aboutsummaryrefslogtreecommitdiff
path: root/libdino/src/service/history_sync.vala
blob: 8ab6d7bb7f9cc3a4024695f543e2dc09aedacc49 (plain) (blame)
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
using Gee;

using Xmpp;
using Xmpp.Xep;
using Dino.Entities;
using Qlite;

public class Dino.HistorySync {

    private StreamInteractor stream_interactor;
    private Database db;

    public HashMap<Account, HashMap<Jid, int>> current_catchup_id = new HashMap<Account, HashMap<Jid, int>>(Account.hash_func, Account.equals_func);
    public WeakMap<Account, XmppStream> sync_streams = new WeakMap<Account, XmppStream>(Account.hash_func, Account.equals_func);
    public HashMap<Account, HashMap<Jid, Cancellable>> cancellables = new HashMap<Account, HashMap<Jid, Cancellable>>(Account.hash_func, Account.equals_func);
    public HashMap<Account, HashMap<string, DateTime>> mam_times = new HashMap<Account, HashMap<string, DateTime>>();
    public HashMap<string, int> hitted_range = new HashMap<string, int>();

    // Server ID of the latest message of the previous segment
    public HashMap<Account, string> catchup_until_id = new HashMap<Account, string>(Account.hash_func, Account.equals_func);
    // Time of the latest message of the previous segment
    public HashMap<Account, DateTime> catchup_until_time = new HashMap<Account, DateTime>(Account.hash_func, Account.equals_func);

    private HashMap<string, Gee.List<Xmpp.MessageStanza>> stanzas = new HashMap<string, Gee.List<Xmpp.MessageStanza>>();

    public class HistorySync(Database db, StreamInteractor stream_interactor) {
        this.stream_interactor = stream_interactor;
        this.db = db;

        stream_interactor.account_added.connect(on_account_added);

        stream_interactor.stream_negotiated.connect((account, stream) => {
            if (current_catchup_id.has_key(account)) {
                debug("MAM: [%s] Reset catchup_id", account.bare_jid.to_string());
                current_catchup_id[account].clear();
            }
        });
    }

    public bool process(Account account, Xmpp.MessageStanza message_stanza) {
        var mam_flag = Xmpp.MessageArchiveManagement.MessageFlag.get_flag(message_stanza);

        if (mam_flag != null) {
            process_mam_message(account, message_stanza, mam_flag);
            return true;
        } else {
            update_latest_db_range(account, message_stanza);
            return false;
        }
    }

    public void update_latest_db_range(Account account, Xmpp.MessageStanza message_stanza) {
        Jid mam_server = stream_interactor.get_module(MucManager.IDENTITY).might_be_groupchat(message_stanza.from.bare_jid, account) ? message_stanza.from.bare_jid : account.bare_jid;

        if (!current_catchup_id.has_key(account) || !current_catchup_id[account].has_key(mam_server)) return;

        string? stanza_id = UniqueStableStanzaIDs.get_stanza_id(message_stanza, mam_server);
        if (stanza_id == null) return;

        db.mam_catchup.update()
                .with(db.mam_catchup.id, "=", current_catchup_id[account][mam_server])
                .set(db.mam_catchup.to_time, (long)new DateTime.now_utc().to_unix())
                .set(db.mam_catchup.to_id, stanza_id)
                .perform();
    }

    public void process_mam_message(Account account, Xmpp.MessageStanza message_stanza, Xmpp.MessageArchiveManagement.MessageFlag mam_flag) {
        Jid mam_server = mam_flag.sender_jid;
        Jid message_author = message_stanza.from;

