmlDocument LoadUnsafeXmlDocument(FileInfo xmlPath, bool preserveNonElements, int? maxCharactersInDocument)
        {
            XmlDocument doc = null;
            // same FileStream options as Reflector shows for XmlDocument.Load(path) / XmlDownloadManager.GetStream:
            using (Stream stream = new FileStream(xmlPath.FullName, FileMode.Open, FileAccess.Read, FileShare.Read))
            {
                doc = LoadUnsafeXmlDocument(stream, preserveNonElements, maxCharactersInDocument);
            }

            return doc;
        }

        /// <exception cref="System.Xml.XmlException"></exception>
        internal static XmlDocument LoadUnsafeXmlDocument(string xmlContents, bool preserveNonElements, int? maxCharactersInDocument)
        {
            using (TextReader textReader = new StringReader(xmlContents))
            {
                return LoadUnsafeXmlDocument(textReader, preserveNonElements, maxCharactersInDocument);
            }
        }

        /// <exception cref="System.Xml.XmlException"></exception>
        internal static XmlDocument LoadUnsafeXmlDocument(Stream stream, bool preserveNonElements, int? maxCharactersInDocument)
        {
            using (TextReader textReader = new StreamReader(stream))
            {
                return LoadUnsafeXmlDocument(textReader, preserveNonElements, maxCharactersInDocument);
            }
        }

        /// <exception cref="System.Xml.XmlException"></exception>
        internal static XmlDocument LoadUnsafeXmlDocument(TextReader textReader, bool preserveNonElements, int? maxCharactersInDocument)
        {
            XmlReaderSettings settings;
            if (maxCharactersInDocument.HasValue || preserveNonElements)
            {
                settings = InternalDeserializer.XmlReaderSettingsForUntrustedXmlDocument.Clone();
                if (maxCharactersInDocument.HasValue)
                {
                    settings.MaxCharactersInDocument = maxCharactersInDocument.Value;
                }

                if (preserveNonElements)
                {
                    settings.IgnoreWhitespace = false;
                    settings.IgnoreProcessingInstructions = false;
                    settings.IgnoreComments = false;
                }
            }
            else
            {
                settings = InternalDeserializer.XmlReaderSettingsForUntrustedXmlDocument;
            }

            try
            {
                XmlReader xmlReader = XmlReader.Create(textReader, settings);
                XmlDocument xmlDocument = new XmlDocument();
                xmlDocument.PreserveWhitespace = preserveNonElements;
                xmlDocument.Load(xmlReader);
                return xmlDocument;
            }
            catch (InvalidOperationException invalidOperationException)
            {
                throw new XmlException(invalidOperationException.Message, invalidOperationException);
            }
        }

        internal static object DeserializeXmlDocument(InternalDeserializer deserializer)
        {
            Dbg.Assert(deserializer != null, "Caller should validate the parameter");
            string docAsString = deserializer.ReadDecodedElementString(SerializationStrings.XmlDocumentTag);

            try
            {
                int? maxCharactersInDocument = null;
                if (deserializer._context.MaximumAllowedMemory.HasValue)
                {
                    maxCharactersInDocument = deserializer._context.MaximumAllowedMemory.Value / sizeof(char);
                }

                XmlDocument doc = InternalDeserializer.LoadUnsafeXmlDocument(
                    docAsString,
                    true, /* preserve whitespace, comments, etc. */
                    maxCharactersInDocument);

                deserializer._context.LogExtraMemoryUsage((docAsString.Length - doc.OuterXml.Length) * sizeof(char));

                return doc;
            }
            catch (XmlException e)
            {
                throw deserializer.NewXmlException(Serialization.InvalidPrimitiveType, e, typeof(XmlDocument).FullName);
            }
        }

        internal static object DeserializeProgressRecord(InternalDeserializer deserializer)
        {
            Dbg.Assert(deserializer != null, "Caller should validate the parameter");

            //
            // read deserialized elements of a progress record
            //

            deserializer.ReadStartElement(SerializationStrings.ProgressRecord);

            string activity = null, currentOperation = null, prt = null, statusDescription = null;
            int activityId = 0, parentActivityId = 0, percentComplete = 0, secondsRemaining = 0;

            Exception recognizedException = null;
            try
            {
                activity = deserializer.ReadDecodedElementString(SerializationStrings.ProgressRecordActivity);
                activityId = int.Parse(deserializer.ReadDecodedElementString(SerializationStrings.ProgressRecordActivityId), CultureInfo.InvariantCulture);

                object tmp = deserializer.ReadOneObject();
                currentOperation = tmp?.ToString();

                parentActivityId = int.Parse(deserializer.ReadDecodedElementString(SerializationStrings.ProgressRecordParentActivityId), CultureInfo.InvariantCulture);
                percentComplete = int.Parse(deserializer.ReadDecodedElementString(SerializationStrings.ProgressRecordPercentComplete), CultureInfo.InvariantCulture);
                prt = deserializer.ReadDecodedElementString(SerializationStrings.ProgressRecordType);
                secondsRemaining = int.Parse(deserializer.ReadDecodedElementString(SerializationStrings.ProgressRecordSecondsRemaining), CultureInfo.InvariantCulture);
                statusDescription = deserializer.ReadDecodedElementString(SerializationStrings.ProgressRecordStatusDescription);
            }
            catch (FormatException e)
            {
                recognizedException = e;
            }
            catch (OverflowException e)
            {
                recognizedException = e;
            }

            if (recognizedException != null)
            {
                throw deserializer.NewXmlException(Serialization.InvalidPrimitiveType, recognizedException, typeof(UInt64).FullName);
            }

            deserializer.ReadEndElement();

            //
            // Build the progress record
            //

            ProgressRecordType type;
            try
            {
                type = (ProgressRecordType)Enum.Parse(typeof(ProgressRecordType), prt, true);
            }
            catch (ArgumentException e)
            {
                throw deserializer.NewXmlException(Serialization.InvalidPrimitiveType, e, typeof(ProgressRecord).FullName);
            }

            try
            {
                ProgressRecord record = new ProgressRecord(activityId, activity, statusDescription);

                if (!string.IsNullOrEmpty(currentOperation))
                {
                    record.CurrentOperation = currentOperation;
                }

                record.ParentActivityId = parentActivityId;
                record.PercentComplete = percentComplete;
                record.RecordType = type;
                record.SecondsRemaining = secondsRemaining;

                return record;
            }
            catch (ArgumentException e)
            {
                throw deserializer.NewXmlException(Serialization.InvalidPrimitiveType, e, typeof(ProgressRecord).FullName);
            }
        }

        internal static object DeserializeSecureString(InternalDeserializer deserializer)
        {
            Dbg.Assert(deserializer != null, "Caller should validate the parameter");

            //
            // read deserialized elements of a Secure String
            //
            return deserializer.ReadSecureString();
        }

        #endregion known type deserialization

        #region misc

        /// <summary>
        /// Check if LocalName of next element is "tag"
        /// </summary>
        /// <param name="tag"></param>
        /// <returns></returns>
        private bool IsNextElement(string tag)
        {
            Dbg.Assert(!string.IsNullOrEmpty(tag), "Caller should validate the parameter");
            return (_reader.LocalName == tag) &&
                (((_context.options & DeserializationOptions.NoNamespace) != 0) ||
                 (_reader.NamespaceURI == SerializationStrings.MonadNamespace));
        }

        /// <summary>
        /// Read start element in monad namespace.
        /// </summary>
        /// <param name="element">Element tag to read.</param>
        /// <returns>True if not an empty element else false.</returns>
        internal bool ReadStartElementAndHandleEmpty(string element)
        {
            Dbg.Assert(!string.IsNullOrEmpty(element), "Caller should validate the parameter");

            // IsEmpty is set to true when element is of the form <tag/>
            bool isEmpty = _reader.IsEmptyElement;

            this.ReadStartElement(element);

            // This takes care of the case: <tag></tag> or <tag>  </tag>. In
            // this case isEmpty is false.
            if (!isEmpty && _reader.NodeType == XmlNodeType.EndElement)
            {
                ReadEndElement();
                isEmpty = true;
            }

            return !isEmpty;
        }

        private void ReadStartElement(string element)
        {
            Dbg.Assert(!string.IsNullOrEmpty(element), "Caller should validate the parameter");

            if ((_context.options & DeserializationOptions.NoNamespace) == DeserializationOptions.NoNamespace)
            {
                _reader.ReadStartElement(element);
            }
            else
            {
                _reader.ReadStartElement(element, SerializationStrings.MonadNamespace);
            }

            _reader.MoveToContent();
        }

        private void ReadEndElement()
        {
            _reader.ReadEndElement();
            _reader.MoveToContent();
        }

        private string ReadDecodedElementString(string element)
        {
            Dbg.Assert(!string.IsNullOrEmpty(element), "Caller should validate the parameter");
            this.CheckIfStopping();

            string temp = null;
            if ((_context.options & DeserializationOptions.NoNamespace) == DeserializationOptions.NoNamespace)
            {
                temp = _reader.ReadElementContentAsString(element, string.Empty);
            }
            else
            {
                temp = _reader.ReadElementContentAsString(element, SerializationStrings.MonadNamespace);
            }

            _reader.MoveToContent();
            temp = DecodeString(temp);
            return temp;
        }

        /// <summary>
        /// Skips an element and all its child elements.
        /// Moves cursor to next content Node.
        /// </summary>
        private void Skip()
        {
            _reader.Skip();
            _reader.MoveToContent();
        }

        /// <summary>
        /// Reads Primary known type.
        /// </summary>
        /// <param name="pktInfo"></param>
        /// <returns></returns>
        private object ReadPrimaryKnownType(TypeSerializationInfo pktInfo)
        {
            Dbg.Assert(pktInfo != null, "Deserializer should be available");
            Dbg.Assert(pktInfo.Deserializer != null, "Deserializer should be available");
            object result = pktInfo.Deserializer(this);
            _reader.MoveToContent();
            return result;
        }

        private object ReadSecureString()
        {
            string encryptedString = _reader.ReadElementContentAsString();

            try
            {
                object result;
                if (_context.cryptoHelper != null)
                {
                    result = _context.cryptoHelper.DecryptSecureString(encryptedString);
                }
                else
                {
                    result = Microsoft.PowerShell.SecureStringHelper.Unprotect(encryptedString);
                }

                _reader.MoveToContent();
                return result;
            }
            catch (PSCryptoException)
            {
                throw NewXmlException(Serialization.DeserializeSecureStringFailed, null);
            }
        }

        /// <summary>
        /// Helper function for building XmlException.
        /// </summary>
        /// <param name="resourceString">
        /// resource String
        /// </param>
        /// <param name="innerException"></param>
        /// <param name="args">
        /// params for format string obtained from resourceId
        /// </param>
        private XmlException NewXmlException
        (
            string resourceString,
            Exception innerException,
            params object[] args
        )
        {
            Dbg.Assert(!string.IsNullOrEmpty(resourceString), "Caller should validate the parameter");

            string message = StringUtil.Format(resourceString, args);

            XmlException ex = null;
            IXmlLineInfo xmlLineInfo = _reader as IXmlLineInfo;
            if (xmlLineInfo != null)
            {
                if (xmlLineInfo.HasLineInfo())
                {
                    ex = new XmlException
                        (
                            message,
                            innerException,
                            xmlLineInfo.LineNumber,
                            xmlLineInfo.LinePosition
                        );
                }
            }

            return ex ?? new XmlException(message, innerException);
        }

        private string ReadNameAttribute()
        {
            string encodedName = _reader.GetAttribute(SerializationStrings.NameAttribute);
            if (encodedName == null)
            {
                throw NewXmlException(Serialization.AttributeExpected, null, SerializationStrings.NameAttribute);
            }

            return DecodeString(encodedName);
        }

        private static string DecodeString(string s)
        {
            Dbg.Assert(s != null, "Caller should validate the parameter");
            return XmlConvert.DecodeName(s);
        }

        #endregion misc

        [TraceSourceAttribute("InternalDeserializer", "InternalDeserializer class")]
        private static readonly PSTraceSource s_trace = PSTraceSource.GetTracer("InternalDeserializer", "InternalDeserializer class");
    }

    /// <summary>
    /// Helper class for generating reference id.
    /// </summary>
    internal class ReferenceIdHandlerForSerializer<T> where T : class
    {
        /// <summary>
        /// Get new reference id.
        /// </summary>
        /// <returns>New reference id.</returns>
        private UInt64 GetNewReferenceId()
        {
            UInt64 refId = _seed++;
            return refId;
        }

        /// <summary>
        /// Seed is incremented by one after each reference generation.
        /// </summary>
        private UInt64 _seed;

        // note:
        // any boxed UInt64 takes 16 bytes on the heap
        // one-character string (i.e. "7") takes 20 bytes on the heap
        private readonly IDictionary<T, UInt64> _object2refId;

        internal ReferenceIdHandlerForSerializer(IDictionary<T, UInt64> dictionary)
        {
            _object2refId = dictionary;
        }

        /// <summary>
        /// Assigns a RefId to the given object.
        /// </summary>
        /// <param name="t">Object to assign a RefId to.</param>
        /// <returns>RefId assigned to the object.</returns>
        internal string SetRefId(T t)
        {
            if (_object2refId != null)
            {
                Dbg.Assert(!_object2refId.ContainsKey(t), "SetRefId shouldn't be called when the object is already assigned a ref id");
                UInt64 refId = GetNewReferenceId();
                _object2refId.Add(t, refId);
                return refId.ToString(System.Globalization.CultureInfo.InvariantCulture);
            }
            else
            {
                return null;
            }
        }

