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construct/include/ircd/m/vm.h

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12 KiB
C++

// Matrix Construct
//
// Copyright (C) Matrix Construct Developers, Authors & Contributors
// Copyright (C) 2016-2018 Jason Volk <jason@zemos.net>
//
// Permission to use, copy, modify, and/or distribute this software for any
// purpose with or without fee is hereby granted, provided that the above
// copyright notice and this permission notice is present in all copies. The
// full license for this software is available in the LICENSE file.
#pragma once
#define HAVE_IRCD_M_VM_H
/// Matrix Virtual Machine
///
namespace ircd::m::vm
{
struct error; // custom exception
struct opts;
struct copts;
struct eval;
enum fault :uint;
using fault_t = std::underlying_type<fault>::type;
string_view reflect(const fault &);
http::code http_code(const fault &);
string_view loghead(const mutable_buffer &, const eval &);
string_view loghead(const eval &); // single tls buffer
extern const opts default_opts;
extern const copts default_copts;
extern log::log log;
extern ctx::dock dock;
extern bool ready;
}
namespace ircd::m::vm::sequence
{
extern ctx::dock dock;
extern uint64_t retired; // already written; always monotonic
extern uint64_t committed; // pending write; usually monotonic
extern uint64_t uncommitted; // evaluating; not monotonic
static size_t pending;
const uint64_t &get(const eval &);
uint64_t get(id::event::buf &); // [GET]
uint64_t max();
uint64_t min();
};
/// Event Evaluation Device
///
/// This object conducts the evaluation of an event or a tape of multiple
/// events. An event is evaluated in an attempt to execute it. Events which
/// fail during evaluation won't be executed; such is the case for events which
/// have already been executed, or events which are invalid or lead to invalid
/// transitions or actions of the machine etc.
///
struct ircd::m::vm::eval
:instance_list<eval>
{
static uint64_t id_ctr;
static uint executing;
static uint injecting;
static uint injecting_room;
const vm::opts *opts {&default_opts};
const vm::copts *copts {nullptr};
ctx::ctx *ctx {ctx::current};
uint64_t id {++id_ctr};
uint64_t sequence {0};
uint64_t sequence_shared[2] {0}; // min, max
std::shared_ptr<db::txn> txn;
const json::iov *issue {nullptr};
const event *event_ {nullptr};
json::array pdus;
string_view room_id;
event::id::buf event_id;
event::conforms report;
static bool for_each_pdu(const std::function<bool (const json::object &)> &);
public:
operator const event::id::buf &() const;
fault operator()(const event &);
fault operator()(json::iov &event, const json::iov &content);
fault operator()(const room &, json::iov &event, const json::iov &content);
eval(const vm::opts &);
eval(const vm::copts &);
eval(const event &, const vm::opts & = default_opts);
eval(const json::array &event, const vm::opts & = default_opts);
eval(json::iov &event, const json::iov &content, const vm::copts & = default_copts);
eval(const room &, json::iov &event, const json::iov &content);
eval() = default;
eval(eval &&) = delete;
eval(const eval &) = delete;
eval &operator=(eval &&) = delete;
eval &operator=(const eval &) = delete;
~eval() noexcept;
static bool for_each(const ctx::ctx *const &, const std::function<bool (eval &)> &);
static bool for_each(const std::function<bool (eval &)> &);
static size_t count(const ctx::ctx *const &);
static eval *find(const event::id &);
static eval &get(const event::id &);
static bool sequnique(const uint64_t &seq);
static eval *seqnext(const uint64_t &seq);
static eval *seqmax();
static eval *seqmin();
static void seqsort();
};
/// Evaluation faults. These are reasons which evaluation has halted but may
/// continue after the user defaults the fault. They are basically types of
/// interrupts and traps, which are supposed to be recoverable. Only the
/// GENERAL protection fault (#gp) is an abort and is not supposed to be
/// recoverable. The fault codes have the form of bitflags so they can be
/// used in masks; outside of that case only one fault is dealt with at
/// a time so they can be switched as they appear in the enum.
