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
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
#![cfg_attr(docsrs, feature(doc_auto_cfg, doc_cfg))]
#![doc = include_str!("../README.md")]
// @@ begin lint list maintained by maint/add_warning @@
#![cfg_attr(not(ci_arti_stable), allow(renamed_and_removed_lints))]
#![cfg_attr(not(ci_arti_nightly), allow(unknown_lints))]
#![warn(missing_docs)]
#![warn(noop_method_call)]
#![warn(unreachable_pub)]
#![warn(clippy::all)]
#![deny(clippy::await_holding_lock)]
#![deny(clippy::cargo_common_metadata)]
#![deny(clippy::cast_lossless)]
#![deny(clippy::checked_conversions)]
#![warn(clippy::cognitive_complexity)]
#![deny(clippy::debug_assert_with_mut_call)]
#![deny(clippy::exhaustive_enums)]
#![deny(clippy::exhaustive_structs)]
#![deny(clippy::expl_impl_clone_on_copy)]
#![deny(clippy::fallible_impl_from)]
#![deny(clippy::implicit_clone)]
#![deny(clippy::large_stack_arrays)]
#![warn(clippy::manual_ok_or)]
#![deny(clippy::missing_docs_in_private_items)]
#![warn(clippy::needless_borrow)]
#![warn(clippy::needless_pass_by_value)]
#![warn(clippy::option_option)]
#![deny(clippy::print_stderr)]
#![deny(clippy::print_stdout)]
#![warn(clippy::rc_buffer)]
#![deny(clippy::ref_option_ref)]
#![warn(clippy::semicolon_if_nothing_returned)]
#![warn(clippy::trait_duplication_in_bounds)]
#![deny(clippy::unchecked_duration_subtraction)]
#![deny(clippy::unnecessary_wraps)]
#![warn(clippy::unseparated_literal_suffix)]
#![deny(clippy::unwrap_used)]
#![allow(clippy::let_unit_value)] // This can reasonably be done for explicitness
#![allow(clippy::uninlined_format_args)]
#![allow(clippy::significant_drop_in_scrutinee)] // arti/-/merge_requests/588/#note_2812945
#![allow(clippy::result_large_err)] // temporary workaround for arti#587
#![allow(clippy::needless_raw_string_hashes)] // complained-about code is fine, often best
//! <!-- @@ end lint list maintained by maint/add_warning @@ -->

// This clippy lint produces a false positive on `use strum`, below.
// Attempting to apply the lint to just the use statement fails to suppress
// this lint and instead produces another lint about a useless clippy attribute.
#![allow(clippy::single_component_path_imports)]

pub mod authority;
mod bootstrap;
pub mod config;
mod docid;
mod docmeta;
mod err;
mod event;
mod retry;
mod shared_ref;
mod state;
mod storage;

#[cfg(feature = "bridge-client")]
pub mod bridgedesc;
#[cfg(feature = "dirfilter")]
pub mod filter;

use crate::docid::{CacheUsage, ClientRequest, DocQuery};
use crate::err::BootstrapAction;
#[cfg(not(feature = "experimental-api"))]
use crate::shared_ref::SharedMutArc;
#[cfg(feature = "experimental-api")]
pub use crate::shared_ref::SharedMutArc;
use crate::storage::{DynStore, Store};
use bootstrap::AttemptId;
use event::DirProgress;
use postage::watch;
pub use retry::{DownloadSchedule, DownloadScheduleBuilder};
use scopeguard::ScopeGuard;
use tor_circmgr::CircMgr;
use tor_dirclient::SourceInfo;
use tor_error::{info_report, into_internal, warn_report};
use tor_netdir::params::NetParameters;
use tor_netdir::{DirEvent, MdReceiver, NetDir, NetDirProvider};

use async_trait::async_trait;
use futures::{stream::BoxStream, task::SpawnExt};
use tor_async_utils::oneshot;
use tor_rtcompat::scheduler::{TaskHandle, TaskSchedule};
use tor_rtcompat::Runtime;
use tracing::{debug, info, trace, warn};

use std::marker::PhantomData;
use std::sync::atomic::{AtomicBool, Ordering};
use std::sync::{Arc, Mutex};
use std::time::Duration;
use std::{collections::HashMap, sync::Weak};
use std::{fmt::Debug, time::SystemTime};

use crate::state::{DirState, NetDirChange};
pub use authority::{Authority, AuthorityBuilder};
pub use config::{
    DirMgrConfig, DirTolerance, DirToleranceBuilder, DownloadScheduleConfig,
    DownloadScheduleConfigBuilder, NetworkConfig, NetworkConfigBuilder,
};
pub use docid::DocId;
pub use err::Error;
pub use event::{DirBlockage, DirBootstrapEvents, DirBootstrapStatus};
pub use storage::DocumentText;
pub use tor_guardmgr::fallback::{FallbackDir, FallbackDirBuilder};
pub use tor_netdir::Timeliness;

/// Re-export of `strum` crate for use by an internal macro
use strum;

/// A Result as returned by this crate.
pub type Result<T> = std::result::Result<T, Error>;

/// Storage manager used by [`DirMgr`] and
/// [`BridgeDescMgr`](bridgedesc::BridgeDescMgr)
///
/// Internally, this wraps up a sqlite database.
///
/// This is a handle, which is cheap to clone; clones share state.
#[derive(Clone)]
pub struct DirMgrStore<R: Runtime> {
    /// The actual store
    pub(crate) store: Arc<Mutex<crate::DynStore>>,

    /// Be parameterized by Runtime even though we don't use it right now
    pub(crate) runtime: PhantomData<R>,
}

impl<R: Runtime> DirMgrStore<R> {
    /// Open the storage, according to the specified configuration
    pub fn new(config: &DirMgrConfig, runtime: R, offline: bool) -> Result<Self> {
        let store = Arc::new(Mutex::new(config.open_store(offline)?));
        drop(runtime);
        let runtime = PhantomData;
        Ok(DirMgrStore { store, runtime })
    }
}

/// Trait for DirMgr implementations
#[async_trait]
pub trait DirProvider: NetDirProvider {
    /// Try to change our configuration to `new_config`.
    ///
    /// Actual behavior will depend on the value of `how`.
    fn reconfigure(
        &self,
        new_config: &DirMgrConfig,
        how: tor_config::Reconfigure,
    ) -> std::result::Result<(), tor_config::ReconfigureError>;

    /// Bootstrap a `DirProvider` that hasn't been bootstrapped yet.
    async fn bootstrap(&self) -> Result<()>;

