introduce socket.channel, and rewrite redis/mongo driver

lualib-src/lua-mongo.c

@@ -521,24 +521,6 @@ reply_length(lua_State *L) {
 	return 1;
 }
 
-static int
-copy_result(lua_State *L) {
-	if (lua_type(L,2) == LUA_TNIL)
-		return 0;
-	int n1 = lua_rawlen(L,1);
-	int n2 = lua_rawlen(L,2);
-	int i;
-	for (i=0;i<n1;i++) {
-		lua_rawgeti(L,1,i+1);
-		lua_rawseti(L,2,i+1);
-	}
-	for (i=n1;i<n2;i++) {
-		lua_pushnil(L);
-		lua_rawseti(L,2,i+1);
-	}
-	return 0;
-}
-
 int
 luaopen_mongo_driver(lua_State *L) {
 	luaL_checkversion(L);
@@ -551,7 +533,6 @@ luaopen_mongo_driver(lua_State *L) {
 		{ "update", op_update },
 		{ "insert", op_insert },
 		{ "length", reply_length },
-		{ "copy_result", copy_result },
 		{ NULL, NULL },
 	};
 

lualib/mongo.lua

@@ -63,74 +63,28 @@ local collection_meta = {
 	end
 }
 
-local function try_connect(host, port)
-	-- try 10 times
-	for i = 1, 10 do
-		local sock = socket.open(host, port)
-		if not sock then
-			-- todo: write log
-			print("Try to connect " .. host .. " failed")
-			skynet.sleep(100*i)
-		else
-			return sock
-		end
-	end
-	error("Connect to mongo " .. host .. " failed")
-end
-
-local function reconnect(obj)
-	for _,v in pairs(obj.__request) do
-		v.succ = nil
-		-- wakeup request coroutine and send a failure.
-		skynet.wakeup(v.co)
-	end
-	-- todo: reconnect is too simple now.
-	local sock = try_connect(obj.host, obj.port)
-	obj.__sock = sock
-	return sock
-end
-
-local function reply_queue(obj)
-	local sock = obj.__sock
-	local tmp = {}
-	local request_set = obj.__request
-	while true do
-		local len_reply = socket.read(sock, 4)
-		if not len_reply then
-			if not obj.__sock then
-				return
-			end
-			sock = reconnect(obj)
-		else
-			local length = driver.length(len_reply)
-			local reply = socket.read(sock, length)
-			if not reply then
-				if not obj.__sock then
-					return
-				end
-				sock = reconnect(obj)
-			else
-				local succ, reply_id, document, cursor_id, startfrom = driver.reply(reply, tmp)
-				local result = assert(request_set[reply_id])
-				driver.copy_result(tmp, result.result)
-				result.succ = succ
-				result.document = document
-				result.cursor_id = cursor_id
-				result.startfrom = startfrom
-				result.data = reply
-				skynet.wakeup(result.co)
-			end
-		end
-	end
+local function dispatch_reply(so)
+	local len_reply = so:read(4)
+	local reply = so:read(driver.length(len_reply))
+	local result = {}
+	local succ, reply_id, document, cursor_id, startfrom = driver.reply(reply, result)
+	result.document = document
+	result.cursor_id = cursor_id
+	result.startfrom = startfrom
+	result.data = reply
+	return reply_id, succ, result
 end
 
 function mongo.client( obj )
 	obj.port = obj.port or 27017
 	obj.__id = 0
-	obj.__sock = try_connect(obj.host, obj.port)
-	obj.__request = {}
+	obj.__sock = socket.channel {
+		host = obj.host,
+		port = obj.port,
+		response = dispatch_reply,
+	}
 	setmetatable(obj, client_meta)
-	skynet.fork(reply_queue, obj)
+	obj.__sock:connect()
 	return obj
 end
 
@@ -168,14 +122,6 @@ function mongo_client:runCommand(...)
 	return self.admin:runCommand(...)
 end
 
-local function get_reply(conn, request_id, result)
-	local r = { result = result , co = coroutine.running() }
-	conn.__request[request_id] = r
-	skynet.wait()
-	conn.__request[request_id] = nil
-	return r.data, r.succ, r.document, r.cursor_id, r.startfrom
-end
-
 function mongo_db:runCommand(cmd,cmd_v,...)
 	local conn = self.connection
 	local request_id = conn:genId()
@@ -187,11 +133,7 @@ function mongo_db:runCommand(cmd,cmd_v,...)
 		bson_cmd = bson_encode_order(cmd,cmd_v,...)
 	end
 	local pack = driver.query(request_id, 0, self.__cmd, 0, 1, bson_cmd)
-	-- todo: check send
-	assert(socket.write(sock, pack), "write fail")
-	local _, succ, doc = get_reply(conn,request_id)
-	-- todo: check succ and doc
-	assert(succ, "runCommand error")
+	local doc = sock:request(pack, request_id).document
 	return bson_decode(doc)
 end
 
