ferrum-interfaces 0.8.4

Core trait contracts for the Ferrum LLM inference engine
Documentation
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
use serde::{Deserialize, Serialize};
use std::collections::BTreeSet;

use super::{
    canonical_fingerprint, has_aborted, has_active, has_completed, invalid_event,
    same_operation_authority_except_observation, sha256_bytes, validate_sha256,
    BatchOperationIdentity, CompletionDrainReceipt, CompletionQuarantineReceipt, CompletionSlotId,
    ContractVersion, ExecutionEvent, ExecutionEventCursor, ExecutionEventDetail,
    ExecutionEventKind, ExecutionIdentityEnvelope, IdentifiedFailure, OperationCompletionReceipt,
    OperationParticipantCompletionDisposition, OperationParticipantCompletionReceipt,
    PlanRuntimeCloseReceipt, PlanRuntimeQuarantineReceipt, ResolvedModelPlan, ResourcePoolEvent,
    ResourcePoolEventCursor, ResourcePoolEvidence, ResourcePoolId,
    SubmittedOperationParticipantReceipt, SubmittedOperationReceipt, TrustedAbortedSequenceBinding,
    TrustedActiveSequenceBinding, TrustedCompletedSequenceBinding, TrustedExecutionEventContext,
    TrustedExecutionTopology, UnvalidatedExecutionIdentityParts, VNextError,
    EXECUTION_IDENTITY_VERSION, MAX_REPLAY_IDENTITY_WIRE_BYTES,
};

/// Independent evidence needed to rebuild a replay identity. None of these
/// values are accepted from the serialized replay envelope itself.
pub struct ReplayEvidence<'a> {
    resolved_plan: &'a ResolvedModelPlan,
    request_input: &'a [u8],
    initial_state: &'a [u8],
    random_seed: u64,
    request_journal: &'a [ExecutionEvent],
    active_binding: &'a TrustedActiveSequenceBinding,
    completed_binding: Option<&'a TrustedCompletedSequenceBinding>,
    aborted_binding: Option<&'a TrustedAbortedSequenceBinding>,
    cleanup_requirement: ReplayCleanupRequirement,
    plan_cleanup: ReplayPlanCleanupEvidence<'a>,
    operation_completions: &'a [OperationCompletionReceipt],
    operation_drains: &'a [CompletionDrainReceipt],
    // Quarantine retains invocation ownership and is never terminal replay evidence.
    operation_quarantines: &'a [CompletionQuarantineReceipt],
    pool_evidence: Option<&'a ResourcePoolEvidence>,
    pool_journal: &'a [ResourcePoolEvent],
}

impl<'a> ReplayEvidence<'a> {
    pub fn new(
        resolved_plan: &'a ResolvedModelPlan,
        request_input: &'a [u8],
        initial_state: &'a [u8],
        random_seed: u64,
        request_journal: &'a [ExecutionEvent],
        active_binding: &'a TrustedActiveSequenceBinding,
        completed_binding: Option<&'a TrustedCompletedSequenceBinding>,
        aborted_binding: Option<&'a TrustedAbortedSequenceBinding>,
        cleanup_requirement: ReplayCleanupRequirement,
        plan_cleanup: ReplayPlanCleanupEvidence<'a>,
        operation_completions: &'a [OperationCompletionReceipt],
        operation_drains: &'a [CompletionDrainReceipt],
        operation_quarantines: &'a [CompletionQuarantineReceipt],
        pool_evidence: &'a ResourcePoolEvidence,
        pool_journal: &'a [ResourcePoolEvent],
    ) -> Self {
        Self {
            resolved_plan,
            request_input,
            initial_state,
            random_seed,
            request_journal,
            active_binding,
            completed_binding,
            aborted_binding,
            cleanup_requirement,
            plan_cleanup,
            operation_completions,
            operation_drains,
            operation_quarantines,
            pool_evidence: Some(pool_evidence),
            pool_journal,
        }
    }

    #[allow(clippy::too_many_arguments)]
    pub fn new_no_static(
        resolved_plan: &'a ResolvedModelPlan,
        request_input: &'a [u8],
        initial_state: &'a [u8],
        random_seed: u64,
        request_journal: &'a [ExecutionEvent],
        active_binding: &'a TrustedActiveSequenceBinding,
        completed_binding: Option<&'a TrustedCompletedSequenceBinding>,
        aborted_binding: Option<&'a TrustedAbortedSequenceBinding>,
        cleanup_requirement: ReplayCleanupRequirement,
        plan_cleanup: ReplayPlanCleanupEvidence<'a>,
        operation_completions: &'a [OperationCompletionReceipt],
        operation_drains: &'a [CompletionDrainReceipt],
        operation_quarantines: &'a [CompletionQuarantineReceipt],
    ) -> Self {
        Self {
            resolved_plan,
            request_input,
            initial_state,
            random_seed,
            request_journal,
            active_binding,
            completed_binding,
            aborted_binding,
            cleanup_requirement,
            plan_cleanup,
            operation_completions,
            operation_drains,
            operation_quarantines,
            pool_evidence: None,
            pool_journal: &[],
        }
    }