    /// Return a stream of [`DirBootstrapStatus`] events to tell us about changes
    /// in the latest directory's bootstrap status.
    ///
    /// Note that this stream can be lossy: the caller will not necessarily
    /// observe every event on the stream
    fn bootstrap_events(&self) -> BoxStream<'static, DirBootstrapStatus>;

    /// Return a [`TaskHandle`] that can be used to manage the download process.
    fn download_task_handle(&self) -> Option<TaskHandle> {
        None
    }
}

// NOTE(eta): We can't implement this for Arc<DirMgr<R>> due to trait coherence rules, so instead
//            there's a blanket impl for Arc<T> in tor-netdir.
impl<R: Runtime> NetDirProvider for DirMgr<R> {
    fn netdir(&self, timeliness: Timeliness) -> tor_netdir::Result<Arc<NetDir>> {
        use tor_netdir::Error as NetDirError;
        let netdir = self.netdir.get().ok_or(NetDirError::NoInfo)?;
        let lifetime = match timeliness {
            Timeliness::Strict => netdir.lifetime().clone(),
            Timeliness::Timely => self
                .config
                .get()
                .tolerance
                .extend_lifetime(netdir.lifetime()),
            Timeliness::Unchecked => return Ok(netdir),
        };
        let now = SystemTime::now();
        if lifetime.valid_after() > now {
            Err(NetDirError::DirNotYetValid)
        } else if lifetime.valid_until() < now {
            Err(NetDirError::DirExpired)
        } else {
            Ok(netdir)
        }
    }

    fn events(&self) -> BoxStream<'static, DirEvent> {
        Box::pin(self.events.subscribe())
    }

    fn params(&self) -> Arc<dyn AsRef<tor_netdir::params::NetParameters>> {
        if let Some(netdir) = self.netdir.get() {
            // We have a directory, so we'd like to give it out for its
            // parameters.
            //
            // We do this even if the directory is expired, since parameters
            // don't really expire on any plausible timescale.
            netdir
        } else {
            // We have no directory, so we'll give out the default parameters as
            // modified by the provided override_net_params configuration.
            //
            self.default_parameters
                .lock()
                .expect("Poisoned lock")
                .clone()
        }
        // TODO(nickm): If we felt extremely clever, we could add a third case
        // where, if we have a pending directory with a validated consensus, we
        // give out that consensus's network parameters even if we _don't_ yet
        // have a full directory.  That's significant refactoring, though, for
        // an unclear amount of benefit.
    }
}

#[async_trait]
impl<R: Runtime> DirProvider for Arc<DirMgr<R>> {
    fn reconfigure(
        &self,
        new_config: &DirMgrConfig,
        how: tor_config::Reconfigure,
    ) -> std::result::Result<(), tor_config::ReconfigureError> {
        DirMgr::reconfigure(self, new_config, how)
    }

    async fn bootstrap(&self) -> Result<()> {
        DirMgr::bootstrap(self).await
    }

    fn bootstrap_events(&self) -> BoxStream<'static, DirBootstrapStatus> {
        Box::pin(DirMgr::bootstrap_events(self))
    }

    fn download_task_handle(&self) -> Option<TaskHandle> {
        Some(self.task_handle.clone())
    }
}

/// A directory manager to download, fetch, and cache a Tor directory.
///
/// A DirMgr can operate in three modes:
///   * In **offline** mode, it only reads from the cache, and can
///     only read once.
///   * In **read-only** mode, it reads from the cache, but checks
///     whether it can acquire an associated lock file.  If it can, then
///     it enters read-write mode.  If not, it checks the cache
///     periodically for new information.
///   * In **read-write** mode, it knows that no other process will be
///     writing to the cache, and it takes responsibility for fetching
///     data from the network and updating the directory with new
///     directory information.
pub struct DirMgr<R: Runtime> {
    /// Configuration information: where to find directories, how to
    /// validate them, and so on.
    config: tor_config::MutCfg<DirMgrConfig>,
    /// Handle to our sqlite cache.
    // TODO(nickm): I'd like to use an rwlock, but that's not feasible, since
    // rusqlite::Connection isn't Sync.
    // TODO is needed?
    store: Arc<Mutex<DynStore>>,
    /// Our latest sufficiently bootstrapped directory, if we have one.
    ///
    /// We use the RwLock so that we can give this out to a bunch of other
    /// users, and replace it once a new directory is bootstrapped.
    // TODO(eta): Eurgh! This is so many Arcs! (especially considering this
    //            gets wrapped in an Arc)
    netdir: Arc<SharedMutArc<NetDir>>,

    /// A set of network parameters to hand out when we have no directory.
    default_parameters: Mutex<Arc<NetParameters>>,

    /// A publisher handle that we notify whenever the consensus changes.
    events: event::FlagPublisher<DirEvent>,

    /// A publisher handle that we notify whenever our bootstrapping status
    /// changes.
    send_status: Mutex<watch::Sender<event::DirBootstrapStatus>>,

    /// A receiver handle that gets notified whenever our bootstrapping status
    /// changes.
    ///
    /// We don't need to keep this drained, since `postage::watch` already knows
    /// to discard unread events.
    receive_status: DirBootstrapEvents,

    /// A circuit manager, if this DirMgr supports downloading.
    circmgr: Option<Arc<CircMgr<R>>>,

    /// Our asynchronous runtime.
    runtime: R,

    /// Whether or not we're operating in offline mode.
    offline: bool,

    /// If we're not in offline mode, stores whether or not the `DirMgr` has attempted
    /// to bootstrap yet or not.
    ///
    /// This exists in order to prevent starting two concurrent bootstrap tasks.
    ///
    /// (In offline mode, this does nothing.)
    bootstrap_started: AtomicBool,

    /// A filter that gets applied to directory objects before we use them.
    #[cfg(feature = "dirfilter")]
    filter: crate::filter::FilterConfig,

    /// A task schedule that can be used if we're bootstrapping.  If this is
    /// None, then there's currently a scheduled task in progress.
    task_schedule: Mutex<Option<TaskSchedule<R>>>,

    /// A task handle that we return to anybody who needs to manage our download process.
    task_handle: TaskHandle,
}

