ircd:Ⓜ️:event: Start an event::horizon interface around dbs::event_horizon.

include/ircd/m/event/event.h

@@ -95,6 +95,7 @@ struct ircd::m::event
 {
 	struct prev;
 	struct refs;
+	struct horizon;
 	struct auth;
 	struct fetch;
 	struct conforms;
@@ -138,6 +139,7 @@ struct ircd::m::event
 
 #include "prev.h"
 #include "refs.h"
+#include "horizon.h"
 #include "auth.h"
 #include "index.h"
 #include "event_id.h"

include/ircd/m/event/horizon.h

@@ -0,0 +1,47 @@
+// Matrix Construct
+//
+// Copyright (C) Matrix Construct Developers, Authors & Contributors
+// Copyright (C) 2016-2019 Jason Volk <jason@zemos.net>
+//
+// Permission to use, copy, modify, and/or distribute this software for any
+// purpose with or without fee is hereby granted, provided that the above
+// copyright notice and this permission notice is present in all copies. The
+// full license for this software is available in the LICENSE file.
+
+#pragma once
+#define HAVE_IRCD_M_EVENT_HORIZON_H
+
+/// Interface to the set of unresolved events. This set contains event_id's
+/// which the server does not have. For each event_id in the set, there is an
+/// event::idx of an event which made a reference to the event_id. There may be
+/// multiple entries for an event_id.
+///
+/// This information helps construct the dependency graph in event::refs out of
+/// order; it is anti-reference which is removed after the event is processed.
+/// Each event::idx for an event_id in the set is then able to be "reprocessed"
+/// in some way; at a minimum the reprocessing removes the event_id|event::idx
+/// entry (see: dbs/event_horizon related).
+///
+class ircd::m::event::horizon
+{
+	event::id event_id;
+
+  public:
+	using closure_bool = event::closure_idx_bool;
+
+	bool for_each(const closure_bool &) const;
+	bool has(const event::idx &) const;
+	size_t count() const;
+
+	horizon(const event::id &);
+
+	static bool has(const event::id &);
+	static size_t rebuild();
+};
+
+inline
+ircd::m::event::horizon::horizon(const event::id &event_id)
+:event_id{event_id}
+{
+	assert(event_id);
+}

ircd/m_event.cc

@@ -2555,6 +2555,89 @@ ircd::m::event::auth::chain::for_each(const auth::chain &c,
 	return true;
 }
 
+///////////////////////////////////////////////////////////////////////////////
+//
+// event/horizon.h
+//
+
+size_t
+ircd::m::event::horizon::rebuild()
+{
+	throw not_implemented{};
+}
+
+bool
+ircd::m::event::horizon::has(const event::id &event_id)
+{
+	char buf[m::dbs::EVENT_HORIZON_KEY_MAX_SIZE];
+	const string_view &key
+	{
+		m::dbs::event_horizon_key(buf, event_id, 0UL)
+	};
+
+	auto it
+	{
+		m::dbs::event_horizon.begin(key)
+	};
+
+	return bool(it);
+}
+
+size_t
+ircd::m::event::horizon::count()
+const
+{
+	size_t ret(0);
+	for_each([&ret](const auto &)
+	{
+		++ret;
+		return true;
+	});
+
+	return ret;
+}
+
+bool
+ircd::m::event::horizon::has(const event::idx &event_idx)
+const
+{
+	return !for_each([&event_idx]
+	(const auto &_event_idx)
+	{
+		// false to break; true to continue.
+		return _event_idx == event_idx? false : true;
+	});
+}
+
+bool
+ircd::m::event::horizon::for_each(const closure_bool &closure)
+const
+{
+	char buf[m::dbs::EVENT_HORIZON_KEY_MAX_SIZE];
+	const string_view &key
+	{
+		m::dbs::event_horizon_key(buf, event_id, 0UL)
+	};
+
+	auto it
+	{
+		m::dbs::event_horizon.begin(key)
+	};
+
+	for(; it; ++it)
+	{
+		const auto &event_idx
+		{
+			std::get<0>(m::dbs::event_horizon_key(it->first))
+		};
+
+		if(!closure(event_idx))
+			return false;
+	}
+
+	return true;
+}
+
 ///////////////////////////////////////////////////////////////////////////////
 //
 // event/refs.h

modules/console.cc

@@ -6454,19 +6454,14 @@ console_cmd__event__horizon(opt &out, const string_view &line)
 		return true;
 	}
 
-	char buf[m::dbs::EVENT_HORIZON_KEY_MAX_SIZE];
-	const string_view &key
+	const m::event::horizon horizon
 	{
-		m::dbs::event_horizon_key(buf, event_id, 0UL)
+		event_id
 	};
 
-	for(auto it(m::dbs::event_horizon.begin(key)); it; ++it)
+	horizon.for_each([&out, &event_id]
+	(const auto &event_idx)
 	{
-		const auto &event_idx
-		{
-			std::get<0>(m::dbs::event_horizon_key(it->first))
-		};
-
 		const auto _event_id
 		{
 			m::event_id(event_idx, std::nothrow)
@@ -6478,7 +6473,9 @@ console_cmd__event__horizon(opt &out, const string_view &line)
 		    << " "
 		    << _event_id
 		    << std::endl;
-	}
+
+		return true;
+	});
 
 	return true;
 }