1 files changed, 74 insertions, 0 deletions
diff --git a/net/cqueues.lua b/net/cqueues.lua
new file mode 100644
index 00000000..8c4c756f
--- /dev/null
+++ b/net/cqueues.lua
@@ -0,0 +1,74 @@
+-- Prosody IM
+-- Copyright (C) 2014 Daurnimator
+--
+-- This project is MIT/X11 licensed. Please see the
+-- COPYING file in the source package for more information.
+--
+-- This module allows you to use cqueues with a net.server mainloop
+--
+
+local server = require "net.server";
+local cqueues = require "cqueues";
+assert(cqueues.VERSION >= 20150113, "cqueues newer than 20150113 required")
+
+-- Create a single top level cqueue
+local cq;
+
+if server.cq then -- server provides cqueues object
+	cq = server.cq;
+elseif server.get_backend() == "select" and server._addtimer then -- server_select
+	cq = cqueues.new();
+	local function step()
+		assert(cq:loop(0));
+	end
+
+	-- Use wrapclient (as wrapconnection isn't exported) to get server_select to watch cq fd
+	local handler = server.wrapclient({
+		getfd = function() return cq:pollfd(); end;
+		settimeout = function() end; -- Method just needs to exist
+		close = function() end; -- Need close method for 'closeall'
+	}, nil, nil, {});
+
+	-- Only need to listen for readable; cqueues handles everything under the hood
+	-- readbuffer is called when `select` notes an fd as readable
+	handler.readbuffer = step;
+
+	-- Use server_select low lever timer facility,
+	-- this callback gets called *every* time there is a timeout in the main loop
+	server._addtimer(function(current_time)
+		-- This may end up in extra step()'s, but cqueues handles it for us.
+		step();
+		return cq:timeout();
+	end);
+elseif server.event and server.base then -- server_event
+	cq = cqueues.new();
+	-- Only need to listen for readable; cqueues handles everything under the hood
+	local EV_READ = server.event.EV_READ;
+	-- Convert a cqueues timeout to an acceptable timeout for luaevent
+	local function luaevent_safe_timeout(cq)
+		local t = cq:timeout();
+		-- if you give luaevent 0 or nil, it re-uses the previous timeout.
+		if t == 0 then
+			t = 0.000001; -- 1 microsecond is the smallest that works (goes into a `struct timeval`)
+		elseif t == nil then -- pick something big if we don't have one
+			t = 0x7FFFFFFF; -- largest 32bit int
+		end
+		return t
+	end
+	local event_handle;
+	event_handle = server.base:addevent(cq:pollfd(), EV_READ, function(e)
+			-- Need to reference event_handle or this callback will get collected
+			-- This creates a circular reference that can only be broken if event_handle is manually :close()'d
+			local _ = event_handle;
+			-- Run as many cqueues things as possible (with a timeout of 0)
+			-- If an error is thrown, it will break the libevent loop; but prosody resumes after logging a top level error
+			assert(cq:loop(0));
+			return EV_READ, luaevent_safe_timeout(cq);
+		end, luaevent_safe_timeout(cq));
+else
+	error "NYI"
+end
+
+return {
+	cq = cq;
+}