    pub fn resolved_plan(&self) -> &ResolvedModelPlan {
        self.resolved_plan
    }

    pub fn request_input(&self) -> &[u8] {
        self.request_input
    }

    pub fn initial_state(&self) -> &[u8] {
        self.initial_state
    }

    pub const fn random_seed(&self) -> u64 {
        self.random_seed
    }

    pub fn request_journal(&self) -> &[ExecutionEvent] {
        self.request_journal
    }

    pub fn active_binding(&self) -> &TrustedActiveSequenceBinding {
        self.active_binding
    }

    pub fn completed_binding(&self) -> Option<&TrustedCompletedSequenceBinding> {
        self.completed_binding
    }

    pub fn aborted_binding(&self) -> Option<&TrustedAbortedSequenceBinding> {
        self.aborted_binding
    }

    pub const fn cleanup_requirement(&self) -> ReplayCleanupRequirement {
        self.cleanup_requirement
    }

    pub const fn plan_cleanup(&self) -> ReplayPlanCleanupEvidence<'a> {
        self.plan_cleanup
    }

    pub fn operation_completions(&self) -> &[OperationCompletionReceipt] {
        self.operation_completions
    }

    pub fn operation_drains(&self) -> &[CompletionDrainReceipt] {
        self.operation_drains
    }

    pub fn operation_quarantines(&self) -> &[CompletionQuarantineReceipt] {
        self.operation_quarantines
    }

    pub fn pool_evidence(&self) -> Option<&ResourcePoolEvidence> {
        self.pool_evidence
    }

    pub fn pool_journal(&self) -> &[ResourcePoolEvent] {
        self.pool_journal
    }
}

#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
enum ReplayOperationTerminalKey {
    Completion(usize),
    Drain(usize),
    Quarantine(usize),
}

#[derive(Clone, Copy)]
enum ReplayOperationTerminalRef<'a> {
    Completion(&'a OperationCompletionReceipt),
    Drain(&'a CompletionDrainReceipt),
    Quarantine(&'a CompletionQuarantineReceipt),
}

impl<'a> ReplayOperationTerminalRef<'a> {
    fn slot_id(self) -> CompletionSlotId {
        match self {
            Self::Completion(receipt) => receipt.submission().slot_id(),
            Self::Drain(receipt) => receipt.slot_id(),
            Self::Quarantine(receipt) => receipt.slot_id(),
        }
    }

    fn batch_identity(self) -> &'a BatchOperationIdentity {
        match self {
            Self::Completion(receipt) => receipt.submission().batch_identity(),
            Self::Drain(receipt) => receipt.batch_identity(),
            Self::Quarantine(receipt) => receipt.batch_identity(),
        }
    }

    fn participant_submission(
        self,
        identity: &ExecutionIdentityEnvelope,
    ) -> Option<&'a SubmittedOperationParticipantReceipt> {
        self.submission()?
            .participants()
            .iter()
            .find(|participant| participant.identity() == identity)
    }

    fn submission(self) -> Option<&'a SubmittedOperationReceipt> {
        match self {
            Self::Completion(receipt) => Some(receipt.submission()),
            Self::Drain(receipt) => receipt.submission(),
            Self::Quarantine(receipt) => receipt.submission(),
        }
    }

    fn participant_completion(
        self,
        identity: &ExecutionIdentityEnvelope,
    ) -> Option<&'a OperationParticipantCompletionReceipt> {
        match self {
            Self::Completion(receipt) => receipt.participants().iter().find(|participant| {
                same_operation_authority_except_observation(
                    identity.parts(),
                    participant.submission().identity().parts(),
                )
            }),
            Self::Drain(_) | Self::Quarantine(_) => None,
        }
    }

    fn contains_identity(self, identity: &ExecutionIdentityEnvelope) -> bool {
        self.batch_identity()
            .participants()
            .iter()
            .any(|participant| participant.identity() == identity)
    }

    fn had_submission_fence(self) -> bool {
        match self {
            Self::Completion(_) => true,
            Self::Drain(receipt) => receipt.had_submission_fence(),
            Self::Quarantine(receipt) => receipt.had_submission_fence(),
        }
    }

    fn exact_failed_completion(
        self,
        identity: &ExecutionIdentityEnvelope,
    ) -> Option<&'a IdentifiedFailure> {
        self.participant_completion(identity)
            .and_then(|participant| match participant.disposition() {
                OperationParticipantCompletionDisposition::FailedButQuiescent(failure) => {
                    Some(failure)
                }
                OperationParticipantCompletionDisposition::Succeeded
                | OperationParticipantCompletionDisposition::ContractFailedButQuiescent(_) => None,
            })
    }

    fn participant_is_success(self, identity: &ExecutionIdentityEnvelope) -> bool {
        self.participant_completion(identity)
            .is_some_and(|participant| {
                matches!(
                    participant.disposition(),
                    OperationParticipantCompletionDisposition::Succeeded
                )
            })
    }
}