        // MUC servers may only send MAM messages from that MUC
        bool is_muc_mam = stream_interactor.get_module(MucManager.IDENTITY).might_be_groupchat(mam_server, account) &&
                message_author.equals_bare(mam_server);

        bool from_our_server = mam_server.equals_bare(account.bare_jid);

        if (!is_muc_mam && !from_our_server) {
            warning("Received alleged MAM message from %s, ignoring", mam_server.to_string());
            return;
        }

        if (!stanzas.has_key(mam_flag.query_id)) stanzas[mam_flag.query_id] = new ArrayList<Xmpp.MessageStanza>();
        stanzas[mam_flag.query_id].add(message_stanza);
    }

    private void on_unprocessed_message(Account account, XmppStream stream, MessageStanza message) {
        // Check that it's a legit MAM server
        bool is_muc_mam = stream_interactor.get_module(MucManager.IDENTITY).might_be_groupchat(message.from, account);
        bool from_our_server = message.from.equals_bare(account.bare_jid);
        if (!is_muc_mam && !from_our_server) return;

        // Get the server time of the message and store it in `mam_times`
        string? id = message.stanza.get_deep_attribute(Xmpp.MessageArchiveManagement.NS_URI + ":result", "id");
        if (id == null) return;
        StanzaNode? delay_node = message.stanza.get_deep_subnode(Xmpp.MessageArchiveManagement.NS_URI + ":result", StanzaForwarding.NS_URI + ":forwarded", DelayedDelivery.NS_URI + ":delay");
        if (delay_node == null) {
            warning("MAM result did not contain delayed time %s", message.stanza.to_string());
            return;
        }
        DateTime? time = DelayedDelivery.get_time_for_node(delay_node);
        if (time == null) return;
        mam_times[account][id] = time;

        // Check if this is the target message
        string? query_id = message.stanza.get_deep_attribute(Xmpp.MessageArchiveManagement.NS_URI + ":result", Xmpp.MessageArchiveManagement.NS_URI + ":queryid");
        if (query_id != null && id == catchup_until_id[account]) {
            debug("[%s] Hitted range (id) %s", account.bare_jid.to_string(), id);
            hitted_range[query_id] = -2;
        }
    }

    public void on_server_id_duplicate(Account account, Xmpp.MessageStanza message_stanza, Entities.Message message) {
        Xmpp.MessageArchiveManagement.MessageFlag? mam_flag = Xmpp.MessageArchiveManagement.MessageFlag.get_flag(message_stanza);
        if (mam_flag == null) return;

//        debug(@"MAM: [%s] Hitted range duplicate server id. id %s qid %s", account.bare_jid.to_string(), message.server_id, mam_flag.query_id);
        if (catchup_until_time.has_key(account) && mam_flag.server_time.compare(catchup_until_time[account]) < 0) {
            hitted_range[mam_flag.query_id] = -1;
//            debug(@"MAM: [%s] In range (time) %s < %s", account.bare_jid.to_string(), mam_flag.server_time.to_string(), catchup_until_time[account].to_string());
        }
    }

    public async void fetch_everything(Account account, Jid mam_server, Cancellable? cancellable = null, DateTime until_earliest_time = new DateTime.from_unix_utc(0)) {
        debug("Fetch everything for %s %s", mam_server.to_string(), until_earliest_time != null ? @"(until $until_earliest_time)" : "");
        RowOption latest_row_opt = db.mam_catchup.select()
                .with(db.mam_catchup.account_id, "=", account.id)
                .with(db.mam_catchup.server_jid, "=", mam_server.to_string())
                .with(db.mam_catchup.to_time, ">=", (long) until_earliest_time.to_unix())
                .order_by(db.mam_catchup.to_time, "DESC")
                .single().row();
        Row? latest_row = latest_row_opt.is_present() ? latest_row_opt.inner : null;

        Row? new_row = yield fetch_latest_page(account, mam_server, latest_row, until_earliest_time, cancellable);

        if (new_row != null) {
            current_catchup_id[account][mam_server] = new_row[db.mam_catchup.id];
        } else if (latest_row != null) {
            current_catchup_id[account][mam_server] = latest_row[db.mam_catchup.id];
        }

