| 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
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369 |
2x
2x
2x
2x
2x
2x
2x
2x
2x
2x
2x
2x
2x
2x
441x
441x
441x
441x
2x
618x
618x
216x
216x
216x
216x
216x
216x
216x
180x
180x
180x
180x
36x
36x
36x
36x
36x
216x
216x
216x
216x
216x
216x
216x
2x
84x
2x
402x
402x
402x
402x
402x
402x
402x
402x
402x
402x
1307x
1307x
396x
396x
396x
1307x
1307x
394x
402x
1608x
2954x
2954x
402x
395x
395x
402x
395x
388x
388x
388x
402x
402x
2164x
2164x
2164x
2164x
2164x
7x
7x
7x
7x
7x
7x
7x
7x
2157x
2157x
402x
402x
402x
2x
217x
217x
217x
217x
217x
217x
217x
217x
217x
217x
217x
2x
| /**
* Copyright 2017 Google Inc.
*
* 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.
*/
import {
ErrorCode,
EventType,
WebChannel,
XhrIoPool,
createWebChannelTransport
} from '@firebase/webchannel-wrapper';
import { Token } from '../api/credentials';
import { DatabaseId, DatabaseInfo } from '../core/database_info';
import { SDK_VERSION } from '../core/version';
import { Connection, Stream } from '../remote/connection';
import {
mapCodeFromHttpStatus,
mapCodeFromRpcStatus
} from '../remote/rpc_error';
import { StreamBridge } from '../remote/stream_bridge';
import { assert, fail } from '../util/assert';
import { Code, FirestoreError } from '../util/error';
import * as log from '../util/log';
import { Rejecter, Resolver } from '../util/promise';
import { StringMap } from '../util/types';
const LOG_TAG = 'Connection';
const RPC_STREAM_SERVICE = 'google.firestore.v1beta1.Firestore';
const RPC_URL_VERSION = 'v1beta1';
/** Maps RPC names to the corresponding REST endpoint name. */
const RPC_NAME_REST_MAPPING = {
BatchGetDocuments: 'batchGet',
Commit: 'commit'
};
// TODO(b/38203344): The SDK_VERSION is set independently from Firebase because
// we are doing out-of-band releases. Once we release as part of Firebase, we
// should use the Firebase version instead.
const X_GOOG_API_CLIENT_VALUE = 'gl-js/ fire/' + SDK_VERSION;
const XHR_TIMEOUT_SECS = 15;
export class WebChannelConnection implements Connection {
private readonly databaseId: DatabaseId;
private readonly baseUrl: string;
private readonly pool: XhrIoPool;
constructor(info: DatabaseInfo) {
this.databaseId = info.databaseId;
this.pool = new XhrIoPool();
const proto = info.ssl ? 'https' : 'http';
this.baseUrl = proto + '://' + info.host;
}
/**
* Modifies the headers for a request, adding any authorization token if
* present and any additional headers for the request.
*/
private modifyHeadersForRequest(headers: StringMap, token: Token | null) {
Iif (token) {
for (const header in token.authHeaders) {
if (token.authHeaders.hasOwnProperty(header)) {
headers[header] = token.authHeaders[header];
}
}
}
headers['X-Goog-Api-Client'] = X_GOOG_API_CLIENT_VALUE;
}
invokeRPC<Req, Resp>(
rpcName: string,
request: Req,
token: Token | null
): Promise<Resp> {
const url = this.makeUrl(rpcName);
return new Promise((resolve: Resolver<Resp>, reject: Rejecter) => {
// tslint:disable-next-line:no-any XhrIoPool doesn't have TS typings.