#[derive(Serialize)]
struct ReplayOperationTerminalFingerprint<'a> {
    completions: &'a [OperationCompletionReceipt],
    drains: &'a [CompletionDrainReceipt],
    quarantines: &'a [CompletionQuarantineReceipt],
}

fn replay_operation_terminals<'a>(
    evidence: &'a ReplayEvidence<'_>,
) -> Vec<(ReplayOperationTerminalKey, ReplayOperationTerminalRef<'a>)> {
    evidence
        .operation_completions
        .iter()
        .enumerate()
        .map(|(index, receipt)| {
            (
                ReplayOperationTerminalKey::Completion(index),
                ReplayOperationTerminalRef::Completion(receipt),
            )
        })
        .chain(
            evidence
                .operation_drains
                .iter()
                .enumerate()
                .map(|(index, receipt)| {
                    (
                        ReplayOperationTerminalKey::Drain(index),
                        ReplayOperationTerminalRef::Drain(receipt),
                    )
                }),
        )
        .chain(
            evidence
                .operation_quarantines
                .iter()
                .enumerate()
                .map(|(index, receipt)| {
                    (
                        ReplayOperationTerminalKey::Quarantine(index),
                        ReplayOperationTerminalRef::Quarantine(receipt),
                    )
                }),
        )
        .collect()
}

#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum ReplayCleanupRequirement {
    RequireClean,
    AllowPending,
}

/// Independent root-cleanup evidence supplied while rebuilding replay. Pending
/// is explicit and is accepted only when the caller allows pending cleanup.
/// The receipt variants are core-signed outputs and cannot be deserialized or
/// constructed by the replay caller.
#[derive(Clone, Copy)]
pub enum ReplayPlanCleanupEvidence<'a> {
    Pending,
    Closed(&'a PlanRuntimeCloseReceipt),
    Quarantined(&'a PlanRuntimeQuarantineReceipt),
}

#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
#[serde(rename_all = "snake_case")]
pub enum ReplayCleanupStatus {
    Completed,
    SequenceQuiescent,
    Quarantined,
    CleanupPending,
}

/// A replay identity is trusted output. Deserialization always goes through
/// `UnvalidatedReplayIdentity` and reconstruction from independent evidence.
#[derive(Debug, Clone, PartialEq, Eq, Serialize)]
pub struct ReplayIdentity {
    identity_version: ContractVersion,
    terminal_identity: ExecutionIdentityEnvelope,
    resolved_plan_fingerprint: String,
    execution_topology_fingerprint: String,
    request_input_fingerprint: String,
    initial_state_fingerprint: String,
    random_seed: u64,
    request_journal_event_count: u64,
    request_journal_fingerprint: String,
    active_sequence_fingerprint: String,
    completed_sequence_fingerprint: Option<String>,
    aborted_sequence_fingerprint: Option<String>,
    cleanup_status: ReplayCleanupStatus,
    operation_terminal_evidence_count: u64,
    operation_terminal_evidence_fingerprint: String,
    resource_pool_id: Option<ResourcePoolId>,
    resource_pool_identity_fingerprint: Option<String>,
    pool_journal_event_count: u64,
    pool_journal_fingerprint: Option<String>,
    plan_cleanup_fingerprint: Option<String>,
}

#[derive(Debug, Clone, PartialEq, Eq)]
pub struct UnvalidatedReplayIdentity {
    identity_version: ContractVersion,
    terminal_identity: UnvalidatedExecutionIdentityParts,
    resolved_plan_fingerprint: String,
    execution_topology_fingerprint: String,
    request_input_fingerprint: String,
    initial_state_fingerprint: String,
    random_seed: u64,
    request_journal_event_count: u64,
    request_journal_fingerprint: String,
    active_sequence_fingerprint: String,
    completed_sequence_fingerprint: Option<String>,
    aborted_sequence_fingerprint: Option<String>,
    cleanup_status: ReplayCleanupStatus,
    operation_terminal_evidence_count: u64,
    operation_terminal_evidence_fingerprint: String,
    resource_pool_id: Option<ResourcePoolId>,
    resource_pool_identity_fingerprint: Option<String>,
    pool_journal_event_count: u64,
    pool_journal_fingerprint: Option<String>,
    plan_cleanup_fingerprint: Option<String>,
}

