From 8d6dfa7cd54103a62af48f1351b1c94de3bc0a78 Mon Sep 17 00:00:00 2001
From: Jason Volk <jason@zemos.net>
Date: Mon, 23 Mar 2020 20:31:21 -0700
Subject: [PATCH] ircd::m: Add room_id(event_idx) to convenience suite.

---
 include/ircd/m/room/room.h |  2 ++
 matrix/room.cc             | 22 ++++++++++++++++++++++
 2 files changed, 24 insertions(+)

diff --git a/include/ircd/m/room/room.h b/include/ircd/m/room/room.h
index 75d92fb1e..97ee1f685 100644
--- a/include/ircd/m/room/room.h
+++ b/include/ircd/m/room/room.h
@@ -49,9 +49,11 @@ namespace ircd::m
 	string_view display_name(const mutable_buffer &out, const room &);
 	id::user::buf any_user(const room &, const string_view &host, const string_view &memshp = "join");
 
+	id::room room_id(const mutable_buffer &, const event::idx &); // db
 	id::room room_id(const mutable_buffer &, const id::event &); // db
 	id::room room_id(const mutable_buffer &, const id::room_alias &); // db + net
 	id::room room_id(const mutable_buffer &, const string_view &mxid);
+	id::room::buf room_id(const event::idx &); // db
 	id::room::buf room_id(const id::event &); // db
 	id::room::buf room_id(const id::room_alias &); // db + net
 	id::room::buf room_id(const string_view &id_or_alias);
diff --git a/matrix/room.cc b/matrix/room.cc
index 787b6b093..26480c03c 100644
--- a/matrix/room.cc
+++ b/matrix/room.cc
@@ -363,6 +363,14 @@ ircd::m::room_id(const string_view &mxid)
 	return room_id(buf, mxid);
 }
 
+ircd::m::id::room::buf
+ircd::m::room_id(const event::idx &event_idx)
+{
+	char buf[m::id::MAX_SIZE + 1];
+	static_assert(sizeof(buf) <= 256);
+	return room_id(buf, event_idx);
+}
+
 ircd::m::id::room
 ircd::m::room_id(const mutable_buffer &out,
                  const string_view &mxid)
@@ -392,6 +400,20 @@ ircd::m::room_id(const mutable_buffer &out,
 	}
 }
 
+ircd::m::id::room
+ircd::m::room_id(const mutable_buffer &out,
+                 const event::idx &event_idx)
+{
+	room::id ret;
+	m::get(event_idx, "room_id", [&out, &ret]
+	(const room::id &room_id)
+	{
+		ret = string_view { data(out), copy(out, room_id) };
+	});
+
+	return ret;
+}
+
 ircd::m::id::room
 ircd::m::room_id(const mutable_buffer &out,
                  const id::event &event_id)