ircd:Ⓜ️ Improve interface to current event convenience suite.

include/ircd/m/room.h

@@ -29,16 +29,21 @@ namespace ircd::m
 	bool exists(const id::room &);
 	bool exists(const id::room_alias &, const bool &remote = false);
 
+	// [GET]
 	id::room room_id(const mutable_buffer &, const id::room_alias &);
 	id::room::buf room_id(const id::room_alias &);
 
-	// [GET] Current Event suite (non-locking) (one)
+	// [GET] Current Event ID and depth suite (non-locking) (one only)
-	id::event::buf head(std::nothrow_t, const id::room &, int64_t &);
+	std::tuple<int64_t, id::event::buf> top(std::nothrow_t, const id::room &);
-	id::event::buf head(const id::room &, uint64_t &);
+	std::tuple<int64_t, id::event::buf> top(const id::room &);
+
+	// [GET] Current Event ID (non-locking) (one only)
 	id::event::buf head(std::nothrow_t, const id::room &);
 	id::event::buf head(const id::room &);
+
+	// [GET] Current Event depth (non-locking) (one only)
 	int64_t depth(std::nothrow_t, const id::room &);
-	uint64_t depth(const id::room &);
+	int64_t depth(const id::room &);
 
 	// [SET] Lowest-level
 	event::id::buf commit(const room &, json::iov &event, const json::iov &content);

ircd/m/room.cc

@@ -10,57 +10,49 @@
 
 #include <ircd/m/m.h>
 
-uint64_t
+int64_t
 ircd::m::depth(const id::room &room_id)
 {
-	uint64_t depth;
+	return std::get<0>(top(room_id));
-	head(room_id, depth);
-	return depth;
 }
 
 int64_t
 ircd::m::depth(std::nothrow_t,
                const id::room &room_id)
 {
-	int64_t depth;
+	return std::get<0>(top(std::nothrow, room_id));
-	head(std::nothrow, room_id, depth);
-	return depth;
 }
 
 ircd::m::id::event::buf
 ircd::m::head(const id::room &room_id)
 {
-	uint64_t depth;
+	return std::get<1>(top(room_id));
-	return head(room_id, depth);
 }
 
 ircd::m::id::event::buf
 ircd::m::head(std::nothrow_t,
               const id::room &room_id)
 {
-	int64_t depth;
+	return std::get<1>(top(std::nothrow, room_id));
-	return head(std::nothrow, room_id, depth);
 }
 
-ircd::m::id::event::buf
+std::tuple<int64_t, ircd::m::id::event::buf>
-ircd::m::head(const id::room &room_id,
+ircd::m::top(const id::room &room_id)
-              uint64_t &depth)
 {
 	const auto ret
 	{
-		head(std::nothrow, room_id, reinterpret_cast<int64_t &>(depth))
+		top(std::nothrow, room_id)
 	};
 
-	if(depth == uint64_t(-1))
+	if(std::get<0>(ret) == -1)
 		throw m::NOT_FOUND{};
 
 	return ret;
 }
 
-ircd::m::id::event::buf
+std::tuple<int64_t, ircd::m::id::event::buf>
-ircd::m::head(std::nothrow_t,
+ircd::m::top(std::nothrow_t,
-              const id::room &room_id,
+             const id::room &room_id)
-              int64_t &depth)
 {
 	const auto it
 	{
@@ -68,10 +60,10 @@ ircd::m::head(std::nothrow_t,
 	};
 
 	if(!it)
-	{
+		return
-		depth = -1;
+		{
-		return {};
+			-1, id::event::buf{}
-	}
+		};
 
 	const auto &key{it->first};
 	const auto part
@@ -79,8 +71,12 @@ ircd::m::head(std::nothrow_t,
 		dbs::room_events_key(key)
 	};
 
-	depth = std::get<0>(part);
+	const auto &depth{std::get<0>(part)};
-	return std::get<1>(part);
+	const auto &event_id{std::get<1>(part)};
+	return
+	{
+		depth, event_id
+	};
 }
 
 bool

ircd/m/vm.cc

@@ -402,11 +402,8 @@ ircd::m::vm::_eval_pdu(eval &eval,
 		}
 
 		int64_t top;
-		const id::event::buf head
+		id::event::buf head;
-		{
+		std::tie(top, head) = m::top(std::nothrow, room_id);
-			m::head(std::nothrow, room_id, top)
-		};
-
 		if(top < 0 && (opts.head_must_exist || opts.history))
 			throw error
 			{

modules/client/rooms/rooms.cc

@@ -202,10 +202,8 @@ commit__iov_iov(const room &room,
 	};
 
 	int64_t depth;
-	const event::id::buf prev_event_id
+	event::id::buf prev_event_id;
-	{
+	std::tie(depth, prev_event_id) = m::top(std::nothrow, room.room_id);
-		head(std::nothrow, room.room_id, depth)
-	};
 
 	//TODO: X
 	const json::iov::set_if depth_

modules/federation/make_join.cc

@@ -61,11 +61,9 @@ get__make_join(client &client,
 		url::decode(request.parv[1], user_id)
 	};
 
-	uint64_t depth;
+	int64_t depth;
-	const m::event::id::buf prev_event_id
+	m::id::event::buf prev_event_id;
-	{
+	std::tie(depth, prev_event_id) = m::top(room_id);
-		m::head(room_id, depth)
-	};
 
 	const m::event::fetch evf
 	{
@@ -124,7 +122,7 @@ get__make_join(client &client,
 		{ event,    { "type",              "m.room.member"           }},
 		{ event,    { "state_key",         user_id                   }},
 		{ event,    { "sender",            user_id                   }},
-		{ event,    { "depth",             int64_t(depth) + 1        }},
+		{ event,    { "depth",             depth + 1                 }},
 		{ event,    { "membership",        "join"                    }},
 		{ content,  { "membership",        "join"                    }},
 		{ event,    { "auth_events",       { auths, 1 }              }},

modules/federation/make_leave.cc

@@ -61,11 +61,9 @@ get__make_leave(client &client,
 		url::decode(request.parv[1], user_id)
 	};
 
-	uint64_t depth;
+	int64_t depth;
-	const m::event::id::buf prev_event_id
+	m::id::event::buf prev_event_id;
-	{
+	std::tie(depth, prev_event_id) = m::top(room_id);
-		m::head(room_id, depth)
-	};
 
 	const m::event::fetch evf
 	{
@@ -101,7 +99,7 @@ get__make_leave(client &client,
 		{ event,    { "type",              "m.room.member"           }},
 		{ event,    { "sender",            user_id                   }},
 		{ event,    { "state_key",         user_id                   }},
-		{ event,    { "depth",             int64_t(depth) + 1        }},
+		{ event,    { "depth",             depth + 1                 }},
 		{ event,    { "membership",        "leave"                   }},
 		{ content,  { "membership",        "leave"                   }},
 		{ event,    { "auth_events",       auth_events               }},