/// The possible origins of a document.
///
/// Used (for example) to report where we got a document from if it fails to
/// parse.
#[derive(Debug, Clone)]
#[non_exhaustive]
pub enum DocSource {
    /// We loaded the document from our cache.
    LocalCache,
    /// We fetched the document from a server.
    DirServer {
        /// Information about the server we fetched the document from.
        source: Option<SourceInfo>,
    },
}

impl std::fmt::Display for DocSource {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        match self {
            DocSource::LocalCache => write!(f, "local cache"),
            DocSource::DirServer { source: None } => write!(f, "directory server"),
            DocSource::DirServer { source: Some(info) } => write!(f, "directory server {}", info),
        }
    }
}

impl<R: Runtime> DirMgr<R> {
    /// Try to load the directory from disk, without launching any
    /// kind of update process.
    ///
    /// This function runs in **offline** mode: it will give an error
    /// if the result is not up-to-date, or not fully downloaded.
    ///
    /// In general, you shouldn't use this function in a long-running
    /// program; it's only suitable for command-line or batch tools.
    // TODO: I wish this function didn't have to be async or take a runtime.
    pub async fn load_once(runtime: R, config: DirMgrConfig) -> Result<Arc<NetDir>> {
        let store = DirMgrStore::new(&config, runtime.clone(), true)?;
        let dirmgr = Arc::new(Self::from_config(config, runtime, store, None, true)?);

        // TODO: add some way to return a directory that isn't up-to-date
        let attempt = AttemptId::next();
        trace!(%attempt, "Trying to load a full directory from cache");
        let outcome = dirmgr.load_directory(attempt).await;
        trace!(%attempt, "Load result: {outcome:?}");
        let _success = outcome?;

        dirmgr
            .netdir(Timeliness::Timely)
            .map_err(|_| Error::DirectoryNotPresent)
    }

    /// Return a current netdir, either loading it or bootstrapping it
    /// as needed.
    ///
    /// Like load_once, but will try to bootstrap (or wait for another
    /// process to bootstrap) if we don't have an up-to-date
    /// bootstrapped directory.
    ///
    /// In general, you shouldn't use this function in a long-running
    /// program; it's only suitable for command-line or batch tools.
    pub async fn load_or_bootstrap_once(
        config: DirMgrConfig,
        runtime: R,
        store: DirMgrStore<R>,
        circmgr: Arc<CircMgr<R>>,
    ) -> Result<Arc<NetDir>> {
        let dirmgr = DirMgr::bootstrap_from_config(config, runtime, store, circmgr).await?;
        dirmgr
            .timely_netdir()
            .map_err(|_| Error::DirectoryNotPresent)
    }

    /// Create a new `DirMgr` in online mode, but don't bootstrap it yet.
    ///
    /// The `DirMgr` can be bootstrapped later with `bootstrap`.
    pub fn create_unbootstrapped(
        config: DirMgrConfig,
        runtime: R,
        store: DirMgrStore<R>,
        circmgr: Arc<CircMgr<R>>,
    ) -> Result<Arc<Self>> {
        Ok(Arc::new(DirMgr::from_config(
            config,
            runtime,
            store,
            Some(circmgr),
            false,
        )?))
    }

    /// Bootstrap a `DirMgr` created in online mode that hasn't been bootstrapped yet.
    ///
    /// This function will not return until the directory is bootstrapped enough to build circuits.
    /// It will also launch a background task that fetches any missing information, and that
    /// replaces the directory when a new one is available.
    ///
    /// This function is intended to be used together with `create_unbootstrapped`. There is no
    /// need to call this function otherwise.
    ///
    /// If bootstrapping has already successfully taken place, returns early with success.
    ///
    /// # Errors
    ///
    /// Returns an error if bootstrapping fails. If the error is [`Error::CantAdvanceState`],
    /// it may be possible to successfully bootstrap later on by calling this function again.
    ///
    /// # Panics
    ///
    /// Panics if the `DirMgr` passed to this function was not created in online mode, such as
    /// via `load_once`.
    pub async fn bootstrap(self: &Arc<Self>) -> Result<()> {
        if self.offline {
            return Err(Error::OfflineMode);
        }

        // The semantics of this are "attempt to replace a 'false' value with 'true'.
        // If the value in bootstrap_started was not 'false' when the attempt was made, returns
        // `Err`; this means another bootstrap attempt is in progress or has completed, so we
        // return early.

        // NOTE(eta): could potentially weaken the `Ordering` here in future
        if self
            .bootstrap_started
            .compare_exchange(false, true, Ordering::SeqCst, Ordering::SeqCst)
            .is_err()
        {
            debug!("Attempted to bootstrap twice; ignoring.");
            return Ok(());
        }

        // Use a RAII guard to reset `bootstrap_started` to `false` if we return early without
        // completing bootstrap.
        let reset_bootstrap_started = scopeguard::guard(&self.bootstrap_started, |v| {
            v.store(false, Ordering::SeqCst);
        });

        let schedule = {
            let sched = self.task_schedule.lock().expect("poisoned lock").take();
            match sched {
                Some(sched) => sched,
                None => {
                    debug!("Attempted to bootstrap twice; ignoring.");
                    return Ok(());
                }
            }
        };

        // Try to load from the cache.
        let attempt_id = AttemptId::next();
        trace!(attempt=%attempt_id, "Starting to bootstrap directory");
        let have_directory = self.load_directory(attempt_id).await?;

        let (mut sender, receiver) = if have_directory {
            info!("Loaded a good directory from cache.");
            (None, None)
        } else {
            info!("Didn't get usable directory from cache.");
            let (sender, receiver) = oneshot::channel();
            (Some(sender), Some(receiver))
        };

        // Whether we loaded or not, we now start downloading.
        let dirmgr_weak = Arc::downgrade(self);
        self.runtime
            .spawn(async move {
                // Use an RAII guard to make sure that when this task exits, the
                // TaskSchedule object is put back.
                //
                // TODO(nick): Putting the schedule back isn't actually useful
                // if the task exits _after_ we've bootstrapped for the first
                // time, because of how bootstrap_started works.
                let mut schedule = scopeguard::guard(schedule, |schedule| {
                    if let Some(dm) = Weak::upgrade(&dirmgr_weak) {
                        *dm.task_schedule.lock().expect("poisoned lock") = Some(schedule);
                    }
                });

                // Don't warn when these are Error::ManagerDropped: that
                // means that the DirMgr has been shut down.
                if let Err(e) =
                    Self::reload_until_owner(&dirmgr_weak, &mut schedule, attempt_id, &mut sender)
                        .await
                {
                    match e {
                        Error::ManagerDropped => {}
                        _ => warn_report!(e, "Unrecovered error while waiting for bootstrap",),
                    }
                } else if let Err(e) =
                    Self::download_forever(dirmgr_weak.clone(), &mut schedule, attempt_id, sender)
                        .await
                {
                    match e {
                        Error::ManagerDropped => {}
                        _ => warn_report!(e, "Unrecovered error while downloading"),
                    }
                }
            })
            .map_err(|e| Error::from_spawn("directory updater task", e))?;

        if let Some(receiver) = receiver {
            match receiver.await {
                Ok(()) => {
                    info!("We have enough information to build circuits.");
                    // Disarm the RAII guard, since we succeeded.  Now bootstrap_started will remain true.
                    let _ = ScopeGuard::into_inner(reset_bootstrap_started);
                }
                Err(_) => {
                    warn!("Bootstrapping task exited before finishing.");
                    return Err(Error::CantAdvanceState);
                }
            }
        }
        Ok(())
    }