#[derive(Deserialize)]
#[serde(deny_unknown_fields)]
struct ReplayIdentityWire {
    identity_version: ContractVersion,
    terminal_identity: UnvalidatedExecutionIdentityParts,
    resolved_plan_fingerprint: String,
    execution_topology_fingerprint: String,
    request_input_fingerprint: String,
    initial_state_fingerprint: String,
    random_seed: u64,
    request_journal_event_count: u64,
    request_journal_fingerprint: String,
    active_sequence_fingerprint: String,
    completed_sequence_fingerprint: Option<String>,
    aborted_sequence_fingerprint: Option<String>,
    cleanup_status: ReplayCleanupStatus,
    operation_terminal_evidence_count: u64,
    operation_terminal_evidence_fingerprint: String,
    resource_pool_id: Option<ResourcePoolId>,
    resource_pool_identity_fingerprint: Option<String>,
    pool_journal_event_count: u64,
    pool_journal_fingerprint: Option<String>,
    plan_cleanup_fingerprint: Option<String>,
}

impl From<ReplayIdentityWire> for UnvalidatedReplayIdentity {
    fn from(wire: ReplayIdentityWire) -> Self {
        Self {
            identity_version: wire.identity_version,
            terminal_identity: wire.terminal_identity,
            resolved_plan_fingerprint: wire.resolved_plan_fingerprint,
            execution_topology_fingerprint: wire.execution_topology_fingerprint,
            request_input_fingerprint: wire.request_input_fingerprint,
            initial_state_fingerprint: wire.initial_state_fingerprint,
            random_seed: wire.random_seed,
            request_journal_event_count: wire.request_journal_event_count,
            request_journal_fingerprint: wire.request_journal_fingerprint,
            active_sequence_fingerprint: wire.active_sequence_fingerprint,
            completed_sequence_fingerprint: wire.completed_sequence_fingerprint,
            aborted_sequence_fingerprint: wire.aborted_sequence_fingerprint,
            cleanup_status: wire.cleanup_status,
            operation_terminal_evidence_count: wire.operation_terminal_evidence_count,
            operation_terminal_evidence_fingerprint: wire.operation_terminal_evidence_fingerprint,
            resource_pool_id: wire.resource_pool_id,
            resource_pool_identity_fingerprint: wire.resource_pool_identity_fingerprint,
            pool_journal_event_count: wire.pool_journal_event_count,
            pool_journal_fingerprint: wire.pool_journal_fingerprint,
            plan_cleanup_fingerprint: wire.plan_cleanup_fingerprint,
        }
    }
}

fn validate_replay_plan_cleanup(
    active: &TrustedActiveSequenceBinding,
    aborted: bool,
    requirement: ReplayCleanupRequirement,
    cleanup: ReplayPlanCleanupEvidence<'_>,
) -> Result<(ReplayCleanupStatus, Option<String>), VNextError> {
    let expected_static_resources = active.static_entries().len();
    match cleanup {
        ReplayPlanCleanupEvidence::Pending => {
            if requirement == ReplayCleanupRequirement::RequireClean {
                return Err(invalid_event(
                    "clean replay requires an exact plan close or quarantine receipt",
                ));
            }
            Ok((ReplayCleanupStatus::CleanupPending, None))
        }
        ReplayPlanCleanupEvidence::Closed(receipt) => {
            if receipt.evidence() != active.plan()
                || receipt.released_static_resources() != expected_static_resources
            {
                return Err(invalid_event(
                    "replay plan close receipt differs from the active plan or static resource set",
                ));
            }
            Ok((
                if aborted {
                    ReplayCleanupStatus::SequenceQuiescent
                } else {
                    ReplayCleanupStatus::Completed
                },
                Some(canonical_fingerprint(receipt)),
            ))
        }
        ReplayPlanCleanupEvidence::Quarantined(receipt) => {
            let accounted_static_resources = receipt
                .released_static_resources()
                .checked_add(receipt.quarantined_static_resources())
                .ok_or_else(|| invalid_event("replay quarantine resource count overflows usize"))?;
            if expected_static_resources == 0
                || receipt.evidence() != active.plan()
                || accounted_static_resources != expected_static_resources
            {
                return Err(invalid_event(
                    "replay quarantine receipt differs from the active static plan resource set",
                ));
            }
            Ok((
                ReplayCleanupStatus::Quarantined,
                Some(canonical_fingerprint(receipt)),
            ))
        }
    }
}