///
enum ircd::m::vm::fault
:uint
{
ACCEPT = 0x00, ///< No fault.
EXISTS = 0x01, ///< Replaying existing event. (#ex)
GENERAL = 0x02, ///< General protection fault. (#gp)
INVALID = 0x04, ///< Non-conforming event format. (#ud)
AUTH = 0x08, ///< Auth rules violation. (#av)
STATE = 0x10, ///< Required state is missing (#st)
EVENT = 0x20, ///< Eval requires addl events in the ef register (#ef)
INTERRUPT = 0x40, ///< ctx::interrupted (#nmi)
};
/// Evaluation Options
struct ircd::m::vm::opts
{
/// The remote server name which is conducting this eval.
string_view node_id;
/// The mxid of the user which is conducting this eval.
string_view user_id;
/// Call conform hooks (detailed behavior can be tweaked below)
bool conform {true};
/// Make fetches or false to bypass fetch stage.
bool fetch {true};
/// Call eval hooks or false to bypass this stage.
bool eval {true};
/// Make writes to database
bool write {true};
/// Call post hooks or false to bypass post-write / pre-notify effects.
bool post {true};
/// Broadcast to clients/servers. When true, individual notify options
/// that follow are considered. When false, no notifications occur.
short notify {true};
/// Broadcast to local clients (/sync stream).
bool notify_clients {true};
/// Broadcast to federation servers (/federation/send/).
bool notify_servers {true};
/// Apply effects of this event or false to bypass this stage.
bool effects {true};
/// False to allow a dirty conforms report (not recommended).
bool conforming {true};
/// Mask of conformity failures to allow without considering dirty.
event::conforms non_conform;
/// If the event was already checked before the eval, set this to true
/// and include the report (see below).
bool conformed {false};
/// When conformed=true, this report will be included instead of generating
/// one during the eval. This is useful if a conformity check was already
/// done before eval.
event::conforms report;
/// Toggles whether event may be considered a "present event" and may
/// update the optimized present state table of the room if it is proper.
bool present {true};
/// Toggles whether event may be added to the room head table which means
/// it is considered unreferenced by any other event at this time. It is
/// safe for this to always be true if events are evaluated in order. If
/// `present` is false this should be set to false but they are not tied.
bool room_head {true};
/// Toggles whether the prev_events of this event are removed from the
/// room head table, now that this event has referenced them. It is safe
/// for this to always be true.
bool room_refs {true};
/// Toggles whether the state btree is updated; this should be consistently
/// true or false for all events in a room.
bool history {true};
/// Bypass check for event having already been evaluated so it can be
/// replayed through the system (not recommended).
bool replays {false};
/// If the input event has a reference to already-strung json we can use
/// that directly when writing to the DB. When this is false we will
/// re-stringify the event internally either from a referenced source or
/// the tuple if no source is referenced. This should only be set to true
/// if the evaluator already performed this and the json source is good.
bool json_source {false};
// Verify the origin signature
bool verify {true};
/// Performs a query during the fetch stage to check if the event's auth
/// exists locally. This query is required for any fetching to be
/// possible.
bool fetch_auth_check {true};
/// Whether to automatically fetch the auth events when they do not exist.
bool fetch_auth {true};
/// Waits for auth events to be processed before continuing. Without
/// waiting, if any auth events are missing fault::EVENT is thrown.
