ircd:Ⓜ️ Simplify m::visible(); refactor implementation.

include/ircd/m/visible.h

@@ -17,5 +17,4 @@ namespace ircd::m
 	// authentication is supplied (m::id cannot be empty because that's
 	// considered an invalid mxid). In that case the test is for public vis.
 	bool visible(const event &, const string_view &mxid);
-	bool visible(const id::event &, const string_view &mxid);
 }

ircd/m.cc

@@ -1673,46 +1673,6 @@ ircd::m::redacted::prefetch(const event::idx &event_idx)
 	return refs.prefetch(dbs::ref::M_ROOM_REDACTION);
 }
 
-///////////////////////////////////////////////////////////////////////////////
-//
-// m/visible.h
-//
-
-bool
-ircd::m::visible(const event::id &event_id,
-                 const string_view &mxid)
-{
-	m::room::id::buf room_id
-	{
-		get(event_id, "room_id", room_id)
-	};
-
-	const m::event event
-	{
-		json::members
-		{
-			{ "event_id",  event_id  },
-			{ "room_id",   room_id   },
-		}
-	};
-
-	return visible(event, mxid);
-}
-
-bool
-ircd::m::visible(const event &event,
-                 const string_view &mxid)
-{
-	using prototype = bool (const m::event &, const string_view &);
-
-	static mods::import<prototype> call
-	{
-		"m_room_history_visibility", "ircd::m::visible"
-	};
-
-	return call(event, mxid);
-}
-
 ///////////////////////////////////////////////////////////////////////////////
 //
 // m/presence.h

modules/client/events.cc

@@ -345,19 +345,28 @@ get_events_from(client &client,
 	size_t i(0), j(0);
 	for(; it && i < size_t(events_limit); --it, ++i)
 	{
-		if(!visible(it.event_id(), request.user_id))
+		const m::event &event{*it};
+		if(!visible(event, request.user_id))
 			continue;
 
-		j += append_event(chunk, *it, it.event_idx(), room_depth, user_room);
+		const auto &event_idx(it.event_idx());
+		j += append_event(chunk, event, event_idx, room_depth, user_room);
 	}
 
 	if(!j)
 		return j;
 
 	chunk.~array();
+	const m::event::id::buf end_token
+	{
+		it?
+			m::event_id(it.event_idx()):
+			room_head
+	};
+
 	json::stack::member
 	{
-		out, "end", it? it.event_id() : room_head
+		out, "end", end_token
 	};
 
 	return j;

modules/client/initialsync.cc

@@ -551,13 +551,17 @@ initialsync_room_timeline_events(client &client,
 	// 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::idx event_idx{0};
 	m::event::id::buf event_id;
 	m::room::events it{room};
 	for(; it && i < 10; --it, ++i)
-		event_id = it.event_id();
+	{
+		event_idx = it.event_idx();
+		event_id = m::event_id(event_idx);
+	}
 
 	if(i > 0 && !it)
-		it.seek(event_id);
+		it.seek(event_idx);
 
 	if(i > 0)
 		for(; it && i > -1; ++it, --i)

modules/client/rooms/context.cc

@@ -183,7 +183,7 @@ get__context(client &client,
 			--before;
 
 		if(before)
-			start = before.event_id();
+			start = m::event_id(before.event_idx());
 		else
 			start = {};
 	}
@@ -223,7 +223,7 @@ get__context(client &client,
 			++after;
 
 		if(after)
-			end = after.event_id();
+			end = m::event_id(after.event_idx());
 		else
 			end = {};
 	}

modules/client/rooms/initialsync.cc

@@ -192,9 +192,6 @@ get__initialsync_local(client &client,
 	room_state.for_each(m::event::id::closure_bool{[&]
 	(const m::event::id &event_id)
 	{
-		if(!visible(event_id, user.user_id))
-			return true;
-
 		const m::event::fetch event
 		{
 			event_id, std::nothrow
@@ -203,6 +200,9 @@ get__initialsync_local(client &client,
 		if(!event.valid)
 			return true;
 
