construct/modules/client/sync.cc

// 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.

#include "sync.int.h"

mapi::header
IRCD_MODULE
{
	"Client 6.2.1 :Sync"
};

//
// sync resource
//

resource
sync_resource
{
	"/_matrix/client/r0/sync",
	{
		sync_description
	}
};

const string_view
sync_description
{R"(

6.2.1

Synchronise the client's state with the latest state on the server. Clients
use this API when they first log in to get an initial snapshot of the state
on the server, and then continue to call this API to get incremental deltas
to the state, and to receive new messages.

)"};

//
// GET sync
//

resource::method
get_sync
{
	sync_resource, "GET", sync,
	{
		get_sync.REQUIRES_AUTH,
		-1s,
	}
};

resource::response
sync(client &client,
     const resource::request &request)
{
	const syncargs args
	{
		request
	};

	return since_sync(client, request, args);
}

conf::item<milliseconds>
sync_timeout_max
{
	{ "name",     "ircd.client.sync.timeout.max" },
	{ "default",  15 * 1000L                    },
};

conf::item<milliseconds>
sync_timeout_min
{
	{ "name",     "ircd.client.sync.timeout.min" },
	{ "default",  5 * 1000L                     },
};

conf::item<milliseconds>
sync_timeout_default
{
	{ "name",     "ircd.client.sync.timeout.default" },
	{ "default",  10 * 1000L                        },
};

conf::item<size_t>
sync_flush_hiwat
{
	{ "name",     "ircd.client.sync.flush.hiwat" },
	{ "default",  long(24_KiB)                   },
};

syncargs::syncargs(const resource::request &request)
:filter_id
{
	// 6.2.1 The ID of a filter created using the filter API or a filter JSON object
	// encoded as a string. The server will detect whether it is an ID or a JSON object
	// by whether the first character is a "{" open brace. Passing the JSON inline is best
	// suited to one off requests. Creating a filter using the filter API is recommended
	// for clients that reuse the same filter multiple times, for example in long poll requests.
	request.query["filter"]
}
,since
{
	// 6.2.1 A point in time to continue a sync from.
	request.query.get<uint64_t>("since", 0)
}
,timesout{[&request]
{
	// 6.2.1 The maximum time to poll in milliseconds before returning this request.
	auto ret(request.query.get("timeout", milliseconds(sync_timeout_default)));
	ret = std::min(ret, milliseconds(sync_timeout_max));
	ret = std::max(ret, milliseconds(sync_timeout_min));
	return now<steady_point>() + ret;
}()}
,full_state
{
	// 6.2.1 Controls whether to include the full state for all rooms the user is a member of.
	// If this is set to true, then all state events will be returned, even if since is non-empty.
	// The timeline will still be limited by the since parameter. In this case, the timeout
	// parameter will be ignored and the query will return immediately, possibly with an
	// empty timeline. If false, and since is non-empty, only state which has changed since
	// the point indicated by since will be returned. By default, this is false.
	request.query.get("full_state", false)
}
,set_presence
{
	// 6.2.1 Controls whether the client is automatically marked as online by polling this API.
	// If this parameter is omitted then the client is automatically marked as online when it
	// uses this API. Otherwise if the parameter is set to "offline" then the client is not
	// marked as being online when it uses this API. One of: ["offline"]
	request.query.get("set_presence", true)
}
{
}

resource::response
since_sync(client &client,
           const resource::request &request,
           const syncargs &args)
{
	if(!shortpoll_sync(client, request, args))
		longpoll_sync(client, request, args);

	return {};
}

bool
shortpoll_sync(client &client,
               const resource::request &request,
               const syncargs &args)
try
{
	shortpoll sp
	{
		client, request, args
	};

	if(sp.since > sp.current)
		throw m::NOT_FOUND
		{
			"Since parameter is in the future..."
		};

	json::stack::object top
	{
		sp.out
	};

	static const auto max_linear_sync
	{
		8 //TODO: conf
	};

	return
		sp.delta == 0?
			false:
		sp.delta > max_linear_sync?
			polylog_sync(client, request, sp, top):
			linear_sync(client, request, sp, top);
}
catch(const bad_lex_cast &e)
{
	throw m::BAD_REQUEST
	{
		"Since parameter invalid :%s", e.what()
	};
}

bool
linear_sync(client &client,
            const resource::request &request,
            shortpoll &sp,
            json::stack::object &object)
{
	uint64_t since
	{
		sp.since
	};

	std::map<std::string, std::vector<std::string>, std::less<>> r;

