Repository navigation
Expand file tree
/
Copy pathreplicache.ts
More file actions
923 lines (835 loc) · 27.7 KB
/
Copy pathreplicache.ts
File metadata and controls
923 lines (835 loc) · 27.7 KB
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
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
import {deepEqual, JSONValue} from './json.js';
import type {KeyTypeForScanOptions, ScanOptions} from './scan-options.js';
import {
Invoker,
Invoke,
OpenTransactionRequest,
REPMWasmInvoker,
InitInput,
OpenResponse,
RPC,
} from './repm-invoker.js';
import {
CreateIndexDefinition,
IndexTransactionImpl,
ReadTransactionImpl,
WriteTransactionImpl,
} from './transactions.js';
import {ScanResult} from './scan-iterator.js';
import type {ReadTransaction, WriteTransaction} from './transactions.js';
import {ConnectionLoop} from './connection-loop.js';
type BeginPullResult = {
requestID: string;
syncHead: string;
ok: boolean;
};
export const httpStatusUnauthorized = 401;
export type MaybePromise<T> = T | Promise<T>;
/** The key name to use in localStorage when synchronizing changes. */
const storageKeyName = (name: string) => `/replicache/root/${name}`;
/** The maximum number of time to call out to getDataLayerAuth before giving up and throwing an error. */
const MAX_REAUTH_TRIES = 8;
/**
* The options passed to [[Replicache]].
*/
export interface ReplicacheOptions {
/**
* This is the
* [authentication](https://github.com/rocicorp/replicache/blob/main/SERVER_SETUP.md#authentication)
* token used when doing a [push
* ](https://github.com/rocicorp/replicache/blob/main/SERVER_SETUP.md#step-4-upstream-sync).
*/
pushAuth?: string;
/**
* This is the URL to the server endpoint dealing with the push updates. See
* [Server Setup Upstream Sync](https://github.com/rocicorp/replicache/blob/main/SERVER_SETUP.md#step-4-upstream-sync)
* for more details.
*/
pushURL?: string;
/**
* This is the
* [authentication](https://github.com/rocicorp/replicache/blob/main/SERVER_SETUP.md#authentication)
* token used when doing a [pull
* ](https://github.com/rocicorp/replicache/blob/main/SERVER_SETUP.md#step-4-upstream-sync).
*/
pullAuth?: string;
/**
* This is the URL to the server endpoint dealing with pull. See [Server Setup
* Downstream
* Sync](https://github.com/rocicorp/replicache/blob/main/SERVER_SETUP.md#step-1-downstream-sync)
* for more details.
*/
pullURL?: string;
/**
* The name of the Replicache database. This defaults to `"default"`.
*
* You can use multiple Replicache instances as long as the names are unique.
*
* Using different names for different users allows you to switch users even
* when you are offline.
*/
name?: string;
/**
* The schema version of the data understood by this application. This enables
* versioning of mutators (in the push direction) and the client view (in the
* pull direction).
*/
schemaVersion?: string;
/**
* The duration between each [[pull]]. Set this to `null` to prevent pulling
* in the background.
*/
pullInterval?: number | null;
/**
* The delay between when a change is made to Replicache and when Replicache
* attempts to push that change.
*/
pushDelay?: number;
/**
* By default we will load the Replicache wasm module relative to the
* Replicache js files but under some circumstances (like bundling with old
* versions of Webpack) it is useful to manually configure where the wasm
* module is located on the web server.
*
* If you provide your own path to the wasm module it probably makes sense to
* use a relative URL relative to your current file.
*
* ```js
* wasmModule: new URL('./relative/path/to/replicache.wasm', import.meta.url),
* ```
*
* You might also want to consider using an absolute URL so that we can find
* the wasm module no matter where your js file is loaded from:
*
* ```js
* wasmModule: '/static/replicache.wasm',
* ```
*/
wasmModule?: InitInput | undefined;
/**
* Allows using an in memory store instead of IndexedDB. This is useful for
* testing for example. Notice that when this is `true` no data is persisted
* in Replicache and all the data that has not yet been synced when Replicache
* is [[closed]] or the page is unloaded is lost.