@@ -214,9 +156,8 @@ function mongo_collection:insert(doc)
 	end
 	local sock = self.connection.__sock
 	local pack = driver.insert(0, self.full_name, bson_encode(doc))
-	-- todo: check send
 	-- flags support 1: ContinueOnError
-	assert(socket.write(sock, pack), "write fail")
+	sock:request(pack)
 end
 
 function mongo_collection:batch_insert(docs)
@@ -228,23 +169,20 @@ function mongo_collection:batch_insert(docs)
 	end
 	local sock = self.connection.__sock
 	local pack = driver.insert(0, self.full_name, docs)
-	-- todo: check send
-	assert(socket.write(sock, pack), "write fail")
+	sock:request(pack)
 end
 
 function mongo_collection:update(selector,update,upsert,multi)
 	local flags = (upsert and 1 or 0) + (multi and 2 or 0)
 	local sock = self.connection.__sock
 	local pack = driver.update(self.full_name, flags, bson_encode(selector), bson_encode(update))
-	-- todo: check send
-	assert(socket.write(sock, pack),"write fail")
+	sock:request(pack)
 end
 
 function mongo_collection:delete(selector, single)
 	local sock = self.connection.__sock
 	local pack = driver.delete(self.full_name, single, bson_encode(selector))
-	-- todo: check send
-	assert(socket.write(sock, pack), "write fail")
+	sock:request(pack)
 end
 
 function mongo_collection:findOne(query, selector)
@@ -252,12 +190,7 @@ function mongo_collection:findOne(query, selector)
 	local request_id = conn:genId()
 	local sock = conn.__sock
 	local pack = driver.query(request_id, 0, self.full_name, 0, 1, query and bson_encode(query) or empty_bson, selector and bson_encode(selector))
-
-	-- todo: check send
-	assert(socket.write(sock, pack),"write fail")
-
-	local _, succ, doc = get_reply(conn, request_id)
-	-- todo: check succ
+	local doc = sock:request(pack, request_id).document
 	return bson_decode(doc)
 end
 
@@ -296,12 +229,14 @@ function mongo_cursor:hasNext()
 			end
 		end
 
-		--todo: check send
-		assert(socket.write(sock, pack),"write fail")
+		local ok, result = pcall(sock.request,sock,pack, request_id)
 
-		local data, succ, doc, cursor = get_reply(conn, request_id, self.__document)
-		if succ then
+		local doc = result.document
+		local cursor = result.cursor_id
+
+		if ok then
 			if doc then
+				self.__document = doc
 				self.__data = data
 				self.__ptr = 1
 				self.__cursor = cursor
@@ -346,8 +281,7 @@ function mongo_cursor:close()
 	if self.__cursor then
 		local sock = self.__collection.connection.__sock
 		local pack = driver.kill(self.__cursor)
-		-- todo: check send
-		assert(socket.write(sock, pack),"write fail")
+		sock:request(pack)
 	end
 end
 

lualib/redis.lua

@@ -4,8 +4,6 @@ local config = require "config"
 local redis_conf = skynet.getenv "redis"
 local name = config (redis_conf)
 
-local readline = socket.readline
-local readbytes = socket.read
 local table = table
 local string = string
 
@@ -14,26 +12,87 @@ local command = {}
 local meta = {
 	__index = command,
 	__gc = function(self)
-		socket.close(self.__handle)
+		self[1]:close()
 	end,
 }
 
-function redis.connect(dbname)
-	local db_conf   =   name[dbname]
-	local fd = assert(socket.open(db_conf.host, db_conf.port or 6379))
-	local r = setmetatable( { __handle = fd, __mode = false }, meta )
-	if db_conf.auth ~= nil then
-		r:auth(db_conf.auth)
-	end
-	if db_conf.db ~= nil then
-		r:select(db_conf.db)
-	end
+---------- redis response
+local redcmd = {}
 