impl ReplayIdentity {
    pub fn from_evidence(evidence: &ReplayEvidence<'_>) -> Result<Self, VNextError> {
        if evidence.request_journal.is_empty() {
            return Err(invalid_event(
                "replay evidence requires a non-empty request journal",
            ));
        }
        if !evidence.operation_quarantines.is_empty() {
            if evidence
                .operation_quarantines
                .iter()
                .any(|receipt| !receipt.is_current())
            {
                return Err(invalid_event(
                    "completion quarantine replay evidence was superseded by a successful drain",
                ));
            }
            if evidence.cleanup_requirement != ReplayCleanupRequirement::AllowPending
                || !matches!(evidence.plan_cleanup, ReplayPlanCleanupEvidence::Pending)
            {
                return Err(invalid_event(
                    "current completion quarantine is pending ownership and requires explicitly pending replay cleanup",
                ));
            }
        }

        let topology =
            TrustedExecutionTopology::from_plan(evidence.resolved_plan.execution_plan())?;
        let active = evidence.active_binding;
        let completed = evidence.completed_binding;
        let aborted = evidence.aborted_binding;
        if completed.is_some() == aborted.is_some() {
            return Err(invalid_event(
                "replay requires exactly one external sequence completion or abort binding",
            ));
        }
        if active.plan().plan_id() != topology.plan_id()
            || active.plan().plan_hash() != topology.plan_hash()
            || active.plan().device_id() != topology.device_id()
            || active.plan().runtime_implementation_fingerprint()
                != topology.device_runtime_implementation_fingerprint()
            || active.runtime_implementation_fingerprint()
                != topology.device_runtime_implementation_fingerprint()
        {
            return Err(invalid_event(
                "replay plan and active binding do not share one authority",
            ));
        }
        if let Some(completed) = completed {
            if completed.active_sequence_fingerprint() != active.fingerprint()
                || completed.sequence_authority() != active.sequence_authority()
                || completed.run_id() != active.run_id()
                || completed.request_id() != active.request_id()
                || completed.activation_epoch() != active.activation_epoch()
                || completed.runtime_implementation_fingerprint()
                    != active.runtime_implementation_fingerprint()
            {
                return Err(invalid_event(
                    "replay completion evidence differs from its active sequence",
                ));
            }
        }
        if let Some(aborted) = aborted {
            if !active.matches_abort_disposition(aborted.disposition())
                || aborted.active_sequence_fingerprint() != active.fingerprint()
                || aborted.sequence_authority() != active.sequence_authority()
                || aborted.run_id() != active.run_id()
                || aborted.request_id() != active.request_id()
                || aborted.activation_epoch() != active.activation_epoch()
                || aborted.runtime_implementation_fingerprint()
                    != active.runtime_implementation_fingerprint()
            {
                return Err(invalid_event(
                    "replay abort evidence differs from its active sequence",
                ));
            }
        }

        let first = evidence
            .request_journal
            .first()
            .expect("non-empty request journal");
        let terminal = evidence
            .request_journal
            .last()
            .expect("non-empty request journal");
        let run_id = &first.identity().parts().run_id;
        let request_id = &first.identity().parts().request_id;
        if run_id != active.run_id() || request_id != active.request_id() {
            return Err(invalid_event(
                "replay request journal differs from the active run/request binding",
            ));
        }

        let operation_terminals = replay_operation_terminals(evidence);
        let mut terminal_slots = BTreeSet::new();
        if operation_terminals
            .iter()
            .any(|(_, terminal)| !terminal_slots.insert(terminal.slot_id()))
        {
            return Err(invalid_event(
                "replay operation terminal evidence reuses a completion slot across terminal types",
            ));
        }