        // Set the previous and current row
        Row? previous_row = null;
        Row? current_row = null;
        if (new_row != null) {
            current_row = new_row;
            previous_row = latest_row;
        } else if (latest_row != null) {
            current_row = latest_row;
            RowOption previous_row_opt = db.mam_catchup.select()
                    .with(db.mam_catchup.account_id, "=", account.id)
                    .with(db.mam_catchup.server_jid, "=", mam_server.to_string())
                    .with(db.mam_catchup.to_time, "<", current_row[db.mam_catchup.from_time])
                    .with(db.mam_catchup.to_time, ">=", (long) until_earliest_time.to_unix())
                    .order_by(db.mam_catchup.to_time, "DESC")
                    .single().row();
            previous_row = previous_row_opt.is_present() ? previous_row_opt.inner : null;
        }

        // Fetch messages between two db ranges and merge them
        while (current_row != null && previous_row != null) {
            if (current_row[db.mam_catchup.from_end]) return;

            debug("[%s] Fetching between ranges %s - %s", mam_server.to_string(), previous_row[db.mam_catchup.to_time].to_string(), current_row[db.mam_catchup.from_time].to_string());
            current_row = yield fetch_between_ranges(account, mam_server, previous_row, current_row, cancellable);
            if (current_row == null) return;

            RowOption previous_row_opt = db.mam_catchup.select()
                    .with(db.mam_catchup.account_id, "=", account.id)
                    .with(db.mam_catchup.server_jid, "=", mam_server.to_string())
                    .with(db.mam_catchup.to_time, "<", current_row[db.mam_catchup.from_time])
                    .with(db.mam_catchup.to_time, ">=", (long) until_earliest_time.to_unix())
                    .order_by(db.mam_catchup.to_time, "DESC")
                    .single().row();
            previous_row = previous_row_opt.is_present() ? previous_row_opt.inner : null;
        }

        // We're at the earliest range. Try to expand it even further back.
        if (current_row == null || current_row[db.mam_catchup.from_end]) return;
        // We don't want to fetch before the earliest range over and over again in MUCs if it's after until_earliest_time.
        // For now, don't query if we are within a week of until_earliest_time
        if (until_earliest_time != null &&
                current_row[db.mam_catchup.from_time] > until_earliest_time.add(-TimeSpan.DAY * 7).to_unix()) return;
        yield fetch_before_range(account, mam_server, current_row, until_earliest_time);
    }

    // Fetches the latest page (up to previous db row). Extends the previous db row if it was reached, creates a new row otherwise.
    public async Row? fetch_latest_page(Account account, Jid mam_server, Row? latest_row, DateTime? until_earliest_time, Cancellable? cancellable = null) {
        debug("[%s | %s] Fetching latest page", account.bare_jid.to_string(), mam_server.to_string());

        int latest_row_id = -1;
        DateTime latest_message_time = until_earliest_time;
        string? latest_message_id = null;

        if (latest_row != null) {
            latest_row_id = latest_row[db.mam_catchup.id];
            latest_message_time = (new DateTime.from_unix_utc(latest_row[db.mam_catchup.to_time])).add_minutes(-5);
            latest_message_id = latest_row[db.mam_catchup.to_id];

            // Make sure we only fetch to until_earliest_time if latest_message_time is further back
            if (until_earliest_time != null && latest_message_time.compare(until_earliest_time) < 0) {
                latest_message_time = until_earliest_time.add_minutes(-5);
                latest_message_id = null;
            }
        }

        var query_params = new Xmpp.MessageArchiveManagement.V2.MamQueryParams.query_latest(mam_server, latest_message_time, latest_message_id);

        PageRequestResult page_result = yield get_mam_page(account, query_params, null, cancellable);
        debug("[%s | %s] Latest page result: %s", account.bare_jid.to_string(), mam_server.to_string(), page_result.page_result.to_string());

        if (page_result.page_result == PageResult.Error || page_result.page_result == PageResult.Cancelled) {
            return null;
        }

        // Catchup finished within first page. Update latest db entry.
        if (latest_row_id != -1 &&
                page_result.page_result in new PageResult[] { PageResult.TargetReached, PageResult.NoMoreMessages }) {

            if (page_result.stanzas == null) return null;

            string latest_mam_id = page_result.query_result.last;
            long latest_mam_time = (long) mam_times[account][latest_mam_id].to_unix();

            var query = db.mam_catchup.update()
                    .with(db.mam_catchup.id, "=", latest_row_id)
                    .set(db.mam_catchup.to_time, latest_mam_time)
                    .set(db.mam_catchup.to_id, latest_mam_id);

            if (page_result.page_result == PageResult.NoMoreMessages) {
                // If the server doesn't have more messages, store that this range is at its end.
                query.set(db.mam_catchup.from_end, true);
            }
            query.perform();
            return null;
        }

        if (page_result.query_result.first == null || page_result.query_result.last == null) {
            return null;
        }