        /// <summary>
        /// Gets a RefId already assigned for the given object or <see langword="null"/> if there is no associated ref id.
        /// </summary>
        /// <param name="t"></param>
        /// <returns></returns>
        internal string GetRefId(T t)
        {
            UInt64 refId;
            if ((_object2refId != null) && (_object2refId.TryGetValue(t, out refId)))
            {
                return refId.ToString(System.Globalization.CultureInfo.InvariantCulture);
            }
            else
            {
                return null;
            }
        }
    }

    internal class ReferenceIdHandlerForDeserializer<T> where T : class
    {
        private readonly Dictionary<string, T> _refId2object = new Dictionary<string, T>();

        internal void SetRefId(T o, string refId, bool duplicateRefIdsAllowed)
        {
#if DEBUG
            if (!duplicateRefIdsAllowed)
            {
                Dbg.Assert(!_refId2object.ContainsKey(refId), "You can't change refId association");
            }
#endif
            _refId2object[refId] = o;
        }

        internal T GetReferencedObject(string refId)
        {
            Dbg.Assert(_refId2object.ContainsKey(refId), "Reference id wasn't seen earlier");
            T t;
            if (_refId2object.TryGetValue(refId, out t))
            {
                return t;
            }
            else
            {
                return null;
            }
        }
    }

    /// <summary>
    /// A delegate for serializing known type.
    /// </summary>
    internal delegate void TypeSerializerDelegate(InternalSerializer serializer, string streamName, string property, object source, TypeSerializationInfo entry);
    /// <summary>
    /// A delegate for deserializing known type.
    /// </summary>
    internal delegate object TypeDeserializerDelegate(InternalDeserializer deserializer);

    /// <summary>
    /// This class contains serialization information about a type.
    /// </summary>
    internal class TypeSerializationInfo
    {
        /// <summary>
        /// Constructor.
        /// </summary>
        /// <param name="type">Type for which this entry is created.</param>
        /// <param name="itemTag">ItemTag for the type.</param>
        /// <param name="propertyTag">PropertyTag for the type.</param>
        /// <param name="serializer">TypeSerializerDelegate for serializing the type.</param>
        /// <param name="deserializer">TypeDeserializerDelegate for deserializing the type.</param>
        internal TypeSerializationInfo(Type type, string itemTag, string propertyTag, TypeSerializerDelegate serializer, TypeDeserializerDelegate deserializer)
        {
            Type = type;
            Serializer = serializer;
            Deserializer = deserializer;
            ItemTag = itemTag;
            PropertyTag = propertyTag;
        }

        #region properties

        /// <summary>
        /// Get the type for which this TypeSerializationInfo is created.
        /// </summary>
        internal Type Type { get; }

        /// <summary>
        /// Get the item tag for this type.
        /// </summary>
        internal string ItemTag { get; }

        /// <summary>
        /// Get the Property tag for this type.
        /// </summary>
        internal string PropertyTag { get; }

        /// <summary>
        /// Gets the delegate to serialize this type.
        /// </summary>
        internal TypeSerializerDelegate Serializer { get; }

        /// <summary>
        /// Gets the delegate to deserialize this type.
        /// </summary>
        internal TypeDeserializerDelegate Deserializer { get; }

        #endregion properties

        #region private

        #endregion private
    }

    /// <summary>
    /// A class for identifying types which are treated as KnownType by Monad.
    /// A KnownType is guranteed to be available on machine on which monad is
    /// running.
    /// </summary>
    internal static class KnownTypes
    {
        /// <summary>
        /// Static constructor.
        /// </summary>
        static KnownTypes()
        {
            for (int i = 0; i < s_typeSerializationInfo.Length; i++)
            {
                s_knownTableKeyType.Add(s_typeSerializationInfo[i].Type.FullName, s_typeSerializationInfo[i]);
                s_knownTableKeyItemTag.Add(s_typeSerializationInfo[i].ItemTag, s_typeSerializationInfo[i]);
            }
        }

        /// <summary>
        /// Gets the type serialization information about a type.
        /// </summary>
        /// <param name="type">Type for which information is retrieved.</param>
        /// <returns>TypeSerializationInfo for the type, null if it doesn't exist.</returns>
        internal static TypeSerializationInfo GetTypeSerializationInfo(Type type)
        {
            TypeSerializationInfo temp;
            if (!s_knownTableKeyType.TryGetValue(type.FullName, out temp) && typeof(XmlDocument).IsAssignableFrom(type))
            {
                temp = s_xdInfo;
            }

            return temp;
        }

        /// <summary>
        /// Get TypeSerializationInfo using ItemTag as key.
        /// </summary>
        /// <param name="itemTag">ItemTag for which TypeSerializationInfo is to be fetched.</param>
        /// <returns>TypeSerializationInfo entry, null if no entry exist for the tag.</returns>
        internal static TypeSerializationInfo GetTypeSerializationInfoFromItemTag(string itemTag)
        {
            TypeSerializationInfo temp;
            s_knownTableKeyItemTag.TryGetValue(itemTag, out temp);
            return temp;
        }

        #region private_fields

        // TypeSerializationInfo for XmlDocument
        private static readonly TypeSerializationInfo s_xdInfo =
            new TypeSerializationInfo(typeof(XmlDocument),
                SerializationStrings.XmlDocumentTag,
                SerializationStrings.XmlDocumentTag,
                InternalSerializer.WriteXmlDocument,
                InternalDeserializer.DeserializeXmlDocument);

        /// <summary>
        /// Array of known types.
        /// </summary>
        private static readonly TypeSerializationInfo[] s_typeSerializationInfo = new TypeSerializationInfo[]
        {
            new TypeSerializationInfo(typeof(bool),
                                SerializationStrings.BooleanTag,
                                SerializationStrings.BooleanTag,
                                InternalSerializer.WriteBoolean,
                                InternalDeserializer.DeserializeBoolean),

            new TypeSerializationInfo(typeof(byte),
                                SerializationStrings.UnsignedByteTag,
                                SerializationStrings.UnsignedByteTag,
                                null,
                                InternalDeserializer.DeserializeByte),

            new TypeSerializationInfo(typeof(char),
                                SerializationStrings.CharTag,
                                SerializationStrings.CharTag,
                                InternalSerializer.WriteChar,
                                InternalDeserializer.DeserializeChar),

            new TypeSerializationInfo(typeof(DateTime),
                                SerializationStrings.DateTimeTag,
                                SerializationStrings.DateTimeTag,
                                InternalSerializer.WriteDateTime,
                                InternalDeserializer.DeserializeDateTime),

            new TypeSerializationInfo(typeof(decimal),
                                SerializationStrings.DecimalTag,
                                SerializationStrings.DecimalTag,
                                null,
                                InternalDeserializer.DeserializeDecimal),

            new TypeSerializationInfo(typeof(double),
                                SerializationStrings.DoubleTag,
                                SerializationStrings.DoubleTag,
                                InternalSerializer.WriteDouble,
                                InternalDeserializer.DeserializeDouble),

            new TypeSerializationInfo(typeof(Guid),
                                SerializationStrings.GuidTag,
                                SerializationStrings.GuidTag,
                                null,
                                InternalDeserializer.DeserializeGuid),
            new TypeSerializationInfo(typeof(Int16),
                                SerializationStrings.ShortTag,
                                SerializationStrings.ShortTag,
                                null,
                                InternalDeserializer.DeserializeInt16),

            new TypeSerializationInfo(typeof(Int32),
                                SerializationStrings.IntTag,
                                SerializationStrings.IntTag,
                                null,
                                InternalDeserializer.DeserializeInt32),

            new TypeSerializationInfo(typeof(Int64),
                                SerializationStrings.LongTag,
                                SerializationStrings.LongTag,
                                null,
                                InternalDeserializer.DeserializeInt64),

            new TypeSerializationInfo(typeof(sbyte),
                                SerializationStrings.ByteTag,
                                SerializationStrings.ByteTag,
                                null,
                                InternalDeserializer.DeserializeSByte),

            new TypeSerializationInfo(typeof(Single),
                                SerializationStrings.FloatTag,
                                SerializationStrings.FloatTag,
                                InternalSerializer.WriteSingle,
                                InternalDeserializer.DeserializeSingle),

            new TypeSerializationInfo(typeof(ScriptBlock),
                                SerializationStrings.ScriptBlockTag,
                                SerializationStrings.ScriptBlockTag,
                                InternalSerializer.WriteScriptBlock,
                                InternalDeserializer.DeserializeScriptBlock),

            new TypeSerializationInfo(typeof(string),
                                SerializationStrings.StringTag,
                                SerializationStrings.StringTag,
                                InternalSerializer.WriteEncodedString,
                                InternalDeserializer.DeserializeString),

            new TypeSerializationInfo(typeof(TimeSpan),
                                SerializationStrings.DurationTag,
                                SerializationStrings.DurationTag,
                                InternalSerializer.WriteTimeSpan,
                                InternalDeserializer.DeserializeTimeSpan),

            new TypeSerializationInfo(typeof(UInt16),
                                SerializationStrings.UnsignedShortTag,
                                SerializationStrings.UnsignedShortTag,
                                null,
                                InternalDeserializer.DeserializeUInt16),

            new TypeSerializationInfo(typeof(UInt32),
                                SerializationStrings.UnsignedIntTag,
                                SerializationStrings.UnsignedIntTag,
                                null,
                                InternalDeserializer.DeserializeUInt32),

            new TypeSerializationInfo(typeof(UInt64),
                                SerializationStrings.UnsignedLongTag,
                                SerializationStrings.UnsignedLongTag,
                                null,
                                InternalDeserializer.DeserializeUInt64),

            new TypeSerializationInfo(typeof(Uri),
                                SerializationStrings.AnyUriTag,
                                SerializationStrings.AnyUriTag,
                                InternalSerializer.WriteUri,
                                InternalDeserializer.DeserializeUri),

            new TypeSerializationInfo(typeof(byte[]),
                                      SerializationStrings.Base64BinaryTag,
                                      SerializationStrings.Base64BinaryTag,
                                      InternalSerializer.WriteByteArray,
                                      InternalDeserializer.DeserializeByteArray),

            new TypeSerializationInfo(typeof(System.Version),
                                      SerializationStrings.VersionTag,
                                      SerializationStrings.VersionTag,
                                      InternalSerializer.WriteVersion,
                                      InternalDeserializer.DeserializeVersion),

            s_xdInfo,

            new TypeSerializationInfo(typeof(ProgressRecord),
                                      SerializationStrings.ProgressRecord,
                                      SerializationStrings.ProgressRecord,
                                      InternalSerializer.WriteProgressRecord,
                                      InternalDeserializer.DeserializeProgressRecord),

            new TypeSerializationInfo(typeof(SecureString),
                                      SerializationStrings.SecureStringTag,
                                      SerializationStrings.SecureStringTag,
                                      InternalSerializer.WriteSecureString,
                                      InternalDeserializer.DeserializeSecureString),
        };

        /// <summary>
        /// Hashtable of knowntypes.
        /// Key is Type.FullName and value is Type object.
        /// </summary>
        private static readonly Dictionary<string, TypeSerializationInfo> s_knownTableKeyType = new Dictionary<string, TypeSerializationInfo>();

        /// <summary>
        /// Hashtable of knowntypes. Key is ItemTag.
        /// </summary>
        private static readonly Dictionary<string, TypeSerializationInfo> s_knownTableKeyItemTag = new Dictionary<string, TypeSerializationInfo>();

        #endregion private_fields
    }

    /// <summary>
    /// This class contains helper routined for serialization/deserialization.
    /// </summary>
    internal static class SerializationUtilities
    {
        /// <summary>
        /// Extracts the value of a note property from a PSObject; returns null if the property does not exist.
        /// </summary>
        internal static object GetPropertyValue(PSObject psObject, string propertyName)
        {
            PSNoteProperty property = (PSNoteProperty)psObject.Properties[propertyName];

            if (property == null)
            {
                return null;
            }

            return property.Value;
        }

        /// <summary>
        /// Returns the BaseObject of a note property encoded as a PSObject; returns null if the property does not exist.
        /// </summary>
        internal static object GetPsObjectPropertyBaseObject(PSObject psObject, string propertyName)
        {
            PSObject propertyPsObject = (PSObject)GetPropertyValue(psObject, propertyName);

            if (propertyPsObject == null)
            {
                return null;
            }

            return propertyPsObject.BaseObject;
        }

        /// <summary>
        /// Checks if source is known container type and returns appropriate
        /// information.
        /// </summary>
        /// <param name="source"></param>
        /// <param name="ct"></param>
        /// <param name="dictionary"></param>
        /// <param name="enumerable"></param>
        internal static void GetKnownContainerTypeInfo(
            object source,
            out ContainerType ct,
            out IDictionary dictionary,
            out IEnumerable enumerable)
        {
            Dbg.Assert(source != null, "caller should validate the parameter");

            ct = ContainerType.None;
            dictionary = null;
            enumerable = null;

            dictionary = source as IDictionary;
            if (dictionary != null)
            {
                ct = ContainerType.Dictionary;
            }
            else if (source is Stack)
            {
                ct = ContainerType.Stack;
                enumerable = LanguagePrimitives.GetEnumerable(source);
                Dbg.Assert(enumerable != null, "Stack is enumerable");
            }
            else if (source is Queue)
            {
                ct = ContainerType.Queue;
                enumerable = LanguagePrimitives.GetEnumerable(source);
                Dbg.Assert(enumerable != null, "Queue is enumerable");
            }
            else if (source is IList)
            {
                ct = ContainerType.List;
                enumerable = LanguagePrimitives.GetEnumerable(source);
                Dbg.Assert(enumerable != null, "IList is enumerable");
            }
            else
            {
                Type gt = source.GetType();
                if (gt.IsGenericType)
                {
                    if (DerivesFromGenericType(gt, typeof(Stack<>)))
                    {
                        ct = ContainerType.Stack;
                        enumerable = LanguagePrimitives.GetEnumerable(source);
                        Dbg.Assert(enumerable != null, "Stack is enumerable");
                    }
                    else if (DerivesFromGenericType(gt, typeof(Queue<>)))
                    {
                        ct = ContainerType.Queue;
                        enumerable = LanguagePrimitives.GetEnumerable(source);
                        Dbg.Assert(enumerable != null, "Queue is enumerable");
                    }
                    else if (DerivesFromGenericType(gt, typeof(List<>)))
                    {
                        ct = ContainerType.List;
                        enumerable = LanguagePrimitives.GetEnumerable(source);
                        Dbg.Assert(enumerable != null, "Queue is enumerable");
                    }
                }
            }

