From 6c71ec39b29725b9b04ef8bc75275f49d203e884 Mon Sep 17 00:00:00 2001
From: Jason Volk <jason@zemos.net>
Date: Fri, 18 Dec 2020 21:09:47 -0800
Subject: [PATCH] ircd::m: Parallel event::idx convenience for event::auth;
 simplify definitions.

---
 include/ircd/m/event/auth.h  | 13 +-----------
 include/ircd/m/event/index.h |  3 ++-
 include/ircd/m/event/prev.h  | 13 +-----------
 matrix/event_index.cc        | 41 ++++++++++++++++++++++++------------
 4 files changed, 32 insertions(+), 38 deletions(-)

diff --git a/include/ircd/m/event/auth.h b/include/ircd/m/event/auth.h
index 058d149f6..defa75f1d 100644
--- a/include/ircd/m/event/auth.h
+++ b/include/ircd/m/event/auth.h
@@ -56,20 +56,9 @@ inline ircd::vector_view<ircd::m::event::idx>
 ircd::m::event::auth::idxs(event::idx (&out)[N])
 const
 {
-	event::id buf[N];
-	const auto &ids
-	{
-		auth::ids(buf)
-	};
-
-	const auto &found
-	{
-		m::index(out, ids)
-	};
-
 	return vector_view<event::idx>
 	(
-		out, out + ids.size()
+		out, m::index(out, *this)
 	);
 }
 
diff --git a/include/ircd/m/event/index.h b/include/ircd/m/event/index.h
index b34a2e789..4d46a0788 100644
--- a/include/ircd/m/event/index.h
+++ b/include/ircd/m/event/index.h
@@ -16,8 +16,9 @@ namespace ircd::m
 	// Parallel query; returns number of successful results (positions are fixed)
 	size_t index(const vector_view<event::idx> &out, const vector_view<const event::id> &in);
 
-	// Parallel query; returns number of successful results (positions are fixed)
+	// Parallel query; returns number number of ids. Successful results non-zero.
 	size_t index(const vector_view<event::idx> &out, const m::event::prev &);
+	size_t index(const vector_view<event::idx> &out, const m::event::auth &);
 
 	// Responds with idx in closure; returns false if no action.
 	bool index(std::nothrow_t, const event::id &, const event::closure_idx &);
diff --git a/include/ircd/m/event/prev.h b/include/ircd/m/event/prev.h
index 7772b9298..0884cd7ee 100644
--- a/include/ircd/m/event/prev.h
+++ b/include/ircd/m/event/prev.h
@@ -63,20 +63,9 @@ inline ircd::vector_view<ircd::m::event::idx>
 ircd::m::event::prev::idxs(event::idx (&out)[N])
 const
 {
-	event::id buf[N];
-	const auto &ids
-	{
-		prev::ids(buf)
-	};
-
-	const auto &found
-	{
-		m::index(out, ids)
-	};
-
 	return vector_view<event::idx>
 	(
-		out, out + ids.size()
+		out, m::index(out, *this)
 	);
 }
 
diff --git a/matrix/event_index.cc b/matrix/event_index.cc
index d96db5c4b..2966496f1 100644
--- a/matrix/event_index.cc
+++ b/matrix/event_index.cc
@@ -100,25 +100,40 @@ ircd::m::index(std::nothrow_t,
 
 size_t
 ircd::m::index(const vector_view<event::idx> &out,
-               const event::prev &prev)
+               const event::auth &auth)
 {
-	const auto num
+	event::id ids[event::auth::MAX];
+	const auto &event_ids
 	{
-		std::min(prev.prev_events_count(), event::prev::MAX)
+		auth.ids(ids)
 	};
 
-	size_t i(0);
-	event::id event_id[num];
-	m::for_each(prev, [&num, &i, &event_id]
-	(const auto &prev_id)
+	const auto &found
 	{
-		assert(i < num);
-		event_id[i++] = prev_id;
-		return i < num;
-	});
+		index(out, event_ids)
+	};
 
-	assert(i == num);
-	return index(out, vector_view<const event::id>(event_id, i));
+	assert(found <= event_ids.size());
+	return event_ids.size();
+}
+
+size_t
+ircd::m::index(const vector_view<event::idx> &out,
+               const event::prev &prev)
+{
+	event::id ids[event::prev::MAX];
+	const auto &event_ids
+	{
+		prev.ids(ids)
+	};
+
+	const auto &found
+	{
+		index(out, event_ids)
+	};
+
+	assert(found <= event_ids.size());
+	return event_ids.size();
 }
 
 size_t