-	return r
+redcmd[42] = function(fd, data)	-- '*'
+	local n = tonumber(data)
+	if n < 0 then
+		return true, nil
+	end
+	local bulk = {}
+	for i = 1,n do
+		local line = fd:readline "\r\n"
+		local bytes = tonumber(string.sub(line,2))
+		if bytes >= 0 then
+			local data = fd:read(bytes + 2)
+			-- bulk[i] = nil when bytes < 0
+			bulk[i] = string.sub(data,1,-3)
+		end
+	end
+	return true, bulk
+end
+
+redcmd[36] = function(fd, data) -- '$'
+	local bytes = tonumber(data)
+	if bytes < 0 then
+		return true,nil
+	end
+	local firstline = fd:read(bytes+2)
+	return true,string.sub(firstline,1,-3)
+end
+
+redcmd[43] = function(fd, data) -- '+'
+	return true,data
+end
+
+redcmd[45] = function(fd, data) -- '-'
+	return false,data
+end
+
+redcmd[58] = function(fd, data) -- ':'
+	-- todo: return string later
+	return true, tonumber(data)
+end
+
+local function read_response(fd)
+	local result = fd:readline "\r\n"
+	local firstchar = string.byte(result)
+	local data = string.sub(result,2)
+	return redcmd[firstchar](fd,data)
+end
+-------------------
+
+local function redis_login(auth, db)
+	if auth == nil and db == nil then
+		return
+	end
+	return function(so)
+		if auth then
+			so:request("AUTH "..auth.."\r\n", read_response)
+		end
+		if db then
+			so:request("SELECT "..db.."\r\n", read_response)
+		end
+	end
+end
+
+function redis.connect(dbname)
+	local db_conf = name[dbname]
+	local channel = socket.channel {
+		host = db_conf.host,
+		port = db_conf.port or 6379,
+		auth = redis_login(db_conf.auth, db_conf.db),
+	}
+	return setmetatable( { channel }, meta )
 end
 
 function command:disconnect()
-	socket.close(self.__handle)
+	self[1]:close()
 	setmetatable(self, nil)
 end
 
@@ -58,140 +117,32 @@ local function compose_message(msg)
 	return cmd
 end
 
-local redcmd = {}
-
-redcmd[42] = function(fd, data)	-- '*'
-	local n = tonumber(data)
-	if n < 0 then
-		return true, nil
-	end
-	local bulk = {}
-	for i = 1,n do
-		local line = readline(fd,"\r\n")
-		local bytes = tonumber(string.sub(line,2))
-		if bytes >= 0 then
-			local data = readbytes(fd, bytes + 2)
-			-- bulk[i] = nil when bytes < 0
-			bulk[i] = string.sub(data,1,-3)
-		end
-	end
-	return true, bulk
-end
-
-redcmd[36] = function(fd, data) -- '$'
-	local bytes = tonumber(data)
-	if bytes < 0 then
-		return true,nil
-	end
-	local firstline = readbytes(fd, bytes+2)
-	return true,string.sub(firstline,1,-3)
-end
-
-redcmd[43] = function(fd, data) -- '+'
-	return true,data
-end
-
-redcmd[45] = function(fd, data) -- '-'
-	return false,data
-end
-
-redcmd[58] = function(fd, data) -- ':'
-	-- todo: return string later
-	return true, tonumber(data)
-end
-
-local function read_response(fd)
-	local result = readline(fd, "\r\n")
-	local firstchar = string.byte(result)
-	local data = string.sub(result,2)
-	return redcmd[firstchar](fd,data)
-end
-
 setmetatable(command, { __index = function(t,k)
 	local cmd = string.upper(k)
 	local f = function (self, ...)
-		local fd = self.__handle
-		if self.__mode then
-			socket.write(fd, compose_message { cmd, ... })
-			self.__batch = self.__batch + 1
-		else
-			socket.lock(fd)
-			socket.write(fd, compose_message { cmd, ... })
-			local ok, ret = read_response(fd)
-			socket.unlock(fd)
-			assert(ok, ret)
-			return ret
-		end
+		return self[1]:request(compose_message { cmd, ... }, read_response)
 	end
 	t[k] = f
 	return f
 end})
 