            // Check if LanguagePrimitive.GetEnumerable can do some magic to get IEnumerable instance
            if (ct == ContainerType.None)
            {
                try
                {
                    enumerable = LanguagePrimitives.GetEnumerable(source);
                    if (enumerable != null)
                    {
                        ct = ContainerType.Enumerable;
                    }
                }
                catch (Exception exception)
                {
                    // Catch-all OK. This is a third-party call-out.
                    PSEtwLog.LogAnalyticWarning(PSEventId.Serializer_EnumerationFailed, PSOpcode.Exception,
                        PSTask.Serialization, PSKeyword.Serializer, source.GetType().AssemblyQualifiedName,
                        exception.ToString());
                }
            }

            // Check if type is IEnumerable
            // (LanguagePrimitives.GetEnumerable above should be enough - the check below is to preserve
            // backcompatibility in some corner-cases (see bugs in Windows7 - #372562 and #372563))
            if (ct == ContainerType.None)
            {
                enumerable = source as IEnumerable;
                if (enumerable != null)
                {
                    // WinBlue: 206515 - There are no elements in the source. The source is of type XmlLinkedNode (which derives from XmlNode which implements IEnumerable).
                    // So, adding an additional check to see if this contains any elements
                    IEnumerator enumerator = enumerable.GetEnumerator();
                    if (enumerator != null && enumerator.MoveNext())
                    {
                        ct = ContainerType.Enumerable;
                    }
                }
            }
        }

        /// <summary>
        /// Checks if derived is of type baseType or a type derived from baseType.
        /// </summary>
        /// <param name="derived"></param>
        /// <param name="baseType"></param>
        /// <returns></returns>
        private static bool DerivesFromGenericType(Type derived, Type baseType)
        {
            Dbg.Assert(derived != null, "caller should validate the parameter");
            Dbg.Assert(baseType != null, "caller should validate the parameter");
            while (derived != null)
            {
                if (derived.IsGenericType)
                    derived = derived.GetGenericTypeDefinition();

                if (derived == baseType)
                {
                    return true;
                }

                derived = derived.BaseType;
            }

            return false;
        }

        /// <summary>
        /// Gets the "ToString" from PSObject.
        /// </summary>
        /// <param name="source">
        /// PSObject to be converted to string
        /// </param>
        /// <returns>
        /// "ToString" value
        /// </returns>
        internal static string GetToString(object source)
        {
            Dbg.Assert(source != null, "caller should have validated the information");

            // fall back value
            string result = null;

            try
            {
                result = Convert.ToString(source, CultureInfo.InvariantCulture);
            }
            catch (Exception e)
            {
                // Catch-all OK. This is a third-party call-out.
                PSEtwLog.LogAnalyticWarning(
                    PSEventId.Serializer_ToStringFailed, PSOpcode.Exception, PSTask.Serialization,
                    PSKeyword.Serializer | PSKeyword.UseAlwaysAnalytic,
                    source.GetType().AssemblyQualifiedName,
                    e.ToString());
            }

            return result;
        }

        internal static string GetToStringForPrimitiveObject(PSObject pso)
        {
            // if object is not wrapped in a PSObject, then nothing modifies the ToString value of the primitive object
            if (pso == null)
            {
                return null;
            }

            // preserve ToString throughout deserialization/*re*serialization
            if (pso.ToStringFromDeserialization != null)
            {
                return pso.ToStringFromDeserialization;
            }

            // preserve token text (i.e. double: 0E1517567410;  see Windows 7 bug #694057 for more details)
            string token = pso.TokenText;
            if (token != null)
            {
                string originalToString = GetToString(pso.BaseObject);
                if (originalToString == null || !string.Equals(token, originalToString, StringComparison.Ordinal))
                {
                    return token;
                }
            }

            // no need to write <ToString> element otherwise - the ToString method of a deserialized, live primitive object will return the right value
            return null;
        }

        internal static PSMemberInfoInternalCollection<PSPropertyInfo> GetSpecificPropertiesToSerialize(PSObject source, Collection<CollectionEntry<PSPropertyInfo>> allPropertiesCollection, TypeTable typeTable)
        {
            if (source == null)
            {
                return null;
            }

            if (source.GetSerializationMethod(typeTable) == SerializationMethod.SpecificProperties)
            {
                PSEtwLog.LogAnalyticVerbose(
                    PSEventId.Serializer_ModeOverride, PSOpcode.SerializationSettings, PSTask.Serialization,
                    PSKeyword.Serializer | PSKeyword.UseAlwaysAnalytic,
                    source.InternalTypeNames.Key,
                    (UInt32)(SerializationMethod.SpecificProperties));

                PSMemberInfoInternalCollection<PSPropertyInfo> specificProperties =
                    new PSMemberInfoInternalCollection<PSPropertyInfo>();
                PSMemberInfoIntegratingCollection<PSPropertyInfo> allProperties =
                    new PSMemberInfoIntegratingCollection<PSPropertyInfo>(
                        source,
                        allPropertiesCollection);

                Collection<string> namesOfPropertiesToSerialize = source.GetSpecificPropertiesToSerialize(typeTable);
                foreach (string propertyName in namesOfPropertiesToSerialize)
                {
                    PSPropertyInfo property = allProperties[propertyName];
                    if (property == null)
                    {
                        PSEtwLog.LogAnalyticWarning(
                            PSEventId.Serializer_SpecificPropertyMissing, PSOpcode.Exception, PSTask.Serialization,
                            PSKeyword.Serializer | PSKeyword.UseAlwaysAnalytic,
                            source.InternalTypeNames.Key,
                            propertyName);
                    }
                    else
                    {
                        specificProperties.Add(property);
                    }
                }

                return specificProperties;
            }

            return null;
        }

        internal static object GetPropertyValueInThreadSafeManner(PSPropertyInfo property, bool canUseDefaultRunspaceInThreadSafeManner, out bool success)
        {
            Dbg.Assert(property != null, "Caller should validate the parameter");

            if (!property.IsGettable)
            {
                success = false;
                return null;
            }

            PSAliasProperty alias = property as PSAliasProperty;
            if (alias != null)
            {
                property = alias.ReferencedMember as PSPropertyInfo;
            }

            PSScriptProperty script = property as PSScriptProperty;
            Dbg.Assert(script == null || script.GetterScript != null, "scriptProperty.IsGettable => (scriptProperty.GetterScript != null)");
            if ((script != null) && (!canUseDefaultRunspaceInThreadSafeManner))
            {
                PSEtwLog.LogAnalyticWarning(
                    PSEventId.Serializer_ScriptPropertyWithoutRunspace, PSOpcode.Exception, PSTask.Serialization,
                    PSKeyword.Serializer | PSKeyword.UseAlwaysAnalytic,
                    property.Name,
                    property.instance == null ? string.Empty : PSObject.GetTypeNames(property.instance).Key,
                    script.GetterScript.ToString());

                success = false;
                return null;
            }

            try
            {
                object value = property.Value;
                success = true;
                return value;
            }
            catch (ExtendedTypeSystemException e)
            {
                PSEtwLog.LogAnalyticWarning(
                    PSEventId.Serializer_PropertyGetterFailed, PSOpcode.Exception, PSTask.Serialization,
                    PSKeyword.Serializer | PSKeyword.UseAlwaysAnalytic,
                    property.Name,
                    property.instance == null ? string.Empty : PSObject.GetTypeNames(property.instance).Key,
                    e.ToString(),
                    e.InnerException == null ? string.Empty : e.InnerException.ToString());

                success = false;
                return null;
            }
        }
    }

    /// <summary>
    /// A dictionary from object to T where
    /// 1) keys are objects,
    /// 2) keys use reference equality,
    /// 3) dictionary keeps only weak references to keys.
    /// </summary>
    /// <typeparam name="T">type of dictionary values</typeparam>
    internal class WeakReferenceDictionary<T> : IDictionary<object, T>
    {
        private sealed class WeakReferenceEqualityComparer : IEqualityComparer<WeakReference>
        {
            public bool Equals(WeakReference x, WeakReference y)
            {
                object tx = x.Target;
                if (tx == null)
                {
                    return false; // collected object is not equal to anything (object.ReferenceEquals(null, null) == true)
                }

                object ty = y.Target;
                if (ty == null)
                {
                    return false; // collected object is not equal to anything (object.ReferenceEquals(null, null) == true)
                }

                return object.ReferenceEquals(tx, ty);
            }

            public int GetHashCode(WeakReference obj)
            {
                object t = obj.Target;
                if (t == null)
                {
                    // collected object doesn't have a hash code
                    // return an arbitrary hashcode here and fall back on Equal method for comparison
                    return RuntimeHelpers.GetHashCode(obj); // RuntimeHelpers.GetHashCode(null) returns 0 - this would cause many hashtable collisions for WeakReferences to dead objects
                }
                else
                {
                    return RuntimeHelpers.GetHashCode(t);
                }
            }
        }

        private readonly IEqualityComparer<WeakReference> _weakEqualityComparer;
        private Dictionary<WeakReference, T> _dictionary;

        public WeakReferenceDictionary()
        {
            _weakEqualityComparer = new WeakReferenceEqualityComparer();
            _dictionary = new Dictionary<WeakReference, T>(_weakEqualityComparer);
        }

#if DEBUG
        private const int initialCleanupTriggerSize = 2; // 2 will stress this code more
#else
        private const int initialCleanupTriggerSize = 1000;
#endif
        private int _cleanupTriggerSize = initialCleanupTriggerSize;

        private void CleanUp()
        {
            if (this.Count > _cleanupTriggerSize)
            {
                Dictionary<WeakReference, T> alive = new Dictionary<WeakReference, T>(_weakEqualityComparer);
                foreach (KeyValuePair<WeakReference, T> weakKeyValuePair in _dictionary)
                {
                    object key = weakKeyValuePair.Key.Target;
                    if (key != null)
                    {
                        alive.Add(weakKeyValuePair.Key, weakKeyValuePair.Value);
                    }
                }

                _dictionary = alive;
                _cleanupTriggerSize = initialCleanupTriggerSize + this.Count * 2;
            }
        }

        #region IDictionary<object,T> Members

        public void Add(object key, T value)
        {
            _dictionary.Add(new WeakReference(key), value);
            this.CleanUp();
        }

        public bool ContainsKey(object key)
        {
            return _dictionary.ContainsKey(new WeakReference(key));
        }

        public ICollection<object> Keys
        {
            get
            {
                List<object> keys = new List<object>(_dictionary.Keys.Count);
                foreach (WeakReference weakKey in _dictionary.Keys)
                {
                    object key = weakKey.Target;
                    if (key != null)
                    {
                        keys.Add(key);
                    }
                }

                return keys;
            }
        }

        public bool Remove(object key)
        {
            return _dictionary.Remove(new WeakReference(key));
        }

        public bool TryGetValue(object key, out T value)
        {
            WeakReference weakKey = new WeakReference(key);
            return _dictionary.TryGetValue(weakKey, out value);
        }

        public ICollection<T> Values
        {
            get
            {
                return _dictionary.Values;
            }
        }

        public T this[object key]
        {
            get
            {
                return _dictionary[new WeakReference(key)];
            }

            set
            {
                _dictionary[new WeakReference(key)] = value;
                this.CleanUp();
            }
        }

        #endregion

        #region ICollection<KeyValuePair<object,T>> Members

        private ICollection<KeyValuePair<WeakReference, T>> WeakCollection
        {
            get
            {
                return _dictionary;
            }
        }

        private static KeyValuePair<WeakReference, T> WeakKeyValuePair(KeyValuePair<object, T> publicKeyValuePair)
        {
            return new KeyValuePair<WeakReference, T>(new WeakReference(publicKeyValuePair.Key), publicKeyValuePair.Value);
        }

        public void Add(KeyValuePair<object, T> item)
        {
            this.WeakCollection.Add(WeakKeyValuePair(item));
            this.CleanUp();
        }

        public void Clear()
        {
            this.WeakCollection.Clear();
        }

        public bool Contains(KeyValuePair<object, T> item)
        {
            return this.WeakCollection.Contains(WeakKeyValuePair(item));
        }

        public void CopyTo(KeyValuePair<object, T>[] array, int arrayIndex)
        {
            List<KeyValuePair<object, T>> rawList = new List<KeyValuePair<object, T>>(this.WeakCollection.Count);
            foreach (KeyValuePair<object, T> keyValuePair in this)
            {
                rawList.Add(keyValuePair);
            }

            rawList.CopyTo(array, arrayIndex);
        }

        public int Count
        {
            get
            {
                return this.WeakCollection.Count;
            }
        }

        public bool IsReadOnly
        {
            get
            {
                return this.WeakCollection.IsReadOnly;
            }
        }

        public bool Remove(KeyValuePair<object, T> item)
        {
            return this.WeakCollection.Remove(WeakKeyValuePair(item));
        }

