最近迷上了skynet，代码质量很高，算开源游戏服务器框架中的佼佼者，不管是Python的firefly，C++/Python的kbengine，C#的scut，还是nodejs的pomelo，skynet在并发上和商业应用都有很大的优势，根据http://thislinux.com/blog/5_panic.html描述，skynet能支持单机3w在线用户，性能很是给力。
最近做的都是一些h5小游戏，用tornado/django基本上也都绰绰有余，下个小游戏打算试试skynet，skynet没有带websocket库，于是就很happy的去造*去了，虽然有lua-resty-websocket这个nginx扩展库，有2个原因我不喜欢。
1.lua-resty-websocket实在太老了，现在已经是lua53的时代了
2.还是喜欢tornado websocket的基于回调的方式，当然我写的既可使用回调方式，也可使用lua-resty-websocket
基于直接recv的方式
其实解析websocket还是比较简单的，比较复杂点的是websocket 的close操作。和握手一样，close也是需要客户端-服务器
端确认的。
当客户端->close ->服务端，服务端接收到opcode为8的close事件，服务端发送close frame,然后关闭客户端socket
当服务端->close ->客户端，服务器发送close frame，此时客户端得到close事件，客户端接着会主动发送close frame给服务端，服务端接收到
opcode为8的close事件，关闭客户端socket。
这里需要注意，如果用js 的话，var ws = new WebSocket('XXXX')，在onclose事件中不需要主动调用ws.close()，底层会帮你调用。
local skynet = require "skynet"
local string = require "string"
local crypt = require "crypt"
local socket = require "socket"
local httpd = require "http.httpd"
local sockethelper = require "http.sockethelper"
local urllib = require "http.url"
local ws = {}
local ws_mt = { __index = ws }
local function response(id, ...)
return httpd.write_response(sockethelper.writefunc(id), ...)
end
local function write(id, data)
socket.write(id, data)
end
local function read(id, sz)
return socket.read(id, sz)
end
local function challenge_response(key, protocol)
local accept = crypt.base64encode(crypt.sha1(key .. "258EAFA5-E914-47DA-95CA-C5AB0DC85B11"))
return string.format("HTTP/1.1 101 Switching Protocols\r\n" ..
"Upgrade: websocket\r\n" ..
"Connection: Upgrade\r\n" ..
"Sec-WebSocket-Accept: %s\r\n" ..
"%s\r\n", accept, protocol or "")
end
local function accept_connection(header, check_origin, check_origin_ok)
-- Upgrade header should be present and should be equal to WebSocket
if not header["upgrade"] or header["upgrade"]:lower() ~= "websocket" then
return 400, "Can \"Upgrade\" only to \"WebSocket\"."
end
-- Connection header should be upgrade. Some proxy servers/load balancers
-- might mess with it.
if not header["connection"] or not header["connection"]:lower():find("upgrade", 1,true) then
return 400, "\"Connection\" must be \"Upgrade\"."
end
-- Handle WebSocket Origin naming convention differences
-- The difference between version 8 and 13 is that in 8 the
-- client sends a "Sec-Websocket-Origin" header and in 13 it's
-- simply "Origin".
local origin = header["origin"] or header["sec-websocket-origin"]
if origin and check_origin and not check_origin_ok(origin, header["host"]) then
return 403, "Cross origin websockets not allowed"
end
if not header["sec-websocket-version"] or header["sec-websocket-version"] ~= "13" then
return 400, "HTTP/1.1 Upgrade Required\r\nSec-WebSocket-Version: 13\r\n\r\n"
end
local key = header["sec-websocket-key"]
if not key then
return 400, "\"Sec-WebSocket-Key\" must not be nil."
end
local protocol = header["sec-websocket-protocol"]
if protocol then
local i = protocol:find(",", 1, true)
protocol = "Sec-WebSocket-Protocol: " .. protocol:sub(1, i or i-1)
end
return nil, challenge_response(key, protocol)
end
local H = {}
function H.check_origin_ok(origin, host)
return urllib.parse(origin) == host
end
function H.on_open(ws)
end
function H.on_message(ws, message)
end
function H.on_close(ws, code, reason)
end
function H.on_pong(ws, data)
-- Invoked when the response to a ping frame is received.
