mojo/public/js/bindings/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/js/bindings/connector", [
   6   "mojo/public/js/bindings/codec",
   7   "mojo/public/js/bindings/core",
   8   "mojo/public/js/bindings/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     this.errorHandler_ = null;
  18
  19     this.waitToReadMore_();
  20   }
  21
  22   Connector.prototype.close = function() {
  23     if (this.readWaitCookie_) {
  24       support.cancelWait(this.readWaitCookie_);
  25       this.readWaitCookie_ = null;
  26     }
  27     if (this.handle_ != core.kInvalidHandle) {
  28       core.close(this.handle_);
  29       this.handle_ = core.kInvalidHandle;
  30     }
  31   };
  32
  33   Connector.prototype.accept = function(message) {
  34     if (this.error_)
  35       return false;
  36
  37     if (this.dropWrites_)
  38       return true;
  39
  40     var result = core.writeMessage(this.handle_,
  41                                    new Uint8Array(message.buffer.arrayBuffer),
  42                                    message.handles,
  43                                    core.WRITE_MESSAGE_FLAG_NONE);
  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.setErrorHandler = function(handler) {
  71     this.errorHandler_ = handler;
  72   };
  73
  74   Connector.prototype.encounteredError = function() {
  75     return this.error_;
  76   };
  77
  78   Connector.prototype.waitToReadMore_ = function() {
  79     this.readWaitCookie_ = support.asyncWait(this.handle_,
  80                                              core.WAIT_FLAG_READABLE,
  81                                              this.readMore_.bind(this));
  82   };
  83
  84   Connector.prototype.readMore_ = function(result) {
  85     for (;;) {
  86       var read = core.readMessage(this.handle_,
  87                                   core.READ_MESSAGE_FLAG_NONE);
  88       if (read.result == core.RESULT_SHOULD_WAIT) {
  89         this.waitToReadMore_();
  90         return;
  91       }
  92       if (read.result != core.RESULT_OK) {
  93         this.error_ = true;
  94         if (this.errorHandler_)
  95           this.errorHandler_.onError(read.result);
  96         return;
  97       }
  98       var buffer = new codec.Buffer(read.buffer);
  99       var message = new codec.Message(buffer, read.handles);
 100       if (this.incomingReceiver_) {
 101           this.incomingReceiver_.accept(message);
 102       }
 103     }
 104   };
 105
 106   var exports = {};
 107   exports.Connector = Connector;
 108   return exports;
 109 });