From b5a61a7a6bfebf8f4481d64a4f034298b70e5d02 Mon Sep 17 00:00:00 2001
From: Jason Volk <jason@zemos.net>
Date: Sun, 16 Jun 2019 00:12:06 -0700
Subject: [PATCH] ircd::m::room::state::space: Improve interface; fixes.

---
 include/ircd/m/room/state_space.h |  7 ++++++-
 ircd/m_dbs.cc                     |  2 +-
 ircd/m_room.cc                    | 20 ++------------------
 3 files changed, 9 insertions(+), 20 deletions(-)

diff --git a/include/ircd/m/room/state_space.h b/include/ircd/m/room/state_space.h
index e7dde3cb7..11f59554a 100644
--- a/include/ircd/m/room/state_space.h
+++ b/include/ircd/m/room/state_space.h
@@ -11,7 +11,11 @@
 #pragma once
 #define HAVE_IRCD_M_ROOM_STATE_SPACE_H
 
-/// Interface to all room states.
+/// Interface to all room states. This is a super-dimension of m::room::state.
+/// This contains all state events without overwriting them; we refer to this
+/// as the state-space. We use this interface as a tool to reconstruct the
+/// state of the room at the point of an event in the past; or efficiently
+/// rebuild the present state table after inconsistencies, etc.
 ///
 struct ircd::m::room::state::space
 {
@@ -20,6 +24,7 @@ struct ircd::m::room::state::space
 
 	m::room room;
 
+  public:
 	bool for_each(const string_view &type, const string_view &state_key, const int64_t &depth, const closure &) const;
 	bool for_each(const string_view &type, const string_view &state_key, const closure &) const;
 	bool for_each(const string_view &type, const closure &) const;
diff --git a/ircd/m_dbs.cc b/ircd/m_dbs.cc
index 8b16f8f13..51b484fbb 100644
--- a/ircd/m_dbs.cc
+++ b/ircd/m_dbs.cc
@@ -3116,7 +3116,6 @@ ircd::m::dbs::room_state_space_key(const mutable_buffer &out_,
 
 	consume(out, copy(out, "\0"_sv));
 	consume(out, copy(out, state_key));
-	consume(out, copy(out, "\0"_sv));
 
 	if(depth < 0)
 	{
@@ -3124,6 +3123,7 @@ ircd::m::dbs::room_state_space_key(const mutable_buffer &out_,
 		return { data(out_), data(out) };
 	}
 
+	consume(out, copy(out, "\0"_sv));
 	consume(out, copy(out, byte_view<string_view>(depth)));
 
 	if(!event_idx)
diff --git a/ircd/m_room.cc b/ircd/m_room.cc
index 285d7db89..189b2723d 100644
--- a/ircd/m_room.cc
+++ b/ircd/m_room.cc
@@ -2657,23 +2657,7 @@ bool
 ircd::m::room::state::space::for_each(const closure &closure)
 const
 {
-	auto it
-	{
-		dbs::room_state_space.begin(room.room_id)
-	};
-
-	for(; it; ++it)
-	{
-		const auto &key
-		{
-			dbs::room_state_space_key(it->first)
-		};
-
-		if(!closure(std::get<0>(key), std::get<1>(key), std::get<2>(key), std::get<3>(key)))
-			return false;
-	}
-
-	return true;
+	return for_each(string_view{}, string_view{}, -1L, closure);
 }
 
 bool
@@ -2703,7 +2687,7 @@ const
 	char buf[dbs::ROOM_STATE_SPACE_KEY_MAX_SIZE];
 	const string_view &key
 	{
-		dbs::room_state_space_key(buf, room.room_id, type, state_key, depth)
+		dbs::room_state_space_key(buf, room.room_id, type, state_key, depth, -1UL)
 	};
 
 	auto it