+local function read_boolean(so)
+	local ok, result = read_response(so)
+	return ok, result ~= 0
+end
+
 function command:exists(key)
-	assert(not self.__mode, "exists can't used in batch mode")
-	local fd = self.__handle
-	socket.lock(fd)
-	socket.write(fd, compose_message { "EXISTS", key })
-	local ok, exists = read_response(fd)
-	socket.unlock(fd)
-	assert(ok, exists)
-	return exists ~= 0
+	local fd = self[1]
+	return fd:request(compose_message { "EXISTS", key }, read_boolean)
 end
 
 function command:sismember(key, value)
-	assert(not self.__mode, "sismember can't used in batch mode")
-	local fd = self.__handle
-	socket.lock(fd)
-	socket.write(fd, compose_message { "SISMEMBER", key, value })
-	local ok, ismember = read_response(fd)
-	socket.unlock(fd)
-	assert(ok, ismember)
-	return ismember ~= 0
-end
-
-function command:batch(mode)
-	if mode == "end" then
-		local fd = self.__handle
-		if self.__mode == "read" then
-			local allok = true
-			local allret = {}
-			for i = 1, self.__batch do
-				local ok, ret = read_response(fd)
-				allok = allok and ok
-				allret[i] = ret
-			end
-			self.__mode = false
-			socket.unlock(self.__handle)
-			assert(allok, "batch read failed")
-			return allret
-		else
-			local allok = true
-			for i = 1, self.__batch do
-				local ok = read_response(fd)
-				allok = allok and ok
-			end
-			self.__mode = false
-			socket.unlock(self.__handle)
-			return allok
-		end
-	else
-		assert(mode == "read" or mode == "write")
-		socket.lock(self.__handle)
-		self.__mode = mode
-		self.__batch = 0
-	end
-end
-
-function command:multi()
-	local fd = self.__handle
-	socket.lock(fd)
-	self.__mode = "multi"
-	self.__batch = 0
-	socket.write(fd, "MULTI\r\n")
+	local fd = self[1]
+	return fd:request(compose_message { "SISMEMBER", key, value }, read_boolean)
 end
 
 local function read_exec(fd)
-	local result = readline(fd, "\r\n")
+	local result = fd:readline "\r\n"
 	local firstchar = string.byte(result)
 	local data = string.sub(result,2)
 	if firstchar ~= 42 then
@@ -203,57 +154,24 @@ local function read_exec(fd)
 	local err = nil
 	for i = 1,n do
 		local ok, r = read_response(fd)
-		result[i] = r
-		if err then
-			err[i] = ok
+		if ok then
+			result[i] = r
 		else
-			if ok == false then
+			if not err then
 				err = {}
-				for j = 1, i-1 do
-					err[j] = true
-				end
-				err[i] = false
 			end
+			table.insert(err, i .. ":" .. r)
 		end
 	end
-	return result, err
+	if err then
+		return false, table.concat(err,",")
+	else
+		return true, result
+	end
 end
 
 function command:exec()
-	if self.__mode ~= "multi" then
-		error "call multi first"
-	end
-	local fd = self.__handle
-	socket.write(fd, "EXEC\r\n")
-	local allok = true
-	for i = 0, self.__batch do
-		local ok, queue = read_response(fd)
-		allok = allok and ok
-	end
-	if not allok then
-		self.__mode = false
-		socket.unlock(fd)
-		error "Queue command error"
-	end
-
-	local result, err = read_exec(fd)
-
-	self.__mode = false
-	socket.unlock(fd)
-
-	if not result then
-		error(err)
-	elseif err then
-		local errmsg = ""
-		for k,v in ipairs(err) do
-			if v == false then
-				errmsg = errmsg .. k .. ":" .. result[k]
-			end
-		end
-		error(errmsg)
-	end
-
-	return result
+	return self[1]:request( "EXEC\r\n" , read_exec)
 end
 
 return redis

lualib/socket.lua

@@ -93,11 +93,14 @@ end
 
 -- SKYNET_SOCKET_TYPE_ERROR = 5
 socket_message[5] = function(id)
-	print("error on ", id)
 	local s = socket_pool[id]
 	if s == nil then
+		print("socket: error on unknown", id)
 		return
 	end
+	if s.connected then
+		print("socket: error on", id)
+	end
 	s.connected = false
 	wakeup(s)
 end
@@ -146,6 +149,18 @@ function socket.start(id, func)
 	return connect(id, func)
 end
 
+local function clear_socket(id)
+	local s = socket_pool[id]
+	if s then
+		if s.buffer then
+			driver.clear(s.buffer,buffer_pool)
+		end
+		if s.connected then
+			driver.close(id)
+		end
+	end
+end
+
 function socket.close(id)
 	local s = socket_pool[id]
 	if s == nil then
@@ -163,10 +178,9 @@ function socket.close(id)
 		else
 			suspend(s)
 		end
+		s.connected = false
 	end
-	if s.buffer then
-		driver.clear(s.buffer,buffer_pool)
-	end
+	clear_socket(id)
 	assert(s.lock_set == nil or next(s.lock_set) == nil)
 	socket_pool[id] = nil
 end
@@ -235,6 +249,17 @@ function socket.readline(id, sep)
 	end
 end
 