        #endregion

        #region IEnumerable<KeyValuePair<object,T>> Members

        public IEnumerator<KeyValuePair<object, T>> GetEnumerator()
        {
            foreach (KeyValuePair<WeakReference, T> weakKeyValuePair in this.WeakCollection)
            {
                object key = weakKeyValuePair.Key.Target;
                if (key != null)
                {
                    yield return new KeyValuePair<object, T>(key, weakKeyValuePair.Value);
                }
            }
        }

        #endregion

        #region IEnumerable Members

        IEnumerator IEnumerable.GetEnumerator()
        {
            IEnumerable<KeyValuePair<object, T>> enumerable = this;
            IEnumerator<KeyValuePair<object, T>> enumerator = enumerable.GetEnumerator();
            return enumerator;
        }

        #endregion
    }

    /// <summary>
    /// <see cref="PSPrimitiveDictionary"/> is a <see cref="Hashtable"/> that is limited to
    /// 1) case-insensitive strings as keys and
    /// 2) values that can be serialized and deserialized during PowerShell remoting handshake
    ///    (in major-version compatible versions of PowerShell remoting)
    /// </summary>
    [Serializable]
    public sealed class PSPrimitiveDictionary : Hashtable
    {
        #region Constructors

        /// <summary>
        /// Initializes a new empty instance of the <see cref="PSPrimitiveDictionary"/> class.
        /// </summary>
        public PSPrimitiveDictionary()
            : base(StringComparer.OrdinalIgnoreCase)
        {
        }

        /// <summary>
        /// Initializes a new instance of the <see cref="PSPrimitiveDictionary"/> class with contents
        /// copied from the <paramref name="other"/> hashtable.
        /// </summary>
        /// <param name="other">Hashtable to copy into the new instance of <see cref="PSPrimitiveDictionary"/></param>
        /// <exception cref="ArgumentException">
        /// This constructor will throw if the <paramref name="other"/> hashtable contains keys that are not a strings
        /// or values that are not one of primitive types that will work during PowerShell remoting handshake.
        /// </exception>
        [SuppressMessage("Microsoft.Usage", "CA2214:DoNotCallOverridableMethodsInConstructors", Justification = "The class is sealed")]
        public PSPrimitiveDictionary(Hashtable other)
            : base(StringComparer.OrdinalIgnoreCase)
        {
            if (other == null)
            {
                throw new ArgumentNullException(nameof(other));
            }

            foreach (DictionaryEntry entry in other)
            {
                Hashtable valueAsHashtable = PSObject.Base(entry.Value) as Hashtable;
                if (valueAsHashtable != null)
                {
                    this.Add(entry.Key, new PSPrimitiveDictionary(valueAsHashtable));
                }
                else
                {
                    this.Add(entry.Key, entry.Value);
                }
            }
        }

#if !CORECLR // No .NET Serialization In CoreCLR
        /// <summary>
        /// Support for .NET serialization.
        /// </summary>
        private PSPrimitiveDictionary(System.Runtime.Serialization.SerializationInfo info, System.Runtime.Serialization.StreamingContext context)
                : base(info, context)
        {
        }
#endif
        #endregion

        #region Plumbing to make Hashtable reject all non-primitive types

        private static string VerifyKey(object key)
        {
            key = PSObject.Base(key);
            string keyAsString = key as string;
            if (keyAsString == null)
            {
                string message = StringUtil.Format(Serialization.PrimitiveHashtableInvalidKey,
                    key.GetType().FullName);
                throw new ArgumentException(message);
            }
            else
            {
                return keyAsString;
            }
        }

        private static readonly Type[] s_handshakeFriendlyTypes = new Type[] {
                typeof(bool),
                typeof(byte),
                typeof(char),
                typeof(DateTime),
                typeof(decimal),
                typeof(double),
                typeof(Guid),
                typeof(Int32),
                typeof(Int64),
                typeof(sbyte),
                typeof(Single),
                // typeof(ScriptBlock) - don't want ScriptBlocks, because they are deserialized into strings
                typeof(string),
                typeof(TimeSpan),
                typeof(UInt16),
                typeof(UInt32),
                typeof(UInt64),
                typeof(Uri),
                typeof(byte[]),
                typeof(Version),
                typeof(ProgressRecord),
                typeof(XmlDocument),

                typeof(PSPrimitiveDictionary)
            };

        private void VerifyValue(object value)
        {
            // null is a primitive type
            if (value == null)
            {
                return;
            }

            value = PSObject.Base(value);

            // this list is based on the list inside KnownTypes
            // it is copied here to make sure that a list of "handshake friendly types"
            // won't change even if we add new primitive types in v.next

            Type valueType = value.GetType();

            // if "value" is a "primitiveType" then we are good
            foreach (Type goodType in s_handshakeFriendlyTypes)
            {
                if (valueType == goodType)
                {
                    return;
                }
            }

            // if "value" is an array of "primitiveType" items then we are good
            // (note: we could have used IEnumerable<> or ICollection<> (covariance/contravariance concerns),
            //        but it is safer to limit the types to arrays.
            //        (one concern is that in v.next we might allow overriding SerializationMethod for
            //         types [i.e. check SerializationMethod *before* HandleKnownContainerTypes)
            if ((valueType.IsArray) || valueType == typeof(ArrayList))
            {
                foreach (object o in (IEnumerable)value)
                {
                    VerifyValue(o);
                }

                return;
            }

            string message = StringUtil.Format(Serialization.PrimitiveHashtableInvalidValue,
                value.GetType().FullName);
            throw new ArgumentException(message);
        }

        /// <summary>
        /// Adds an element with the specified key and value into the Hashtable.
        /// </summary>
        /// <param name="key">The key of the element to add.</param>
        /// <param name="value">The value of the element to add.</param>
        /// <exception cref="ArgumentException">
        /// This method will throw if the <paramref name="key"/> is not a string and the <paramref name="value"/>
        /// is not one of primitive types that will work during PowerShell remoting handshake.
        /// Use of strongly-typed overloads of this method is suggested if throwing an exception is not acceptable.
        /// </exception>
        public override void Add(object key, object value)
        {
            string keyAsString = VerifyKey(key);
            this.VerifyValue(value);
            base.Add(keyAsString, value);
        }

        /// <summary>
        /// Gets or sets the value associated with the specified key.
        /// </summary>
        /// <param name="key">The key whose value to get or set.</param>
        /// <returns>The value associated with the specified key.</returns>
        /// <remarks>
        /// If the specified key is not found, attempting to get it returns <see langword="null"/>
        /// and attempting to set it creates a new element using the specified key.
        /// </remarks>
        /// <exception cref="ArgumentException">
        /// The setter will throw if the <paramref name="key"/> is not a string and the value
        /// is not one of primitive types that will work during PowerShell remoting handshake.
        /// Use of strongly-typed overloads of Add method is suggested if throwing an exception is not acceptable.
        /// </exception>
        public override object this[object key]
        {
            get
            {
                return base[key];
            }

            set
            {
                string keyAsString = VerifyKey(key);
                this.VerifyValue(value);
                base[keyAsString] = value;
            }
        }

        /// <summary>
        /// Gets or sets the value associated with the specified key.
        /// </summary>
        /// <param name="key">The key whose value to get or set.</param>
        /// <returns>The value associated with the specified key.</returns>
        /// <remarks>
        /// If the specified key is not found, attempting to get it returns <see langword="null"/>
        /// and attempting to set it creates a new element using the specified key.
        /// </remarks>
        /// <exception cref="ArgumentException">
        /// The setter will throw if the value
        /// is not one of primitive types that will work during PowerShell remoting handshake.
        /// Use of strongly-typed overloads of Add method is suggested if throwing an exception is not acceptable.
        /// </exception>
        public object this[string key]
        {
            get
            {
                return base[key];
            }

            set
            {
                this.VerifyValue(value);
                base[key] = value;
            }
        }

        #endregion

        #region Helper methods

        /// <summary>
        /// Creates a new instance by doing a shallow copy of the current instance.
        /// </summary>
        /// <returns></returns>
        public override object Clone()
        {
            return new PSPrimitiveDictionary(this);
        }

        /// <summary>
        /// Adds an element with the specified key and value into the Hashtable.
        /// </summary>
        /// <param name="key">The key of the element to add.</param>
        /// <param name="value">The value of the element to add.</param>
        public void Add(string key, bool value)
        {
            this.Add((object)key, (object)value);
        }

        /// <summary>
        /// Adds an element with the specified key and value into the Hashtable.
        /// </summary>
        /// <param name="key">The key of the element to add.</param>
        /// <param name="value">The value of the element to add.</param>
        public void Add(string key, bool[] value)
        {
            this.Add((object)key, (object)value);
        }

        /// <summary>
        /// Adds an element with the specified key and value into the Hashtable.
        /// </summary>
        /// <param name="key">The key of the element to add.</param>
        /// <param name="value">The value of the element to add.</param>
        public void Add(string key, byte value)
        {
            this.Add((object)key, (object)value);
        }

        /// <summary>
        /// Adds an element with the specified key and value into the Hashtable.
        /// </summary>
        /// <param name="key">The key of the element to add.</param>
        /// <param name="value">The value of the element to add.</param>
        public void Add(string key, byte[] value)
        {
            this.Add((object)key, (object)value);
        }

        /// <summary>
        /// Adds an element with the specified key and value into the Hashtable.
        /// </summary>
        /// <param name="key">The key of the element to add.</param>
        /// <param name="value">The value of the element to add.</param>
        public void Add(string key, char value)
        {
            this.Add((object)key, (object)value);
        }

        /// <summary>
        /// Adds an element with the specified key and value into the Hashtable.
        /// </summary>
        /// <param name="key">The key of the element to add.</param>
        /// <param name="value">The value of the element to add.</param>
        public void Add(string key, char[] value)
        {
            this.Add((object)key, (object)value);
        }

        /// <summary>
        /// Adds an element with the specified key and value into the Hashtable.
        /// </summary>
        /// <param name="key">The key of the element to add.</param>
        /// <param name="value">The value of the element to add.</param>
        public void Add(string key, DateTime value)
        {
            this.Add((object)key, (object)value);
        }

        /// <summary>
        /// Adds an element with the specified key and value into the Hashtable.
        /// </summary>
        /// <param name="key">The key of the element to add.</param>
        /// <param name="value">The value of the element to add.</param>
        public void Add(string key, DateTime[] value)
        {
            this.Add((object)key, (object)value);
        }

        /// <summary>
        /// Adds an element with the specified key and value into the Hashtable.
        /// </summary>
        /// <param name="key">The key of the element to add.</param>
        /// <param name="value">The value of the element to add.</param>
        public void Add(string key, Decimal value)
        {
            this.Add((object)key, (object)value);
        }

        /// <summary>
        /// Adds an element with the specified key and value into the Hashtable.
        /// </summary>
        /// <param name="key">The key of the element to add.</param>
        /// <param name="value">The value of the element to add.</param>
        public void Add(string key, Decimal[] value)
        {
            this.Add((object)key, (object)value);
        }

        /// <summary>
        /// Adds an element with the specified key and value into the Hashtable.
        /// </summary>
        /// <param name="key">The key of the element to add.</param>
        /// <param name="value">The value of the element to add.</param>
        public void Add(string key, double value)
        {
            this.Add((object)key, (object)value);
        }

        /// <summary>
        /// Adds an element with the specified key and value into the Hashtable.
        /// </summary>
        /// <param name="key">The key of the element to add.</param>
        /// <param name="value">The value of the element to add.</param>
        public void Add(string key, double[] value)
        {
            this.Add((object)key, (object)value);
        }

        /// <summary>
        /// Adds an element with the specified key and value into the Hashtable.
        /// </summary>
        /// <param name="key">The key of the element to add.</param>
        /// <param name="value">The value of the element to add.</param>
        public void Add(string key, Guid value)
        {
            this.Add((object)key, (object)value);
        }

        /// <summary>
        /// Adds an element with the specified key and value into the Hashtable.
        /// </summary>
        /// <param name="key">The key of the element to add.</param>
        /// <param name="value">The value of the element to add.</param>
        public void Add(string key, Guid[] value)
        {
            this.Add((object)key, (object)value);
        }

        /// <summary>
        /// Adds an element with the specified key and value into the Hashtable.
        /// </summary>
        /// <param name="key">The key of the element to add.</param>
        /// <param name="value">The value of the element to add.</param>
        public void Add(string key, Int32 value)
        {
            this.Add((object)key, (object)value);
        }

        /// <summary>
        /// Adds an element with the specified key and value into the Hashtable.
        /// </summary>
        /// <param name="key">The key of the element to add.</param>
        /// <param name="value">The value of the element to add.</param>
        public void Add(string key, Int32[] value)
        {
            this.Add((object)key, (object)value);
        }

        /// <summary>
        /// Adds an element with the specified key and value into the Hashtable.
        /// </summary>
        /// <param name="key">The key of the element to add.</param>
        /// <param name="value">The value of the element to add.</param>
        public void Add(string key, Int64 value)
        {
            this.Add((object)key, (object)value);
        }

        /// <summary>
        /// Adds an element with the specified key and value into the Hashtable.
        /// </summary>
        /// <param name="key">The key of the element to add.</param>
        /// <param name="value">The value of the element to add.</param>
        public void Add(string key, Int64[] value)
        {
            this.Add((object)key, (object)value);
        }

        /// <summary>
        /// Adds an element with the specified key and value into the Hashtable.
        /// </summary>
        /// <param name="key">The key of the element to add.</param>
        /// <param name="value">The value of the element to add.</param>
        public void Add(string key, sbyte value)
        {
            this.Add((object)key, (object)value);
        }