*/
useMemstore?: boolean;
}
export class Replicache implements ReadTransaction {
private _pullAuth: string;
private readonly _pullURL: string;
private _pushAuth: string;
private readonly _pushURL: string;
private readonly _name: string;
private readonly _repmInvoker: Invoker;
private readonly _useMemstore: boolean;
private readonly _schemaVersion: string = '';
private _closed = false;
private _online = true;
private _openResponse!: Promise<OpenResponse>;
private _root: Promise<string | undefined> = Promise.resolve(undefined);
private readonly _mutatorRegistry = new Map<
string,
(tx: WriteTransaction, args?: JSONValue) => MaybePromise<void | JSONValue>
>();
// Number of pushes/pulls at the moment.
private _pushCounter = 0;
private _pullCounter = 0;
private _pullConnectionLoop: ConnectionLoop;
private _pushConnectionLoop: ConnectionLoop;
private readonly _subscriptions = new Set<
Subscription<JSONValue | undefined, unknown>
>();
/**
* The duration between each periodic [[pull]]. Setting this to `null`
* disables periodic pull completely. Pull will still happen if you call
* [[pull]] manually.
*/
pullInterval: number | null;
/**
* The delay between when a change is made to Replicache and when Replicache
* attempts to push that change.
*/
pushDelay: number;
/**
* `onSync` is called when a sync begins, and again when the sync ends. The parameter `syncing`
* is set to `true` when `onSync` is called at the beginning of a sync, and `false` when it
* is called at the end of a sync.
*
* This can be used in a React like app by doing something like the following:
*
* ```js
* const [syncing, setSyncing] = useState(false);
* useEffect(() => {
* rep.>
* }, [rep]);
* ```
*/
onSync: ((syncing: boolean) => void) | null = null;
/**
* This gets called when we get an HTTP unauthorized (410) response from the
* pull endpoint. Set this to a function that will ask your user to
* reauthenticate.
*/
getPullAuth:
| (() => MaybePromise<string | null | undefined>)
| null
| undefined = null;
/**
* This gets called when we get an HTTP unauthorized (410) response from the push
* endpoint. Set this to a function that will ask your user to reauthenticate.
*/
getPushAuth:
| (() => MaybePromise<string | null | undefined>)
| null
| undefined = null;
constructor(options: ReplicacheOptions) {
const {
name = 'default',
pullAuth = '',
pullURL = '',
pushAuth = '',
pushDelay = 10,
pushURL = '',
schemaVersion = '',
pullInterval = 60_000,
useMemstore = false,
wasmModule,
} = options;
this._pullAuth = pullAuth;
this._pullURL = pullURL;
this._pushAuth = pushAuth;
this._pushURL = pushURL;
this._name = name;
this._repmInvoker = new REPMWasmInvoker(wasmModule);
this._schemaVersion = schemaVersion;
this.pullInterval = pullInterval;
this.pushDelay = pushDelay;
this._useMemstore = useMemstore;
this._pullConnectionLoop = new ConnectionLoop({
invokeSend: () => this._invokePull(),
watchdogTimer: () => this.pullInterval,
debounceDelay: () => 0,
maxConnections: 1,
});
this._pushConnectionLoop = new ConnectionLoop({
invokeSend: () => this._invokePush(MAX_REAUTH_TRIES),
debounceDelay: () => this.pushDelay,
maxConnections: 1,
});
this._open().then(() => {
this.pull();
this._push();
});
}
private async _open(): Promise<void> {
this._openResponse = this._repmInvoker.invoke(this._name, RPC.Open, {
useMemstore: this._useMemstore,
});
this._setRoot(this._getRoot());
await this._root;
window.addEventListener('storage', this._onStorage);
}
/**
* The client ID for this instance of Replicache. Each web browser and
* instance of Replicache gets a unique client ID keyed by the
* {@link ReplicacheOptions.name | name}. This is persisted locally between
* sessions (unless [[useMemstore]] is true in which case it is reset every
* time a new Replicache instance is created).
*/
get clientID(): Promise<string> {
return this._openResponse;
}
/**
* A rough heuristic for whether the client is currently online. Note that there is no way to know
* for certain whether a client is online - the next request can always fail. This is true if the last
* sync attempt succeeded, and false otherwise.
*/
get online(): boolean {
return this._online;
}
/**
* Whether the Replicache database has been closed. Once Replicache has been
* closed it no longer syncs and you can no longer read or write data out of
* it. After it has been closed it is pretty much useless and should not be
* used any more.
*/
get closed(): boolean {
return this._closed;
}
/**
* Closes this Replicache instance.
*
* When closed all subscriptions end and no more read or writes are allowed.