+		if(!visible(event, user.user_id))
+			return true;
+
 		m::event::append::opts opts;
 		opts.event_idx = &event.event_idx;
 		opts.user_id = &user.user_id;
@@ -223,7 +223,7 @@ get__initialsync_local(client &client,
 	if(it)
 		json::stack::member
 		{
-			messages, "start", it.event_id()
+			messages, "start", m::event_id(it.event_idx())
 		};
 
 	// seek down first to give events in chronological order.
@@ -231,7 +231,7 @@ get__initialsync_local(client &client,
 	if(it)
 		json::stack::member
 		{
-			messages, "end", it.event_id()
+			messages, "end", m::event_id(it.event_idx())
 		};
 
 	json::stack::array chunk
@@ -241,12 +241,10 @@ get__initialsync_local(client &client,
 
 	for(; it; ++it)
 	{
-		const auto &event_id(it.event_id());
-		if(!visible(event_id, user.user_id))
-			continue;
-
-		const m::event &event(*it);
 		const auto &event_idx(it.event_idx());
+		const m::event &event(*it);
+		if(!visible(event, user.user_id))
+			continue;
 
 		m::event::append::opts opts;
 		opts.event_idx = &event_idx;

modules/console.cc

@@ -7406,12 +7406,17 @@ console_cmd__event__visible(opt &out, const string_view &line)
 		param[1]
 	};
 
-	const bool visible
+	const m::event event
 	{
-		m::visible(event_id, mxid)
+		event_id
 	};
 
-	out << event_id << " is "
+	const bool visible
+	{
+		m::visible(event, mxid)
+	};
+
+	out << event.event_id << " is "
 	    << (visible? "VISIBLE" : "NOT VISIBLE")
 	    << (mxid? " to " : "")
 	    << mxid

modules/federation/backfill.cc

@@ -91,12 +91,6 @@ get__backfill(client &client,
 			m::head(room_id)
 	};
 
-	if(!visible(event_id, request.node_id))
-		throw m::ACCESS_DENIED
-		{
-			"You are not permitted to view the room at this event."
-		};
-
 	const size_t limit
 	{
 		calc_limit(request)

modules/federation/backfill_ids.cc

@@ -127,9 +127,10 @@ get__backfill_ids(client &client,
 	size_t count{0};
 	for(; it && count < limit; ++count, --it)
 	{
-		const auto &event_id(it.event_id());
-		if(!visible(event_id, request.node_id))
-			continue;
+		const auto event_id
+		{
+			m::event_id(it.event_idx())
+		};
 
 		pdus.append(event_id);
 	}

modules/federation/event.cc

@@ -44,17 +44,17 @@ handle_get(client &client,
 		url::decode(event_id, request.parv[0])
 	};
 
-	if(!visible(event_id, request.node_id))
-		throw m::ACCESS_DENIED
-		{
-			"You are not permitted to view this event"
-		};
-
 	const m::event::fetch event
 	{
 		event_id
 	};
 
+	if(!visible(event, request.node_id))
+		throw m::ACCESS_DENIED
+		{
+			"You are not permitted to view this event"
+		};
+
 	resource::response::chunked response
 	{
 		client, http::OK

modules/m_room_history_visibility.cc

@@ -8,100 +8,42 @@
 // copyright notice and this permission notice is present in all copies. The
 // full license for this software is available in the LICENSE file.
 