        /// <summary>
        /// Adds an element with the specified key and value into the Hashtable.
        /// </summary>
        /// <param name="key">The key of the element to add.</param>
        /// <param name="value">The value of the element to add.</param>
        public void Add(string key, sbyte[] value)
        {
            this.Add((object)key, (object)value);
        }

        /// <summary>
        /// Adds an element with the specified key and value into the Hashtable.
        /// </summary>
        /// <param name="key">The key of the element to add.</param>
        /// <param name="value">The value of the element to add.</param>
        public void Add(string key, Single value)
        {
            this.Add((object)key, (object)value);
        }

        /// <summary>
        /// Adds an element with the specified key and value into the Hashtable.
        /// </summary>
        /// <param name="key">The key of the element to add.</param>
        /// <param name="value">The value of the element to add.</param>
        public void Add(string key, Single[] value)
        {
            this.Add((object)key, (object)value);
        }

        /// <summary>
        /// Adds an element with the specified key and value into the Hashtable.
        /// </summary>
        /// <param name="key">The key of the element to add.</param>
        /// <param name="value">The value of the element to add.</param>
        public void Add(string key, string value)
        {
            this.Add((object)key, (object)value);
        }

        /// <summary>
        /// Adds an element with the specified key and value into the Hashtable.
        /// </summary>
        /// <param name="key">The key of the element to add.</param>
        /// <param name="value">The value of the element to add.</param>
        public void Add(string key, string[] value)
        {
            this.Add((object)key, (object)value);
        }

        /// <summary>
        /// Adds an element with the specified key and value into the Hashtable.
        /// </summary>
        /// <param name="key">The key of the element to add.</param>
        /// <param name="value">The value of the element to add.</param>
        public void Add(string key, TimeSpan value)
        {
            this.Add((object)key, (object)value);
        }

        /// <summary>
        /// Adds an element with the specified key and value into the Hashtable.
        /// </summary>
        /// <param name="key">The key of the element to add.</param>
        /// <param name="value">The value of the element to add.</param>
        public void Add(string key, TimeSpan[] value)
        {
            this.Add((object)key, (object)value);
        }

        /// <summary>
        /// Adds an element with the specified key and value into the Hashtable.
        /// </summary>
        /// <param name="key">The key of the element to add.</param>
        /// <param name="value">The value of the element to add.</param>
        public void Add(string key, UInt16 value)
        {
            this.Add((object)key, (object)value);
        }

        /// <summary>
        /// Adds an element with the specified key and value into the Hashtable.
        /// </summary>
        /// <param name="key">The key of the element to add.</param>
        /// <param name="value">The value of the element to add.</param>
        public void Add(string key, UInt16[] value)
        {
            this.Add((object)key, (object)value);
        }

        /// <summary>
        /// Adds an element with the specified key and value into the Hashtable.
        /// </summary>
        /// <param name="key">The key of the element to add.</param>
        /// <param name="value">The value of the element to add.</param>
        public void Add(string key, UInt32 value)
        {
            this.Add((object)key, (object)value);
        }

        /// <summary>
        /// Adds an element with the specified key and value into the Hashtable.
        /// </summary>
        /// <param name="key">The key of the element to add.</param>
        /// <param name="value">The value of the element to add.</param>
        public void Add(string key, UInt32[] value)
        {
            this.Add((object)key, (object)value);
        }

        /// <summary>
        /// Adds an element with the specified key and value into the Hashtable.
        /// </summary>
        /// <param name="key">The key of the element to add.</param>
        /// <param name="value">The value of the element to add.</param>
        public void Add(string key, UInt64 value)
        {
            this.Add((object)key, (object)value);
        }

        /// <summary>
        /// Adds an element with the specified key and value into the Hashtable.
        /// </summary>
        /// <param name="key">The key of the element to add.</param>
        /// <param name="value">The value of the element to add.</param>
        public void Add(string key, UInt64[] value)
        {
            this.Add((object)key, (object)value);
        }

        /// <summary>
        /// Adds an element with the specified key and value into the Hashtable.
        /// </summary>
        /// <param name="key">The key of the element to add.</param>
        /// <param name="value">The value of the element to add.</param>
        public void Add(string key, Uri value)
        {
            this.Add((object)key, (object)value);
        }

        /// <summary>
        /// Adds an element with the specified key and value into the Hashtable.
        /// </summary>
        /// <param name="key">The key of the element to add.</param>
        /// <param name="value">The value of the element to add.</param>
        public void Add(string key, Uri[] value)
        {
            this.Add((object)key, (object)value);
        }

        /// <summary>
        /// Adds an element with the specified key and value into the Hashtable.
        /// </summary>
        /// <param name="key">The key of the element to add.</param>
        /// <param name="value">The value of the element to add.</param>
        public void Add(string key, Version value)
        {
            this.Add((object)key, (object)value);
        }

        /// <summary>
        /// Adds an element with the specified key and value into the Hashtable.
        /// </summary>
        /// <param name="key">The key of the element to add.</param>
        /// <param name="value">The value of the element to add.</param>
        public void Add(string key, Version[] value)
        {
            this.Add((object)key, (object)value);
        }

        /// <summary>
        /// Adds an element with the specified key and value into the Hashtable.
        /// </summary>
        /// <param name="key">The key of the element to add.</param>
        /// <param name="value">The value of the element to add.</param>
        public void Add(string key, PSPrimitiveDictionary value)
        {
            this.Add((object)key, (object)value);
        }

        /// <summary>
        /// Adds an element with the specified key and value into the Hashtable.
        /// </summary>
        /// <param name="key">The key of the element to add.</param>
        /// <param name="value">The value of the element to add.</param>
        public void Add(string key, PSPrimitiveDictionary[] value)
        {
            this.Add((object)key, (object)value);
        }

        #endregion

        #region Internal Methods

        /// <summary>
        /// If originalHash contains PSVersionTable, then just returns the Cloned copy of
        /// the original hash. Othewise, creates a clone copy and add PSVersionInfo.GetPSVersionTable
        /// to the clone and returns.
        /// </summary>
        /// <param name="originalHash"></param>
        /// <returns></returns>
        internal static PSPrimitiveDictionary CloneAndAddPSVersionTable(PSPrimitiveDictionary originalHash)
        {
            if ((originalHash != null) &&
                (originalHash.ContainsKey(PSVersionInfo.PSVersionTableName)))
            {
                return (PSPrimitiveDictionary)originalHash.Clone();
            }

            PSPrimitiveDictionary result = originalHash;
            if (originalHash != null)
            {
                result = (PSPrimitiveDictionary)originalHash.Clone();
            }
            else
            {
                result = new PSPrimitiveDictionary();
            }

            PSPrimitiveDictionary versionTable = new PSPrimitiveDictionary(PSVersionInfo.GetPSVersionTableForDownLevel())
            {
                {"PSSemanticVersion", PSVersionInfo.PSVersion.ToString()}
            };
            result.Add(PSVersionInfo.PSVersionTableName, versionTable);

            return result;
        }

        /// <summary>
        /// Tries to get a value that might be present in a chain of nested PSPrimitiveDictionaries.
        /// For example to get $sessionInfo.ApplicationPrivateData.ImplicitRemoting.Hash you could call
        /// TryPathGet&lt;string&gt;($sessionInfo.ApplicationPrivateData, out myHash, "ImplicitRemoting", "Hash").
        /// </summary>
        /// <typeparam name="T">Expected type of the value</typeparam>
        /// <param name="data">The root dictionary.</param>
        /// <param name="result"></param>
        /// <param name="keys">A chain of keys leading from the root dictionary (<paramref name="data"/>) to the value.</param>
        /// <returns><see langword="true"/> if the value was found and was of the correct type; <see langword="false"/> otherwise.</returns>
        internal static bool TryPathGet<T>(IDictionary data, out T result, params string[] keys)
        {
            Dbg.Assert(keys != null, "Caller should verify that keys != null");
            Dbg.Assert(keys.Length >= 1, "Caller should verify that keys.Length >= 1");
            Dbg.Assert(keys[0] != null, "Caller should verify that keys[i] != null");

            if (data == null || !data.Contains(keys[0]))
            {
                result = default(T);
                return false;
            }

            if (keys.Length == 1)
            {
                return LanguagePrimitives.TryConvertTo<T>(data[keys[0]], out result);
            }
            else
            {
                IDictionary subData;
                if (LanguagePrimitives.TryConvertTo<IDictionary>(data[keys[0]], out subData)
                    && subData != null)
                {
                    string[] subKeys = new string[keys.Length - 1];
                    Array.Copy(keys, 1, subKeys, 0, subKeys.Length);
                    return TryPathGet<T>(subData, out result, subKeys);
                }
                else
                {
                    result = default(T);
                    return false;
                }
            }
        }

        #endregion
    }
}

namespace Microsoft.PowerShell
{
    using System.Management.Automation;
    using System.Security.Principal;

    /// <summary>
    /// Rehydrating type converter used during deserialization.
    /// It takes results of serializing some common types
    /// and rehydrates them back from property bags into live objects.
    /// </summary>
    /// <!--
    /// To add a new type for rehydration:
    /// - Add a new T RehydrateT(PSObject pso) method below
    /// - Add this method to converters dictionary in the static constructor below
    /// - If implicit rehydration is required then
    ///   - Add appropriate types.ps1 xml entries for
    ///     - SerializationDepth=X
    ///     - For types depending only on ToString for rehydration set
    ///       - SerializationMethod=SpecificProperties
    ///       - PropertySerializationSet=<empty>
    ///     - TargetTypeForDeserialization=DeserializingTypeConverter
    ///   - Add a field of that type in unit tests / S.M.A.Test.SerializationTest+RehydratedType
    ///     (testsrc\admintest\monad\DRT\engine\UnitTests\SerializationTest.cs)
    /// -->
    public sealed class DeserializingTypeConverter : PSTypeConverter
    {
        #region Infrastructure

        private static readonly Dictionary<Type, Func<PSObject, object>> s_converter;

        static DeserializingTypeConverter()
        {
            s_converter = new Dictionary<Type, Func<PSObject, object>>();

            s_converter.Add(typeof(PSPrimitiveDictionary), RehydratePrimitiveHashtable);

            s_converter.Add(typeof(SwitchParameter), RehydrateSwitchParameter);
            s_converter.Add(typeof(PSListModifier), RehydratePSListModifier);
            s_converter.Add(typeof(PSCredential), RehydratePSCredential);
            s_converter.Add(typeof(PSSenderInfo), RehydratePSSenderInfo);
            s_converter.Add(typeof(CultureInfo), RehydrateCultureInfo);
            s_converter.Add(typeof(ParameterSetMetadata), RehydrateParameterSetMetadata);

            s_converter.Add(typeof(System.Security.Cryptography.X509Certificates.X509Certificate2), RehydrateX509Certificate2);
            s_converter.Add(typeof(System.Security.Cryptography.X509Certificates.X500DistinguishedName), RehydrateX500DistinguishedName);
            s_converter.Add(typeof(System.Net.IPAddress), RehydrateIPAddress);

            s_converter.Add(typeof(MailAddress), RehydrateMailAddress);

            s_converter.Add(typeof(System.Security.AccessControl.DirectorySecurity), RehydrateObjectSecurity<System.Security.AccessControl.DirectorySecurity>);
            s_converter.Add(typeof(System.Security.AccessControl.FileSecurity), RehydrateObjectSecurity<System.Security.AccessControl.FileSecurity>);
            s_converter.Add(typeof(System.Security.AccessControl.RegistrySecurity), RehydrateObjectSecurity<System.Security.AccessControl.RegistrySecurity>);

            s_converter.Add(typeof(ExtendedTypeDefinition), RehydrateExtendedTypeDefinition);
            s_converter.Add(typeof(FormatViewDefinition), RehydrateFormatViewDefinition);
            s_converter.Add(typeof(PSControl), RehydratePSControl);
            s_converter.Add(typeof(PSControlGroupBy), RehydrateGroupBy);
            s_converter.Add(typeof(DisplayEntry), RehydrateDisplayEntry);
            s_converter.Add(typeof(EntrySelectedBy), RehydrateEntrySelectedBy);
            s_converter.Add(typeof(TableControlColumnHeader), RehydrateTableControlColumnHeader);
            s_converter.Add(typeof(TableControlRow), RehydrateTableControlRow);
            s_converter.Add(typeof(TableControlColumn), RehydrateTableControlColumn);
            s_converter.Add(typeof(ListControlEntry), RehydrateListControlEntry);
            s_converter.Add(typeof(ListControlEntryItem), RehydrateListControlEntryItem);
            s_converter.Add(typeof(WideControlEntryItem), RehydrateWideControlEntryItem);
            s_converter.Add(typeof(CustomControlEntry), RehydrateCustomControlEntry);
            s_converter.Add(typeof(CustomItemBase), RehydrateCustomItemBase);

            s_converter.Add(typeof(CompletionResult), RehydrateCompletionResult);
            s_converter.Add(typeof(ModuleSpecification), RehydrateModuleSpecification);
            s_converter.Add(typeof(CommandCompletion), RehydrateCommandCompletion);
            s_converter.Add(typeof(JobStateInfo), RehydrateJobStateInfo);
            s_converter.Add(typeof(JobStateEventArgs), RehydrateJobStateEventArgs);
            s_converter.Add(typeof(PSSessionOption), RehydratePSSessionOption);
            s_converter.Add(typeof(LineBreakpoint), RehydrateLineBreakpoint);
            s_converter.Add(typeof(CommandBreakpoint), RehydrateCommandBreakpoint);
            s_converter.Add(typeof(VariableBreakpoint), RehydrateVariableBreakpoint);
            s_converter.Add(typeof(BreakpointUpdatedEventArgs), RehydrateBreakpointUpdatedEventArgs);
            s_converter.Add(typeof(DebuggerCommand), RehydrateDebuggerCommand);
            s_converter.Add(typeof(DebuggerCommandResults), RehydrateDebuggerCommandResults);
            s_converter.Add(typeof(DebuggerStopEventArgs), RehydrateDebuggerStopEventArgs);
        }