+function socket.block(id)
+	local s = socket_pool[id]
+	if not s or not s.connected then
+		return false
+	end
+	assert(not s.read_required)
+	s.read_required = 0
+	suspend(s)
+	return s.connected
+end
+
 socket.write = assert(driver.send)
 
 function socket.invalid(id)
@@ -251,10 +276,10 @@ function socket.lock(id)
 		lock_set = {}
 		s.lock = lock_set
 	end
-	local co = coroutine.running()
 	if #lock_set == 0 then
-		lock_set[1] = co
+		lock_set[1] = true
 	else
+		local co = coroutine.running()
 		table.insert(lock_set, co)
 		skynet.wait()
 	end
@@ -263,12 +288,9 @@ end
 function socket.unlock(id)
 	local s = socket_pool[id]
 	assert(s)
-	local lock_set = s.lock
-	assert(lock_set)
-	local co = coroutine.running()
-	assert(lock_set[1] == co)
+	local lock_set = assert(s.lock)
 	table.remove(lock_set,1)
-	co = lock_set[1]
+	local co = lock_set[1]
 	if co then
 		skynet.wakeup(co)
 	end
@@ -284,4 +306,251 @@ function socket.abandon(id)
 	socket_pool[id] = nil
 end
 
+-- channel support auto reconnect , and capture socket error in request/response transaction
+-- { host = "", port = , auth = function(so) , response = function(so) session, data }
+
+local channel = {}
+local channel_socket = {}
+local channel_meta = { __index = channel }
+local channel_socket_meta = {
+	__index = channel_socket,
+	__gc = function(cs)
+		local fd = cs[1]
+		cs[1] = false
+		if fd then
+			clear_socket(fd)
+		end
+	end
+}
+local socket_error = channel_socket	-- alias for error object
+
+function socket.channel(desc)
+	local c = {
+		__host = assert(desc.host),
+		__port = assert(desc.port),
+		__auth = desc.auth,
+		__response = desc.response,
+		__request = {},	-- request seq { response func or session }
+		__thread = {}, -- coroutine seq or session->coroutine map
+		__result = {}, -- response result { coroutine -> result }
+		__result_data = {},
+		__connecting = {},
+		__sock = false,
+		__closed = false,
+	}
+
+	return setmetatable(c, channel_meta)
+end
+
+local function close_channel_socket(self)
+	if self.__sock then
+		local so = self.__sock
+		self.__sock = false
+		socket.close(so[1])
+	end
+end
+
+local function wakeup_all(self, errmsg)
+	for i = 1, #self.__thread do
+		local co = self.__thread[i]
+		self.__thread[i] = nil
+		self.__result[co] = socket_error
+		self.__result_data[co] = errmsg
+		skynet.wakeup(co)
+	end
+end
+
+local function dispatch_response(self)
+	local response = self.__response
+	if response then
+		-- response() return session
+		while self.__sock do
+			local ok , session, result_ok, result_data = pcall(response, self.__sock)
+			if ok then
+				local co = self.__thread[session]
+				self.__thread[session] = nil
+				if co then
+					self.__result[co] = result_ok
+					self.__result_data[co] = result_data
+					skynet.wakeup(co)
+				else
+					print("socket: unknown session :", session)
+				end
+			else
+				close_channel_socket(self)
+				local errormsg
+				if session ~= socket_error then
+					errormsg = session
+				end
+				for k,co in pairs(self.__thread) do
+					-- throw error (errormsg)
+					self.__thread[k] = nil
+					self.__result[co] = socket_error
+					self.__result_data[co] = errormsg
+					skynet.wakeup(co)
+				end
+			end
+		end
+	else
+		-- pop response function from __request
+		while self.__sock do
+			local func = table.remove(self.__request, 1)
+			if func == nil then
+				if not socket.block(self.__sock[1]) then
+					close_channel_socket(self)
+					wakeup_all(self)
+				end
+			else
+				local ok, result_ok, result_data = pcall(func, self.__sock)
+				if ok then
+					local co = table.remove(self.__thread, 1)
+					self.__result[co] = result_ok
+					self.__result_data[co] = result_data
+					skynet.wakeup(co)
+				else
+					close_channel_socket(self)
+					local errmsg
+					if result ~= socket_error then