    /// Returns `true` if a bootstrap attempt is in progress, or successfully completed.
    pub fn bootstrap_started(&self) -> bool {
        self.bootstrap_started.load(Ordering::SeqCst)
    }

    /// Return a new directory manager from a given configuration,
    /// bootstrapping from the network as necessary.
    pub async fn bootstrap_from_config(
        config: DirMgrConfig,
        runtime: R,
        store: DirMgrStore<R>,
        circmgr: Arc<CircMgr<R>>,
    ) -> Result<Arc<Self>> {
        let dirmgr = Self::create_unbootstrapped(config, runtime, store, circmgr)?;

        dirmgr.bootstrap().await?;

        Ok(dirmgr)
    }

    /// Try forever to either lock the storage (and thereby become the
    /// owner), or to reload the database.
    ///
    /// If we have begin to have a bootstrapped directory, send a
    /// message using `on_complete`.
    ///
    /// If we eventually become the owner, return Ok().
    async fn reload_until_owner(
        weak: &Weak<Self>,
        schedule: &mut TaskSchedule<R>,
        attempt_id: AttemptId,
        on_complete: &mut Option<oneshot::Sender<()>>,
    ) -> Result<()> {
        let mut logged = false;
        let mut bootstrapped;
        {
            let dirmgr = upgrade_weak_ref(weak)?;
            bootstrapped = dirmgr.netdir.get().is_some();
        }

        loop {
            {
                let dirmgr = upgrade_weak_ref(weak)?;
                trace!("Trying to take ownership of the directory cache lock");
                if dirmgr.try_upgrade_to_readwrite()? {
                    // We now own the lock!  (Maybe we owned it before; the
                    // upgrade_to_readwrite() function is idempotent.)  We can
                    // do our own bootstrapping.
                    if logged {
                        info!("The previous owning process has given up the lock. We are now in charge of managing the directory.");
                    }
                    return Ok(());
                }
            }

            if !logged {
                logged = true;
                if bootstrapped {
                    info!("Another process is managing the directory. We'll use its cache.");
                } else {
                    info!("Another process is bootstrapping the directory. Waiting till it finishes or exits.");
                }
            }

            // We don't own the lock.  Somebody else owns the cache.  They
            // should be updating it.  Wait a bit, then try again.
            let pause = if bootstrapped {
                std::time::Duration::new(120, 0)
            } else {
                std::time::Duration::new(5, 0)
            };
            schedule.sleep(pause).await?;
            // TODO: instead of loading the whole thing we should have a
            // database entry that says when the last update was, or use
            // our state functions.
            {
                let dirmgr = upgrade_weak_ref(weak)?;
                trace!("Trying to load from the directory cache");
                if dirmgr.load_directory(attempt_id).await? {
                    // Successfully loaded a bootstrapped directory.
                    if let Some(send_done) = on_complete.take() {
                        let _ = send_done.send(());
                    }
                    if !bootstrapped {
                        info!("The directory is now bootstrapped.");
                    }
                    bootstrapped = true;
                }
            }
        }
    }

    /// Try to fetch our directory info and keep it updated, indefinitely.
    ///
    /// If we have begin to have a bootstrapped directory, send a
    /// message using `on_complete`.
    async fn download_forever(
        weak: Weak<Self>,
        schedule: &mut TaskSchedule<R>,
        mut attempt_id: AttemptId,
        mut on_complete: Option<oneshot::Sender<()>>,
    ) -> Result<()> {
        let mut state: Box<dyn DirState> = {
            let dirmgr = upgrade_weak_ref(&weak)?;
            Box::new(state::GetConsensusState::new(
                dirmgr.runtime.clone(),
                dirmgr.config.get(),
                CacheUsage::CacheOkay,
                Some(dirmgr.netdir.clone()),
                #[cfg(feature = "dirfilter")]
                dirmgr
                    .filter
                    .clone()
                    .unwrap_or_else(|| Arc::new(crate::filter::NilFilter)),
            ))
        };

        trace!("Entering download loop.");

        loop {
            let mut usable = false;

            let retry_config = {
                let dirmgr = upgrade_weak_ref(&weak)?;
                // TODO(nickm): instead of getting this every time we loop, it
                // might be a good idea to refresh it with each attempt, at
                // least at the point of checking the number of attempts.
                dirmgr.config.get().schedule.retry_bootstrap
            };
            let mut retry_delay = retry_config.schedule();

            'retry_attempt: for try_num in retry_config.attempts() {
                trace!(attempt=%attempt_id, ?try_num, "Trying to download a directory.");
                let outcome = bootstrap::download(
                    Weak::clone(&weak),
                    &mut state,
                    schedule,
                    attempt_id,
                    &mut on_complete,
                )
                .await;
                trace!(attempt=%attempt_id, ?try_num, ?outcome, "Download is over.");

                if let Err(err) = outcome {
                    if state.is_ready(Readiness::Usable) {
                        usable = true;
                        info_report!(err, "Unable to completely download a directory. (Nevertheless, the directory is usable, so we'll pause for now)");
                        break 'retry_attempt;
                    }

                    match err.bootstrap_action() {
                        BootstrapAction::Nonfatal => {
                            return Err(into_internal!(
                                "Nonfatal error should not have propagated here"
                            )(err)
                            .into());
                        }
                        BootstrapAction::Reset => {}
                        BootstrapAction::Fatal => return Err(err),
                    }

                    let delay = retry_delay.next_delay(&mut rand::thread_rng());
                    warn_report!(
                        err,
                        "Unable to download a usable directory. (We will restart in {})",
                        humantime::format_duration(delay),
                    );
                    {
                        let dirmgr = upgrade_weak_ref(&weak)?;
                        dirmgr.note_reset(attempt_id);
                    }
                    schedule.sleep(delay).await?;
                    state = state.reset();
                } else {
                    info!(attempt=%attempt_id, "Directory is complete.");
                    usable = true;
                    break 'retry_attempt;
                }
            }

            if !usable {
                // we ran out of attempts.
                warn!(
                    "We failed {} times to bootstrap a directory. We're going to give up.",
                    retry_config.n_attempts()
                );
                return Err(Error::CantAdvanceState);
            } else {
                // Report success, if appropriate.
                if let Some(send_done) = on_complete.take() {
                    let _ = send_done.send(());
                }
            }

            let reset_at = state.reset_time();
            match reset_at {
                Some(t) => {
                    trace!("Sleeping until {}", time::OffsetDateTime::from(t));
                    schedule.sleep_until_wallclock(t).await?;
                }
                None => return Ok(()),
            }
            attempt_id = bootstrap::AttemptId::next();
            trace!(attempt=%attempt_id, "Beginning new attempt to bootstrap directory");
            state = state.reset();
        }
    }