        /// <summary>
        /// Determines if the converter can convert the <paramref name="sourceValue"/> parameter to the <paramref name="destinationType"/> parameter.
        /// </summary>
        /// <param name="sourceValue">The value to convert from.</param>
        /// <param name="destinationType">The type to convert to.</param>
        /// <returns>True if the converter can convert the <paramref name="sourceValue"/> parameter to the <paramref name="destinationType"/> parameter, otherwise false.</returns>
        public override bool CanConvertFrom(PSObject sourceValue, Type destinationType)
        {
            foreach (Type type in s_converter.Keys)
            {
                if (Deserializer.IsDeserializedInstanceOfType(sourceValue, type))
                {
                    return true;
                }
            }

            return false;
        }

        /// <summary>
        /// Converts the <paramref name="sourceValue"/> parameter to the <paramref name="destinationType"/> parameter using formatProvider and ignoreCase.
        /// </summary>
        /// <param name="sourceValue">The value to convert from.</param>
        /// <param name="destinationType">The type to convert to.</param>
        /// <param name="formatProvider">The format provider to use like in IFormattable's ToString.</param>
        /// <param name="ignoreCase">True if case should be ignored.</param>
        /// <returns>The <paramref name="sourceValue"/> parameter converted to the <paramref name="destinationType"/> parameter using formatProvider and ignoreCase.</returns>
        /// <exception cref="InvalidCastException">If no conversion was possible.</exception>
        public override object ConvertFrom(PSObject sourceValue, Type destinationType, IFormatProvider formatProvider, bool ignoreCase)
        {
            if (destinationType == null)
            {
                throw PSTraceSource.NewArgumentNullException(nameof(destinationType));
            }

            if (sourceValue == null)
            {
                throw new PSInvalidCastException(
                    "InvalidCastWhenRehydratingFromNull",
                    PSTraceSource.NewArgumentNullException(nameof(sourceValue)),
                    ExtendedTypeSystem.InvalidCastFromNull,
                    destinationType.ToString());
            }

            foreach (KeyValuePair<Type, Func<PSObject, object>> item in s_converter)
            {
                Type type = item.Key;
                Func<PSObject, object> typeConverter = item.Value;
                if (Deserializer.IsDeserializedInstanceOfType(sourceValue, type))
                {
                    return ConvertFrom(sourceValue, typeConverter);
                }
            }

            throw new PSInvalidCastException(
                "InvalidCastEnumFromTypeNotAString",
                null,
                ExtendedTypeSystem.InvalidCastException,
                sourceValue,
                typeof(PSObject),
                destinationType);
        }

        private static object ConvertFrom(PSObject o, Func<PSObject, object> converter)
        {
            // rehydrate
            PSObject dso = o;
            object rehydratedObject = converter(dso);

            // re-add instance properties
            // (dso.InstanceMembers includes both instance and *type table* properties;
            //  therefore this will also re-add type table properties if they are not present when the deserializer runs;
            //  this is ok)
            bool returnPSObject = false;
            PSObject rehydratedPSObject = PSObject.AsPSObject(rehydratedObject);
            foreach (PSMemberInfo member in dso.InstanceMembers)
            {
                if (member.MemberType == (member.MemberType & (PSMemberTypes.Properties | PSMemberTypes.MemberSet | PSMemberTypes.PropertySet)))
                {
                    if (rehydratedPSObject.Members[member.Name] == null)
                    {
                        rehydratedPSObject.InstanceMembers.Add(member);
                        returnPSObject = true;
                    }
                }
            }

            if (returnPSObject)
            {
                return rehydratedPSObject;
            }
            else
            {
                return rehydratedObject;
            }
        }

        /// <summary>
        /// Returns true if the converter can convert the <paramref name="sourceValue"/> parameter to the <paramref name="destinationType"/> parameter.
        /// </summary>
        /// <param name="sourceValue">The value to convert from.</param>
        /// <param name="destinationType">The type to convert to.</param>
        /// <returns>True if the converter can convert the <paramref name="sourceValue"/> parameter to the <paramref name="destinationType"/> parameter, otherwise false.</returns>
        public override bool CanConvertTo(object sourceValue, Type destinationType)
        {
            return false;
        }

        /// <summary>
        /// Converts the <paramref name="sourceValue"/> parameter to the <paramref name="destinationType"/> parameter using formatProvider and ignoreCase.
        /// </summary>
        /// <param name="sourceValue">The value to convert from.</param>
        /// <param name="destinationType">The type to convert to.</param>
        /// <param name="formatProvider">The format provider to use like in IFormattable's ToString.</param>
        /// <param name="ignoreCase">True if case should be ignored.</param>
        /// <returns>SourceValue converted to the <paramref name="destinationType"/> parameter using formatProvider and ignoreCase.</returns>
        /// <exception cref="InvalidCastException">If no conversion was possible.</exception>
        public override object ConvertTo(object sourceValue, Type destinationType, IFormatProvider formatProvider, bool ignoreCase)
        {
            throw PSTraceSource.NewNotSupportedException();
        }

        /// <summary>
        /// This method is not implemented - an overload taking a PSObject is implemented instead.
        /// </summary>
        public override bool CanConvertFrom(object sourceValue, Type destinationType)
        {
            throw new NotImplementedException();
        }

        /// <summary>
        /// This method is not implemented - an overload taking a PSObject is implemented instead.
        /// </summary>
        public override bool CanConvertTo(PSObject sourceValue, Type destinationType)
        {
            throw new NotImplementedException();
        }

        /// <summary>
        /// This method is not implemented - an overload taking a PSObject is implemented instead.
        /// </summary>
        public override object ConvertFrom(object sourceValue, Type destinationType, IFormatProvider formatProvider, bool ignoreCase)
        {
            throw new NotImplementedException();
        }

        /// <summary>
        /// This method is not implemented - an overload taking a PSObject is implemented instead.
        /// </summary>
        public override object ConvertTo(PSObject sourceValue, Type destinationType, IFormatProvider formatProvider, bool ignoreCase)
        {
            throw new NotImplementedException();
        }

        #endregion

        #region Rehydration helpers

        [Flags]
        internal enum RehydrationFlags
        {
            NullValueBad = 0,
            NullValueOk = 0x1,
            NullValueMeansEmptyList = 0x3,

            MissingPropertyBad = 0,
            MissingPropertyOk = 0x4,
        }

        /// <summary>
        /// Gets value of a property (has to be present, value has to be non-null).
        /// Can throw any exception (which is ok - LanguagePrimitives.ConvertTo will catch that).
        /// </summary>
        /// <typeparam name="T">Expected type of the property</typeparam>
        /// <param name="pso">Deserialized object.</param>
        /// <param name="propertyName">Property name.</param>
        /// <returns></returns>
        private static T GetPropertyValue<T>(PSObject pso, string propertyName)
        {
            return GetPropertyValue<T>(pso, propertyName, RehydrationFlags.NullValueBad | RehydrationFlags.MissingPropertyBad);
        }

        /// <summary>
        /// Gets value of a property.  Can throw any exception (which is ok - LanguagePrimitives.ConvertTo will catch that).
        /// </summary>
        /// <typeparam name="T">Expected type of the property</typeparam>
        /// <param name="pso">Deserialized object.</param>
        /// <param name="propertyName">Property name.</param>
        /// <param name="flags"></param>
        /// <returns></returns>
        internal static T GetPropertyValue<T>(PSObject pso, string propertyName, RehydrationFlags flags)
        {
            Dbg.Assert(pso != null, "Caller should verify pso != null");
            Dbg.Assert(!string.IsNullOrEmpty(propertyName), "Caller should verify propertyName != null");

            PSPropertyInfo property = pso.Properties[propertyName];
            if ((property == null) && ((flags & RehydrationFlags.MissingPropertyOk) == RehydrationFlags.MissingPropertyOk))
            {
                return default(T);
            }
            else
            {
                object propertyValue = property.Value;
                if ((propertyValue == null) && ((flags & RehydrationFlags.NullValueOk) == RehydrationFlags.NullValueOk))
                {
                    return default(T);
                }
                else
                {
                    T t = (T)LanguagePrimitives.ConvertTo(propertyValue, typeof(T), CultureInfo.InvariantCulture);
                    return t;
                }
            }
        }

        private static TList RehydrateList<TList, TItem>(PSObject pso, string propertyName, RehydrationFlags flags)
            where TList : IList, new()
        {
            ArrayList deserializedList = GetPropertyValue<ArrayList>(pso, propertyName, flags);
            if (deserializedList == null)
            {
                if ((flags & RehydrationFlags.NullValueMeansEmptyList) == RehydrationFlags.NullValueMeansEmptyList)
                {
                    return new TList();
                }
                else
                {
                    return default(TList);
                }
            }
            else
            {
                TList newList = new TList();
                foreach (object deserializedItem in deserializedList)
                {
                    TItem item = (TItem)LanguagePrimitives.ConvertTo(deserializedItem, typeof(TItem), CultureInfo.InvariantCulture);
                    newList.Add(item);
                }

                return newList;
            }
        }

        #endregion

        #region Rehydration of miscellaneous types

        private static object RehydratePrimitiveHashtable(PSObject pso)
        {
            Hashtable hashtable = (Hashtable)LanguagePrimitives.ConvertTo(pso, typeof(Hashtable), CultureInfo.InvariantCulture);
            return new PSPrimitiveDictionary(hashtable);
        }

        private static object RehydrateSwitchParameter(PSObject pso)
        {
            return GetPropertyValue<SwitchParameter>(pso, "IsPresent");
        }

        private static CultureInfo RehydrateCultureInfo(PSObject pso)
        {
            string s = pso.ToString();
            return new CultureInfo(s);
        }

        private static PSListModifier RehydratePSListModifier(PSObject pso)
        {
            Hashtable h = new Hashtable();

            PSPropertyInfo addProperty = pso.Properties[PSListModifier.AddKey];
            if ((addProperty != null) && (addProperty.Value != null))
            {
                h.Add(PSListModifier.AddKey, addProperty.Value);
            }

            PSPropertyInfo removeProperty = pso.Properties[PSListModifier.RemoveKey];
            if ((removeProperty != null) && (removeProperty.Value != null))
            {
                h.Add(PSListModifier.RemoveKey, removeProperty.Value);
            }

            PSPropertyInfo replaceProperty = pso.Properties[PSListModifier.ReplaceKey];
            if ((replaceProperty != null) && (replaceProperty.Value != null))
            {
                h.Add(PSListModifier.ReplaceKey, replaceProperty.Value);
            }

            return new PSListModifier(h);
        }

        private static CompletionResult RehydrateCompletionResult(PSObject pso)
        {
            string completionText = GetPropertyValue<string>(pso, "CompletionText");
            string listItemText = GetPropertyValue<string>(pso, "ListItemText");
            string toolTip = GetPropertyValue<string>(pso, "ToolTip");
            CompletionResultType resultType = GetPropertyValue<CompletionResultType>(pso, "ResultType");

            return new CompletionResult(completionText, listItemText, resultType, toolTip);
        }

        private static ModuleSpecification RehydrateModuleSpecification(PSObject pso)
        {
            return new ModuleSpecification
            {
                Name = GetPropertyValue<string>(pso, "Name"),
                Guid = GetPropertyValue<Guid?>(pso, "Guid"),
                Version = GetPropertyValue<Version>(pso, "Version"),
                MaximumVersion = GetPropertyValue<string>(pso, "MaximumVersion"),
                RequiredVersion =
                                                    GetPropertyValue<Version>(pso, "RequiredVersion")
            };
        }

        private static CommandCompletion RehydrateCommandCompletion(PSObject pso)
        {
            var completions = new Collection<CompletionResult>();
            foreach (var match in GetPropertyValue<ArrayList>(pso, "CompletionMatches"))
            {
                completions.Add((CompletionResult)match);
            }

            var currentMatchIndex = GetPropertyValue<int>(pso, "CurrentMatchIndex");
            var replacementIndex = GetPropertyValue<int>(pso, "ReplacementIndex");
            var replacementLength = GetPropertyValue<int>(pso, "ReplacementLength");
            return new CommandCompletion(completions, currentMatchIndex, replacementIndex, replacementLength);
        }

        private static JobStateInfo RehydrateJobStateInfo(PSObject pso)
        {
            var jobState = GetPropertyValue<JobState>(pso, "State");