        // Either we need to fetch more pages or this is the first db entry ever
        debug("[%s | %s] Creating new db range for latest page", account.bare_jid.to_string(), mam_server.to_string());

        string from_id = page_result.query_result.first;
        string to_id = page_result.query_result.last;

        if (!mam_times[account].has_key(from_id) || !mam_times[account].has_key(to_id)) {
            debug("Missing from/to id %s %s", from_id, to_id);
            return null;
        }

        long from_time = (long) mam_times[account][from_id].to_unix();
        long to_time = (long) mam_times[account][to_id].to_unix();

        int new_row_id = (int) db.mam_catchup.insert()
                .value(db.mam_catchup.account_id, account.id)
                .value(db.mam_catchup.server_jid, mam_server.to_string())
                .value(db.mam_catchup.from_id, from_id)
                .value(db.mam_catchup.from_time, from_time)
                .value(db.mam_catchup.from_end, page_result.page_result == PageResult.NoMoreMessages)
                .value(db.mam_catchup.to_id, to_id)
                .value(db.mam_catchup.to_time, to_time)
                .perform();
        return db.mam_catchup.select().with(db.mam_catchup.id, "=", new_row_id).single().row().inner;
    }

    /** Fetches messages between the end of `earlier_range` and start of `later_range`
     ** Merges the `earlier_range` db row into the `later_range` db row.
     ** @return The resulting range comprising `earlier_range`, `later_rage`, and everything in between. null if fetching/merge failed.
     **/
    private async Row? fetch_between_ranges(Account account, Jid mam_server, Row earlier_range, Row later_range, Cancellable? cancellable = null) {
        int later_range_id = (int) later_range[db.mam_catchup.id];
        DateTime earliest_time = new DateTime.from_unix_utc(earlier_range[db.mam_catchup.to_time]);
        DateTime latest_time = new DateTime.from_unix_utc(later_range[db.mam_catchup.from_time]);
        debug("[%s | %s] Fetching between %s (%s) and %s (%s)", account.bare_jid.to_string(), mam_server.to_string(), earliest_time.to_string(), earlier_range[db.mam_catchup.to_id], latest_time.to_string(), later_range[db.mam_catchup.from_id]);

        var query_params = new Xmpp.MessageArchiveManagement.V2.MamQueryParams.query_between(mam_server,
            earliest_time, earlier_range[db.mam_catchup.to_id],
            latest_time, later_range[db.mam_catchup.from_id]);

        PageRequestResult page_result = yield fetch_query(account, query_params, later_range_id, cancellable);

        if (page_result.page_result == PageResult.TargetReached || page_result.page_result == PageResult.NoMoreMessages) {
            debug("[%s | %s] Merging range %i into %i", account.bare_jid.to_string(), mam_server.to_string(), earlier_range[db.mam_catchup.id], later_range_id);
            // Merge earlier range into later one.
            db.mam_catchup.update()
                .with(db.mam_catchup.id, "=", later_range_id)
                .set(db.mam_catchup.from_time, earlier_range[db.mam_catchup.from_time])
                .set(db.mam_catchup.from_id, earlier_range[db.mam_catchup.from_id])
                .set(db.mam_catchup.from_end, earlier_range[db.mam_catchup.from_end])
                .perform();

            db.mam_catchup.delete().with(db.mam_catchup.id, "=", earlier_range[db.mam_catchup.id]).perform();

