add luajit bindings

bindings/luajit/pollnet.lua

@@ -0,0 +1,144 @@
+--[[ 
+pollnet bindings for luajit
+
+example usage to read twitch chat:
+local pollnet = require("pollnet")
+local async = require("async") -- assuming you have some kind of async
+async.run(function()
+  local url = "wss://irc-ws.chat.twitch.tv:443"
+  local sock = pollnet.open_ws(url)
+  sock:send("PASS doesntmatter")
+  -- special nick for anon read-only access on twitch
+  local anon_user_name = "justinfan" .. math.random(1, 100000)
+  local target_channel = "your_channel_name_here"
+  sock:send("NICK " .. anon_user_name)
+  sock:send("JOIN #" .. target_channel)
+  
+  while sock:poll() do
+    local msg = sock:last_message()
+    if msg then
+      if msg == "PING :tmi.twitch.tv" then
+        sock:send("PONG :tmi.twitch.tv")
+      end
+      print(msg) 
+    end
+    async.await_frames(1)
+  end
+  print("Socket closed: ", sock:last_message())
+end)
+]]
+
+local ffi = require("ffi")
+ffi.cdef[[
+struct pnctx* pollnet_init();
+void pollnet_shutdown(struct pnctx* ctx);
+unsigned int pollnet_open_ws(struct pnctx* ctx, const char* url);
+void pollnet_close(struct pnctx* ctx, unsigned int handle);
+void pollnet_send(struct pnctx* ctx, unsigned int handle, const char* msg);
+unsigned int pollnet_update(struct pnctx* ctx, unsigned int handle);
+int pollnet_get(struct pnctx* ctx, unsigned int handle, char* dest, unsigned int dest_size);
+int pollnet_get_error(struct pnctx* ctx, unsigned int handle, char* dest, unsigned int dest_size);
+]]
+
+local POLLNET_RESULT_CODES = {
+  [0] = "invalid_handle",
+  [1] = "closed",
+  [2] = "opening",
+  [3] = "nodata",
+  [4] = "hasdata",
+  [5] = "error",
+}
+
+local pollnet = ffi.load("pollnet")
+local _ctx = nil
+
+local function init_ctx()
+  if _ctx then return end
+  _ctx = pollnet.pollnet_init()
+  assert(_ctx ~= nil)
+end
+
+local function shutdown_ctx()
+  if not _ctx then return end
+  pollnet.pollnet_shutdown(_ctx)
+  _ctx = nil
+end
+
+local socket_mt = {}
+function socket_mt:_open(scratch_size, opener, ...)
+  init_ctx()
+  if self._socket then self:close() end
+  if not scratch_size then scratch_size = 64000 end
+  self._socket = opener(_ctx, ...) --pollnet.pollnet_open(url)
+  self._scratch = ffi.new("int8_t[?]", scratch_size)
+  self._scratch_size = scratch_size
+  self._status = "unpolled"
+end
+
+function socket_mt:open_ws(url, scratch_size)
+  self:_open(scratch_size, pollnet.pollnet_open_ws, url)
+end
+
+function socket_mt:poll()
+  if not self._socket then 
+    self._status = "invalid"
+    return false, "invalid"
+  end
+  local res = POLLNET_RESULT_CODES[pollnet.pollnet_update(_ctx, self._socket)] or "error"
+  self._status = res
+  self._last_message = nil
+  if res == "hasdata" then
+    self._status = "open"
+    local msg_size = pollnet.pollnet_get(_ctx, self._socket, self._scratch, self._scratch_size)
+    if msg_size > 0 then
+      self._last_message = ffi.string(self._scratch, msg_size)
+    end
+    return true, self._last_message
+  elseif res == "nodata" then
+    self._status = "open"
+    return true
+  elseif res == "opening" then
+    self._status = "opening"
+    return true
+  elseif res == "error" then
+    self._last_message = self:error_msg()
+    self._socket = nil -- hmm
+    return false, self._last_message
+  elseif res == "closed" then
+    return false, "closed"
+  end
+end
+
+function socket_mt:last_message()
+  return self._last_message
+end
+function socket_mt:status()
+  return self._status
+end
+function socket_mt:send(msg)
+  assert(self._socket)
+  pollnet.pollnet_send(_ctx, self._socket, msg)
+end
+function socket_mt:close()
+  assert(self._socket)
+  pollnet.pollnet_close(_ctx, self._socket)
+  self._socket = nil
+end
+function socket_mt:error_msg()
+  if not self._socket then return "No socket!" end
+  local msg_size = pollnet.pollnet_get_error(_ctx, self._socket, self._scratch, self._scratch_size)
+  if msg_size > 0 then
+    local smsg = ffi.string(self._scratch, msg_size)
+    return smsg
+  else
+    return nil
+  end
+end
+
+local function open_ws(url, scratch_size)
+  local socket = setmetatable({}, {__index = socket_mt})
+  socket:open_ws(url, scratch_size)
+  return socket
+end
+
+return {init = init_ctx, shutdown = shutdown_ctx, open_ws = open_ws, pollnet = pollnet}