    /// Get a reference to the circuit manager, if we have one.
    fn circmgr(&self) -> Result<Arc<CircMgr<R>>> {
        self.circmgr.clone().ok_or(Error::NoDownloadSupport)
    }

    /// Try to change our configuration to `new_config`.
    ///
    /// Actual behavior will depend on the value of `how`.
    pub fn reconfigure(
        &self,
        new_config: &DirMgrConfig,
        how: tor_config::Reconfigure,
    ) -> std::result::Result<(), tor_config::ReconfigureError> {
        let config = self.config.get();
        // We don't support changing these: doing so basically would require us
        // to abort all our in-progress downloads, since they might be based on
        // no-longer-viable information.
        if new_config.cache_dir != config.cache_dir {
            how.cannot_change("storage.cache_dir")?;
        }
        if new_config.authorities() != config.authorities() {
            how.cannot_change("network.authorities")?;
        }

        if how == tor_config::Reconfigure::CheckAllOrNothing {
            return Ok(());
        }

        let params_changed = new_config.override_net_params != config.override_net_params;

        self.config
            .map_and_replace(|cfg| cfg.update_from_config(new_config));

        if params_changed {
            let _ignore_err = self.netdir.mutate(|netdir| {
                netdir.replace_overridden_parameters(&new_config.override_net_params);
                Ok(())
            });
            {
                let mut params = self.default_parameters.lock().expect("lock failed");
                *params = Arc::new(NetParameters::from_map(&new_config.override_net_params));
            }

            // (It's okay to ignore the error, since it just means that there
            // was no current netdir.)
            self.events.publish(DirEvent::NewConsensus);
        }

        Ok(())
    }

    /// Return a stream of [`DirBootstrapStatus`] events to tell us about changes
    /// in the latest directory's bootstrap status.
    ///
    /// Note that this stream can be lossy: the caller will not necessarily
    /// observe every event on the stream
    pub fn bootstrap_events(&self) -> event::DirBootstrapEvents {
        self.receive_status.clone()
    }

    /// Replace the latest status with `progress` and broadcast to anybody
    /// watching via a [`DirBootstrapEvents`] stream.
    fn update_progress(&self, attempt_id: AttemptId, progress: DirProgress) {
        // TODO(nickm): can I kill off this lock by having something else own the sender?
        let mut sender = self.send_status.lock().expect("poisoned lock");
        let mut status = sender.borrow_mut();

        status.update_progress(attempt_id, progress);
    }

    /// Update our status tracker to note that some number of errors has
    /// occurred.
    fn note_errors(&self, attempt_id: AttemptId, n_errors: usize) {
        if n_errors == 0 {
            return;
        }
        let mut sender = self.send_status.lock().expect("poisoned lock");
        let mut status = sender.borrow_mut();

        status.note_errors(attempt_id, n_errors);
    }

    /// Update our status tracker to note that we've needed to reset our download attempt.
    fn note_reset(&self, attempt_id: AttemptId) {
        let mut sender = self.send_status.lock().expect("poisoned lock");
        let mut status = sender.borrow_mut();

        status.note_reset(attempt_id);
    }

    /// Try to make this a directory manager with read-write access to its
    /// storage.
    ///
    /// Return true if we got the lock, or if we already had it.
    ///
    /// Return false if another process has the lock
    fn try_upgrade_to_readwrite(&self) -> Result<bool> {
        self.store
            .lock()
            .expect("Directory storage lock poisoned")
            .upgrade_to_readwrite()
    }

    /// Return a reference to the store, if it is currently read-write.
    #[cfg(test)]
    fn store_if_rw(&self) -> Option<&Mutex<DynStore>> {
        let rw = !self
            .store
            .lock()
            .expect("Directory storage lock poisoned")
            .is_readonly();
        // A race-condition is possible here, but I believe it's harmless.
        if rw {
            Some(&self.store)
        } else {
            None
        }
    }

    /// Construct a DirMgr from a DirMgrConfig.
    ///
    /// If `offline` is set, opens the SQLite store read-only and sets the offline flag in the
    /// returned manager.
    #[allow(clippy::unnecessary_wraps)] // API compat and future-proofing
    fn from_config(
        config: DirMgrConfig,
        runtime: R,
        store: DirMgrStore<R>,
        circmgr: Option<Arc<CircMgr<R>>>,
        offline: bool,
    ) -> Result<Self> {
        let netdir = Arc::new(SharedMutArc::new());
        let events = event::FlagPublisher::new();
        let default_parameters = NetParameters::from_map(&config.override_net_params);
        let default_parameters = Mutex::new(Arc::new(default_parameters));

        let (send_status, receive_status) = postage::watch::channel();
        let send_status = Mutex::new(send_status);
        let receive_status = DirBootstrapEvents {
            inner: receive_status,
        };
        #[cfg(feature = "dirfilter")]
        let filter = config.extensions.filter.clone();

        // We create these early so the client code can access task_handle before bootstrap() returns.
        let (task_schedule, task_handle) = TaskSchedule::new(runtime.clone());
        let task_schedule = Mutex::new(Some(task_schedule));

        Ok(DirMgr {
            config: config.into(),
            store: store.store,
            netdir,
            default_parameters,
            events,
            send_status,
            receive_status,
            circmgr,
            runtime,
            offline,
            bootstrap_started: AtomicBool::new(false),
            #[cfg(feature = "dirfilter")]
            filter,
            task_schedule,
            task_handle,
        })
    }

    /// Load the latest non-pending non-expired directory from the
    /// cache, if it is newer than the one we have.
    ///
    /// Return false if there is no such consensus.
    async fn load_directory(self: &Arc<Self>, attempt_id: AttemptId) -> Result<bool> {
        let state = state::GetConsensusState::new(
            self.runtime.clone(),
            self.config.get(),
            CacheUsage::CacheOnly,
            None,
            #[cfg(feature = "dirfilter")]
            self.filter
                .clone()
                .unwrap_or_else(|| Arc::new(crate::filter::NilFilter)),
        );
        let _ = bootstrap::load(Arc::clone(self), Box::new(state), attempt_id).await?;