	bool limited{false};
	m::events::for_each(since, [&]
	(const uint64_t &sequence, const m::event &event)
	{
		if(!r.empty() && (since - sp.since > 128))
		{
			limited = true;
			return false;
		}

		since = sequence;
		if(!json::get<"room_id"_>(event))
			return true;

		const m::room room
		{
			json::get<"room_id"_>(event)
		};

		if(!room.membership(request.user_id))
			return true;

		auto it
		{
			r.lower_bound(room.room_id)
		};

		if(it == end(r) || it->first != room.room_id)
			it = r.emplace_hint(it, std::string{room.room_id}, std::vector<std::string>{});

		it->second.emplace_back(json::strung{event});
		return true;
	});

	if(r.empty())
		return false;

	std::vector<json::member> joins;

	for(auto &p : r)
	{
		const auto &room_id{p.first};
		auto &vec{p.second};

		std::vector<std::string> timeline;
		std::vector<std::string> state;
		std::vector<std::string> ephemeral;

		for(std::string &event : vec)
			if(json::object{event}.has("state_key"))
				state.emplace_back(std::move(event));
			else if(!json::object{event}.has("prev_events"))
				ephemeral.emplace_back(std::move(event));
			else
				timeline.emplace_back(std::move(event));

		const json::strung timeline_serial{timeline.data(), timeline.data() + timeline.size()};
		const json::strung state_serial{state.data(), state.data() + state.size()};
		const json::strung ephemeral_serial{ephemeral.data(), ephemeral.data() + ephemeral.size()};

		const string_view prev_batch
		{
			!timeline.empty()?
				unquote(json::object{timeline.front()}.at("event_id")):
				string_view{}
		};

		const json::members body
		{
			{ "ephemeral",
			{
				{ "events", ephemeral_serial },
			}},
			{ "state",
			{
				{ "events", state_serial }
			}},
			{ "timeline",
			{
				{ "events",      timeline_serial  },
				{ "prev_batch",  prev_batch       },
				{ "limited",     limited          },
			}},
		};

		joins.emplace_back(room_id, body);
	};

	const json::value join
	{
		joins.data(), joins.size()
	};

	const json::members rooms
	{
		{ "join",   join           },
		{ "leave",  json::object{} },
		{ "invite", json::object{} },
	};

	resource::response
	{
		client, json::members
		{
			{ "next_batch",  json::value { lex_cast(int64_t(since)), json::STRING } },
			{ "rooms",       rooms   },
			{ "presence",    json::object{} },
		}
	};

	return true;
}

static bool
synchronize(client &client,
            const resource::request &request,
            const syncargs &args,
            const m::event &event);

void
longpoll_sync(client &client,
              const resource::request &request,
              const syncargs &args)
try
{
	std::unique_lock<decltype(m::vm::accept)> lock
	{
		m::vm::accept
	};

	while(1)
	{
		auto &accepted
		{
			m::vm::accept.wait_until(lock, args.timesout)
		};

		if(synchronize(client, request, args, accepted))
			return;
	}
}
catch(const ctx::timeout &e)
{
	const ctx::exception_handler eh;

	const int64_t &since
	{
		int64_t(m::vm::current_sequence)
	};

	resource::response
	{
		client, json::members
		{
			{ "next_batch",  json::value { lex_cast(int64_t(since)), json::STRING }  },
			{ "rooms",       json::object{}  },
			{ "presence",    json::object{}  },
		}
	};
}

static bool
synchronize(client &client,
            const resource::request &request,
            const syncargs &args,
            const m::event &event,
            const m::room::id &room_id);

bool
synchronize(client &client,
            const resource::request &request,
            const syncargs &args,
            const m::event &event)
{
	const auto &room_id
	{
		json::get<"room_id"_>(event)
	};

	if(room_id)
		return synchronize(client, request, args, event, room_id);

	return false;
}

resource::response
update_sync(client &client,
            const resource::request &request,
            const syncargs &args,
            const m::event &event,
            const m::room &room);

bool
synchronize(client &client,
            const resource::request &request,
            const syncargs &args,
            const m::event &event,
            const m::room::id &room_id)
{
	const m::room room
	{
		room_id
	};

	const m::user::id &user_id
	{
		request.user_id
	};

	if(!room.membership(user_id, "join"))
		return false;

	update_sync(client, request, args, event, room);
	return true;
}

std::string
update_sync_room(client &client,
                 const m::room &room,
                 const uint64_t &since,
                 const m::event &event)
{
	std::vector<std::string> state;
	if(defined(json::get<"event_id"_>(event)) && defined(json::get<"state_key"_>(event)))
		state.emplace_back(json::strung(event));

	const json::strung state_serial
	{
		state.data(), state.data() + state.size()
	};