            // Return the updated version of the later range
            return db.mam_catchup.select().with(db.mam_catchup.id, "=", later_range_id).single().row().inner;
        }

        return null;
    }

    private async void fetch_before_range(Account account, Jid mam_server, Row range, DateTime? until_earliest_time, Cancellable? cancellable = null) {
        DateTime latest_time = new DateTime.from_unix_utc(range[db.mam_catchup.from_time]);
        string latest_id = range[db.mam_catchup.from_id];
        debug("[%s | %s] Fetching before range < %s, %s", account.bare_jid.to_string(), mam_server.to_string(), latest_time.to_string(), latest_id);

        Xmpp.MessageArchiveManagement.V2.MamQueryParams query_params;
        if (until_earliest_time == null) {
            query_params = new Xmpp.MessageArchiveManagement.V2.MamQueryParams.query_before(mam_server, latest_time, latest_id);
        } else {
            query_params = new Xmpp.MessageArchiveManagement.V2.MamQueryParams.query_between(
                    mam_server,
                    until_earliest_time, null,
                    latest_time, latest_id
            );
        }
        yield fetch_query(account, query_params, range[db.mam_catchup.id], cancellable);
    }

    /**
     * Iteratively fetches all pages returned for a query (until a PageResult other than MorePagesAvailable is returned)
     * @return The last PageRequestResult result
     **/
    private async PageRequestResult fetch_query(Account account, Xmpp.MessageArchiveManagement.V2.MamQueryParams query_params, int db_id, Cancellable? cancellable = null) {
        debug("[%s | %s] Fetch query %s - %s", account.bare_jid.to_string(), query_params.mam_server.to_string(), query_params.start != null ? query_params.start.to_string() : "", query_params.end != null ? query_params.end.to_string() : "");
        PageRequestResult? page_result = null;
        do {
            page_result = yield get_mam_page(account, query_params, page_result, cancellable);
            debug("[%s | %s] Page result %s (got stanzas: %s)", account.bare_jid.to_string(), query_params.mam_server.to_string(), page_result.page_result.to_string(), (page_result.stanzas != null).to_string());

            if (page_result.page_result == PageResult.Error || page_result.page_result == PageResult.Cancelled || page_result.query_result.first == null) return page_result;

            string earliest_mam_id = page_result.query_result.first;
            long earliest_mam_time = (long)mam_times[account][earliest_mam_id].to_unix();

            debug("Updating %s to %s, %s", query_params.mam_server.to_string(), earliest_mam_time.to_string(), earliest_mam_id);
            var query = db.mam_catchup.update()
                    .with(db.mam_catchup.id, "=", db_id)
                    .set(db.mam_catchup.from_time, earliest_mam_time)
                    .set(db.mam_catchup.from_id, earliest_mam_id);

            if (page_result.page_result == PageResult.NoMoreMessages) {
                // If the server doesn't have more messages, store that this range is at its end.
                query.set(db.mam_catchup.from_end, true);
            }
            query.perform();
        } while (page_result.page_result == PageResult.MorePagesAvailable);

        return page_result;
    }

    enum PageResult {
        MorePagesAvailable,
        TargetReached,
        NoMoreMessages,
        Error,
        Cancelled
    }

    /**
     * prev_page_result: null if this is the first page request
     **/
    private async PageRequestResult get_mam_page(Account account, Xmpp.MessageArchiveManagement.V2.MamQueryParams query_params, PageRequestResult? prev_page_result, Cancellable? cancellable = null) {
        XmppStream stream = stream_interactor.get_stream(account);
        Xmpp.MessageArchiveManagement.QueryResult query_result = null;
        if (prev_page_result == null) {
            query_result = yield Xmpp.MessageArchiveManagement.V2.query_archive(stream, query_params, cancellable);
        } else {
            query_result = yield Xmpp.MessageArchiveManagement.V2.page_through_results(stream, query_params, prev_page_result.query_result, cancellable);
        }
        return yield process_query_result(account, query_params, query_result, cancellable);
    }

    private async PageRequestResult process_query_result(Account account, Xmpp.MessageArchiveManagement.V2.MamQueryParams query_params, Xmpp.MessageArchiveManagement.QueryResult query_result, Cancellable? cancellable = null) {
        PageResult page_result = PageResult.MorePagesAvailable;

        if (query_result.malformed || query_result.error) {
            page_result = PageResult.Error;
        }

