# System.IO.Compression

``` diff
+namespace System.IO.Compression {
+    public enum CompressionLevel {
+        Fastest = 1,
+        NoCompression = 2,
+        Optimal = 0,
+    }
+    public enum CompressionMode {
+        Compress = 1,
+        Decompress = 0,
+    }
+    public class DeflateStream : Stream {
+        public DeflateStream(Stream stream, CompressionLevel compressionLevel);
+        public DeflateStream(Stream stream, CompressionLevel compressionLevel, bool leaveOpen);
+        public DeflateStream(Stream stream, CompressionMode mode);
+        public DeflateStream(Stream stream, CompressionMode mode, bool leaveOpen);
+        public Stream BaseStream { get; }
+        public override bool CanRead { get; }
+        public override bool CanSeek { get; }
+        public override bool CanWrite { get; }
+        public override long Length { get; }
+        public override long Position { get; set; }
+        protected override void Dispose(bool disposing);
+        public override void Flush();
+        public override int Read(byte[] array, int offset, int count);
+        public override Task<int> ReadAsync(byte[] array, int offset, int count, CancellationToken cancellationToken);
+        public override long Seek(long offset, SeekOrigin origin);
+        public override void SetLength(long value);
+        public override void Write(byte[] array, int offset, int count);
+        public override Task WriteAsync(byte[] array, int offset, int count, CancellationToken cancellationToken);
+    }
+    public class GZipStream : Stream {
+        public GZipStream(Stream stream, CompressionLevel compressionLevel);
+        public GZipStream(Stream stream, CompressionLevel compressionLevel, bool leaveOpen);
+        public GZipStream(Stream stream, CompressionMode mode);
+        public GZipStream(Stream stream, CompressionMode mode, bool leaveOpen);
+        public Stream BaseStream { get; }
+        public override bool CanRead { get; }
+        public override bool CanSeek { get; }
+        public override bool CanWrite { get; }
+        public override long Length { get; }
+        public override long Position { get; set; }
+        protected override void Dispose(bool disposing);
+        public override void Flush();
+        public override int Read(byte[] array, int offset, int count);
+        public override Task<int> ReadAsync(byte[] array, int offset, int count, CancellationToken cancellationToken);
+        public override long Seek(long offset, SeekOrigin origin);
+        public override void SetLength(long value);
+        public override void Write(byte[] array, int offset, int count);
+        public override Task WriteAsync(byte[] array, int offset, int count, CancellationToken cancellationToken);
+    }
+    public class ZipArchive : IDisposable {
+        public ZipArchive(Stream stream);
+        public ZipArchive(Stream stream, ZipArchiveMode mode);
+        public ZipArchive(Stream stream, ZipArchiveMode mode, bool leaveOpen);
+        public ZipArchive(Stream stream, ZipArchiveMode mode, bool leaveOpen, Encoding entryNameEncoding);
+        public ReadOnlyCollection<ZipArchiveEntry> Entries { get; }
+        public ZipArchiveMode Mode { get; }
+        public ZipArchiveEntry CreateEntry(string entryName);
+        public ZipArchiveEntry CreateEntry(string entryName, CompressionLevel compressionLevel);
+        public void Dispose();
+        protected virtual void Dispose(bool disposing);
+        public ZipArchiveEntry GetEntry(string entryName);
+    }
+    public class ZipArchiveEntry {
+        public ZipArchive Archive { get; }
+        public long CompressedLength { get; }
+        public string FullName { get; }
+        public DateTimeOffset LastWriteTime { get; set; }
+        public long Length { get; }
+        public string Name { get; }
+        public void Delete();
+        public Stream Open();
+        public override string ToString();
+    }
+    public enum ZipArchiveMode {
+        Create = 1,
+        Read = 0,
+        Update = 2,
+    }
+    public static class ZipFile {
+        public static void CreateFromDirectory(string sourceDirectoryName, string destinationArchiveFileName);
+        public static void CreateFromDirectory(string sourceDirectoryName, string destinationArchiveFileName, CompressionLevel compressionLevel, bool includeBaseDirectory);
+        public static void CreateFromDirectory(string sourceDirectoryName, string destinationArchiveFileName, CompressionLevel compressionLevel, bool includeBaseDirectory, Encoding entryNameEncoding);
+        public static void ExtractToDirectory(string sourceArchiveFileName, string destinationDirectoryName);
+        public static void ExtractToDirectory(string sourceArchiveFileName, string destinationDirectoryName, Encoding entryNameEncoding);
+        public static ZipArchive Open(string archiveFileName, ZipArchiveMode mode);
+        public static ZipArchive Open(string archiveFileName, ZipArchiveMode mode, Encoding entryNameEncoding);
+        public static ZipArchive OpenRead(string archiveFileName);
+    }
+    public static class ZipFileExtensions {
+        public static ZipArchiveEntry CreateEntryFromFile(this ZipArchive destination, string sourceFileName, string entryName);
+        public static ZipArchiveEntry CreateEntryFromFile(this ZipArchive destination, string sourceFileName, string entryName, CompressionLevel compressionLevel);
+        public static void ExtractToDirectory(this ZipArchive source, string destinationDirectoryName);
+        public static void ExtractToFile(this ZipArchiveEntry source, string destinationFileName);
+        public static void ExtractToFile(this ZipArchiveEntry source, string destinationFileName, bool overwrite);
+    }
+}
```