	std::vector<std::string> timeline;
	if(defined(json::get<"event_id"_>(event)) && !defined(json::get<"state_key"_>(event)))
		timeline.emplace_back(json::strung(event));

	const json::strung timeline_serial
	{
		timeline.data(), timeline.data() + timeline.size()
	};

	std::vector<std::string> ephemeral;
	if(json::get<"type"_>(event) == "m.typing") //TODO: X
		ephemeral.emplace_back(json::strung{event});

	if(json::get<"type"_>(event) == "m.receipt") //TODO: X
		ephemeral.emplace_back(json::strung(event));

	const json::strung ephemeral_serial
	{
		ephemeral.data(), ephemeral.data() + ephemeral.size()
	};

	const auto &prev_batch
	{
		!timeline.empty()?
			unquote(json::object{timeline.front()}.get("event_id")):
			string_view{}
	};

	//TODO: XXX
	const bool limited
	{
		false
	};

	const int64_t notes
	{
		0
	};

	const json::members body
	{
		{ "account_data", json::members{} },
		{ "unread_notifications",
		{
			{ "highlight_count",    int64_t(0) },
			{ "notification_count", notes },
		}},
		{ "ephemeral",
		{
			{ "events", ephemeral_serial },
		}},
		{ "state",
		{
			{ "events", state_serial }
		}},
		{ "timeline",
		{
			{ "events",      timeline_serial  },
			{ "prev_batch",  prev_batch       },
			{ "limited",     limited          },
		}},
	};

	return json::strung(body);
}

std::string
update_sync_rooms(client &client,
                  const resource::request &request,
                  const m::user::id &user_id,
                  const m::room &room,
                  const uint64_t &since,
                  const m::event &event)
{
	std::vector<std::string> r[3];
	std::vector<json::member> m[3];
	r[0].emplace_back(update_sync_room(client, room, since, event));
	m[0].emplace_back(room.room_id, r[0].back());

	const std::string join{json::strung(m[0].data(), m[0].data() + m[0].size())};
	const std::string leave{json::strung(m[1].data(), m[1].data() + m[1].size())};
	const std::string invite{json::strung(m[2].data(), m[2].data() + m[2].size())};
	return json::strung(json::members
	{
		{ "join",     join    },
		{ "leave",    leave   },
		{ "invite",   invite  },
	});
}

resource::response
update_sync(client &client,
            const resource::request &request,
            const syncargs &args,
            const m::event &event,
            const m::room &room)
{
	const auto rooms
	{
		update_sync_rooms(client, request, request.user_id, room, args.since, event)
	};

	const m::user::room ur
	{
		m::user::id{request.user_id}
	};

	std::vector<json::value> presents;
	ur.get(std::nothrow, "ircd.presence", [&]
	(const m::event &event)
	{
		const auto &content
		{
			at<"content"_>(event)
		};

		presents.emplace_back(event);
	});

	const json::members presence
	{
		{ "events", json::value { presents.data(), presents.size() } },
	};

	const auto &next_batch
	{
		int64_t(m::vm::current_sequence)
	};

	return resource::response
	{
		client, json::members
		{
			{ "next_batch",  json::value { lex_cast(next_batch), json::STRING } },
			{ "rooms",       rooms       },
			{ "presence",    presence    },
		}
	};
}

static void
polylog_sync_rooms(shortpoll &sp,
                   json::stack::object &object);

static void
polylog_sync_presence(shortpoll &sp,
                      json::stack::object &object);

static void
polylog_sync_account_data(shortpoll &sp,
                          json::stack::object &object);

bool
polylog_sync(client &client,
             const resource::request &request,
             shortpoll &sp,
             json::stack::object &object)
try
{
	{
		json::stack::member member{object, "rooms"};
		json::stack::object object{member};
		polylog_sync_rooms(sp, object);
	}

	{
		json::stack::member member{object, "presence"};
		json::stack::object object{member};
		polylog_sync_presence(sp, object);
	}

	{
		json::stack::member member{object, "account_data"};
		json::stack::object object{member};
		polylog_sync_account_data(sp, object);
	}

	{
		json::stack::member member
		{
			object, "next_batch", json::value(lex_cast(int64_t(sp.current)), json::STRING)
		};
	}

	return sp.committed;
}
catch(const std::exception &e)
{
	log::error
	{
		"polylog sync FAILED %lu to %lu (vm @ %zu) :%s"
		,sp.since
		,sp.current
		,m::vm::current_sequence
		,e.what()
	};

	throw;
}

void
polylog_sync_presence(shortpoll &sp,
                      json::stack::object &out)
{
	json::stack::member member{out, "events"};
	json::stack::array array{member};
	const m::user::mitsein mitsein
	{
		sp.user
	};

	mitsein.for_each("join", [&sp, &array]
	(const m::user &user)
	{
		const m::user::room user_room{user};
		if(head_idx(std::nothrow, user_room) <= sp.since)
			return;