*/
async close(): Promise<void> {
this._closed = true;
const p = this._invoke(RPC.Close);
this._pullConnectionLoop.close();
this._pushConnectionLoop.close();
window.removeEventListener('storage', this._onStorage);
// Clear subscriptions
for (const subscription of this._subscriptions) {
subscription.onDone?.();
}
this._subscriptions.clear();
await p;
}
private async _getRoot(): Promise<string | undefined> {
if (this._closed) {
return undefined;
}
const res = await this._invoke(RPC.GetRoot);
return res.root;
}
private _setRoot(root: Promise<string | undefined>) {
this._root = root;
this._setStorage(root);
}
private async _setStorage(root: Promise<string | undefined>) {
// Also set an item in localStorage so that we can synchronize multiple
// windows/tabs.
localStorage[storageKeyName(this._name)] = await root;
}
// Callback for when window.onstorage fires which happens when a different tab
// changes the db.
private _onStorage = (e: StorageEvent): void => {
if (e.key === storageKeyName(this._name)) {
this._checkChange(e.newValue as string);
}
};
private async _checkChange(root: string | undefined): Promise<void> {
const currentRoot = await this._root; // instantaneous except maybe first time
if (root !== undefined && root !== currentRoot) {
this._setRoot(Promise.resolve(root));
await this._fireOnChange();
}
}
private _invoke: Invoke = async (
rpc: RPC,
args?: JSONValue,
): Promise<JSONValue> => {
await this._openResponse;
return await this._repmInvoker.invoke(this._name, rpc, args);
};
/** Get a single value from the database. */
get(key: string): Promise<JSONValue | undefined> {
return this.query(tx => tx.get(key));
}
/** Determines if a single `key` is present in the database. */
has(key: string): Promise<boolean> {
return this.query(tx => tx.has(key));
}
/** Whether the database is empty. */
isEmpty(): Promise<boolean> {
return this.query(tx => tx.isEmpty());
}
/**
* Gets many values from the database. This returns a `ScanResult` which
* implements `AsyncIterable`. It also has methods to iterate over the `keys`
* and `entries`.
*
* If `options` has an `indexName`, then this does a scan over an index with
* that name. A scan over an index uses a tuple for the key consisting of
* `[secondary: string, primary: string]`.
*/
scan<O extends ScanOptions, K extends KeyTypeForScanOptions<O>>(
options?: O,
): ScanResult<K> {
let tx: ReadTransactionImpl;
return new ScanResult<K>(
options,
this._invoke,
async () => {
if (tx) {
return tx;
}
tx = new ReadTransactionImpl(this._invoke);
await tx.open({});
return tx;
},
true,
);
}
/**
* Convenience form of `scan()` which returns all the entries as an array.
*/
async scanAll<O extends ScanOptions, K extends KeyTypeForScanOptions<O>>(
options?: O,
): Promise<[K, JSONValue][]> {
const tx = new ReadTransactionImpl(this._invoke);
try {
await tx.open({});
return await tx.scanAll(options);
} finally {
tx.close();
}
}
/**
* Creates a persistent secondary index in Replicache which can be used with scan.
*
* If the named index already exists with the same definition this returns success
* immediately. If the named index already exists, but with a different definition
* an error is thrown.
*/
async createIndex(def: CreateIndexDefinition): Promise<void> {
await this._indexOp(tx => tx.createIndex(def));
}
/**
* Drops an index previously created with [[createIndex]].
*/
async dropIndex(name: string): Promise<void> {
await this._indexOp(tx => tx.dropIndex(name));
}
private async _indexOp(
f: (tx: IndexTransactionImpl) => Promise<void>,
): Promise<void> {
const tx = new IndexTransactionImpl(this._invoke);
try {
await tx.open({});
await f(tx);
} finally {
tx.commit();
}
}
protected async _maybeEndPull(
beginPullResult: BeginPullResult,
): Promise<void> {
if (this._closed) {
return;
}
let {syncHead} = beginPullResult;
const {replayMutations} = await this._invoke(
RPC.MaybeEndTryPull,
beginPullResult,
);
if (!replayMutations || replayMutations.length === 0) {
// All done.
await this._checkChange(syncHead);
return;
}
// Replay.
console.group('Replaying');
for (const mutation of replayMutations) {
syncHead = await this._replay(
syncHead,
mutation.original,
mutation.name,
JSON.parse(mutation.args),
);
}
console.groupEnd();
await this._maybeEndPull({...beginPullResult, syncHead});
}
private async _replay<A extends JSONValue>(
basis: string,
original: string,
name: string,
args: A,
): Promise<string> {
let mutatorImpl = this._mutatorRegistry.get(name);
if (!mutatorImpl) {
// Developers must not remove mutator names from the set once registered,
// because Replicache needs to be able to replay mutations during sync.