+						errmsg = result_ok
+					end
+					wakeup_all(self, errmsg)
+				end
+			end
+		end
+	end
+end
+
+local function try_connect(self)
+	assert(not self.__sock)
+	local fd = socket.open(self.__host, self.__port)
+	if not fd then
+		return
+	end
+	self.__sock = setmetatable( {fd} , channel_socket_meta )
+	skynet.fork(dispatch_response, self)
+
+	if self.__auth then
+		local ok , message = pcall(self.__auth, self)
+		if not ok then
+			close_channel_socket(self)
+			if message ~= socket_error then
+				error(message)
+			end
+		end
+	end
+end
+
+function channel:connect()
+	if self.__sock then
+		return true
+	end
+	if self.__closed then
+		self.__closed = false
+	end
+	if #self.__connecting > 0 then
+		-- connecting in other coroutine
+		local co = coroutine.running()
+		table.insert(self.__connecting, co)
+		skynet.wait()
+	else
+		self.__connecting[1] = true
+		try_connect(self)
+		self.__connecting[1] = nil
+		for i=2, #self.__connecting do
+			local co = self.__connecting[i]
+			self.__connecting[i] = nil
+			skynet.wakeup(co)
+		end
+	end
+
+	if self.__sock then
+		return true
+	else
+		return false
+	end
+end
+
+local function reconnect_channel(self)
+	local t = 100
+	while not self.__closed do
+		if self:connect() then
+			return
+		end
+		if t > 1000 then
+			print("socket: try to reconnect", self.__host, self.__port)
+			skynet.sleep(t)
+			t = 0
+		else
+			skynet.sleep(t)
+		end
+		t = t + 100
+	end
+end
+
+function channel:request(request, response)
+	if not self.__sock then
+		assert(not self.__closed)
+		reconnect_channel(self)
+	end
+
+	if not socket.write(self.__sock[1], request) then
+		return self:request(request, response)
+	end
+
+	if response == nil then
+		-- no response
+		return
+	end
+
+	local co = coroutine.running()
+
+	if self.__response then
+		-- response is session
+		self.__thread[response] = co
+	else
+		-- response is a function, push it to __request
+		table.insert(self.__request, response)
+		table.insert(self.__thread, co)
+	end
+	skynet.wait()
+
+	local result = self.__result[co]
+	self.__result[co] = nil
+	local result_data = self.__result_data[co]
+	self.__result_data[co] = nil
+
+	if result == socket_error then
+		if result_data then
+			print("socket: dispatch", request, result_data)
+		end
+		return self:request(request, response)
+	else
+		assert(result, result_data)
+		return result_data
+	end
+end
+
+function channel:close()
+	if not self.__closed then
+		self.__closed = true
+		close_channel_socket(self)
+	end
+end
+
+channel_meta.__gc = channel.close
+
+local function wrapper_socket_function(f)
+	return function(self, ...)
+		local result = f(self[1], ...)
+		if not result then
+			error(socket_error)
+		else
+			return result
+		end
+	end
+end
+
+channel_socket.read = wrapper_socket_function(socket.read)
+channel_socket.readline = wrapper_socket_function(socket.readline)
+
 return socket

service/testredis.lua

@@ -3,34 +3,32 @@ local redis = require "redis"
 
 skynet.start(function()
 	local db = redis.connect "main"
-	print(db:select(0))
-	db:batch "write"	-- ignore results
-		db:del "C"
-		db:set("A", "hello")
-		db:set("B", "world")
-		db:sadd("C", "one")
-	print(db:batch "end")
+	db:del "C"
+	db:set("A", "hello")
+	db:set("B", "world")
+	db:sadd("C", "one")
 
-	db:batch "read"
-		db:get("A")
-		db:get("B")
-	local r = db:batch "end" -- return all results in a table
-	for k,v in pairs(r) do
-		print(k,v)
-	end
+	print(db:get("A"))
+	print(db:get("B"))
 
-	db:batch "write"
 	db:del "D"
 	for i=1,1000 do
 		db:hset("D",i,i)
 	end
-	db:batch "end"
 	local r = db:hvals "D"
 	for k,v in pairs(r) do
 		print(k,v)
 	end
 
-
+--[[
+	db:multi()
+	db:get "A"
+	db:get "B"
+	local t = db:exec()
+	for k,v in ipairs(t) do
+		print("Exec", v)
+	end
+]]
 	print(db:exists "A")
 	print(db:get "A")
 	print(db:set("A","hello world"))