        // We wait until all the messages from the page are processed (and we got the `mam_times` from them)
        Idle.add(process_query_result.callback, Priority.LOW);
        yield;

        // We might have successfully reached the target or the server doesn't have all messages stored anymore
        // If it's the former, we'll overwrite the value with PageResult.MorePagesAvailable below.
        if (query_result.complete) {
            page_result = PageResult.NoMoreMessages;
        }

        string query_id = query_params.query_id;
        string? after_id = query_params.start_id;

        var stanzas_for_query = stanzas.has_key(query_id) && !stanzas[query_id].is_empty ? stanzas[query_id] : null;
        if (cancellable != null && cancellable.is_cancelled()) {
            stanzas.unset(query_id);
            return new PageRequestResult(PageResult.Cancelled, query_result, stanzas_for_query);
        }

        if (stanzas_for_query != null) {

            // Check it we reached our target (from_id)
            foreach (Xmpp.MessageStanza message in stanzas_for_query) {
                Xmpp.MessageArchiveManagement.MessageFlag? mam_message_flag = Xmpp.MessageArchiveManagement.MessageFlag.get_flag(message);
                if (mam_message_flag != null && mam_message_flag.mam_id != null) {
                    if (after_id != null && mam_message_flag.mam_id == after_id) {
                        // Successfully fetched the whole range
                        yield send_messages_back_into_pipeline(account, query_id, cancellable);
                        if (cancellable != null && cancellable.is_cancelled()) {
                            return new PageRequestResult(PageResult.Cancelled, query_result, stanzas_for_query);
                        }
                        return new PageRequestResult(PageResult.TargetReached, query_result, stanzas_for_query);
                    }
                }
            }
            if (hitted_range.has_key(query_id) && hitted_range[query_id] == -2) {
                // Message got filtered out by xmpp-vala, but succesful range fetch nevertheless
                yield send_messages_back_into_pipeline(account, query_id);
                if (cancellable != null && cancellable.is_cancelled()) {
                    return new PageRequestResult(PageResult.Cancelled, query_result, stanzas_for_query);
                }
                return new PageRequestResult(PageResult.TargetReached, query_result, stanzas_for_query);
            }
        }

        yield send_messages_back_into_pipeline(account, query_id);
        if (cancellable != null && cancellable.is_cancelled()) {
            page_result = PageResult.Cancelled;
        }
        return new PageRequestResult(page_result, query_result, stanzas_for_query);
    }

    private async void send_messages_back_into_pipeline(Account account, string query_id, Cancellable? cancellable = null) {
        if (!stanzas.has_key(query_id)) return;

        foreach (Xmpp.MessageStanza message in stanzas[query_id]) {
            if (cancellable != null && cancellable.is_cancelled()) break;
            yield stream_interactor.get_module(MessageProcessor.IDENTITY).run_pipeline_announce(account, message);
        }
        stanzas.unset(query_id);
    }

    private void on_account_added(Account account) {
        cleanup_db_ranges(db, account);

        mam_times[account] = new HashMap<string, DateTime>();

        stream_interactor.connection_manager.stream_attached_modules.connect((account, stream) => {
            if (!current_catchup_id.has_key(account)) {
                current_catchup_id[account] = new HashMap<Jid, int>(Jid.hash_func, Jid.equals_func);
            } else {
                current_catchup_id[account].clear();
            }
        });

        stream_interactor.module_manager.get_module(account, Xmpp.MessageArchiveManagement.Module.IDENTITY).feature_available.connect((stream) => {
            consider_fetch_everything(account, stream);
        });

        stream_interactor.module_manager.get_module(account, Xmpp.MessageModule.IDENTITY).received_message_unprocessed.connect((stream, message) => {
            on_unprocessed_message(account, stream, message);
        });
    }

    private void consider_fetch_everything(Account account, XmppStream stream) {
        if (sync_streams.has(account, stream)) return;