this.pool.getObject((xhr: any) => {
xhr.listenOnce(EventType.COMPLETE, () => {
try {
switch (xhr.getLastErrorCode()) {
case ErrorCode.NO_ERROR:
const json = xhr.getResponseJson() as Resp;
log.debug(LOG_TAG, 'XHR received:', JSON.stringify(json));
resolve(json);
break;
case ErrorCode.TIMEOUT:
log.debug(LOG_TAG, 'RPC "' + rpcName + '" timed out');
reject(
new FirestoreError(Code.DEADLINE_EXCEEDED, 'Request time out')
);
break;
case ErrorCode.HTTP_ERROR:
const status = xhr.getStatus();
log.debug(
LOG_TAG,
'RPC "' + rpcName + '" failed with status:',
status,
'response text:',
xhr.getResponseText()
);
Eif (status > 0) {
reject(
new FirestoreError(
mapCodeFromHttpStatus(status),
'Server responded with status ' + xhr.getStatusText()
)
);
} else {
// If we received an HTTP_ERROR but there's no status code,
// it's most probably a connection issue
log.debug(LOG_TAG, 'RPC "' + rpcName + '" failed');
reject(
new FirestoreError(Code.UNAVAILABLE, 'Connection failed.')
);
}
break;
default:
fail(
'RPC "' +
rpcName +
'" failed with unanticipated ' +
'webchannel error ' +
xhr.getLastErrorCode() +
': ' +
xhr.getLastError() +
', giving up.'
);
}
} finally {
log.debug(LOG_TAG, 'RPC "' + rpcName + '" completed.');
this.pool.releaseObject(xhr);
}
});
const requestString = JSON.stringify(request);
log.debug(LOG_TAG, 'XHR sending: ', url + ' ' + requestString);
// Content-Type: text/plain will avoid preflight requests which might
// mess with CORS and redirects by proxies. If we add custom headers
// we will need to change this code to potentially use the
// $httpOverwrite parameter supported by ESF to avoid
// triggering preflight requests.
const headers: StringMap = { 'Content-Type': 'text/plain' };
this.modifyHeadersForRequest(headers, token);
xhr.send(url, 'POST', requestString, headers, XHR_TIMEOUT_SECS);
});
});
}
invokeStreamingRPC<Req, Resp>(
rpcName: string,
request: Req,
token: Token | null
): Promise<Resp[]> {
// The REST API automatically aggregates all of the streamed results, so we
// can just use the normal invoke() method.
return this.invokeRPC<Req, Resp[]>(rpcName, request, token);
}
openStream<Req, Resp>(
rpcName: string,
token: Token | null
): Stream<Req, Resp> {
const urlParts = [
this.baseUrl,
'/',
RPC_STREAM_SERVICE,
'/',
rpcName,
'/channel'
];
const webchannelTransport = createWebChannelTransport();
const request = {
// Background channel test avoids the initial two test calls and decreases
// initial cold start time.
// TODO(dimond): wenboz@ mentioned this might affect use with proxies and
// we should monitor closely for any reports.
backgroundChannelTest: true,
// Required for backend stickiness, routing behavior is based on this
// parameter.
httpSessionIdParam: 'gsessionid',
initMessageHeaders: {},
// Send our custom headers as a '$httpHeaders=' url param to avoid CORS
// preflight round-trip. This is formally defined here:
// https://github.com/google/closure-library/blob/b0e1815b13fb92a46d7c9b3c30de5d6a396a3245/closure/goog/net/rpc/httpcors.js#L40
httpHeadersOverwriteParam: '$httpHeaders',
messageUrlParams: {
// This param is used to improve routing and project isolation by the
// backend and must be included in every request.
database: `projects/${this.databaseId.projectId}/databases/${
this.databaseId.database
}`
},
sendRawJson: true,
supportsCrossDomainXhr: true
};
this.modifyHeadersForRequest(request.initMessageHeaders, token);
const url = urlParts.join('');
log.debug(LOG_TAG, 'Creating WebChannel: ' + url + ' ' + request);
// tslint:disable-next-line:no-any Because listen isn't defined on it.
const channel = webchannelTransport.createWebChannel(url, request) as any;
// WebChannel supports sending the first message with the handshake - saving
// a network round trip. However, it will have to call send in the same
// JS event loop as open. In order to enforce this, we delay actually
// opening the WebChannel until send is called. Whether we have called
// open is tracked with this variable.
