local multicast support

lualib/multicast.lua

@@ -0,0 +1,66 @@
+local skynet = require "skynet"
+local c = require "multicast.c"
+
+local multicastd
+local multicast = {}
+local dispatch = {}
+
+local function default_conf(conf)
+	conf = conf or {}
+	conf.pack = conf.pack or skynet.pack
+	conf.unpack = conf.unpack or skynet.unpack
+
+	return conf
+end
+
+function multicast.newchannel(conf)
+	assert(multicastd, "Init first")
+	local channel = skynet.call(multicastd, "lua", "NEW")
+	dispatch[channel] = default_conf(conf)
+	return channel
+end
+
+function multicast.publish(channel, ...)
+	local conf = assert(dispatch[channel])
+	skynet.call(multicastd, "lua", "PUB", channel, c.pack(conf.pack(...)))
+end
+
+function multicast.subscribe(channel, conf)
+	assert(multicastd, "Init first")
+	assert(conf.dispatch)
+	skynet.call(multicastd, "lua", "SUB", channel)
+	dispatch[channel] = default_conf(conf)
+end
+
+function multicast.unsubscribe(channel)
+	assert(multicastd, "Init first")
+	assert(dispatch[channel])
+	dispatch[channel] = nil
+	skynet.call(multicastd, "lua", "USUB", channel)
+end
+
+local function dispatch_subscribe(channel, source, pack, msg, sz)
+	local conf = dispatch[channel]
+	if not conf then
+		c.close(pack)
+		error ("Unknown channel " .. channel)
+	end
+
+	local ok, err = pcall(conf.dispatch, channel, source, conf.unpack(msg, sz))
+	c.close(pack)
+	assert(ok, err)
+end
+
+local function init()
+	multicastd = skynet.uniqueservice "multicastd"
+	skynet.register_protocol {
+		name = "multicast",
+		id = skynet.PTYPE_MULTICAST,
+		unpack = c.unpack,
+		dispatch = dispatch_subscribe,
+	}
+end
+
+skynet.init(init, "multicast")
+
+return multicast