//
// If we detect that this has happened, stub in a no-op mutator so that at
// least sync can move forward. Note that the server-side mutation will
// still get sent. This doesn't remove the queued local mutation, it just
// removes its visible effects.
console.error(`Unknown mutator ${name}`);
mutatorImpl = async () => {
// no op
};
}
const res = await this._mutate(name, mutatorImpl, args, {
invokeArgs: {
rebaseOpts: {basis, original},
},
isReplay: true,
});
return res.ref;
}
private async _invokePull(): Promise<boolean> {
return await this._wrapInOnlineCheck(async () => {
try {
this._changeSyncCounters(0, 1);
const beginPullResult = await this._beginPull(MAX_REAUTH_TRIES);
if (!beginPullResult.ok) {
return false;
}
if (beginPullResult.syncHead !== '') {
await this._maybeEndPull(beginPullResult);
}
} finally {
this._changeSyncCounters(0, -1);
}
return true;
}, 'Pull');
}
private async _wrapInOnlineCheck(
f: () => Promise<boolean>,
name: string,
): Promise<boolean> {
let >
try {
return await f();
} catch (e) {
// The error paths of beginPull and maybeEndPull need to be reworked.
//
// We want to distinguish between:
// a) network requests failed -- we're offline basically
// b) sync was aborted because one's already in progress
// c) oh noes - something unexpected happened
//
// Right now, all of these come out as errors. We distinguish (b) with a
// hacky string search. (a) and (c) are not distinguishable currently
// because repc doesn't provide sufficient information, so we treat all
// errors that aren't (b) as (a).
if (e.toString().includes('JSLogInfo')) {
>
}
console.info(`${name} returned: ${e}`);
return false;
} finally {
this._online = online;
}
}
private async _invokePush(maxAuthTries: number): Promise<boolean> {
return await this._wrapInOnlineCheck(async () => {
let pushResponse;
try {
this._changeSyncCounters(1, 0);
pushResponse = await this._invoke(RPC.TryPush, {
pushURL: this._pushURL,
pushAuth: this._pushAuth,
schemaVersion: this._schemaVersion,
});
} finally {
this._changeSyncCounters(-1, 0);
}
const {httpRequestInfo} = pushResponse;
if (httpRequestInfo) {
const reauth = checkStatus(httpRequestInfo, 'push', this._pushURL);
// TODO: Add back support for mutationInfos? We used to log all the errors
// here.
if (reauth && this.getPushAuth) {
if (maxAuthTries === 0) {
console.info('Tried to reauthenticate too many times');
return false;
}
const pushAuth = await this.getPushAuth();
if (pushAuth != null) {
this._pushAuth = pushAuth;
// Try again now instead of waiting for next push.
return await this._invokePush(maxAuthTries - 1);
}
}
return httpRequestInfo.httpStatusCode === 200;
}
// No httpRequestInfo means we didn't do a push because there were no
// pending mutations.
return true;
}, 'Push');
}
/**
* Push pushes pending changes to the [[pushURL]].
*
* You do not usually need to manually call push. If [[pushDelay]] is non-zero
* (which it is by default) pushes happen automatically shortly after
* mutations.
*/
private _push(): void {
this._pushConnectionLoop.send();
}
/**
* Pull pulls changes from the [[pullURL]]. If there are any changes
* local changes will get replayed on top of the new server state.
*/
pull(): void {
this._pullConnectionLoop.send();
}
protected async _beginPull(maxAuthTries: number): Promise<BeginPullResult> {
const beginPullResponse = await this._invoke(RPC.BeginTryPull, {
pullAuth: this._pullAuth,
pullURL: this._pullURL,
schemaVersion: this._schemaVersion,
});
const {httpRequestInfo, syncHead, requestID} = beginPullResponse;
const reauth = checkStatus(httpRequestInfo, 'pull', this._pullURL);
if (reauth && this.getPullAuth) {
if (maxAuthTries === 0) {
console.info('Tried to reauthenticate too many times');
return {requestID, syncHead: '', ok: false};
}
let pullAuth;
try {
// Don't want to say we are syncing when we are waiting for auth
this._changeSyncCounters(0, -1);
pullAuth = await this.getPullAuth();
} finally {
this._changeSyncCounters(0, 1);
}
if (pullAuth != null) {
this._pullAuth = pullAuth;
// Try again now instead of waiting for next pull.