end
function ws.new(id, header, handler, conf)
local conf = conf or {}
local handler = handler or {}
setmetatable(handler, { __index = H })
local code, result = accept_connection(header, conf.check_origin, handler.check_origin_ok)
if code then
response(id, code, result)
socket.close(id)
else
write(id, result)
end
local self = {
id = id,
handler = handler,
mask_outgoing = conf.mask_outgoing,
check_origin = conf.check_origin
}
self.handler.on_open(self)
return setmetatable(self, ws_mt)
end
function ws:send_frame(fin, opcode, data)
if fin then
finbit = 0x80
else
finbit = 0
end
frame = string.pack("B", finbit | opcode)
l = #data
if self.mask_outgoing then
mask_bit = 0x80
else
mask_bit = 0
end
if l < 126 then
frame = frame .. string.pack("B", l | mask_bit)
elseif l < 0xFFFF then
frame = frame .. string.pack("!BH", 126 | mask_bit, l)
else
frame = frame .. string.pack("!BL", 127 | mask_bit, l)
end
if self.mask_outgoing then
end
frame = frame .. data
write(self.id, frame)
end
function ws:send_text(data)
self:send_frame(true, 0x1, data)
end
function ws:send_binary(data)
self:send_frame(true, 0x2, data)
end
function ws:send_ping(data)
self:send_frame(true, 0x9, data)
end
function ws:send_pong(data)
self:send_frame(true, 0xA, data)
end
function ws:close(code, reason)
-- 1000 "normal closure" status code
if code == nil and reason ~= nil then
code = 1000
end
local data = ""
if code ~= nil then
data = string.pack(">H", code)
end
if reason ~= nil then
data = data .. reason
end
self:send_frame(true, 0x8, data)
end
function ws:recv()
local data = ""
while true do
local success, final, message = self:recv_frame()
if not success then
return success, message
end
if final then
data = data .. message
break
else
data = data .. message
end
end
self.handler.on_message(self, data)
return data
end
local function websocket_mask(mask, data, length)
umasked = {}
for i=1, length do
umasked[i] = string.char(string.byte(data, i) ~ string.byte(mask, (i-1)%4 + 1))
end
return table.concat(umasked)
end
function ws:recv_frame()
local data, err = read(self.id, 2)
if not data then
return false, nil, "Read first 2 byte error: " .. err
end
local header, payloadlen = string.unpack("BB", data)
local final_frame = header & 0x80 ~= 0
local reserved_bits = header & 0x70 ~= 0
local frame_opcode = header & 0xf
local frame_opcode_is_control = frame_opcode & 0x8 ~= 0
if reserved_bits then
-- client is using as-yet-undefined extensions
return false, nil, "Reserved_bits show using undefined extensions"
end
local mask_frame = payloadlen & 0x80 ~= 0
payloadlen = payloadlen & 0x7f
if frame_opcode_is_control and payloadlen >= 126 then
-- control frames must have payload < 126
return false, nil, "Control frame payload overload"
end
if frame_opcode_is_control and not final_frame then
return false, nil, "Control frame must not be fragmented"
end
local frame_length, frame_mask
if payloadlen < 126 then
frame_length = payloadlen
elseif payloadlen == 126 then
local h_data, err = read(self.id, 2)
if not h_data then
return false, nil, "Payloadlen 126 read true length error:" .. err
end
frame_length = string.pack("!H", h_data)
else --payloadlen == 127
local l_data, err = read(self.id, 8)
if not l_data then
return false, nil, "Payloadlen 127 read true length error:" .. err
end
frame_length = string.pack("!L", l_data)
end
if mask_frame then
local mask, err = read(self.id, 4)
if not mask then
return false, nil, "Masking Key read error:" .. err
end
frame_mask = mask
end
--print('final_frame:', final_frame, "frame_opcode:", frame_opcode, "mask_frame:", mask_frame, "frame_length:", frame_length)
local frame_data = ""
if frame_length > 0 then
local fdata, err = read(self.id, frame_length)
if not fdata then
return false, nil, "Payload data read error:" .. err
end
frame_data = fdata
end
if mask_frame and frame_length > 0 then
frame_data = websocket_mask(frame_mask, frame_data, frame_length)
end
if not final_frame then
return true, false, frame_data
else
if frame_opcode == 0x1 then -- text
return true, true, frame_data
elseif frame_opcode == 0x2 then -- binary
return true, true, frame_data
elseif frame_opcode == 0x8 then -- close
local code, reason
if #frame_data >= 2 then
code = string.unpack(">H", frame_data:sub(1,2))
end
if #frame_data > 2 then
reason = frame_data:sub(3)
end
self:close()
socket.close(self.id)
self.handler.on_close(self, code, reason)
elseif frame_opcode == 0x9 then --Ping
self:send_pong()
elseif frame_opcode == 0xA then -- Pong
self.handler.on_pong(self, frame_data)
end
return true, true, nil
end
end
function ws:start()
while true do
local message, err = self:recv()
if not message then
--print('recv eror:', message, err)
socket.close(self.id)
end
end
end
return ws
是用方法也很简单，基于回调的方式用起来真是舒服
local skynet = require "skynet"local socket = require "socket"local string = require "string"local websocket = require "websocket"local httpd = require "http.httpd"local urllib = require "http.url"local sockethelper = require "http.sockethelper"local handler = {}function handler.on_open(ws) print(string.format("%d::open", ws.id))endfunction handler.on_message(ws, message) print(string.format("%d receive:%s", ws.id, message)) ws:send_text(message .. "from server")endfunction handler.on_close(ws, code, reason) print(string.format("%d close:%d %s", ws.id, code, reason))endlocal function handle_socket(id) -- limit request body size to 8192 (you can pass nil to unlimit) local code, url, method, header, body = httpd.read_request(sockethelper.readfunc(id), 8192) if code then if url == "/ws" then local ws = websocket.new(id, header, handler) ws:start() end endendskynet.start(function() local address = "0.0.0.0:8001" skynet.error("Listening "..address) local id = assert(socket.listen(address)) socket.start(id , function(id, addr) socket.start(id) pcall(handle_socket, id) end)end)
详细信息请到 https://github.com/Skycrab/skynet_websocket