        debug("[%s] MAM available", account.bare_jid.to_string());
        sync_streams[account] = stream;
        if (!cancellables.has_key(account)) {
            cancellables[account] = new HashMap<Jid, Cancellable>();
        }
        if (cancellables[account].has_key(account.bare_jid)) {
            cancellables[account][account.bare_jid].cancel();
        }
        cancellables[account][account.bare_jid] = new Cancellable();
        fetch_everything.begin(account, account.bare_jid, cancellables[account][account.bare_jid], new DateTime.from_unix_utc(0), (_, res) => {
            fetch_everything.end(res);
            cancellables[account].unset(account.bare_jid);
        });
    }

    public static void cleanup_db_ranges(Database db, Account account) {
        var ranges = new HashMap<Jid, ArrayList<MamRange>>(Jid.hash_func, Jid.equals_func);
        foreach (Row row in db.mam_catchup.select().with(db.mam_catchup.account_id, "=", account.id)) {
            var mam_range = new MamRange();
            mam_range.id = row[db.mam_catchup.id];
            mam_range.server_jid = new Jid(row[db.mam_catchup.server_jid]);
            mam_range.from_time = row[db.mam_catchup.from_time];
            mam_range.from_id = row[db.mam_catchup.from_id];
            mam_range.from_end = row[db.mam_catchup.from_end];
            mam_range.to_time = row[db.mam_catchup.to_time];
            mam_range.to_id = row[db.mam_catchup.to_id];

            if (!ranges.has_key(mam_range.server_jid)) ranges[mam_range.server_jid] = new ArrayList<MamRange>();
            ranges[mam_range.server_jid].add(mam_range);
        }

        var to_delete = new ArrayList<MamRange>();

        foreach (Jid server_jid in ranges.keys) {
            foreach (var range1 in ranges[server_jid]) {
                if (to_delete.contains(range1)) continue;

                foreach (MamRange range2 in ranges[server_jid]) {
                    debug("[%s | %s] | %s - %s vs %s - %s", account.bare_jid.to_string(), server_jid.to_string(), range1.from_time.to_string(), range1.to_time.to_string(), range2.from_time.to_string(), range2.to_time.to_string());
                    if (range1 == range2 || to_delete.contains(range2)) continue;

                    // Check if range2 is a subset of range1
                    // range1: #####################
                    // range2:         ######
                    if (range1.from_time <= range2.from_time && range1.to_time >= range2.to_time) {
                        warning("Removing db range which is a subset of %li-%li", range1.from_time, range1.to_time);
                        to_delete.add(range2);
                        continue;
                    }

                    // Check if range2 is an extension of range1 (towards earlier)
                    // range1:        #####################
                    // range2: ###############
                    if (range1.from_time <= range2.to_time <= range1.to_time && range2.from_time <= range1.from_time) {
                        warning("Removing db range that overlapped %li-%li (towards earlier)", range1.from_time, range1.to_time);
                        db.mam_catchup.update()
                                .with(db.mam_catchup.id, "=", range1.id)
                                .set(db.mam_catchup.from_id, range2.from_id)
                                .set(db.mam_catchup.from_time, range2.from_time)
                                .set(db.mam_catchup.from_end, range2.from_end)
                                .perform();
                        to_delete.add(range2);
                        continue;
                    }
                }
            }
        }

        foreach (MamRange row in to_delete) {
            db.mam_catchup.delete().with(db.mam_catchup.id, "=", row.id).perform();
            warning("Removing db range %s %li-%li", row.server_jid.to_string(), row.from_time, row.to_time);
        }
    }

    class MamRange {
        public int id;
        public Jid server_jid;
        public long from_time;
        public string from_id;
        public bool from_end;
        public long to_time;
        public string to_id;
    }

    class PageRequestResult {
        public Gee.List<MessageStanza> stanzas { get; set; }
        public PageResult page_result { get; set; }
        public Xmpp.MessageArchiveManagement.QueryResult query_result { get; set; }

        public PageRequestResult(PageResult page_result, Xmpp.MessageArchiveManagement.QueryResult query_result, Gee.List<MessageStanza>? stanzas) {
            this.page_result = page_result;
            this.query_result = query_result;
            this.stanzas = stanzas;
        }
    }
}