-using namespace ircd;
+namespace ircd::m
+{
+	static bool visible_to_node(const room &, const string_view &node_id, const event &);
+	static bool visible_to_user(const room &, const string_view &history_visibility, const m::user::id &, const event &);
 
-mapi::header
+	static void changed_history_visibility(const event &, vm::eval &);
+	extern hookfn<vm::eval &> changed_history_visibility_hookfn;
+}
+
+ircd::mapi::header
 IRCD_MODULE
 {
 	"Matrix m.room.history_visibility"
 };
 
-static bool
-_visible_to_user(const m::event &event,
-                 const m::user::id &user_id,
-                 const m::room &room,
-                 const string_view &history_visibility)
+decltype(ircd::m::changed_history_visibility_hookfn)
+ircd::m::changed_history_visibility_hookfn
 {
-	char membership_buf[m::room::MEMBERSHIP_MAX_SIZE];
-	string_view membership
+	changed_history_visibility,
 	{
-		m::membership(membership_buf, room, user_id)
+		{ "_site",    "vm.effect"                  },
+		{ "type",     "m.room.history_visibility"  },
+	}
 };
 
-	if(membership == "join")
-		return true;
-
-	if(history_visibility == "joined")
-		return false;
-
-	if(history_visibility == "invited")
-		return membership == "invite";
-
-	assert(history_visibility == "shared");
-	if(membership == "invite")
-		return true;
-
-	// If the room is not at the present event then we have to run another
-	// test for membership here. Otherwise the "join" test already failed.
-	if(room.event_id)
+void
+ircd::m::changed_history_visibility(const event &event,
+                                    vm::eval &)
 {
-		const m::room present{room.room_id};
-		membership = m::membership(membership_buf, present, user_id);
-		return membership == "join" || membership == "invite";
-	}
-
-	return false;
-}
-
-static bool
-_visible_to_node(const m::event &event,
-                 const string_view &node_id,
-                 const m::room &room,
-                 const string_view &history_visibility)
+	log::info
 	{
-	const m::room::origins origins
-	{
-		room
-	};
-
-	// Allow joined servers
-	if(origins.has(node_id))
-		return true;
-
-	// Allow auth chain events XXX: this is too broad
-	if(m::room::auth::is_power_event(event))
-		return true;
-
-	// Allow any event where the state_key string is a user mxid and the server
-	// is the host of that user. Note that applies to any type of event.
-	if(m::valid(m::id::USER, json::get<"state_key"_>(event)))
-		if(m::user::id(at<"state_key"_>(event)).host() == node_id)
-			return true;
-
-	return false;
-}
-
-static bool
-_visible(const m::event &event,
-         const string_view &mxid,
-         const m::room &room,
-         const string_view &history_visibility)
-{
-	if(history_visibility == "world_readable")
-		return true;
-
-	if(empty(mxid))
-		return false;
-
-	if(m::valid(m::id::USER, mxid))
-		return _visible_to_user(event, mxid, room, history_visibility);
-
-	if(rfc3986::valid_remote(std::nothrow, mxid))
-		return _visible_to_node(event, mxid, room, history_visibility);
-
-	throw m::UNSUPPORTED
-	{
-		"Cannot determine visibility for '%s'", mxid
+		log, "Changed visibility of %s to %s by %s => %s",
+		json::get<"room_id"_>(event),
+		json::get<"content"_>(event).get("history_visibility"),
+		json::get<"sender"_>(event),
+		string_view{event.event_id},
 	};
 }
 
@@ -115,61 +57,127 @@ ircd::m::visible(const m::event &event,
 		at<"room_id"_>(event), event.event_id
 	};
 
-	static const m::event::fetch::opts fopts
-	{
-		m::event::keys::include{"content"}
-	};
-
 	const m::room::state state
 	{
-		room, &fopts
+		room
 	};
 
-	bool ret{false};
-	const bool has_state_event
+	const event::idx visibility_event_idx
 	{
-		state.get(std::nothrow, "m.room.history_visibility", "", [&]
-		(const m::event &visibility_event)
-		{
-			const json::object &content
-			{
-				json::get<"content"_>(visibility_event)
+		state.get(std::nothrow, "m.room.history_visibility", "")
 	};
 