        let mut request_cursor = ExecutionEventCursor::new(run_id.clone(), request_id.clone());
        let mut observed_active_identity = false;
        let mut used_submitted_terminals = BTreeSet::new();
        let mut first_failure: Option<IdentifiedFailure> = None;
        for event in evidence.request_journal {
            observed_active_identity |= has_active(event.identity().parts());
            let context = match event.kind() {
                ExecutionEventKind::RequestAccepted => {
                    TrustedExecutionEventContext::pre_plan(run_id, request_id)
                }
                ExecutionEventKind::PlanBuilt => {
                    TrustedExecutionEventContext::bound(run_id, request_id, &topology)
                }
                ExecutionEventKind::FailureObserved => {
                    let failure = match event.detail() {
                        ExecutionEventDetail::Failure(failure) => failure,
                        _ => unreachable!("trusted FailureObserved shape was validated"),
                    };
                    if first_failure.is_some() {
                        return Err(invalid_event(
                            "replay request journal contains more than one first failure",
                        ));
                    }
                    first_failure = Some(failure.clone());
                    let unsubmitted_recoveries = operation_terminals
                        .iter()
                        .filter(|(_, terminal)| {
                            !terminal.had_submission_fence()
                                && terminal.contains_identity(failure.identity())
                        })
                        .collect::<Vec<_>>();
                    if unsubmitted_recoveries.len() > 1 {
                        return Err(invalid_event(
                            "operation failure matches multiple unsubmitted recovery receipts",
                        ));
                    }
                    TrustedExecutionEventContext::replay_failure(
                        run_id,
                        request_id,
                        event
                            .identity()
                            .parts()
                            .plan_id
                            .is_some()
                            .then_some(&topology),
                        has_active(event.identity().parts()).then_some(active),
                        failure,
                        unsubmitted_recoveries.first().map(|_| failure.identity()),
                    )
                }
                ExecutionEventKind::RequestFailed => match event.detail() {
                    ExecutionEventDetail::Failure(failure) => {
                        TrustedExecutionEventContext::failure(
                            run_id,
                            request_id,
                            event
                                .identity()
                                .parts()
                                .plan_id
                                .is_some()
                                .then_some(&topology),
                            has_active(event.identity().parts()).then_some(active),
                            failure,
                        )
                    }
                    ExecutionEventDetail::FailureTerminal { .. } => {
                        let failure = first_failure.as_ref().ok_or_else(|| {
                            invalid_event(
                                "terminal replay failure lacks its first FailureObserved evidence",
                            )
                        })?;
                        TrustedExecutionEventContext::failure_with_disposition(
                            run_id,
                            request_id,
                            &topology,
                            active,
                            has_completed(event.identity().parts())
                                .then_some(completed)
                                .flatten(),
                            has_aborted(event.identity().parts())
                                .then_some(aborted)
                                .flatten(),
                            failure,
                        )
                    }
                    _ => unreachable!("trusted RequestFailed shape was validated"),
                },
                ExecutionEventKind::OperationSubmitted => {
                    let matches = operation_terminals
                        .iter()
                        .filter_map(|(key, terminal)| {
                            terminal
                                .had_submission_fence()
                                .then(|| {
                                    terminal
                                        .participant_submission(event.identity())
                                        .map(|participant| (*key, participant))
                                })
                                .flatten()
                        })
                        .collect::<Vec<_>>();
                    if matches.len() != 1 || !used_submitted_terminals.insert(matches[0].0) {
                        return Err(invalid_event(
                            "replay operation event lacks one exact terminal receipt proving submission",
                        ));
                    }
                    TrustedExecutionEventContext::replay_operation_submitted(
                        run_id,
                        request_id,
                        &topology,
                        active,
                        operation_terminals
                            .iter()
                            .find(|(key, _)| *key == matches[0].0)
                            .and_then(|(_, terminal)| terminal.submission())
                            .expect("matched submitted participant has a batch receipt"),
                    )
                }
                ExecutionEventKind::NodeRetired => {
                    let matches = operation_terminals
                        .iter()
                        .filter_map(|(key, terminal)| {
                            terminal
                                .participant_completion(event.identity())
                                .map(|participant| (*key, participant))
                        })
                        .collect::<Vec<_>>();
                    if matches.len() != 1 || !used_submitted_terminals.contains(&matches[0].0) {
                        return Err(invalid_event(
                            "replay NodeRetired lacks the exact submitted batch completion projection",
                        ));
                    }
                    TrustedExecutionEventContext::replay_node_retired(
                        run_id,
                        request_id,
                        &topology,
                        active,
                        matches[0].1,
                    )
                }
                ExecutionEventKind::SequenceCompleted | ExecutionEventKind::RequestCompleted => {
                    let completed = completed.ok_or_else(|| {
                        invalid_event(
                            "successful replay journal lacks external sequence completion evidence",
                        )
                    })?;
                    TrustedExecutionEventContext::completed(
                        run_id, request_id, &topology, active, completed,
                    )
                }
                ExecutionEventKind::SequenceAborted => {
                    let aborted = aborted.ok_or_else(|| {
                        invalid_event(
                            "failed replay journal lacks external sequence abort evidence",
                        )
                    })?;
                    TrustedExecutionEventContext::aborted(
                        run_id, request_id, &topology, active, aborted,
                    )
                }
                _ => TrustedExecutionEventContext::active(run_id, request_id, &topology, active),
            };
            request_cursor.observe_against(event, &context)?;
        }
        if !request_cursor.is_terminal()
            || !observed_active_identity
            || !matches!(
                terminal.kind(),
                ExecutionEventKind::RequestCompleted | ExecutionEventKind::RequestFailed
            )
        {
            return Err(invalid_event(
                "replay request journal is incomplete or lacks an exact terminal event",
            ));
        }
        let submitted_terminal_count = operation_terminals
            .iter()
            .filter(|(_, terminal)| terminal.had_submission_fence())
            .count();
        if used_submitted_terminals.len() != submitted_terminal_count {
            return Err(invalid_event(
                "replay contains unused or missing operation terminal evidence for submitted work",
            ));
        }

