src/mojo/public/bindings/js/connector.js

   1 // Copyright 2014 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 define("mojo/public/bindings/js/connector", [
   6   "mojo/public/bindings/js/codec",
   7   "mojo/bindings/js/core",
   8   "mojo/bindings/js/support",
   9 ], function(codec, core, support) {
  10
  11   function Connector(handle) {
  12     this.handle_ = handle;
  13     this.dropWrites_ = false;
  14     this.error_ = false;
  15     this.incomingReceiver_ = null;
  16     this.readWaitCookie_ = null;
  17
  18     this.waitToReadMore_();
  19   }
  20
  21   Connector.prototype.close = function() {
  22     if (this.readWaitCookie_) {
  23       support.cancelWait(this.readWaitCookie_);
  24       this.readWaitCookie_ = null;
  25     }
  26     if (this.handle_ != core.kInvalidHandle) {
  27       core.close(this.handle_);
  28       this.handle_ = core.kInvalidHandle;
  29     }
  30   };
  31
  32   Connector.prototype.accept = function(message) {
  33     if (this.error_)
  34       return false;
  35
  36     if (this.dropWrites_)
  37       return true;
  38
  39     var result = core.writeMessage(this.handle_,
  40                                    message.memory,
  41                                    message.handles,
  42                                    core.WRITE_MESSAGE_FLAG_NONE);
  43
  44     switch (result) {
  45       case core.RESULT_OK:
  46         // The handles were successfully transferred, so we don't own them
  47         // anymore.
  48         message.handles = [];
  49         break;
  50       case core.RESULT_FAILED_PRECONDITION:
  51         // There's no point in continuing to write to this pipe since the other
  52         // end is gone. Avoid writing any future messages. Hide write failures
  53         // from the caller since we'd like them to continue consuming any
  54         // backlog of incoming messages before regarding the message pipe as
  55         // closed.
  56         this.dropWrites_ = true;
  57         break;
  58       default:
  59         // This particular write was rejected, presumably because of bad input.
  60         // The pipe is not necessarily in a bad state.
  61         return false;
  62     }
  63     return true;
  64   };
  65
  66   Connector.prototype.setIncomingReceiver = function(receiver) {
  67     this.incomingReceiver_ = receiver;
  68   };
  69
  70   Connector.prototype.encounteredError = function() {
  71     return this.error_;
  72   }
  73
  74   Connector.prototype.waitToReadMore_ = function() {
  75     this.readWaitCookie_ = support.asyncWait(this.handle_,
  76                                              core.WAIT_FLAG_READABLE,
  77                                              this.readMore_.bind(this));
  78   };
  79
  80   Connector.prototype.readMore_ = function(result) {
  81     for (;;) {
  82       var read = core.readMessage(this.handle_,
  83                                   core.READ_MESSAGE_FLAG_NONE);
  84       if (read.result == core.RESULT_SHOULD_WAIT) {
  85         this.waitToReadMore_();
  86         return;
  87       }
  88       if (read.result != core.RESULT_OK) {
  89         this.error_ = true;
  90         return;
  91       }
  92       // TODO(abarth): Should core.readMessage return a Uint8Array?
  93       var memory = new Uint8Array(read.buffer);
  94       var message = new codec.Message(memory, read.handles);
  95       if (this.incomingReceiver_)
  96         this.incomingReceiver_.accept(message);
  97     }
  98   };
  99
 100   var exports = {};
 101   exports.Connector = Connector;
 102   return exports;
 103 });