modules/client/sync: Adjust the object creation for handlers; put the room head idx in data.

include/ircd/m/sync.h

@@ -95,6 +95,7 @@ struct ircd::m::sync::data
 	const m::event *event {nullptr};
 	const m::room *room {nullptr};
 	string_view membership;
+	event::idx room_head {0};
 
 	data(const m::user &user,
 	     const m::events::range &range,

modules/client/sync/rooms.cc

@@ -134,10 +134,20 @@ ircd::m::sync::_rooms_polylog_room(data &data,
 		data.out, room.room_id
 	};
 
+	const event::idx room_head
+	{
+		head_idx(std::nothrow, room)
+	};
+
+	const scope_restore<decltype(data.room_head)> their_head
+	{
+		data.room_head, room_head
+	};
+
 	m::sync::for_each("rooms", [&data]
 	(item &item)
 	{
-		json::stack::member member
+		json::stack::object object
 		{
 			data.out, item.member_name()
 		};

modules/client/sync/rooms/account_data.cc

@@ -33,11 +33,6 @@ ircd::m::sync::room_account_data
 void
 ircd::m::sync::room_account_data_polylog(data &data)
 {
-	json::stack::object object
-	{
-		data.out
-	};
-
 	room_account_data_polylog_events(data);
 }
 

modules/client/sync/rooms/ephemeral.cc

@@ -39,11 +39,6 @@ ircd::m::sync::rooms_ephemeral_linear(data &data)
 void
 ircd::m::sync::rooms_ephemeral_polylog(data &data)
 {
-	json::stack::object object
-	{
-		data.out
-	};
-
 	rooms_ephemeral_events_polylog(data);
 }
 

modules/client/sync/rooms/state.cc

@@ -78,19 +78,7 @@ ircd::m::sync::room_state_linear(data &data)
 void
 ircd::m::sync::room_state_polylog(data &data)
 {
-	json::stack::object object
-	{
-		data.out
-	};
-
-	const auto head_idx
-	{
-		m::head_idx(std::nothrow, *data.room)
-	};
-
-	if(!apropos(data, head_idx))
-		return;
-
+	if(apropos(data, data.room_head))
 		room_state_polylog_events(data);
 }
 

modules/client/sync/rooms/timeline.cc

@@ -99,21 +99,11 @@ ircd::m::sync::_room_timeline_linear_events(data &data,
 void
 ircd::m::sync::room_timeline_polylog(data &data)
 {
-	json::stack::object object
-	{
-		data.out
-	};
-
-	assert(data.room);
-	const auto head_idx
-	{
-		m::head_idx(std::nothrow, *data.room)
-	};
-
-	if(!head_idx || !apropos(data, head_idx))
+	if(!apropos(data, data.room_head))
 		return;
 
 	// events
+	assert(data.room);
 	bool limited{false};
 	m::event::id::buf prev
 	{
@@ -123,13 +113,13 @@ ircd::m::sync::room_timeline_polylog(data &data)
 	// prev_batch
 	json::stack::member
 	{
-		object, "prev_batch", string_view{prev}
+		data.out, "prev_batch", string_view{prev}
 	};
 
 	// limited
 	json::stack::member
 	{
-		object, "limited", json::value{limited}
+		data.out, "limited", json::value{limited}
 	};
 }
 

modules/client/sync/rooms/unread_notifications.cc

@@ -50,16 +50,10 @@ ircd::m::sync::room_unread_notifications_polylog(data &data)
 		index(last_read)
 	};
 
-	data.commit();
-	json::stack::object out
-	{
-		data.out
-	};
-
 	// highlight_count
 	json::stack::member
 	{
-		out, "highlight_count", json::value
+		data.out, "highlight_count", json::value
 		{
 			_highlight_count(room, data.user, start_idx, data.range.second)
 		}
@@ -68,11 +62,13 @@ ircd::m::sync::room_unread_notifications_polylog(data &data)
 	// notification_count
 	json::stack::member
 	{
-		out, "notification_count", json::value
+		data.out, "notification_count", json::value
 		{
 			_notification_count(room, start_idx, data.range.second)
 		}
 	};
+
+	data.commit();
 }
 
 long