        let operation_failures = first_failure
            .iter()
            .filter(|failure| has_active(failure.identity().parts()))
            .collect::<Vec<_>>();
        let submitted_identities = evidence
            .request_journal
            .iter()
            .filter(|event| event.kind() == ExecutionEventKind::OperationSubmitted)
            .map(ExecutionEvent::identity)
            .collect::<Vec<_>>();
        let mut used_operation_failures = BTreeSet::new();
        let request_failed = terminal.kind() == ExecutionEventKind::RequestFailed;
        for (_, operation_terminal) in &operation_terminals {
            let mut relevant_identities = submitted_identities
                .iter()
                .copied()
                .filter(|identity| operation_terminal.contains_identity(identity))
                .collect::<Vec<_>>();
            if relevant_identities.is_empty() {
                relevant_identities.extend(
                    operation_failures
                        .iter()
                        .map(|failure| failure.identity())
                        .filter(|identity| operation_terminal.contains_identity(identity)),
                );
            }
            if relevant_identities.len() != 1 {
                return Err(invalid_event(
                    "operation terminal evidence has no unique participant projection in this request journal",
                ));
            }
            let operation_identity = relevant_identities[0];
            let matching_failures = operation_failures
                .iter()
                .enumerate()
                .filter(|(_, failure)| failure.identity() == operation_identity)
                .collect::<Vec<_>>();
            if operation_terminal.participant_is_success(operation_identity) {
                if !matching_failures.is_empty() {
                    return Err(invalid_event(
                        "successful operation completion coexists with a failure for the same submitted operation",
                    ));
                }
                continue;
            }
            if !request_failed || matching_failures.len() != 1 {
                return Err(invalid_event(
                    "non-success operation terminal evidence requires one exact operation failure and RequestFailed",
                ));
            }
            if let Some(expected_failure) =
                operation_terminal.exact_failed_completion(operation_identity)
            {
                if expected_failure.identity() != operation_identity
                    || *matching_failures[0].1 != expected_failure
                {
                    return Err(invalid_event(
                        "failed-but-quiescent completion differs from the exact observed operation failure",
                    ));
                }
            }
            if !used_operation_failures.insert(matching_failures[0].0) {
                return Err(invalid_event(
                    "one operation failure was reused by multiple terminal evidence receipts",
                ));
            }
        }
        if used_operation_failures.len() != operation_failures.len() {
            return Err(invalid_event(
                "operation FailureObserved lacks one exact non-success terminal evidence receipt",
            ));
        }

        let (
            resource_pool_id,
            resource_pool_identity_fingerprint,
            pool_journal_event_count,
            pool_journal_fingerprint,
        ) = match evidence.pool_evidence {
            Some(pool_evidence) => {
                if evidence.pool_journal.is_empty() {
                    return Err(invalid_event(
                        "static replay evidence requires a non-empty pool journal",
                    ));
                }
                let active_static_pool_id = active.static_pool_id().ok_or_else(|| {
                    invalid_event("static pool replay evidence was supplied for a no-static plan")
                })?;
                let active_static_fingerprint = active
                    .static_pool_identity_fingerprint()
                    .ok_or_else(|| invalid_event("static replay pool lacks identity evidence"))?;
                let active_static_provisioning =
                    active.static_provisioning_identity().ok_or_else(|| {
                        invalid_event("static replay pool lacks provisioning identity evidence")
                    })?;
                if active.static_entries().is_empty()
                    || active_static_pool_id != pool_evidence.pool_id()
                    || active_static_fingerprint != pool_evidence.pool_identity_fingerprint()
                    || active_static_provisioning != pool_evidence.provisioning_identity()
                    || pool_evidence.topology_fingerprint() != topology.fingerprint()
                {
                    return Err(invalid_event(
                        "replay active binding and static pool evidence do not share one authority",
                    ));
                }
                let mut pool_cursor = ResourcePoolEventCursor::new(pool_evidence.clone());
                for event in evidence.pool_journal {
                    pool_cursor.observe(event)?;
                }
                if !pool_cursor.has_opened() || !pool_cursor.proves_active_binding(active) {
                    return Err(invalid_event(
                        "replay pool journal does not prove the complete committed active lease",
                    ));
                }
                (
                    Some(active_static_pool_id),
                    Some(active_static_fingerprint),
                    u64::try_from(evidence.pool_journal.len())
                        .map_err(|_| invalid_event("pool journal length exceeds u64"))?,
                    Some(canonical_fingerprint(&evidence.pool_journal)),
                )
            }
            None => {
                if !evidence.pool_journal.is_empty()
                    || active.static_pool_id().is_some()
                    || active.static_provisioning_identity().is_some()
                    || active.plan().static_provisioning_binding().is_some()
                    || active.plan().static_pool_identity().is_some()
                    || !active.static_entries().is_empty()
                {
                    return Err(invalid_event(
                        "no-static replay evidence contains static pool identity or journal state",
                    ));
                }
                (None, None, 0, None)
            }
        };
        let (cleanup_status, plan_cleanup_fingerprint) = validate_replay_plan_cleanup(
            active,
            aborted.is_some(),
            evidence.cleanup_requirement,
            evidence.plan_cleanup,
        )?;