        Ok(self.netdir.get().is_some())
    }

    /// Return a new asynchronous stream that will receive notification
    /// whenever the consensus has changed.
    ///
    /// Multiple events may be batched up into a single item: each time
    /// this stream yields an event, all you can assume is that the event has
    /// occurred at least once.
    pub fn events(&self) -> impl futures::Stream<Item = DirEvent> {
        self.events.subscribe()
    }

    /// Try to load the text of a single document described by `doc` from
    /// storage.
    pub fn text(&self, doc: &DocId) -> Result<Option<DocumentText>> {
        use itertools::Itertools;
        let mut result = HashMap::new();
        let query: DocQuery = (*doc).into();
        let store = self.store.lock().expect("store lock poisoned");
        query.load_from_store_into(&mut result, &**store)?;
        let item = result.into_iter().at_most_one().map_err(|_| {
            Error::CacheCorruption("Found more than one entry in storage for given docid")
        })?;
        if let Some((docid, doctext)) = item {
            if &docid != doc {
                return Err(Error::CacheCorruption(
                    "Item from storage had incorrect docid.",
                ));
            }
            Ok(Some(doctext))
        } else {
            Ok(None)
        }
    }

    /// Load the text for a collection of documents.
    ///
    /// If many of the documents have the same type, this can be more
    /// efficient than calling [`text`](Self::text).
    pub fn texts<T>(&self, docs: T) -> Result<HashMap<DocId, DocumentText>>
    where
        T: IntoIterator<Item = DocId>,
    {
        let partitioned = docid::partition_by_type(docs);
        let mut result = HashMap::new();
        let store = self.store.lock().expect("store lock poisoned");
        for (_, query) in partitioned.into_iter() {
            query.load_from_store_into(&mut result, &**store)?;
        }
        Ok(result)
    }

    /// Given a request we sent and the response we got from a
    /// directory server, see whether we should expand that response
    /// into "something larger".
    ///
    /// Currently, this handles expanding consensus diffs, and nothing
    /// else.  We do it at this stage of our downloading operation
    /// because it requires access to the store.
    fn expand_response_text(&self, req: &ClientRequest, text: String) -> Result<String> {
        if let ClientRequest::Consensus(req) = req {
            if tor_consdiff::looks_like_diff(&text) {
                if let Some(old_d) = req.old_consensus_digests().next() {
                    let db_val = {
                        let s = self.store.lock().expect("Directory storage lock poisoned");
                        s.consensus_by_sha3_digest_of_signed_part(old_d)?
                    };
                    if let Some((old_consensus, meta)) = db_val {
                        info!("Applying a consensus diff");
                        let new_consensus = tor_consdiff::apply_diff(
                            old_consensus.as_str()?,
                            &text,
                            Some(*meta.sha3_256_of_signed()),
                        )?;
                        new_consensus.check_digest()?;
                        return Ok(new_consensus.to_string());
                    }
                }
                return Err(Error::Unwanted(
                    "Received a consensus diff we did not ask for",
                ));
            }
        }
        Ok(text)
    }

    /// If `state` has netdir changes to apply, apply them to our netdir.
    #[allow(clippy::cognitive_complexity)]
    fn apply_netdir_changes(
        self: &Arc<Self>,
        state: &mut Box<dyn DirState>,
        store: &mut dyn Store,
    ) -> Result<()> {
        if let Some(change) = state.get_netdir_change() {
            match change {
                NetDirChange::AttemptReplace {
                    netdir,
                    consensus_meta,
                } => {
                    // Check the new netdir is sufficient, if we have a circmgr.
                    // (Unwraps are fine because the `Option` is `Some` until we take it.)
                    if let Some(ref cm) = self.circmgr {
                        if !cm
                            .netdir_is_sufficient(netdir.as_ref().expect("AttemptReplace had None"))
                        {
                            debug!("Got a new NetDir, but it doesn't have enough guards yet.");
                            return Ok(());
                        }
                    }
                    let is_stale = {
                        // Done inside a block to not hold a long-lived copy of the NetDir.
                        self.netdir
                            .get()
                            .map(|x| {
                                x.lifetime().valid_after()
                                    > netdir
                                        .as_ref()
                                        .expect("AttemptReplace had None")
                                        .lifetime()
                                        .valid_after()
                            })
                            .unwrap_or(false)
                    };
                    if is_stale {
                        warn!("Got a new NetDir, but it's older than the one we currently have!");
                        return Err(Error::NetDirOlder);
                    }
                    let cfg = self.config.get();
                    let mut netdir = netdir.take().expect("AttemptReplace had None");
                    netdir.replace_overridden_parameters(&cfg.override_net_params);
                    self.netdir.replace(netdir);
                    self.events.publish(DirEvent::NewConsensus);
                    self.events.publish(DirEvent::NewDescriptors);

                    info!("Marked consensus usable.");
                    if !store.is_readonly() {
                        store.mark_consensus_usable(consensus_meta)?;
                        // Now that a consensus is usable, older consensuses may
                        // need to expire.
                        store.expire_all(&crate::storage::EXPIRATION_DEFAULTS)?;
                    }
                    Ok(())
                }
                NetDirChange::AddMicrodescs(mds) => {
                    self.netdir.mutate(|netdir| {
                        for md in mds.drain(..) {
                            netdir.add_microdesc(md);
                        }
                        Ok(())
                    })?;
                    self.events.publish(DirEvent::NewDescriptors);
                    Ok(())
                }
            }
        } else {
            Ok(())
        }
    }
}

/// A degree of readiness for a given directory state object.
#[derive(Debug, Copy, Clone)]
enum Readiness {
    /// There is no more information to download.
    Complete,
    /// There is more information to download, but we don't need to
    Usable,
}

/// Try to upgrade a weak reference to a DirMgr, and give an error on
/// failure.
fn upgrade_weak_ref<T>(weak: &Weak<T>) -> Result<Arc<T>> {
    Weak::upgrade(weak).ok_or(Error::ManagerDropped)
}

/// Given a time `now`, and an amount of tolerated clock skew `tolerance`,
/// return the age of the oldest consensus that we should request at that time.
pub(crate) fn default_consensus_cutoff(
    now: SystemTime,
    tolerance: &DirTolerance,
) -> Result<SystemTime> {
    /// We _always_ allow at least this much age in our consensuses, to account
    /// for the fact that consensuses have some lifetime.
    const MIN_AGE_TO_ALLOW: Duration = Duration::from_secs(3 * 3600);
    let allow_skew = std::cmp::max(MIN_AGE_TO_ALLOW, tolerance.post_valid_tolerance);
    let cutoff = time::OffsetDateTime::from(now - allow_skew);
    // We now round cutoff to the next hour, so that we aren't leaking our exact
    // time to the directory cache.
    //
    // With the time crate, it's easier to calculate the "next hour" by rounding
    // _down_ then adding an hour; rounding up would sometimes require changing
    // the date too.
    let (h, _m, _s) = cutoff.to_hms();
    let cutoff = cutoff.replace_time(
        time::Time::from_hms(h, 0, 0)
            .map_err(tor_error::into_internal!("Failed clock calculation"))?,
    );
    let cutoff = cutoff + Duration::from_secs(3600);