return await this._beginPull(maxAuthTries - 1);
}
}
return {requestID, syncHead, ok: httpRequestInfo.httpStatusCode === 200};
}
private _changeSyncCounters(pushDelta: 0, pullDelta: 1 | -1): void;
private _changeSyncCounters(pushDelta: 1 | -1, pullDelta: 0): void;
private _changeSyncCounters(pushDelta: number, pullDelta: number): void {
this._pushCounter += pushDelta;
this._pullCounter += pullDelta;
const delta = pushDelta + pullDelta;
const counter = this._pushCounter + this._pullCounter;
if ((delta === 1 && counter === 1) || counter === 0) {
const syncing = counter > 0;
Promise.resolve().then(() => this.onSync?.(syncing));
}
}
private async _fireOnChange(): Promise<void> {
type R =
| {ok: true; value: JSONValue | undefined}
| {ok: false; error: unknown};
const subscriptions = [...this._subscriptions];
const results = await this.query(async tx => {
const promises = subscriptions.map(async s => {
// Tag the result so we can deal with success vs error below.
try {
return {ok: true, value: await s.body(tx)} as R;
} catch (ex) {
return {ok: false, error: ex} as R;
}
});
return await Promise.all(promises);
});
for (let i = 0; i < subscriptions.length; i++) {
const s = subscriptions[i];
const result = results[i];
if (result.ok) {
const value: JSONValue | undefined = result.value;
if (!deepEqual(value, s.lastValue)) {
s.lastValue = value;
s.onData(value);
}
} else {
s.onError?.(result.error);
}
}
}
/**
* Subcribe to changes to the underlying data. Every time the underlying data
* changes `body` is called and if the result of `body` changes compared to
* last time `onData` is called. The function is also called once the first
* time the subscription is added.
*
* This returns a function that can be used to cancel the subscription.
*
* If an error occurs in the `body` the `onError` function is called if
* present. Otherwise, the error is thrown.
*/
subscribe<R extends JSONValue | undefined, E>(
body: (tx: ReadTransaction) => Promise<R>,
{
onData,
onError,
onDone,
}: {
onData: (result: R) => void;
onError?: (error: E) => void;
onDone?: () => void;
},
): () => void {
const s = {
body,
onData,
onError,
onDone,
lastValue: undefined,
} as Subscription<R, E>;
this._subscriptions.add(
(s as unknown) as Subscription<JSONValue | undefined, unknown>,
);
(async () => {
try {
const res = await this.query(s.body);
s.lastValue = res;
s.onData(res);
} catch (ex) {
if (s.onError) {
s.onError(ex);
} else {
throw ex;
}
}
})();
return (): void => {
this._subscriptions.delete(
(s as unknown) as Subscription<JSONValue | undefined, unknown>,
);
};
}
/**
* Query is used for read transactions. It is recommended to use transactions
* to ensure you get a consistent view across multiple calls to `get`, `has`
* and `scan`.
*/
async query<R>(body: (tx: ReadTransaction) => Promise<R> | R): Promise<R> {
const tx = new ReadTransactionImpl(this._invoke);
await tx.open({});
try {
return await body(tx);
} finally {
// No need to await the response.
tx.close();
}
}
/**
* Registers a *mutator*, which is used to make changes to the data.
*
* ## Replays
*
* Mutators run once when they are initially invoked, but they might also be
* *replayed* multiple times during sync. As such mutators should not modify
* application state directly. Also, it is important that the set of
* registered mutator names only grows over time. If Replicache syncs and
* needed mutator is not registered, it will substitute a no-op mutator, but
* this might be a poor user experience.
*
* ## Server application
*
* During sync, a description of each mutation is sent to the server's [push
* endpoint](https://github.com/rocicorp/replicache/blob/main/SERVER_SETUP.md#step-5-upstream-sync)
* where it is applied. Once the mutation has been applied successfully, as
* indicated by the [client
* view](https://github.com/rocicorp/replicache/blob/main/SERVER_SETUP.md#step-1-downstream-sync)'s
* `lastMutationId` field, the local version of the mutation is removed. See
* the [design
* doc](https://github.com/rocicorp/replicache/blob/main/design.md) for
* additional details on the sync protocol.