		//TODO: can't check event_idx cuz only closed presence content
		m::presence::get(std::nothrow, user, [&sp, &array]
		(const json::object &event)
		{
			json::stack::object object{array};

			// sender
			{
				json::stack::member member
				{
					object, "sender", unquote(event.get("user_id"))
				};
			}

			// type
			{
				json::stack::member member
				{
					object, "type", json::value{"m.presence"}
				};
			}

			// content
			{
				json::stack::member member
				{
					object, "content", event
				};
			}
		});
	});
}

void
polylog_sync_account_data(shortpoll &sp,
                          json::stack::object &out)
{
	json::stack::member member{out, "events"};
	json::stack::array array{member};
	const m::room::state state
	{
		sp.user_room
	};

	state.for_each("ircd.account_data", [&sp, &array]
	(const m::event &event)
	{
		const auto &event_idx
		{
			index(event, std::nothrow)
		};

		if(event_idx < sp.since || event_idx >= sp.current)
			return;

		json::stack::object object{array};

		// type
		{
			json::stack::member member
			{
				object, "type", at<"state_key"_>(event)
			};
		}

		// content
		{
			json::stack::member member
			{
				object, "content", at<"content"_>(event)
			};
		}
	});
}

static void
polylog_sync_rooms__membership(shortpoll &sp,
                                   json::stack::object &object,
                                   const string_view &membership);

void
polylog_sync_rooms(shortpoll &sp,
                       json::stack::object &object)
{
	{
		json::stack::member member{object, "join"};
		json::stack::object object{member};
		polylog_sync_rooms__membership(sp, object, "join");
	}

	{
		json::stack::member member{object, "leave"};
		json::stack::object object{member};
		polylog_sync_rooms__membership(sp, object, "leave");
	}

	{
		json::stack::member member{object, "invite"};
		json::stack::object object{member};
		polylog_sync_rooms__membership(sp, object, "invite");
	}
}

static void
polylog_sync_room(shortpoll &sp,
                  json::stack::object &object,
                  const m::room &room,
                  const string_view &membership);

void
polylog_sync_rooms__membership(shortpoll &sp,
                               json::stack::object &object,
                               const string_view &membership)
{
	sp.rooms.for_each(membership, [&]
	(const m::room &room, const string_view &)
	{
		if(head_idx(std::nothrow, room) <= sp.since)
			return;

		const m::room::id &room_id{room.room_id};
		json::stack::member member{object, room_id};
		json::stack::object object{member};
		polylog_sync_room(sp, object, room, membership);
	});
}

static void
polylog_sync_room_state(shortpoll &sp,
                        json::stack::object &out,
                        const m::room &room);

static void
polylog_sync_room_timeline(shortpoll &sp,
                           json::stack::object &out,
                           const m::room &room);

static void
polylog_sync_room_ephemeral(shortpoll &sp,
                            json::stack::object &out,
                            const m::room &room);

static void
polylog_sync_room_account_data(shortpoll &sp,
                               json::stack::object &out,
                               const m::room &room);

static void
polylog_sync_room_unread_notifications(shortpoll &sp,
                                       json::stack::object &out,
                                       const m::room &room);

void
polylog_sync_room(shortpoll &sp,
                  json::stack::object &out,
                  const m::room &room,
                  const string_view &membership)
{
	// timeline
	{
		json::stack::member member{out, "timeline"};
		json::stack::object object{member};
		polylog_sync_room_timeline(sp, object, room);
	}

	// state
	{
		json::stack::member member
		{
			out, membership != "invite"?
				"state":
				"invite_state"
		};

		json::stack::object object{member};
		polylog_sync_room_state(sp, object, room);
	}

	// ephemeral
	{
		json::stack::member member{out, "ephemeral"};
		json::stack::object object{member};
		polylog_sync_room_ephemeral(sp, object, room);
	}

	// account_data
	{
		json::stack::member member{out, "account_data"};
		json::stack::object object{member};
		polylog_sync_room_account_data(sp, object, room);
	}

