Add serialization support to the JS DataSender and DataReceiver.

extensions/renderer/resources/data_sender.js

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 define('data_sender', [
     'async_waiter',
     'device/serial/data_stream.mojom',
+    'device/serial/data_stream_serialization.mojom',
     'mojo/public/js/bindings/core',
     'mojo/public/js/bindings/router',
-], function(asyncWaiter, dataStreamMojom, core, routerModule) {
+], function(asyncWaiter, dataStreamMojom, serialization, core, routerModule) {
   /**
    * @module data_sender
    */
 
   /**
    * A pending send operation.
    * @param {ArrayBuffer} data The data to be sent.
    * @constructor
    * @alias module:data_sender~PendingSend
    * @private
@@ skipping 142 matching lines @@
   /**
    * A DataSender that sends data to a DataSink.
    * @param {MojoHandle} handle The handle to the DataSink.
    * @param {number} bufferSize How large a buffer the data pipe should use.
    * @param {number} fatalErrorValue The send error value to report in the
    *     event of a fatal error.
    * @constructor
    * @alias module:data_sender.DataSender
    */
   function DataSender(handle, bufferSize, fatalErrorValue) {
-    /**
-     * The [Router]{@link module:mojo/public/js/bindings/router.Router} for the
-     * connection to the DataSink.
-     * @private
-     */
-    this.router_ = new routerModule.Router(handle);
-    /**
-     * The connection to the DataSink.
-     * @private
-     */
-    this.sink_ = new dataStreamMojom.DataSinkProxy(this.router_);
-    this.router_.setIncomingReceiver(this);
     var dataPipeOptions = {
       flags: core.CREATE_DATA_PIPE_OPTIONS_FLAG_NONE,
       elementNumBytes: 1,
       capacityNumBytes: bufferSize,
     };
     var sendPipe = core.createDataPipe(dataPipeOptions);
+    this.init_(handle, sendPipe.producerHandle, fatalErrorValue);
     this.sink_.init(sendPipe.consumerHandle);
+  }
+
+  DataSender.prototype =
+      $Object.create(dataStreamMojom.DataSinkClientStub.prototype);
+
+  /**
+   * Closes this DataSender.
+   */
+  DataSender.prototype.close = function() {
+    if (this.shutDown_)
+      return;
+    this.shutDown_ = true;
+    this.waiter_.stop();
+    this.router_.close();
+    core.close(this.sendPipe_);
+    while (this.pendingSends_.length) {
+      this.pendingSends_.pop().reportBytesSentAndError(
+          0, this.fatalErrorValue_);
+    }
+    while (this.sendsAwaitingAck_.length) {
+      this.sendsAwaitingAck_.pop().reportBytesSentAndError(
+          0, this.fatalErrorValue_);
+    }
+    this.callCancelCallback_();
+  };
+
+  /**
+   * Initialize this DataSender.
+   * @param {MojoHandle} sink A handle to the DataSink
+   * @param {MojoHandle} dataPipe A handle to use for sending data to the
+   *     DataSink.
+   * @param {number} fatalErrorValue The error to dispatch in the event of a
+   *     fatal error.
+   * @private
+   */
+  DataSender.prototype.init_ = function(sink, dataPipe, fatalErrorValue) {
     /**
      * The handle to the data pipe to use for sending data.
      * @private
      */
-    this.sendPipe_ = sendPipe.producerHandle;
+    this.sendPipe_ = dataPipe;
     /**
      * The error to be dispatched in the event of a fatal error.
      * @type {number}
      * @private
      */
     this.fatalErrorValue_ = fatalErrorValue;
     /**
+     * Whether this DataReceiver has shut down.
+     * @type {boolean}
+     * @private
+     */
+    this.shutDown_ = false;
+    /**
+     * The [Router]{@link module:mojo/public/js/bindings/router.Router} for the
+     * connection to the DataSink.
+     * @private
+     */
+    this.router_ = new routerModule.Router(sink);
+    /**
+     * The connection to the DataSink.
+     * @private
+     */
+    this.sink_ = new dataStreamMojom.DataSinkProxy(this.router_);
+    this.router_.setIncomingReceiver(this);
+    /**
      * The async waiter used to wait for
      * {@link module:data_sender.DataSender#sendPipe_} to be writable.
      * @type module:async_waiter.AsyncWaiter
      * @private
      */
     this.waiter_ = new asyncWaiter.AsyncWaiter(
         this.sendPipe_, core.HANDLE_SIGNAL_WRITABLE,
         this.onHandleReady_.bind(this));
     /**
      * A queue of sends that have not fully written their data to the data pipe.
      * @type module:data_sender~PendingSend[]
      * @private
      */
     this.pendingSends_ = [];
     /**
      * A queue of sends that have written their data to the data pipe, but have
      * not been received by the DataSink.
      * @type module:data_sender~PendingSend[]
      * @private
      */
     this.sendsAwaitingAck_ = [];
+
     /**
      * The callback that will resolve a pending cancel if one is in progress.
      * @type Function
      * @private
      */
     this.pendingCancel_ = null;
+
     /**
-     * Whether this DataReceiver has shut down.
-     * @type {boolean}
+     * The promise that will be resolved when a pending cancel completes if one
+     * is in progress.
+     * @type Promise.<>
      * @private
      */
-    this.shutDown_ = false;
-  }
-
-  DataSender.prototype =
-      $Object.create(dataStreamMojom.DataSinkClientStub.prototype);
-
-  /**
-   * Closes this DataSender.
-   */
-  DataSender.prototype.close = function() {
-    if (this.shutDown_)
-      return;
-    this.shutDown_ = true;
-    this.waiter_.stop();
-    this.router_.close();
-    core.close(this.sendPipe_);
-    while (this.pendingSends_.length) {
-      this.pendingSends_.pop().reportBytesSentAndError(
-          0, this.fatalErrorValue_);
-    }
-    while (this.sendsAwaitingAck_.length) {
-      this.sendsAwaitingAck_.pop().reportBytesSentAndError(
-          0, this.fatalErrorValue_);
-    }
-    if (this.pendingCancel_) {
-      this.pendingCancel_();
-      this.pendingCancel_ = null;
-    }
+    this.cancelPromise = null;
   };
 
