1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
|
/* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is Jetpack.
*
* The Initial Developer of the Original Code is Mozilla.
* Portions created by the Initial Developer are Copyright (C) 2007
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Atul Varma <atul@mozilla.com>
*
* Alternatively, the contents of this file may be used under the terms of
* either the GNU General Public License Version 2 or later (the "GPL"), or
* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
"use strict";
const {Cc,Ci} = require("chrome");
// ## Implementation Notes ##
//
// Making `XMLHttpRequest` objects available to Jetpack code involves a
// few key principles universal to all low-level module implementations:
//
// * **Unloadability**. A Jetpack-based extension using this module can be
// asked to unload itself at any time, e.g. because the user decides to
// uninstall or disable the extension. This means we need to keep track of
// all in-progress reqests and abort them on unload.
//
// * **Developer-Ergonomic Tracebacks**. Whenever an exception is raised
// by a Jetpack-based extension, we want it to be logged in a
// place that is specific to that extension--so that a developer
// can distinguish it from an error on a web page or in another
// extension, for instance. We also want it to be logged with a
// full stack traceback, which the Mozilla platform doesn't usually
// do.
//
// Because of this, we don't actually want to give the Mozilla
// platform's "real" XHR implementation to clients, but instead provide
// a simple wrapper that trivially delegates to the implementation in
// all cases except where callbacks are involved: whenever Mozilla
// platform code calls into the extension, such as during the XHR's
// `onreadystatechange` callback, we want to wrap the client's callback
// in a try-catch clause that traps any exceptions raised by the
// callback and logs them via console.exception() instead of allowing
// them to propagate back into Mozilla platform code.
// This is a private list of all active requests, so we know what to
// abort if we're asked to unload.
var requests = [];
// Events on XHRs that we should listen for, so we know when to remove
// a request from our private list.
const TERMINATE_EVENTS = ["load", "error", "abort"];
// Read-only properties of XMLHttpRequest objects that we want to
// directly delegate to.
const READ_ONLY_PROPS = ["readyState", "responseText", "responseXML",
"status", "statusText"];
// Methods of XMLHttpRequest that we want to directly delegate to.
const DELEGATED_METHODS = ["abort", "getAllResponseHeaders",
"getResponseHeader", "overrideMimeType",
"send", "sendAsBinary", "setRequestHeader",
"open"];
var getRequestCount = exports.getRequestCount = function getRequestCount() {
return requests.length;
};
var XMLHttpRequest = exports.XMLHttpRequest = function XMLHttpRequest() {
var req = Cc["@mozilla.org/xmlextras/xmlhttprequest;1"]
.createInstance(Ci.nsIXMLHttpRequest);
// For the sake of simplicity, don't tie this request to any UI.
req.mozBackgroundRequest = true;
memory.track(req, "XMLHttpRequest");
this._req = req;
this._orsc = null;
requests.push(this);
var self = this;
this._boundCleanup = function _boundCleanup() {
self._cleanup();
};
TERMINATE_EVENTS.forEach(
function(name) {
self._req.addEventListener(name, self._boundCleanup, false);
});
};
XMLHttpRequest.prototype = {
_cleanup: function _cleanup() {
this.onreadystatechange = null;
var index = requests.indexOf(this);
if (index != -1) {
var self = this;
TERMINATE_EVENTS.forEach(
function(name) {
self._req.removeEventListener(name, self._boundCleanup, false);
});
requests.splice(index, 1);
}
},
_unload: function _unload() {
this._req.abort();
this._cleanup();
},
addEventListener: function addEventListener() {
throw new Error("not implemented");
},
removeEventListener: function removeEventListener() {
throw new Error("not implemented");
},
set upload(newValue) {
throw new Error("not implemented");
},
get onreadystatechange() {
return this._orsc;
},
set onreadystatechange(cb) {
this._orsc = cb;
if (cb) {
var self = this;
this._req.onreadystatechange = function() {
try {
self._orsc.apply(self, arguments);
} catch (e) {
console.exception(e);
}
};
} else
this._req.onreadystatechange = null;
}
};
READ_ONLY_PROPS.forEach(
function(name) {
XMLHttpRequest.prototype.__defineGetter__(
name,
function() {
return this._req[name];
});
});
DELEGATED_METHODS.forEach(
function(name) {
XMLHttpRequest.prototype[name] = function() {
return this._req[name].apply(this._req, arguments);
};
});
require("./unload").when(
function() {
requests.slice().forEach(function(request) { request._unload(); });
});
|