-			const string_view &history_visibility
+	char buf[32];
+	string_view history_visibility{"shared"};
+	m::get(std::nothrow, visibility_event_idx, "content", [&buf, &history_visibility]
+	(const json::object &content)
 	{
-				unquote(content.get("history_visibility", "shared"))
+		const json::string &_history_visibility
+		{
+			content.get("history_visibility", "shared")
 		};
 
-			ret = _visible(event, mxid, room, history_visibility);
-		})
+		history_visibility = strncpy
+		{
+			buf, _history_visibility
 		};
+	});
 
-	return !has_state_event?
-		_visible(event, mxid, room, "shared"):
-		ret;
-}
+	if(history_visibility == "world_readable")
+		return true;
 
-static void
-_changed_visibility(const m::event &event,
-                    m::vm::eval &)
+	if(empty(mxid))
+		return false;
+
+	if(m::valid(m::id::USER, mxid))
+		return visible_to_user(room, history_visibility, mxid, event);
+
+	if(rfc3986::valid_remote(std::nothrow, mxid))
+		return visible_to_node(room, mxid, event);
+
+	throw m::UNSUPPORTED
 	{
-	log::info
-	{
-		m::log, "Changed visibility of %s to %s by %s => %s",
-		json::get<"room_id"_>(event),
-		json::get<"content"_>(event).get("history_visibility"),
-		json::get<"sender"_>(event),
-		string_view{event.event_id}
+		"Cannot determine visibility of %s for '%s'",
+		string_view{room.room_id},
+		mxid,
 	};
 }
 
-m::hookfn<m::vm::eval &>
-_changed_visibility_hookfn
+bool
+ircd::m::visible_to_user(const m::room &room,
+                         const string_view &history_visibility,
+                         const m::user::id &user_id,
+                         const m::event &event)
 {
-	_changed_visibility,
+	assert(history_visibility != "world_readable");
+
+	// Allow any member event where the state_key string is a user mxid.
+	if(json::get<"type"_>(event) == "m.room.member")
+		if(at<"state_key"_>(event) == user_id)
+			return true;
+
+	// Get the membership of the user in the room at the event.
+	char buf[m::room::MEMBERSHIP_MAX_SIZE];
+	const string_view membership
 	{
-		{ "_site",    "vm.effect"                  },
-		{ "type",     "m.room.history_visibility"  },
-	}
+		m::membership(buf, room, user_id)
 	};
+
+	if(membership == "join")
+		return true;
+
+	if(history_visibility == "joined")
+		return false;
+
+	if(membership == "invite")
+		return true;
+
+	if(history_visibility == "invited")
+		return false;
+
+	// The history_visibility is now likely "shared"; though we cannot assert
+	// that in case some other string is used for any non-spec customization
+	// or for graceful forward compatibility. We default to "shared" here.
+	//assert(history_visibility == "shared");
+
+	// An m::room instance with no event_id is used to query the room at the
+	// present state.
+	const m::room present
+	{
+		room.room_id
+	};
+
+	// If the room is not at the present event then we have to run another
+	// test for membership here. Otherwise the "join" test already failed.
+	if(!room.event_id)
+		return false;
+
+	return m::membership(present, user_id, m::membership_positive); // join || invite
+}
+
+bool
+ircd::m::visible_to_node(const m::room &room,
+                         const string_view &node_id,
+                         const m::event &event)
+{
+	// Allow auth chain events XXX: this is too broad
+	if(m::room::auth::is_power_event(event))
+		return true;
+
+	// Allow any event where the state_key string is a user mxid and the server
+	// is the host of that user. Note that applies to any type of event.
+	if(m::valid(m::id::USER, json::get<"state_key"_>(event)))
+		if(m::user::id(at<"state_key"_>(event)).host() == node_id)
+			return true;
+
+	const m::room::origins origins
+	{
+		room
+	};
+
+	// Allow joined servers
+	if(origins.has(node_id))
+		return true;
+
+	return false;
+}