chrome app that can send UDP packets to an echo server

1 files changed, 125 insertions, 0 deletions

diff --git a/socket.js b/socket.js
new file mode 100644
index 0000000..a10b335
--- /dev/null
+++ b/socket.js
@@ -0,0 +1,125 @@
+exports.UDPSocket = UDPSocket
+// exports.TCPSocket = TCPSocket
+
+var EventEmitter = require('events').EventEmitter
+var string = require('./lib/string')
+var util = require('util')
+
+util.inherits(BaseSocket, EventEmitter)
+
+function BaseSocket (host, port) {
+  var self = this
+  self.host = host
+  self.port = port
+
+  self.paused = true
+  self.readPending = false
+
+  EventEmitter.call(self)
+}
+
+BaseSocket.prototype.connect = function (cb) {
+  var self = this
+  self._create(function (err, id) {
+    if (err) return cb(err)
+    self.id = id
+    chrome.socket.connect(self.id, self.host, self.port, function (res) {
+      if (res === 0) cb(null)
+      else cb(new Error('Unexpected connect result:' + res))
+    })
+  })
+}
+
+BaseSocket.prototype.end = function () {
+  var self = this
+  if (!self.id) return
+  chrome.socket.destroy(self.id)
+  self.id = null // mark socket as destroyed
+}
+
+BaseSocket.prototype.getInfo = function (cb) {
+  var self = this
+  chrome.socket.getInfo(self.id, cb)
+}
+
+BaseSocket.prototype.pause = function () {
+  var self = this
+  self.paused = true
+}
+
+BaseSocket.prototype.resume = function () {
+  var self = this
+  self.paused = false
+  self.read()
+}
+
+BaseSocket.prototype.read = function (readLength) {
+  var self = self
+  if (self.paused || self.readPending) return
+  self.readPending = true
+
+  chrome.socket.read(self.id, readLength, function (readInfo) {
+    self.readPending = false
+    if (readInfo.resultCode < 0) return self.end()
+
+    if (readInfo.data) {
+      self.emit('data', readInfo.data)
+      try {
+        // only read if not closed
+        if (self.id) self.read()
+      } catch (e) {
+        self.emit('error', e.stack || e.message || e)
+        self.end()
+      }
+    }
+  })
+}
+
+
+util.inherits(UDPSocket, BaseSocket)
+
+function UDPSocket (host, port) {
+  var self = this
+  if (!(self instanceof UDPSocket)) return new UDPSocket(host, port)
+
+  BaseSocket.call(self, host, port)
+}
+
+UDPSocket.prototype._create = function (cb) {
+  var self = this
+  chrome.socket.create('udp', {}, function (createInfo) {
+    cb(null, createInfo.socketId)
+  })
+}
+
+UDPSocket.prototype.write = function (data) {
+  var self = this
+  if (!self.id) return
+
+  if (typeof data === 'string') {
+    data = string.toUTF8Arr(data).buffer
+  } else if (data.buffer) {
+    data = data.buffer
+  }
+
+  chrome.socket.write(self.id, data, function (writeInfo) {
+    if (writeInfo.bytesWritten < 0) {
+      console.warn('UDPSocket ' + self.id + ' write: ' + writeInfo.bytesWritten)
+      return self.end()
+    }
+  })
+}
+
+UDPSocket.prototype.recvLoop = function() {
+  var self = this
+
+  chrome.socket.recvFrom(self.id, function (recvFromInfo) {
+    if (recvFromInfo.resultCode > 0) {
+      self.emit('data', recvFromInfo.data, recvFromInfo.address,
+          recvFromInfo.port)
+      self.recvLoop()
+    } else {
+      console.warn('UDPSocket ' + self.id + ' recvFrom: ', recvFromInfo)
+    }
+  })
+}