            Exception reason = null;
            object propertyValue = null;
            PSPropertyInfo property = pso.Properties["Reason"];
            string message = string.Empty;

            if (property != null)
            {
                propertyValue = property.Value;
            }

            if (propertyValue != null)
            {
                if (Deserializer.IsDeserializedInstanceOfType(propertyValue, typeof(Exception)))
                {
                    // if we have a deserialized remote or any other exception, use its message to construct
                    // an exception
                    message = PSObject.AsPSObject(propertyValue).Properties["Message"].Value as string;
                }
                else if (propertyValue is Exception)
                {
                    reason = (Exception)propertyValue;
                }
                else
                {
                    message = propertyValue.ToString();
                }

                if (!string.IsNullOrEmpty(message))
                {
                    try
                    {
                        reason = (Exception)LanguagePrimitives.ConvertTo(message, typeof(Exception), CultureInfo.InvariantCulture);
                    }
                    catch (Exception)
                    {
                        // it is ok to eat this exception since we do not want
                        // rehydration to fail
                        reason = null;
                    }
                }
            }

            return new JobStateInfo(jobState, reason);
        }

        internal static JobStateEventArgs RehydrateJobStateEventArgs(PSObject pso)
        {
            var jobStateInfo = RehydrateJobStateInfo(PSObject.AsPSObject(pso.Properties["JobStateInfo"].Value));
            JobStateInfo previousJobStateInfo = null;
            var previousJobStateInfoProperty = pso.Properties["PreviousJobStateInfo"];

            if (previousJobStateInfoProperty != null && previousJobStateInfoProperty.Value != null)
            {
                previousJobStateInfo = RehydrateJobStateInfo(PSObject.AsPSObject(previousJobStateInfoProperty.Value));
            }

            return new JobStateEventArgs(jobStateInfo, previousJobStateInfo);
        }

        internal static PSSessionOption RehydratePSSessionOption(PSObject pso)
        {
            PSSessionOption option = new PSSessionOption();

            option.ApplicationArguments = GetPropertyValue<PSPrimitiveDictionary>(pso, "ApplicationArguments");
            option.CancelTimeout = GetPropertyValue<TimeSpan>(pso, "CancelTimeout");
            option.Culture = GetPropertyValue<CultureInfo>(pso, "Culture");
            option.IdleTimeout = GetPropertyValue<TimeSpan>(pso, "IdleTimeout");
            option.MaximumConnectionRedirectionCount = GetPropertyValue<int>(pso, "MaximumConnectionRedirectionCount");
            option.MaximumReceivedDataSizePerCommand = GetPropertyValue<int?>(pso, "MaximumReceivedDataSizePerCommand");
            option.MaximumReceivedObjectSize = GetPropertyValue<int?>(pso, "MaximumReceivedObjectSize");
            option.NoCompression = GetPropertyValue<bool>(pso, "NoCompression");
            option.NoEncryption = GetPropertyValue<bool>(pso, "NoEncryption");
            option.NoMachineProfile = GetPropertyValue<bool>(pso, "NoMachineProfile");
            option.OpenTimeout = GetPropertyValue<TimeSpan>(pso, "OpenTimeout");
            option.OperationTimeout = GetPropertyValue<TimeSpan>(pso, "OperationTimeout");
            option.OutputBufferingMode = GetPropertyValue<OutputBufferingMode>(pso, "OutputBufferingMode");
            option.MaxConnectionRetryCount = GetPropertyValue<int>(pso, "MaxConnectionRetryCount");
            option.ProxyAccessType = GetPropertyValue<ProxyAccessType>(pso, "ProxyAccessType");
            option.ProxyAuthentication = GetPropertyValue<AuthenticationMechanism>(pso, "ProxyAuthentication");
            option.ProxyCredential = GetPropertyValue<PSCredential>(pso, "ProxyCredential");
            option.SkipCACheck = GetPropertyValue<bool>(pso, "SkipCACheck");
            option.SkipCNCheck = GetPropertyValue<bool>(pso, "SkipCNCheck");
            option.SkipRevocationCheck = GetPropertyValue<bool>(pso, "SkipRevocationCheck");
            option.UICulture = GetPropertyValue<CultureInfo>(pso, "UICulture");
            option.UseUTF16 = GetPropertyValue<bool>(pso, "UseUTF16");
            option.IncludePortInSPN = GetPropertyValue<bool>(pso, "IncludePortInSPN");

            return option;
        }

        internal static LineBreakpoint RehydrateLineBreakpoint(PSObject pso)
        {
            string script = GetPropertyValue<string>(pso, "Script");
            int line = GetPropertyValue<int>(pso, "Line");
            int column = GetPropertyValue<int>(pso, "Column");
            int id = GetPropertyValue<int>(pso, "Id");
            bool enabled = GetPropertyValue<bool>(pso, "Enabled");
            ScriptBlock action = RehydrateScriptBlock(
                GetPropertyValue<string>(pso, "Action", RehydrationFlags.MissingPropertyOk));

            var bp = new LineBreakpoint(script, line, column, action, id);
            bp.SetEnabled(enabled);
            return bp;
        }

        internal static CommandBreakpoint RehydrateCommandBreakpoint(PSObject pso)
        {
            string script = GetPropertyValue<string>(pso, "Script", RehydrationFlags.MissingPropertyOk | RehydrationFlags.NullValueOk);
            string command = GetPropertyValue<string>(pso, "Command");
            int id = GetPropertyValue<int>(pso, "Id");
            bool enabled = GetPropertyValue<bool>(pso, "Enabled");
            WildcardPattern pattern = WildcardPattern.Get(command, WildcardOptions.Compiled | WildcardOptions.IgnoreCase);
            ScriptBlock action = RehydrateScriptBlock(
                GetPropertyValue<string>(pso, "Action", RehydrationFlags.MissingPropertyOk));

            var bp = new CommandBreakpoint(script, pattern, command, action, id);
            bp.SetEnabled(enabled);
            return bp;
        }

        internal static VariableBreakpoint RehydrateVariableBreakpoint(PSObject pso)
        {
            string script = GetPropertyValue<string>(pso, "Script", RehydrationFlags.MissingPropertyOk | RehydrationFlags.NullValueOk);
            string variableName = GetPropertyValue<string>(pso, "Variable");
            int id = GetPropertyValue<int>(pso, "Id");
            bool enabled = GetPropertyValue<bool>(pso, "Enabled");
            VariableAccessMode access = GetPropertyValue<VariableAccessMode>(pso, "AccessMode");
            ScriptBlock action = RehydrateScriptBlock(
                GetPropertyValue<string>(pso, "Action", RehydrationFlags.MissingPropertyOk));

            var bp = new VariableBreakpoint(script, variableName, access, action, id);
            bp.SetEnabled(enabled);
            return bp;
        }

        internal static BreakpointUpdatedEventArgs RehydrateBreakpointUpdatedEventArgs(PSObject pso)
        {
            Breakpoint bp = GetPropertyValue<Breakpoint>(pso, "Breakpoint");
            BreakpointUpdateType bpUpdateType = GetPropertyValue<BreakpointUpdateType>(pso, "UpdateType");
            int bpCount = GetPropertyValue<int>(pso, "BreakpointCount");

            return new BreakpointUpdatedEventArgs(bp, bpUpdateType, bpCount);
        }

        internal static DebuggerCommand RehydrateDebuggerCommand(PSObject pso)
        {
            string command = GetPropertyValue<string>(pso, "Command");
            bool repeatOnEnter = GetPropertyValue<bool>(pso, "RepeatOnEnter");
            bool executedByDebugger = GetPropertyValue<bool>(pso, "ExecutedByDebugger");
            DebuggerResumeAction? resumeAction = GetPropertyValue<DebuggerResumeAction?>(pso, "ResumeAction", RehydrationFlags.NullValueOk);

            return new DebuggerCommand(command, resumeAction, repeatOnEnter, executedByDebugger);
        }

        internal static DebuggerCommandResults RehydrateDebuggerCommandResults(PSObject pso)
        {
            DebuggerResumeAction? resumeAction = GetPropertyValue<DebuggerResumeAction?>(pso, "ResumeAction", RehydrationFlags.NullValueOk);
            bool evaluatedByDebugger = GetPropertyValue<bool>(pso, "EvaluatedByDebugger");

            return new DebuggerCommandResults(resumeAction, evaluatedByDebugger);
        }

        internal static DebuggerStopEventArgs RehydrateDebuggerStopEventArgs(PSObject pso)
        {
            PSObject psoInvocationInfo = GetPropertyValue<PSObject>(pso, "SerializedInvocationInfo", RehydrationFlags.NullValueOk | RehydrationFlags.MissingPropertyOk);
            InvocationInfo invocationInfo = (psoInvocationInfo != null) ? new InvocationInfo(psoInvocationInfo) : null;
            DebuggerResumeAction resumeAction = GetPropertyValue<DebuggerResumeAction>(pso, "ResumeAction");
            Collection<Breakpoint> breakpoints = new Collection<Breakpoint>();
            foreach (var item in GetPropertyValue<ArrayList>(pso, "Breakpoints"))
            {
                Breakpoint bp = item as Breakpoint;
                if (bp != null)
                {
                    breakpoints.Add(bp);
                }
            }

            return new DebuggerStopEventArgs(invocationInfo, breakpoints, resumeAction);
        }

        private static ScriptBlock RehydrateScriptBlock(string script)
        {
            if (!string.IsNullOrEmpty(script))
            {
                return ScriptBlock.Create(script);
            }

            return null;
        }

        #endregion

        #region Rehydration of security-related types

        private static PSCredential RehydratePSCredential(PSObject pso)
        {
            string userName = GetPropertyValue<string>(pso, "UserName");
            System.Security.SecureString password = GetPropertyValue<System.Security.SecureString>(pso, "Password");

            if (string.IsNullOrEmpty(userName))
            {
                return PSCredential.Empty;
            }
            else
            {
                return new PSCredential(userName, password);
            }
        }

        internal static PSSenderInfo RehydratePSSenderInfo(PSObject pso)
        {
            PSObject userInfo = GetPropertyValue<PSObject>(pso, "UserInfo");
            PSObject userIdentity = GetPropertyValue<PSObject>(userInfo, "Identity");
            PSObject certDetails = GetPropertyValue<PSObject>(userIdentity, "CertificateDetails");

            PSCertificateDetails psCertDetails = certDetails == null ? null : new PSCertificateDetails(
                GetPropertyValue<string>(certDetails, "Subject"),
                GetPropertyValue<string>(certDetails, "IssuerName"),
                GetPropertyValue<string>(certDetails, "IssuerThumbprint"));
            PSIdentity psIdentity = new PSIdentity(
                GetPropertyValue<string>(userIdentity, "AuthenticationType"),
                GetPropertyValue<bool>(userIdentity, "IsAuthenticated"),
                GetPropertyValue<string>(userIdentity, "Name"),
                psCertDetails);
            PSPrincipal psPrincipal = new PSPrincipal(psIdentity, WindowsIdentity.GetCurrent());

            PSSenderInfo senderInfo = new PSSenderInfo(psPrincipal, GetPropertyValue<string>(pso, "ConnectionString"));

            senderInfo.ClientTimeZone = TimeZoneInfo.Local;
            senderInfo.ApplicationArguments = GetPropertyValue<PSPrimitiveDictionary>(pso, "ApplicationArguments");

            return senderInfo;
        }

        private static System.Security.Cryptography.X509Certificates.X509Certificate2 RehydrateX509Certificate2(PSObject pso)
        {
            byte[] rawData = GetPropertyValue<byte[]>(pso, "RawData");
            return new System.Security.Cryptography.X509Certificates.X509Certificate2(rawData);
        }

        private static System.Security.Cryptography.X509Certificates.X500DistinguishedName RehydrateX500DistinguishedName(PSObject pso)
        {
            byte[] rawData = GetPropertyValue<byte[]>(pso, "RawData");
            return new System.Security.Cryptography.X509Certificates.X500DistinguishedName(rawData);
        }

        private static System.Net.IPAddress RehydrateIPAddress(PSObject pso)
        {
            string s = pso.ToString();
            return System.Net.IPAddress.Parse(s);
        }

        private static MailAddress RehydrateMailAddress(PSObject pso)
        {
            string s = pso.ToString();
            return new MailAddress(s);
        }

        private static T RehydrateObjectSecurity<T>(PSObject pso)
            where T : System.Security.AccessControl.ObjectSecurity, new()
        {
            string sddl = GetPropertyValue<string>(pso, "SDDL");

            T t = new T();
            t.SetSecurityDescriptorSddlForm(sddl);
            return t;
        }

        #endregion

        #region Rehydration of types needed by implicit remoting

        /// <summary>
        /// Gets the boolean properties of ParameterSetMetadata object encoded as an integer.
        /// </summary>
        /// <param name="instance">
        /// The PSObject for which to obtain the flags
        /// </param>
        /// <returns>
        /// Boolean properties of ParameterSetMetadata object encoded as an integer
        /// </returns>
        public static UInt32 GetParameterSetMetadataFlags(PSObject instance)
        {
            if (instance == null)
            {
                throw PSTraceSource.NewArgumentNullException(nameof(instance));
            }

            if (!(instance.BaseObject is ParameterSetMetadata parameterSetMetadata))
            {
                throw PSTraceSource.NewArgumentNullException(nameof(instance));
            }

            return (UInt32)(parameterSetMetadata.Flags);
        }

        /// <summary>
        /// Gets the full remoting serialized PSObject for the InvocationInfo property
        /// of the DebuggerStopEventArgs type.
        /// </summary>
        /// <param name="instance">InvocationInfo instance.</param>
        /// <returns>PSObject containing serialized InvocationInfo.</returns>
        public static PSObject GetInvocationInfo(PSObject instance)
        {
            if (instance == null)
            {
                throw PSTraceSource.NewArgumentNullException(nameof(instance));
            }

            if (!(instance.BaseObject is DebuggerStopEventArgs dbgStopEventArgs))
            {
                throw PSTraceSource.NewArgumentNullException(nameof(instance));
            }

            if (dbgStopEventArgs.InvocationInfo == null)
            {
                return null;
            }