    Ok(cutoff.into())
}

#[cfg(test)]
mod test {
    // @@ begin test lint list maintained by maint/add_warning @@
    #![allow(clippy::bool_assert_comparison)]
    #![allow(clippy::clone_on_copy)]
    #![allow(clippy::dbg_macro)]
    #![allow(clippy::mixed_attributes_style)]
    #![allow(clippy::print_stderr)]
    #![allow(clippy::print_stdout)]
    #![allow(clippy::single_char_pattern)]
    #![allow(clippy::unwrap_used)]
    #![allow(clippy::unchecked_duration_subtraction)]
    #![allow(clippy::useless_vec)]
    #![allow(clippy::needless_pass_by_value)]
    //! <!-- @@ end test lint list maintained by maint/add_warning @@ -->
    use super::*;
    use crate::docmeta::{AuthCertMeta, ConsensusMeta};
    use std::time::Duration;
    use tempfile::TempDir;
    use tor_basic_utils::test_rng::testing_rng;
    use tor_netdoc::doc::netstatus::ConsensusFlavor;
    use tor_netdoc::doc::{authcert::AuthCertKeyIds, netstatus::Lifetime};
    use tor_rtcompat::SleepProvider;

    pub(crate) fn new_mgr<R: Runtime>(runtime: R) -> (TempDir, DirMgr<R>) {
        let dir = TempDir::new().unwrap();
        let config = DirMgrConfig {
            cache_dir: dir.path().into(),
            ..Default::default()
        };
        let store = DirMgrStore::new(&config, runtime.clone(), false).unwrap();
        let dirmgr = DirMgr::from_config(config, runtime, store, None, false).unwrap();

        (dir, dirmgr)
    }

    #[test]
    fn failing_accessors() {
        tor_rtcompat::test_with_one_runtime!(|rt| async {
            let (_tempdir, mgr) = new_mgr(rt);

            assert!(mgr.circmgr().is_err());
            assert!(mgr.netdir(Timeliness::Unchecked).is_err());
        });
    }

    #[test]
    fn load_and_store_internals() {
        tor_rtcompat::test_with_one_runtime!(|rt| async {
            let now = rt.wallclock();
            let tomorrow = now + Duration::from_secs(86400);
            let later = tomorrow + Duration::from_secs(86400);

            let (_tempdir, mgr) = new_mgr(rt);

            // Seed the storage with a bunch of junk.
            let d1 = [5_u8; 32];
            let d2 = [7; 32];
            let d3 = [42; 32];
            let d4 = [99; 20];
            let d5 = [12; 20];
            let certid1 = AuthCertKeyIds {
                id_fingerprint: d4.into(),
                sk_fingerprint: d5.into(),
            };
            let certid2 = AuthCertKeyIds {
                id_fingerprint: d5.into(),
                sk_fingerprint: d4.into(),
            };

            {
                let mut store = mgr.store.lock().unwrap();

                store
                    .store_microdescs(
                        &[
                            ("Fake micro 1", &d1),
                            ("Fake micro 2", &d2),
                            ("Fake micro 3", &d3),
                        ],
                        now,
                    )
                    .unwrap();

                #[cfg(feature = "routerdesc")]
                store
                    .store_routerdescs(&[("Fake rd1", now, &d4), ("Fake rd2", now, &d5)])
                    .unwrap();

                store
                    .store_authcerts(&[
                        (
                            AuthCertMeta::new(certid1, now, tomorrow),
                            "Fake certificate one",
                        ),
                        (
                            AuthCertMeta::new(certid2, now, tomorrow),
                            "Fake certificate two",
                        ),
                    ])
                    .unwrap();

                let cmeta = ConsensusMeta::new(
                    Lifetime::new(now, tomorrow, later).unwrap(),
                    [102; 32],
                    [103; 32],
                );
                store
                    .store_consensus(&cmeta, ConsensusFlavor::Microdesc, false, "Fake consensus!")
                    .unwrap();
            }

            // Try to get it with text().
            let t1 = mgr.text(&DocId::Microdesc(d1)).unwrap().unwrap();
            assert_eq!(t1.as_str(), Ok("Fake micro 1"));

            let t2 = mgr
                .text(&DocId::LatestConsensus {
                    flavor: ConsensusFlavor::Microdesc,
                    cache_usage: CacheUsage::CacheOkay,
                })
                .unwrap()
                .unwrap();
            assert_eq!(t2.as_str(), Ok("Fake consensus!"));

            let t3 = mgr.text(&DocId::Microdesc([255; 32])).unwrap();
            assert!(t3.is_none());

            // Now try texts()
            let d_bogus = DocId::Microdesc([255; 32]);
            let res = mgr
                .texts(vec![
                    DocId::Microdesc(d2),
                    DocId::Microdesc(d3),
                    d_bogus,
                    DocId::AuthCert(certid2),
                    #[cfg(feature = "routerdesc")]
                    DocId::RouterDesc(d5),
                ])
                .unwrap();
            assert_eq!(
                res.get(&DocId::Microdesc(d2)).unwrap().as_str(),
                Ok("Fake micro 2")
            );
            assert_eq!(
                res.get(&DocId::Microdesc(d3)).unwrap().as_str(),
                Ok("Fake micro 3")
            );
            assert!(res.get(&d_bogus).is_none());
            assert_eq!(
                res.get(&DocId::AuthCert(certid2)).unwrap().as_str(),
                Ok("Fake certificate two")
            );
            #[cfg(feature = "routerdesc")]
            assert_eq!(
                res.get(&DocId::RouterDesc(d5)).unwrap().as_str(),
                Ok("Fake rd2")
            );
        });
    }

    #[test]
    fn make_consensus_request() {
        tor_rtcompat::test_with_one_runtime!(|rt| async {
            let now = rt.wallclock();
            let tomorrow = now + Duration::from_secs(86400);
            let later = tomorrow + Duration::from_secs(86400);

            let (_tempdir, mgr) = new_mgr(rt);
            let config = DirMgrConfig::default();