*
* ## Transactionality
*
* Mutators are atomic: all their changes are applied together, or none are.
* Throwing an exception aborts the transaction. Otherwise, it is committed.
* As with [[query]] and [[subscribe]] all reads will see a consistent view of the
* cache while they run.
*
* ## Example
*
* `register` returns the function to use to mutate Replicache.
*
* ```ts
* const createTodo = rep.register('createTodo',
* async (tx: WriteTransaction, args: JSONValue) => {
* const key = `/todo/${args.id}`;
* if (await tx.has(key)) {
* throw new Error('Todo already exists');
* }
* await tx.put(key, args);
* });
* ```
*
* This will create the function to later use:
*
* ```ts
* await createTodo({id: 1234, title: 'Make things work offline', complete: true});
* ```
*/
register<Return extends JSONValue | void>(
name: string,
mutatorImpl: (tx: WriteTransaction) => MaybePromise<Return>,
): () => Promise<Return>;
register<Return extends JSONValue | void, Args extends JSONValue>(
name: string,
mutatorImpl: (tx: WriteTransaction, args: Args) => MaybePromise<Return>,
): (args: Args) => Promise<Return>;
register<Return extends JSONValue | void, Args extends JSONValue>(
name: string,
mutatorImpl: (tx: WriteTransaction, args?: Args) => MaybePromise<Return>,
): (args?: Args) => Promise<Return> {
this._mutatorRegistry.set(
name,
mutatorImpl as (
tx: WriteTransaction,
args: JSONValue | undefined,
) => Promise<void | JSONValue>,
);
return async (args?: Args): Promise<Return> =>
(await this._mutate(name, mutatorImpl, args, {isReplay: false})).result;
}
private async _mutate<R extends JSONValue | void, A extends JSONValue>(
name: string,
mutatorImpl: (tx: WriteTransaction, args?: A) => MaybePromise<R>,
args: A | undefined,
{
invokeArgs,
isReplay,
}: {invokeArgs?: OpenTransactionRequest; isReplay: boolean},
): Promise<{result: R; ref: string}> {
let actualInvokeArgs: OpenTransactionRequest = {
args: args !== undefined ? JSON.stringify(args) : 'null',
name,
};
if (invokeArgs !== undefined) {
actualInvokeArgs = {...actualInvokeArgs, ...invokeArgs};
}
let result: R;
const tx = new WriteTransactionImpl(this._invoke);
await tx.open(actualInvokeArgs);
try {
result = await mutatorImpl(tx, args);
} catch (ex) {
// No need to await the response.
tx.close();
throw ex;
}
const {ref} = await tx.commit();
if (!isReplay) {
this._pushConnectionLoop.send();
await this._checkChange(ref);
}
return {result, ref};
}
/**
* When this is set to `true` the internal Replicache wasm module will log
* more things to the console (using `console.debug`). Setting this to false
* reduces the amount of logging done by the wasm module.
*
* If you want to see the verbose logging from Replicache in Devtools/Web
* Inspector you also need to change the console log level to `Verbose`.
*/
async setVerboseWasmLogging(verbose: boolean): Promise<void> {
await this._invoke(RPC.SetLogLevel, {level: verbose ? 'debug' : 'info'});
}
}
function checkStatus(
data: {httpStatusCode: number; errorMessage: string},
verb: string,
serverURL: string,
): boolean {
const {httpStatusCode, errorMessage} = data;
if (errorMessage || httpStatusCode >= 400) {
console.error(
`Got error response from server (${serverURL}) doing ${verb}: ${httpStatusCode}` +
(errorMessage ? `: ${errorMessage}` : ''),
);
}
return httpStatusCode === httpStatusUnauthorized;
}
export class ReplicacheTest extends Replicache {
beginPull(): Promise<BeginPullResult> {
return super._beginPull(MAX_REAUTH_TRIES);
}
maybeEndPull(beginPullResult: BeginPullResult): Promise<void> {
return super._maybeEndPull(beginPullResult);
}
}
type Subscription<R extends JSONValue | undefined, E> = {
body: (tx: ReadTransaction) => Promise<R>;
onData: (r: R) => void;
onError?: (e: E) => void;
onDone?: () => void;
lastValue?: R;
};
You can’t perform that action at this time.