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      1 // Copyright 2017 The Chromium Authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style license that can be
      3 // found in the LICENSE file.
      4 
      5 (function() {
      6   var internal = mojo.internal;
      7 
      8   function constructRunOrClosePipeMessage(runOrClosePipeInput) {
      9     var runOrClosePipeMessageParams = new
     10         mojo.interfaceControl.RunOrClosePipeMessageParams();
     11     runOrClosePipeMessageParams.input = runOrClosePipeInput;
     12 
     13     var messageName = mojo.interfaceControl.kRunOrClosePipeMessageId;
     14     var payloadSize =
     15         mojo.interfaceControl.RunOrClosePipeMessageParams.encodedSize;
     16     var builder = new internal.MessageV0Builder(messageName, payloadSize);
     17     builder.encodeStruct(mojo.interfaceControl.RunOrClosePipeMessageParams,
     18                          runOrClosePipeMessageParams);
     19     var message = builder.finish();
     20     return message;
     21   }
     22 
     23   function validateControlResponse(message) {
     24     var messageValidator = new internal.Validator(message);
     25     var error = messageValidator.validateMessageIsResponse();
     26     if (error != internal.validationError.NONE) {
     27       throw error;
     28     }
     29 
     30     if (message.getName() != mojo.interfaceControl.kRunMessageId) {
     31       throw new Error("Control message name is not kRunMessageId");
     32     }
     33 
     34     // Validate payload.
     35     error = mojo.interfaceControl.RunResponseMessageParams.validate(
     36         messageValidator, message.getHeaderNumBytes());
     37     if (error != internal.validationError.NONE) {
     38       throw error;
     39     }
     40   }
     41 
     42   function acceptRunResponse(message) {
     43     validateControlResponse(message);
     44 
     45     var reader = new internal.MessageReader(message);
     46     var runResponseMessageParams = reader.decodeStruct(
     47         mojo.interfaceControl.RunResponseMessageParams);
     48 
     49     return Promise.resolve(runResponseMessageParams);
     50   }
     51 
     52  /**
     53   * Sends the given run message through the receiver.
     54   * Accepts the response message from the receiver and decodes the message
     55   * struct to RunResponseMessageParams.
     56   *
     57   * @param  {Router} receiver.
     58   * @param  {RunMessageParams} runMessageParams to be sent via a message.
     59   * @return {Promise} that resolves to a RunResponseMessageParams.
     60   */
     61   function sendRunMessage(receiver, runMessageParams) {
     62     var messageName = mojo.interfaceControl.kRunMessageId;
     63     var payloadSize = mojo.interfaceControl.RunMessageParams.encodedSize;
     64     // |requestID| is set to 0, but is later properly set by Router.
     65     var builder = new internal.MessageV1Builder(messageName,
     66         payloadSize, internal.kMessageExpectsResponse, 0);
     67     builder.encodeStruct(mojo.interfaceControl.RunMessageParams,
     68                          runMessageParams);
     69     var message = builder.finish();
     70 
     71     return receiver.acceptAndExpectResponse(message).then(acceptRunResponse);
     72   }
     73 
     74   function ControlMessageProxy(receiver) {
     75     this.receiver_ = receiver;
     76   }
     77 
     78   ControlMessageProxy.prototype.queryVersion = function() {
     79     var runMessageParams = new mojo.interfaceControl.RunMessageParams();
     80     runMessageParams.input = new mojo.interfaceControl.RunInput();
     81     runMessageParams.input.queryVersion =
     82         new mojo.interfaceControl.QueryVersion();
     83 
     84     return sendRunMessage(this.receiver_, runMessageParams).then(function(
     85         runResponseMessageParams) {
     86       return runResponseMessageParams.output.queryVersionResult.version;
     87     });
     88   };
     89 
     90   ControlMessageProxy.prototype.requireVersion = function(version) {
     91     var runOrClosePipeInput = new mojo.interfaceControl.RunOrClosePipeInput();
     92     runOrClosePipeInput.requireVersion =
     93         new mojo.interfaceControl.RequireVersion({'version': version});
     94     var message = constructRunOrClosePipeMessage(runOrClosePipeInput);
     95     this.receiver_.accept(message);
     96   };
     97 
     98   internal.ControlMessageProxy = ControlMessageProxy;
     99 })();
    100