	// unread_notifications
	{
		json::stack::member member{out, "unread_notifications"};
		json::stack::object object{member};
		polylog_sync_room_unread_notifications(sp, object, room);
	}
}

void
polylog_sync_room_state(shortpoll &sp,
                        json::stack::object &out,
                        const m::room &room)
{
	json::stack::member member
	{
		out, "events"
	};

	json::stack::array array
	{
		member
	};

	const m::room::state state
	{
		room
	};

	state.for_each([&](const m::event &event)
	{
		if(at<"depth"_>(event) >= int64_t(sp.state_at))
			return;

		const auto &event_idx
		{
			index(event, std::nothrow)
		};

		if(event_idx < sp.since || event_idx >= sp.current)
			return;

		array.append(event);
		sp.committed = true;
	});
}

static m::event::id::buf
polylog_sync_room_timeline_events(shortpoll &sp,
                                  json::stack::array &out,
                                  const m::room &room,
                                  bool &limited);

void
polylog_sync_room_timeline(shortpoll &sp,
                           json::stack::object &out,
                           const m::room &room)
{
	// events
	bool limited{false};
	m::event::id::buf prev;
	{
		json::stack::member member{out, "events"};
		json::stack::array array{member};
		prev = polylog_sync_room_timeline_events(sp, array, room, limited);
	}

	// prev_batch
	{
		json::stack::member member
		{
			out, "prev_batch", string_view{prev}
		};
	}

	// limited
	{
		json::stack::member member
		{
			out, "limited", json::value{limited}
		};
	}
}

m::event::id::buf
polylog_sync_room_timeline_events(shortpoll &sp,
                                  json::stack::array &out,
                                  const m::room &room,
                                  bool &limited)
{
	// messages seeks to the newest event, but the client wants the oldest
	// event first so we seek down first and then iterate back up. Due to
	// an issue with rocksdb's prefix-iteration this iterator becomes
	// toxic as soon as it becomes invalid. As a result we have to copy the
	// event_id on the way down in case of renewing the iterator for the
	// way back. This is not a big deal but rocksdb should fix their shit.
	ssize_t i(0);
	m::event::id::buf event_id;
	m::room::messages it{room};
	for(; it && i < 10; --it, ++i)
	{
		event_id = it.event_id();
		if(it.event_idx() < sp.since)
			break;

		if(it.event_idx() >= sp.current)
			break;
	}

	limited = i >= 10;
	sp.committed |= i > 0;

	if(i > 0 && !it)
		it.seek(event_id);

	if(i > 0 && it)
	{
		const m::event &event{*it};
		sp.state_at = at<"depth"_>(event);
	}

	if(i > 0)
		for(; it && i > -1; ++it, --i)
			out.append(*it);

	return event_id;
}

static void
polylog_sync_room_ephemeral_events(shortpoll &sp,
                                   json::stack::array &out,
                                   const m::room &room);

void
polylog_sync_room_ephemeral(shortpoll &sp,
                            json::stack::object &out,
                            const m::room &room)
{
	{
		json::stack::member member{out, "events"};
		json::stack::array array{member};
		polylog_sync_room_ephemeral_events(sp, array, room);
	}
}

void
polylog_sync_room_ephemeral_events(shortpoll &sp,
                                   json::stack::array &out,
                                   const m::room &room)
{
	const m::room::members members{room};
	members.for_each("join", m::room::members::closure{[&]
	(const m::user &user)
	{
		const m::user::room user_room{user};
		if(head_idx(std::nothrow, user_room) <= sp.since)
			return;

		user_room.get(std::nothrow, "ircd.read", room.room_id, [&]
		(const m::event &event)
		{
			const auto &event_idx
			{
				index(event, std::nothrow)
			};

			if(event_idx < sp.since || event_idx >= sp.current)
				return;

			sp.committed = true;
			json::stack::object object{out};

			// type
			{
				json::stack::member member
				{
					object, "type", "m.receipt"
				};
			}

			// content
			{
				const json::object data
				{
					at<"content"_>(event)
				};

				thread_local char buf[1024];
				const json::members reformat
				{
					{ unquote(data.at("event_id")),
					{
						{ "m.read",
						{
							{ at<"sender"_>(event),
							{
								{ "ts", data.at("ts") }
							}}
						}}
					}}
				};

				json::stack::member member
				{
					object, "content", json::stringify(mutable_buffer{buf}, reformat)
				};
			}
		});
	}});
}

void
polylog_sync_room_account_data(shortpoll &sp,
                               json::stack::object &out,
                               const m::room &room)
{

}


void
polylog_sync_room_unread_notifications(shortpoll &sp,
                                       json::stack::object &out,
                                       const m::room &room)
{
	// highlight_count
	{
		json::stack::member member
		{
			out, "highlight_count", json::value{0L}
		};
	}

	// notification_count
	{
		json::stack::member member
		{
			out, "notification_count", json::value{0L}
		};
	}
}