Multicast socket API

chrome/test/data/extensions/api_test/socket/api/multicast.js

+function testMulticast() {
+  function randomHexString(count) {
+    var result = '';
+    for (var i = 0; i < count; i++) {
+      result += (Math.random() * 16 >> 0).toString(16);
+    }
+    return result;
+  }
+
+  var kMulticastAddress = "237.132.100.133";
+  var kTestMessageLength = 128;
+  var kTestMessage = randomHexString(128);
+  var kPort = 11103;
+
+  function arrayBufferToString(arrayBuffer) {
+    // UTF-16LE
+    return String.fromCharCode.apply(String, new Uint16Array(arrayBuffer));
+  }
+
+  function stringToArrayBuffer(string) {
+    // UTF-16LE
+    var buf = new ArrayBuffer(string.length * 2);
+    var bufView = new Uint16Array(buf);
+    for (var i = 0, strLen = string.length; i < strLen; i++) {
+      bufView[i] = string.charCodeAt(i);
+    }
+    return buf;
+  }
+
+  function waitForMessage(socketId, callback) {
+    var cancelled = false;
+    var relayCanceller = null;
+    socket.recvFrom(socketId, 1024, function (result) {
+      if (cancelled)
+        return;
+
+      if (result.resultCode == kTestMessageLength * 2 &&
+          kTestMessage === arrayBufferToString(result.data)) {
+        callback(cancelled);
+      } else {
+        // Restart waiting.
+        relayCanceller = waitForMessage(socketId, callback);
+      }
+    });
+    return function canceller() {
+      if (relayCanceller) {
+        relayCanceller();
+      }
+      cancelled = true;
+      callback(cancelled);
+    };
+  }
+
+  function testSendMessage(message, address) {
+    // Send the UDP message to the address with multicast ttl = 0.
+    address = address || kMulticastAddress;
+    var clientSocketId;
+    socket.create('udp', {}, function (socketInfo) {
+      if (socketInfo) {
+        clientSocketId = socketInfo.socketId;
+        chrome.test.assertTrue(clientSocketId > 0,
+            "Cannot create client udp socket.");
+        socket.setMulticastTimeToLive(clientSocketId, 0, function (result) {
+          chrome.test.assertEq(result, 0, "Cannot create client udp socket.");
+          socket.bind(clientSocketId, "0.0.0.0", kPort + 2, function (result) {
+            chrome.test.assertTrue(clientSocketId > 0,
+                "Cannot bind client udp socket.");
+            socket.sendTo(clientSocketId,
+              stringToArrayBuffer(kTestMessage),
+              address,
+              kPort, function (result) {
+                chrome.test.assertTrue(result.bytesWritten >= 0,
+                    "Send to failed. " + JSON.stringify(result));
+                socket.destroy(clientSocketId);
+              });
+          });
+        });
+      } else {
+        chrome.test.fail("Cannot create client udp socket");
+      }
+    });
+  }
+
+  function recvBeforeAddMembership(serverSocketId) {
+    var recvTimeout;
+    var canceller = waitForMessage(serverSocketId, function (cancelled) {
+      clearTimeout(recvTimeout);
+      if (cancelled) {
+        recvWithMembership(serverSocketId);
+      } else {
+        console.log(JSON.stringify(arrayBufferToString(result.data)));
+        chrome.test.fail("Recieved message before joining the group");
+      }
+    });
+    testSendMessage(kTestMessage); // Meant to be lost.
+    recvTimeout = setTimeout(function () {
+      canceller();
+      testSendMessage(kTestMessage, "127.0.0.1", kPort);
+    }, 2000);
+  }
+
+  function recvWithMembership(serverSocketId) {
+    // Join group.
+    socket.joinGroup(serverSocketId, kMulticastAddress, function (result) {
+      chrome.test.assertEq(0, result, "Join group failed.");
+      var recvTimeout;
+      var canceller = waitForMessage(serverSocketId, function (cancelled) {
+        clearTimeout(recvTimeout);
+        if (!cancelled) {
+          recvWithoutMembership(serverSocketId);
+        } else {
+          console.log(JSON.stringify(arrayBufferToString(result.data)));
+          chrome.test.fail("Recieved message before joining the group");
+        }
+      });
+      testSendMessage(kTestMessage);
+      recvTimeout = setTimeout(function () {
+        canceller();
+        socket.destroy(serverSocketId);
+        chrome.test.fail("Cannot receive from multicast group.");
+      }, 2000);
+    });
+  }
+
+  function recvWithoutMembership(serverSocketId) {
+    socket.leaveGroup(serverSocketId, kMulticastAddress, function (result) {
+      chrome.test.assertEq(0, result, "leave group failed.");
+      var recvTimeout;
+      var canceller = waitForMessage(serverSocketId, function (cancelled) {
+        clearTimeout(recvTimeout);
+        if (cancelled) {
+          chrome.test.succeed();
+        } else {
+          console.log(JSON.stringify(arrayBufferToString(result.data)));
+          chrome.test.fail("Recieved message before joining the group");
+        }
+      });
+      testSendMessage(request);
+      recvTimeout = setTimeout(function () {
+        canceller();
+        socket.destroy(serverSocketId);
+        chrome.test.succeed();
+      }, 2000);
+    });
+  }
+
+  socket.create('udp', {}, function (socketInfo) {
+    var serverSocketId;
+    if (socketInfo) {
+      serverSocketId = socketInfo.socketId;
+      socket.bind(serverSocketId, "0.0.0.0", kPort, function (result) {
+        chrome.test.assertEq(0, result, "Bind failed.");
+        recvBeforeAddMembership(serverSocketId);
+      });
+    } else {
+      chrome.test.fail("Cannot create server udp socket");
+    }
+  });
+}