   /**
+   * Serializes this DataSender.
+   * This will cancel any sends in progress before the returned promise
+   * resolves.
+   * @return {Promise.<?SerializedDataSender>} A promise that will resolve to
+   *     the serialization of this DataSender. If this DataSender has shut down,
+   *     the promise will resolve to null.
+   */
+  DataSender.prototype.serialize = function() {
+    if (this.shutDown_)
+      return Promise.resolve(null);
+
+    var readyToSerialize = Promise.resolve();
+    if (this.pendingSends_.length) {
+      if (this.pendingCancel_)
+        readyToSerialize = this.cancelPromise_;
+      else
+        readyToSerialize = this.cancel(this.fatalErrorValue_);
+    }
+    return readyToSerialize.then(function() {
+      this.waiter_.stop();
+      var serialized = new serialization.SerializedDataSender();
+      serialized.sink = this.router_.connector_.handle_,
+      serialized.data_pipe = this.sendPipe_,
+      serialized.fatal_error_value = this.fatalErrorValue_,
+      this.router_.connector_.handle_ = null;
+      this.router_.close();
+      this.shutDown_ = true;
+      return serialized;
+    }.bind(this));
+  };
+
+  /**
+   * Deserializes a SerializedDataSender.
+   * @param {?SerializedDataSender} serialized The serialized DataSender.
+   * @return {DataSender} The deserialized DataSender.
+   */
+  DataSender.deserialize = function(serialized) {
+    var sender = $Object.create(DataSender.prototype);
+    sender.deserialize_(serialized);
+    return sender;
+  };
+
+  /**
+   * Deserializes a SerializedDataSender into this DataSender.
+   * @param {?SerializedDataSender} serialized The serialized DataSender.
+   * @private
+   */
+  DataSender.prototype.deserialize_ = function(serialized) {
+    if (!serialized) {
+      this.shutDown_ = true;
+      return;
+    }
+    this.init_(
+        serialized.sink, serialized.data_pipe, serialized.fatal_error_value);
+  };
+
+  /**
    * Sends data to the DataSink.
    * @return {Promise.<number>} A promise to the number of bytes sent. If an
    *     error occurs, the promise will reject with an Error object with a
    *     property error containing the error code.
    * @throws Will throw if this has encountered a fatal error or a cancel is in
    *     progress.
    */
   DataSender.prototype.send = function(data) {
     if (this.shutDown_)
       throw new Error('DataSender has been closed');
@@ skipping 17 matching lines @@
    */
   DataSender.prototype.cancel = function(error) {
     if (this.shutDown_)
       throw new Error('DataSender has been closed');
     if (this.pendingCancel_)
       throw new Error('Cancel already in progress');
     if (this.pendingSends_.length + this.sendsAwaitingAck_.length == 0)
       return Promise.resolve();
 
     this.sink_.cancel(error);
-    return new Promise(function(resolve) {
+    this.cancelPromise_ = new Promise(function(resolve) {
       this.pendingCancel_ = resolve;
     }.bind(this));
+    return this.cancelPromise_;
   };
 
   /**
    * Invoked when |handle_| is ready to write. Writes to the data pipe if the
    * wait is successful.
    * @param {number} waitResult The result of the asynchronous wait.
    * @private
    */
   DataSender.prototype.onHandleReady_ = function(result) {
     if (result != core.RESULT_OK) {
@@ skipping 13 matching lines @@
       }
     }
   };
 
   /**
    * Calls and clears the pending cancel callback if one is pending.
    * @private
    */
   DataSender.prototype.callCancelCallback_ = function() {
     if (this.pendingCancel_) {
+      this.cancelPromise_ = null;
       this.pendingCancel_();
       this.pendingCancel_ = null;
     }
   };
 
   /**
    * Invoked by the DataSink to report that data has been successfully sent.
    * @param {number} numBytes The number of bytes sent.
    * @private
    */
@@ skipping 38 matching lines @@
       // Note: Only the first PendingSend in |pendingSends_| will have data to
       // flush as only the first can have written data to the data pipe.
       bytesToFlush += result.bytesToFlush;
     }
     this.callCancelCallback_();
     return Promise.resolve({bytes_to_flush: bytesToFlush});
   };
 
   return {DataSender: DataSender};
 });