let opened = false;
// A flag to determine whether the stream was closed (by us or through an
// error/close event) to avoid delivering multiple close events or sending
// on a closed stream
let closed = false;
const streamBridge = new StreamBridge<Req, Resp>({
sendFn: (msg: Req) => {
Eif (!closed) {
if (!opened) {
log.debug(LOG_TAG, 'Opening WebChannel transport.');
channel.open();
opened = true;
}
log.debug(LOG_TAG, 'WebChannel sending:', msg);
channel.send(msg);
} else {
log.debug(LOG_TAG, 'Not sending because WebChannel is closed:', msg);
}
},
closeFn: () => channel.close()
});
// Closure events are guarded and exceptions are swallowed, so catch any
// exception and rethrow using a setTimeout so they become visible again.
// Note that eventually this function could go away if we are confident
// enough the code is exception free.
const unguardedEventListen = <T>(
type: WebChannel.EventType,
fn: (param?: T) => void
) => {
// TODO(dimond): closure typing seems broken because WebChannel does
// not implement goog.events.Listenable
channel.listen(type, (param?: T) => {
try {
fn(param);
} catch (e) {
setTimeout(() => {
throw e;
}, 0);
}
});
};
unguardedEventListen(WebChannel.EventType.OPEN, () => {
Eif (!closed) {
log.debug(LOG_TAG, 'WebChannel transport opened.');
}
});
unguardedEventListen(WebChannel.EventType.CLOSE, () => {
if (!closed) {
closed = true;
log.debug(LOG_TAG, 'WebChannel transport closed');
streamBridge.callOnClose();
}
});
unguardedEventListen<Error>(WebChannel.EventType.ERROR, err => {
if (!closed) {
closed = true;
log.debug(LOG_TAG, 'WebChannel transport errored:', err);
streamBridge.callOnClose(
new FirestoreError(
Code.UNAVAILABLE,
'The operation could not be completed'
)
);
}
});
// WebChannel delivers message events as array. If batching is not enabled
// (it's off by default) each message will be delivered alone, resulting in
// a single element array.
type WebChannelResponse = { data: Resp[] };
unguardedEventListen<WebChannelResponse>(
WebChannel.EventType.MESSAGE,
msg => {
Eif (!closed) {
const msgData = msg.data[0];
assert(!!msgData, 'Got a webchannel message without data.');
// TODO(b/35143891): There is a bug in One Platform that caused errors
// (and only errors) to be wrapped in an extra array. To be forward
// compatible with the bug we need to check either condition. The latter
// can be removed once the fix has been rolled out.
const error =
// tslint:disable-next-line:no-any msgData.error is not typed.
(msgData as any).error || (msgData[0] && msgData[0].error);
if (error) {
log.debug(LOG_TAG, 'WebChannel received error:', error);
// error.status will be a string like 'OK' or 'NOT_FOUND'.
const status: string = error.status;
let code = mapCodeFromRpcStatus(status);
let message = error.message;
Iif (code === undefined) {
code = Code.INTERNAL;
message =
'Unknown error status: ' +
status +
' with message ' +
error.message;
}
// Mark closed so no further events are propagated
closed = true;
streamBridge.callOnClose(new FirestoreError(code, message));
channel.close();
} else {
log.debug(LOG_TAG, 'WebChannel received:', msgData);
streamBridge.callOnMessage(msgData);
}
}
}
);
setTimeout(() => {
// Technically we could/should wait for the WebChannel opened event,
// but because we want to send the first message with the WebChannel
// handshake we pretend the channel opened here (asynchronously), and
// then delay the actual open until the first message is sent.
streamBridge.callOnOpen();
}, 0);
return streamBridge;
}
// visible for testing
makeUrl(rpcName: string): string {
const urlRpcName = RPC_NAME_REST_MAPPING[rpcName];
assert(urlRpcName !== undefined, 'Unknown REST mapping for: ' + rpcName);
const url = [this.baseUrl, '/', RPC_URL_VERSION];
url.push('/projects/');
url.push(this.databaseId.projectId);
url.push('/databases/');
url.push(this.databaseId.database);
url.push('/documents');
url.push(':');
url.push(urlRpcName);
return url.join('');
}
}
|