/// Note that fault::AUTH is only thrown for authentication failures
/// while fault::EVENT is when the data is missing.
bool fetch_auth_wait {true};
/// Performs a query during the fetch stage to check if the room's state
/// exists locally. This query is required for any fetching to be
/// possible.
bool fetch_state_check {true};
/// Whether to automatically fetch the room state when there is no state
/// or incomplete state for the room found on the this server.
bool fetch_state {true};
/// Waits for a condition where fault::STATE would not be thrown before
/// continuing with the eval.
bool fetch_state_wait {true};
/// Performs a query during the fetch stage to check if the referenced
/// prev_events exist locally. This query is required for any fetching
/// to be possible.
bool fetch_prev_check {true};
/// Dispatches a fetch operation when a prev_event does not exist locally.
bool fetch_prev {true};
/// Waits for prev_events have been acquired before continuing with this
/// evaluation.
bool fetch_prev_wait {true};
/// Throws fault::EVENT if *all* of the prev_events do not exist locally.
/// This is used to enforce that at least one path is traversable. This
/// test is conducted after waiting if fetch_prev and fetch_prev_wait.
bool fetch_prev_any {true};
/// Throws fault::EVENT if *any* of the prev_events do not exist locally.
/// This is used to enforce that all references have been acquired; other
/// corollary conditions are similar to fetch_prev_any.
bool fetch_prev_all {false};
/// Evaluators can set this value to optimize the creation of the database
/// transaction where the event will be stored. This value should be set
/// to the amount of space the event consumes; the JSON-serialized size is
/// a good value here. Default of -1 will automatically use serialized().
size_t reserve_bytes = -1;
/// This value is added to reserve_bytes to account for indexing overhead
/// in the database transaction allocation. Most evaluators have little
/// reason to ever adjust this.
size_t reserve_index {1024};
/// Mask of faults that are not thrown as exceptions out of eval(). If
/// masked, the fault is returned from eval(). By default, the EXISTS
/// fault is masked which means existing events won't kill eval loops.
fault_t nothrows
{
EXISTS
};
/// Mask of faults that are logged to the error facility in vm::log.
fault_t errorlog
{
~(EXISTS)
};
/// Mask of faults that are logged to the warning facility in vm::log
fault_t warnlog
{
EXISTS
};
/// Whether to log a debug message on successful eval.
bool debuglog_accept {false};
/// Whether to log an info message on successful eval.
bool infolog_accept {false};
};
/// Extension structure to vm::opts which includes additional options for
/// commissioning events originating from this server which are then passed
/// through eval (this process is also known as issuing).
struct ircd::m::vm::copts
:opts
{
/// A matrix-spec opaque token from a client identifying this eval.
string_view client_txnid;
/// Hash and include hashes object.
bool add_hash {true};
/// Sign and include signatures object
bool add_sig {true};
/// Generate and include event_id
bool add_event_id {true};
/// Include our origin
bool add_origin {true};
/// Include origin_server_ts
bool add_origin_server_ts {true};
/// Add prev_events
bool add_prev_events {true};
/// Add prev_state
bool add_prev_state {true};
/// Add auth_events
bool add_auth_events {true};
/// Whether to log a debug message before commit
bool debuglog_precommit {false};
/// Whether to log an info message after commit accepted
bool infolog_postcommit {false};
/// Call the issue hook or bypass
bool issue {true};
};
struct ircd::m::vm::error
:m::error
{
vm::fault code;
template<class... args> error(const http::code &, const fault &, const string_view &fmt, args&&... a);
template<class... args> error(const fault &, const string_view &fmt, args&&... a);
template<class... args> error(const string_view &fmt, args&&... a);
};
template<class... args>
ircd::m::vm::error::error(const string_view &fmt,
args&&... a)
:error
{
http::INTERNAL_SERVER_ERROR, fault::GENERAL, fmt, std::forward<args>(a)...
}
{}
template<class... args>
ircd::m::vm::error::error(const fault &code,
const string_view &fmt,
args&&... a)
:error
{
http_code(code), code, fmt, std::forward<args>(a)...
}
{}
template<class... args>
ircd::m::vm::error::error(const http::code &httpcode,
const fault &code,
const string_view &fmt,
args&&... a)
:m::error
{
child, httpcode, reflect(code), fmt, std::forward<args>(a)...
}
,code
{
code
}
{}