bugfix: skynet.exit redirect error, and add datacenter.wait

service/datacenterd.lua

@@ -2,6 +2,8 @@ local skynet = require "skynet"
 
 local command = {}
 local database = {}
+local wait_queue = {}
+local mode = {}
 
 local function query(db, key, ...)
 	if key == nil then
@@ -22,7 +24,7 @@ local function update(db, key, value, ...)
 	if select("#",...) == 0 then
 		local ret = db[key]
 		db[key] = value
-		return ret
+		return ret, value
 	else
 		if db[key] == nil then
 			db[key] = {}
@@ -31,13 +33,82 @@ local function update(db, key, value, ...)
 	end
 end
 
+local function wakeup(db, key1, key2, value, ...)
+	if key1 == nil then
+		return
+	end
+	local q = db[key1]
+	if q == nil then
+		return
+	end
+	if q[mode] == "queue" then
+		db[key1] = nil
+		if value then
+			-- throw error because can't wake up a branch
+			for _,v in ipairs(q) do
+				local session = v[1]
+				local source = v[2]
+				skynet.redirect(source, 0, "error", session, "")
+			end
+		else
+			return q
+		end
+	else
+		-- it's branch
+		return wakeup(q , key2, value, ...)
+	end
+end
+
 function command.UPDATE(...)
-	return update(database, ...)
+	local ret, value = update(database, ...)
+	if ret or value == nil then
+		return ret
+	end
+	local q = wakeup(wait_queue, ...)
+	if q then
+		for _, v in ipairs(q) do
+			local session = v[1]
+			local source = v[2]
+			skynet.redirect(source, 0, "response", session, skynet.pack(value))
+		end
+	end
+end
+
+local function waitfor(session, source, db, key1, key2, ...)
+	if key2 == nil then
+		-- push queue
+		local q = db[key1]
+		if q == nil then
+			q = { [mode] = "queue" }
+			db[key1] = q
+		else
+			assert(q[mode] == "queue")
+		end
+		table.insert(q, { session, source })
+	else
+		local q = db[key1]
+		if q == nil then
+			q = { [mode] = "branch" }
+			db[key1] = q
+		else
+			assert(q[mode] == "branch")
+		end
+		return waitfor(session, source, q, key2, ...)
+	end
 end
 
 skynet.start(function()
-	skynet.dispatch("lua", function (_, source, cmd, ...)
-		local f = assert(command[cmd])
-		skynet.ret(skynet.pack(f(...)))
+	skynet.dispatch("lua", function (session, source, cmd, ...)
+		if cmd == "WAIT" then
+			local ret = command.QUERY(...)
+			if ret then
+				skynet.ret(skynet.pack(ret))
+			else
+				waitfor(session, source, wait_queue, ...)
+			end
+		else
+			local f = assert(command[cmd])
+			skynet.ret(skynet.pack(f(...)))
+		end
 	end)
 end)