            // Try with an empty store.
            let req = {
                let store = mgr.store.lock().unwrap();
                bootstrap::make_consensus_request(
                    now,
                    ConsensusFlavor::Microdesc,
                    &**store,
                    &config,
                )
                .unwrap()
            };
            let tolerance = DirTolerance::default().post_valid_tolerance;
            match req {
                ClientRequest::Consensus(r) => {
                    assert_eq!(r.old_consensus_digests().count(), 0);
                    let date = r.last_consensus_date().unwrap();
                    assert!(date >= now - tolerance);
                    assert!(date <= now - tolerance + Duration::from_secs(3600));
                }
                _ => panic!("Wrong request type"),
            }

            // Add a fake consensus record.
            let d_prev = [42; 32];
            {
                let mut store = mgr.store.lock().unwrap();

                let cmeta = ConsensusMeta::new(
                    Lifetime::new(now, tomorrow, later).unwrap(),
                    d_prev,
                    [103; 32],
                );
                store
                    .store_consensus(&cmeta, ConsensusFlavor::Microdesc, false, "Fake consensus!")
                    .unwrap();
            }

            // Now try again.
            let req = {
                let store = mgr.store.lock().unwrap();
                bootstrap::make_consensus_request(
                    now,
                    ConsensusFlavor::Microdesc,
                    &**store,
                    &config,
                )
                .unwrap()
            };
            match req {
                ClientRequest::Consensus(r) => {
                    let ds: Vec<_> = r.old_consensus_digests().collect();
                    assert_eq!(ds.len(), 1);
                    assert_eq!(ds[0], &d_prev);
                    assert_eq!(r.last_consensus_date(), Some(now));
                }
                _ => panic!("Wrong request type"),
            }
        });
    }

    #[test]
    fn make_other_requests() {
        tor_rtcompat::test_with_one_runtime!(|rt| async {
            use rand::Rng;
            let (_tempdir, mgr) = new_mgr(rt);

            let certid1 = AuthCertKeyIds {
                id_fingerprint: [99; 20].into(),
                sk_fingerprint: [100; 20].into(),
            };
            let mut rng = testing_rng();
            #[cfg(feature = "routerdesc")]
            let rd_ids: Vec<DocId> = (0..1000).map(|_| DocId::RouterDesc(rng.gen())).collect();
            let md_ids: Vec<DocId> = (0..1000).map(|_| DocId::Microdesc(rng.gen())).collect();
            let config = DirMgrConfig::default();

            // Try an authcert.
            let query = DocId::AuthCert(certid1);
            let store = mgr.store.lock().unwrap();
            let reqs =
                bootstrap::make_requests_for_documents(&mgr.runtime, &[query], &**store, &config)
                    .unwrap();
            assert_eq!(reqs.len(), 1);
            let req = &reqs[0];
            if let ClientRequest::AuthCert(r) = req {
                assert_eq!(r.keys().next(), Some(&certid1));
            } else {
                panic!();
            }

            // Try a bunch of mds.
            let reqs =
                bootstrap::make_requests_for_documents(&mgr.runtime, &md_ids, &**store, &config)
                    .unwrap();
            assert_eq!(reqs.len(), 2);
            assert!(matches!(reqs[0], ClientRequest::Microdescs(_)));

            // Try a bunch of rds.
            #[cfg(feature = "routerdesc")]
            {
                let reqs = bootstrap::make_requests_for_documents(
                    &mgr.runtime,
                    &rd_ids,
                    &**store,
                    &config,
                )
                .unwrap();
                assert_eq!(reqs.len(), 2);
                assert!(matches!(reqs[0], ClientRequest::RouterDescs(_)));
            }
        });
    }

    #[test]
    fn expand_response() {
        tor_rtcompat::test_with_one_runtime!(|rt| async {
            let now = rt.wallclock();
            let day = Duration::from_secs(86400);
            let config = DirMgrConfig::default();

            let (_tempdir, mgr) = new_mgr(rt);

            // Try a simple request: nothing should happen.
            let q = DocId::Microdesc([99; 32]);
            let r = {
                let store = mgr.store.lock().unwrap();
                bootstrap::make_requests_for_documents(&mgr.runtime, &[q], &**store, &config)
                    .unwrap()
            };
            let expanded = mgr.expand_response_text(&r[0], "ABC".to_string());
            assert_eq!(&expanded.unwrap(), "ABC");

            // Try a consensus response that doesn't look like a diff in
            // response to a query that doesn't ask for one.
            let latest_id = DocId::LatestConsensus {
                flavor: ConsensusFlavor::Microdesc,
                cache_usage: CacheUsage::CacheOkay,
            };
            let r = {
                let store = mgr.store.lock().unwrap();
                bootstrap::make_requests_for_documents(
                    &mgr.runtime,
                    &[latest_id],
                    &**store,
                    &config,
                )
                .unwrap()
            };
            let expanded = mgr.expand_response_text(&r[0], "DEF".to_string());
            assert_eq!(&expanded.unwrap(), "DEF");

            // Now stick some metadata and a string into the storage so that
            // we can ask for a diff.
            {
                let mut store = mgr.store.lock().unwrap();
                let d_in = [0x99; 32]; // This one, we can fake.
                let cmeta = ConsensusMeta::new(
                    Lifetime::new(now, now + day, now + 2 * day).unwrap(),
                    d_in,
                    d_in,
                );
                store
                    .store_consensus(
                        &cmeta,
                        ConsensusFlavor::Microdesc,
                        false,
                        "line 1\nline2\nline 3\n",
                    )
                    .unwrap();
            }

            // Try expanding something that isn't a consensus, even if we'd like
            // one.
            let r = {
                let store = mgr.store.lock().unwrap();
                bootstrap::make_requests_for_documents(
                    &mgr.runtime,
                    &[latest_id],
                    &**store,
                    &config,
                )
                .unwrap()
            };
            let expanded = mgr.expand_response_text(&r[0], "hello".to_string());
            assert_eq!(&expanded.unwrap(), "hello");

            // Finally, try "expanding" a diff (by applying it and checking the digest.
            let diff = "network-status-diff-version 1
hash 9999999999999999999999999999999999999999999999999999999999999999 8382374ca766873eb0d2530643191c6eaa2c5e04afa554cbac349b5d0592d300
2c
replacement line
.
".to_string();
            let expanded = mgr.expand_response_text(&r[0], diff);

            assert_eq!(expanded.unwrap(), "line 1\nreplacement line\nline 3\n");

            // If the digest is wrong, that should get rejected.
            let diff = "network-status-diff-version 1
hash 9999999999999999999999999999999999999999999999999999999999999999 9999999999999999999999999999999999999999999999999999999999999999
2c
replacement line
.
".to_string();
            let expanded = mgr.expand_response_text(&r[0], diff);
            assert!(expanded.is_err());
        });
    }
}