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
182
183
184
185
186
187
188
189
190
191
192
193
|
/* Copyright 2012 Mozilla Foundation
*
* Licensed under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
function getTypedArray(xhr) {
const data = xhr.response;
if (typeof data !== "string") {
return new Uint8Array(data);
}
return Uint8Array.from(data, ch => ch.charCodeAt(0) & 0xff);
}
const OK_RESPONSE = 200;
const PARTIAL_CONTENT_RESPONSE = 206;
export class NetworkManager {
constructor(url, args = {}) {
this.url = url;
this.isHttp = /^https?:/i.test(url);
this.httpHeaders = (this.isHttp && args.httpHeaders) || {};
this.withCredentials = args.withCredentials || false;
this.getXhr =
args.getXhr ||
function NetworkManager_getXhr() {
return new XMLHttpRequest();
};
this.currXhrId = 0;
this.pendingRequests = Object.create(null);
}
requestRange(begin, end, listeners) {
var args = {
begin,
end,
};
for (var prop in listeners) {
args[prop] = listeners[prop];
}
return this.request(args);
}
request(args) {
var xhr = this.getXhr();
var xhrId = this.currXhrId++;
var pendingRequest = (this.pendingRequests[xhrId] = {
xhr,
});
xhr.open("GET", this.url);
xhr.withCredentials = this.withCredentials;
for (var property in this.httpHeaders) {
var value = this.httpHeaders[property];
if (typeof value === "undefined") {
continue;
}
xhr.setRequestHeader(property, value);
}
if (this.isHttp && "begin" in args && "end" in args) {
var rangeStr = args.begin + "-" + (args.end - 1);
xhr.setRequestHeader("Range", "bytes=" + rangeStr);
pendingRequest.expectedStatus = 206;
xhr.channel.QueryInterface(Ci.nsIHttpChannel).redirectionLimit = 0;
} else {
pendingRequest.expectedStatus = 200;
}
xhr.responseType = "arraybuffer";
if (args.onError) {
xhr.onerror = function (evt) {
args.onError(xhr.status);
};
}
xhr.onreadystatechange = this.onStateChange.bind(this, xhrId);
xhr.onprogress = this.onProgress.bind(this, xhrId);
pendingRequest.onHeadersReceived = args.onHeadersReceived;
pendingRequest.onDone = args.onDone;
pendingRequest.onError = args.onError;
pendingRequest.onProgress = args.onProgress;
xhr.send(null);
return xhrId;
}
onProgress(xhrId, evt) {
var pendingRequest = this.pendingRequests[xhrId];
if (!pendingRequest) {
// Maybe abortRequest was called...
return;
}
var onProgress = pendingRequest.onProgress;
if (onProgress) {
onProgress(evt);
}
}
onStateChange(xhrId, evt) {
var pendingRequest = this.pendingRequests[xhrId];
if (!pendingRequest) {
// Maybe abortRequest was called...
return;
}
var xhr = pendingRequest.xhr;
if (xhr.readyState >= 2 && pendingRequest.onHeadersReceived) {
pendingRequest.onHeadersReceived();
delete pendingRequest.onHeadersReceived;
}
if (xhr.readyState !== 4) {
return;
}
if (!(xhrId in this.pendingRequests)) {
// The XHR request might have been aborted in onHeadersReceived()
// callback, in which case we should abort request
return;
}
delete this.pendingRequests[xhrId];
// success status == 0 can be on ftp, file and other protocols
if (xhr.status === 0 && this.isHttp) {
if (pendingRequest.onError) {
pendingRequest.onError(xhr.status);
}
return;
}
var xhrStatus = xhr.status || OK_RESPONSE;
// From http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.35.2:
// "A server MAY ignore the Range header". This means it's possible to
// get a 200 rather than a 206 response from a range request.
var ok_response_on_range_request =
xhrStatus === OK_RESPONSE &&
pendingRequest.expectedStatus === PARTIAL_CONTENT_RESPONSE;
if (
!ok_response_on_range_request &&
xhrStatus !== pendingRequest.expectedStatus
) {
if (pendingRequest.onError) {
pendingRequest.onError(xhr.status);
}
return;
}
const chunk = getTypedArray(xhr);
if (xhrStatus === PARTIAL_CONTENT_RESPONSE) {
var rangeHeader = xhr.getResponseHeader("Content-Range");
var matches = /bytes (\d+)-(\d+)\/(\d+)/.exec(rangeHeader);
var begin = parseInt(matches[1], 10);
pendingRequest.onDone({
begin,
chunk,
});
} else if (chunk) {
pendingRequest.onDone({
begin: 0,
chunk,
});
} else if (pendingRequest.onError) {
pendingRequest.onError(xhr.status);
}
}
abortAllRequests() {
for (var xhrId in this.pendingRequests) {
this.abortRequest(xhrId | 0);
}
}
abortRequest(xhrId) {
var xhr = this.pendingRequests[xhrId].xhr;
delete this.pendingRequests[xhrId];
xhr.abort();
}
}
|
