// Matrix Construct // // Copyright (C) Matrix Construct Developers, Authors & Contributors // Copyright (C) 2016-2018 Jason Volk // // 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 "rooms.h" using namespace ircd; const size_t default_limit { // 11.20.1.1 - The maximum number of events to return. Default: 10. 10 }; conf::item limit_max { { "name", "ircd.client.rooms.context.limit.max" }, { "default", 128L }, }; conf::item flush_hiwat { { "name", "ircd.client.rooms.context.flush.hiwat" }, { "default", 16384L }, }; log::log context_log { "m.context" }; static bool _append(json::stack::array &, const m::event &, const m::event::idx &, const m::user::room &, const int64_t &, const bool &query_txnid = true); m::resource::response get__context(client &client, const m::resource::request &request, const m::room::id &room_id) { if(request.parv.size() < 3) throw m::NEED_MORE_PARAMS { "event_id path parameter required" }; m::event::id::buf event_id { url::decode(event_id, request.parv[2]) }; const auto limit{[&request] { auto ret(request.query.get("limit", default_limit)); return std::min(ret, size_t(limit_max)); }()}; const m::room room { room_id, event_id }; if(!visible(room, request.user_id)) throw m::ACCESS_DENIED { "You are not permitted to view the room at this event" }; // Non-spec param to allow preventing any state from being returned. const bool include_state { request.query.get("state", true) }; // The standard ?filter= is parsed here. m::filter::get() handles // whether this is a filter_id and conducts a fetch into this buffer; // or inline JSON, and performs URL decoding into this buffer. const std::string filter_json { m::filter::get(request.query["filter"], request.user_id) }; const m::room_event_filter filter { filter_json }; const m::event::fetch event { event_id }; const m::user::room &user_room { request.user_id }; const auto room_depth { m::depth(std::nothrow, room_id) }; m::resource::response::chunked response { client, http::OK }; json::stack out { response.buf, response.flusher(), size_t(flush_hiwat) }; json::stack::object ret { out }; // Output the main event first. { json::stack::object _event { ret, "event" }; // We use m::event::append() to modify/add/remove data for this client. m::event::append::opts opts; opts.event_idx = &event.event_idx; opts.user_id = &user_room.user.user_id; opts.user_room = &user_room; opts.room_depth = &room_depth; m::event::append(_event, event, opts); } // Counters for debug messages struct counts { size_t before {0}; size_t after {0}; size_t state {0}; } counts; m::event::id::buf start; { json::stack::array array { ret, "events_before" }; m::room::events before { room, event_id }; if(before) --before; for(size_t i(0); i < limit && before; --before, ++i) { const m::event &event{*before}; start = event.event_id; if(!visible(event, request.user_id)) continue; counts.before += _append(array, event, before.event_idx(), user_room, room_depth); } if(before && limit > 0) --before; if(before) start = m::event_id(before.event_idx()); else start = {}; } if(start) json::stack::member { ret, "start", json::value{start} }; m::event::id::buf end; { json::stack::array array { ret, "events_after" }; m::room::events after { room, event_id }; if(after) ++after; for(size_t i(0); i < limit && after; ++after, ++i) { const m::event &event{*after}; end = event.event_id; if(!visible(event, request.user_id)) continue; counts.after += _append(array, event, after.event_idx(), user_room, room_depth); } if(after && limit > 0) ++after; if(after) end = m::event_id(after.event_idx()); else end = {}; } if(end) json::stack::member { ret, "end", json::value{end} }; if(include_state) { json::stack::array array { ret, "state" }; const m::room::state state { room }; // Setup the event::fetch instance outside of the closure to avoid // underlying reconstruction costs for now. m::event::fetch event; // Iterate the state. state.for_each([&] (const string_view &type, const string_view &state_key, const m::event::idx &event_idx) { // Conditions to decide if we should skip this state event based // on the lazy-loading spec. const bool lazy_loaded { // The user supplied a filter enabling lazy-loading. json::get<"lazy_load_members"_>(filter) && // The type of this state event is a m.room.member type type == "m.room.member" }; if(lazy_loaded) return true; if(!seek(event, event_idx, std::nothrow)) return true; if(!visible(event, request.user_id)) return true; counts.state += _append(array, event, event_idx, user_room, room_depth, false); return true; }); } log::debug { context_log, "%s %s in %s before:%zu start:%s after:%zu end:%s state:%zu", client.loghead(), string_view{event_id}, string_view{room_id}, counts.before, string_view{start}, counts.after, string_view{end}, counts.state, }; return std::move(response); } bool _append(json::stack::array &chunk, const m::event &event, const m::event::idx &event_idx, const m::user::room &user_room, const int64_t &room_depth, const bool &query_txnid) { m::event::append::opts opts; opts.event_idx = &event_idx; opts.user_id = &user_room.user.user_id; opts.user_room = &user_room; opts.room_depth = &room_depth; return m::event::append(chunk, event, opts); }