            PSObject psoInvocationInfo = new PSObject();
            dbgStopEventArgs.InvocationInfo.ToPSObjectForRemoting(psoInvocationInfo);
            return psoInvocationInfo;
        }

        private static ParameterSetMetadata RehydrateParameterSetMetadata(PSObject pso)
        {
            int position = GetPropertyValue<int>(pso, "Position");
            UInt32 flags = GetPropertyValue<UInt32>(pso, "Flags");
            string helpMessage = GetPropertyValue<string>(pso, "HelpMessage");
            return new ParameterSetMetadata(position, (ParameterSetMetadata.ParameterFlags)flags, helpMessage);
        }

        private static DisplayEntry RehydrateDisplayEntry(PSObject deserializedDisplayEntry)
        {
            var result = new DisplayEntry
            {
                Value = GetPropertyValue<string>(deserializedDisplayEntry, "Value"),
                ValueType = GetPropertyValue<DisplayEntryValueType>(deserializedDisplayEntry, "ValueType")
            };
            return result;
        }

        private static EntrySelectedBy RehydrateEntrySelectedBy(PSObject deserializedEsb)
        {
            var result = new EntrySelectedBy
            {
                TypeNames = RehydrateList<List<string>, string>(deserializedEsb, "TypeNames", RehydrationFlags.MissingPropertyOk),
                SelectionCondition = RehydrateList<List<DisplayEntry>, DisplayEntry>(deserializedEsb, "SelectionCondition", RehydrationFlags.MissingPropertyOk)
            };
            return result;
        }

        private static WideControlEntryItem RehydrateWideControlEntryItem(PSObject deserializedEntryItem)
        {
            var entrySelectedBy = GetPropertyValue<EntrySelectedBy>(deserializedEntryItem, "EntrySelectedBy", RehydrationFlags.MissingPropertyOk);
            if (entrySelectedBy == null)
            {
                var selectedBy = RehydrateList<List<string>, string>(deserializedEntryItem, "SelectedBy", RehydrationFlags.MissingPropertyOk);
                entrySelectedBy = EntrySelectedBy.Get(selectedBy, null);
            }

            var result = new WideControlEntryItem
            {
                DisplayEntry = GetPropertyValue<DisplayEntry>(deserializedEntryItem, "DisplayEntry"),
                EntrySelectedBy = entrySelectedBy,
                FormatString = GetPropertyValue<string>(deserializedEntryItem, "FormatString", RehydrationFlags.MissingPropertyOk),
            };
            return result;
        }

        private static ListControlEntryItem RehydrateListControlEntryItem(PSObject deserializedEntryItem)
        {
            var result = new ListControlEntryItem
            {
                DisplayEntry = GetPropertyValue<DisplayEntry>(deserializedEntryItem, "DisplayEntry"),
                ItemSelectionCondition = GetPropertyValue<DisplayEntry>(deserializedEntryItem, "ItemSelectionCondition", RehydrationFlags.MissingPropertyOk),
                FormatString = GetPropertyValue<string>(deserializedEntryItem, "FormatString", RehydrationFlags.MissingPropertyOk),
                Label = GetPropertyValue<string>(deserializedEntryItem, "Label", RehydrationFlags.NullValueOk)
            };
            return result;
        }

        private static ListControlEntry RehydrateListControlEntry(PSObject deserializedEntry)
        {
            var entrySelectedBy = GetPropertyValue<EntrySelectedBy>(deserializedEntry, "EntrySelectedBy", RehydrationFlags.MissingPropertyOk);
            if (entrySelectedBy == null)
            {
                var selectedBy = RehydrateList<List<string>, string>(deserializedEntry, "SelectedBy", RehydrationFlags.MissingPropertyOk);
                entrySelectedBy = EntrySelectedBy.Get(selectedBy, null);
            }

            var result = new ListControlEntry
            {
                Items = RehydrateList<List<ListControlEntryItem>, ListControlEntryItem>(deserializedEntry, "Items", RehydrationFlags.NullValueBad),
                EntrySelectedBy = entrySelectedBy
            };
            return result;
        }

        private static TableControlColumnHeader RehydrateTableControlColumnHeader(PSObject deserializedHeader)
        {
            var result = new TableControlColumnHeader
            {
                Alignment = GetPropertyValue<Alignment>(deserializedHeader, "Alignment"),
                Label = GetPropertyValue<string>(deserializedHeader, "Label", RehydrationFlags.NullValueOk),
                Width = GetPropertyValue<int>(deserializedHeader, "Width")
            };
            return result;
        }

        private static TableControlColumn RehydrateTableControlColumn(PSObject deserializedColumn)
        {
            var result = new TableControlColumn
            {
                Alignment = GetPropertyValue<Alignment>(deserializedColumn, "Alignment"),
                DisplayEntry = GetPropertyValue<DisplayEntry>(deserializedColumn, "DisplayEntry"),
                FormatString = GetPropertyValue<string>(deserializedColumn, "FormatString", RehydrationFlags.MissingPropertyOk)
            };
            return result;
        }

        private static TableControlRow RehydrateTableControlRow(PSObject deserializedRow)
        {
            var result = new TableControlRow
            {
                Wrap = GetPropertyValue<bool>(deserializedRow, "Wrap", RehydrationFlags.MissingPropertyOk),
                SelectedBy = GetPropertyValue<EntrySelectedBy>(deserializedRow, "EntrySelectedBy", RehydrationFlags.MissingPropertyOk),
                Columns = RehydrateList<List<TableControlColumn>, TableControlColumn>(deserializedRow, "Columns", RehydrationFlags.NullValueBad)
            };
            return result;
        }

        private static CustomControlEntry RehydrateCustomControlEntry(PSObject deserializedEntry)
        {
            var result = new CustomControlEntry
            {
                CustomItems = RehydrateList<List<CustomItemBase>, CustomItemBase>(deserializedEntry, "CustomItems", RehydrationFlags.MissingPropertyBad),
                SelectedBy = GetPropertyValue<EntrySelectedBy>(deserializedEntry, "SelectedBy", RehydrationFlags.MissingPropertyOk)
            };
            return result;
        }

        private static CustomItemBase RehydrateCustomItemBase(PSObject deserializedItem)
        {
            CustomItemBase result;

            if (Deserializer.IsDeserializedInstanceOfType(deserializedItem, typeof(CustomItemNewline)))
            {
                result = new CustomItemNewline
                {
                    Count = GetPropertyValue<int>(deserializedItem, "Count", RehydrationFlags.MissingPropertyBad)
                };
            }
            else if (Deserializer.IsDeserializedInstanceOfType(deserializedItem, typeof(CustomItemText)))
            {
                result = new CustomItemText
                {
                    Text = GetPropertyValue<string>(deserializedItem, "Text", RehydrationFlags.MissingPropertyBad)
                };
            }
            else if (Deserializer.IsDeserializedInstanceOfType(deserializedItem, typeof(CustomItemFrame)))
            {
                result = new CustomItemFrame
                {
                    FirstLineHanging = GetPropertyValue<uint>(deserializedItem, "FirstLineHanging"),
                    FirstLineIndent = GetPropertyValue<uint>(deserializedItem, "FirstLineIndent"),
                    RightIndent = GetPropertyValue<uint>(deserializedItem, "RightIndent"),
                    LeftIndent = GetPropertyValue<uint>(deserializedItem, "LeftIndent"),
                    CustomItems = RehydrateList<List<CustomItemBase>, CustomItemBase>(deserializedItem, "CustomItems", RehydrationFlags.MissingPropertyBad)
                };
            }
            else if (Deserializer.IsDeserializedInstanceOfType(deserializedItem, typeof(CustomItemExpression)))
            {
                result = new CustomItemExpression
                {
                    EnumerateCollection = GetPropertyValue<bool>(deserializedItem, "EnumerateCollection"),
                    CustomControl = GetPropertyValue<CustomControl>(deserializedItem, "CustomControl", RehydrationFlags.MissingPropertyOk),
                    Expression = GetPropertyValue<DisplayEntry>(deserializedItem, "Expression", RehydrationFlags.MissingPropertyOk),
                    ItemSelectionCondition = GetPropertyValue<DisplayEntry>(deserializedItem, "ItemSelectionCondition", RehydrationFlags.MissingPropertyOk)
                };
            }
            else
            {
                throw PSTraceSource.NewArgumentException(nameof(deserializedItem));
            }

            return result;
        }

        private static PSControl RehydratePSControl(PSObject deserializedControl)
        {
            // Earlier versions of PowerShell did not have all of the possible properties in a control, so we must
            // use MissingPropertyOk to allow for connections to those older endpoints.
            PSControl result;
            if (Deserializer.IsDeserializedInstanceOfType(deserializedControl, typeof(TableControl)))
            {
                var tableControl = new TableControl
                {
                    AutoSize = GetPropertyValue<bool>(deserializedControl, "AutoSize", RehydrationFlags.MissingPropertyOk),
                    HideTableHeaders = GetPropertyValue<bool>(deserializedControl, "HideTableHeaders", RehydrationFlags.MissingPropertyOk),
                    Headers = RehydrateList<List<TableControlColumnHeader>, TableControlColumnHeader>(deserializedControl, "Headers", RehydrationFlags.NullValueBad),
                    Rows = RehydrateList<List<TableControlRow>, TableControlRow>(deserializedControl, "Rows", RehydrationFlags.NullValueBad)
                };
                result = tableControl;
            }
            else if (Deserializer.IsDeserializedInstanceOfType(deserializedControl, typeof(ListControl)))
            {
                var listControl = new ListControl
                {
                    Entries = RehydrateList<List<ListControlEntry>, ListControlEntry>(deserializedControl, "Entries", RehydrationFlags.NullValueBad)
                };
                result = listControl;
            }
            else if (Deserializer.IsDeserializedInstanceOfType(deserializedControl, typeof(WideControl)))
            {
                var wideControl = new WideControl
                {
                    AutoSize = GetPropertyValue<bool>(deserializedControl, "Alignment", RehydrationFlags.MissingPropertyOk),
                    Columns = GetPropertyValue<uint>(deserializedControl, "Columns"),
                    Entries = RehydrateList<List<WideControlEntryItem>, WideControlEntryItem>(deserializedControl, "Entries", RehydrationFlags.NullValueBad)
                };
                result = wideControl;
            }
            else if (Deserializer.IsDeserializedInstanceOfType(deserializedControl, typeof(CustomControl)))
            {
                var customControl = new CustomControl
                {
                    Entries = RehydrateList<List<CustomControlEntry>, CustomControlEntry>(deserializedControl, "Entries", RehydrationFlags.NullValueBad)
                };
                result = customControl;
            }
            else
            {
                throw PSTraceSource.NewArgumentException("pso");
            }

            result.GroupBy = GetPropertyValue<PSControlGroupBy>(deserializedControl, "GroupBy", RehydrationFlags.MissingPropertyOk);
            result.OutOfBand = GetPropertyValue<bool>(deserializedControl, "OutOfBand", RehydrationFlags.MissingPropertyOk);
            return result;
        }

        private static PSControlGroupBy RehydrateGroupBy(PSObject deserializedGroupBy)
        {
            var result = new PSControlGroupBy
            {
                CustomControl = GetPropertyValue<CustomControl>(deserializedGroupBy, "CustomControl", RehydrationFlags.MissingPropertyOk),
                Expression = GetPropertyValue<DisplayEntry>(deserializedGroupBy, "Expression", RehydrationFlags.MissingPropertyOk),
                Label = GetPropertyValue<string>(deserializedGroupBy, "Label", RehydrationFlags.NullValueOk)
            };
            return result;
        }

        /// <summary>
        /// Gets the boolean properties of ParameterSetMetadata object encoded as an integer.
        /// </summary>
        /// <param name="instance">
        /// The PSObject for which to obtain the flags
        /// </param>
        /// <returns>
        /// Boolean properties of ParameterSetMetadata object encoded as an integer
        /// </returns>
        public static Guid GetFormatViewDefinitionInstanceId(PSObject instance)
        {
            if (instance == null)
            {
                throw PSTraceSource.NewArgumentNullException(nameof(instance));
            }

            if (!(instance.BaseObject is FormatViewDefinition formatViewDefinition))
            {
                throw PSTraceSource.NewArgumentNullException(nameof(instance));
            }

            return formatViewDefinition.InstanceId;
        }

        private static FormatViewDefinition RehydrateFormatViewDefinition(PSObject deserializedViewDefinition)
        {
            string name = GetPropertyValue<string>(deserializedViewDefinition, "Name");
            Guid instanceId = GetPropertyValue<Guid>(deserializedViewDefinition, "InstanceId");
            PSControl control = GetPropertyValue<PSControl>(deserializedViewDefinition, "Control");

            return new FormatViewDefinition(name, control, instanceId);
        }

        private static ExtendedTypeDefinition RehydrateExtendedTypeDefinition(PSObject deserializedTypeDefinition)
        {
            // Prefer TypeNames to TypeName - as it was incorrect to create multiple ExtendedTypeDefinitions for a group of types.
            // But if a new PowerShell connects to an old endpoint, TypeNames will be missing, so fall back to TypeName in that case.
            string typeName;
            var typeNames = RehydrateList<List<string>, string>(deserializedTypeDefinition, "TypeNames", RehydrationFlags.MissingPropertyOk);
            if (typeNames == null || typeNames.Count == 0)
            {
                typeName = GetPropertyValue<string>(deserializedTypeDefinition, "TypeName");
            }
            else
            {
                typeName = typeNames[0];
            }

            List<FormatViewDefinition> viewDefinitions = RehydrateList<List<FormatViewDefinition>, FormatViewDefinition>(
                deserializedTypeDefinition,
                "FormatViewDefinition",
                RehydrationFlags.NullValueBad);

            var result = new ExtendedTypeDefinition(typeName, viewDefinitions);
            if (typeNames != null && typeNames.Count > 1)
            {
                for (var i = 1; i < typeNames.Count; i++)
                {
                    result.TypeNames.Add(typeNames[i]);
                }
            }

            return result;
        }

        #endregion
    }
}