        let request_journal_event_count = u64::try_from(evidence.request_journal.len())
            .map_err(|_| invalid_event("request journal length exceeds u64"))?;
        let operation_terminal_evidence_len = evidence
            .operation_completions
            .len()
            .checked_add(evidence.operation_drains.len())
            .and_then(|count| count.checked_add(evidence.operation_quarantines.len()))
            .ok_or_else(|| invalid_event("operation terminal evidence count exceeds usize"))?;
        let operation_terminal_evidence_count = u64::try_from(operation_terminal_evidence_len)
            .map_err(|_| invalid_event("operation terminal evidence count exceeds u64"))?;
        let identity = Self {
            identity_version: EXECUTION_IDENTITY_VERSION,
            terminal_identity: terminal.identity().clone(),
            resolved_plan_fingerprint: evidence.resolved_plan.fingerprint().to_owned(),
            execution_topology_fingerprint: topology.fingerprint().to_owned(),
            request_input_fingerprint: sha256_bytes(evidence.request_input),
            initial_state_fingerprint: sha256_bytes(evidence.initial_state),
            random_seed: evidence.random_seed,
            request_journal_event_count,
            request_journal_fingerprint: canonical_fingerprint(&evidence.request_journal),
            active_sequence_fingerprint: active.fingerprint().to_owned(),
            completed_sequence_fingerprint: completed
                .map(|binding| binding.fingerprint().to_owned()),
            aborted_sequence_fingerprint: aborted.map(|binding| binding.fingerprint().to_owned()),
            cleanup_status,
            operation_terminal_evidence_count,
            operation_terminal_evidence_fingerprint: canonical_fingerprint(
                &ReplayOperationTerminalFingerprint {
                    completions: evidence.operation_completions,
                    drains: evidence.operation_drains,
                    quarantines: evidence.operation_quarantines,
                },
            ),
            resource_pool_id,
            resource_pool_identity_fingerprint,
            pool_journal_event_count,
            pool_journal_fingerprint,
            plan_cleanup_fingerprint,
        };
        identity.validate_fingerprint_shape()?;
        Ok(identity)
    }

    fn validate_fingerprint_shape(&self) -> Result<(), VNextError> {
        for (value, label) in [
            (&self.resolved_plan_fingerprint, "resolved plan fingerprint"),
            (
                &self.execution_topology_fingerprint,
                "execution topology fingerprint",
            ),
            (&self.request_input_fingerprint, "request input fingerprint"),
            (&self.initial_state_fingerprint, "initial state fingerprint"),
            (
                &self.request_journal_fingerprint,
                "request journal fingerprint",
            ),
            (
                &self.active_sequence_fingerprint,
                "active sequence fingerprint",
            ),
            (
                &self.operation_terminal_evidence_fingerprint,
                "operation terminal evidence fingerprint",
            ),
        ] {
            validate_sha256(value, label)?;
        }
        if let Some(fingerprint) = &self.completed_sequence_fingerprint {
            validate_sha256(fingerprint, "completed sequence fingerprint")?;
        }
        if let Some(fingerprint) = &self.aborted_sequence_fingerprint {
            validate_sha256(fingerprint, "aborted sequence fingerprint")?;
        }
        if let Some(fingerprint) = &self.resource_pool_identity_fingerprint {
            validate_sha256(fingerprint, "resource pool identity fingerprint")?;
        }
        if let Some(fingerprint) = &self.pool_journal_fingerprint {
            validate_sha256(fingerprint, "pool journal fingerprint")?;
        }
        if let Some(fingerprint) = &self.plan_cleanup_fingerprint {
            validate_sha256(fingerprint, "plan cleanup fingerprint")?;
        }
        let has_static_pool = self.resource_pool_id.is_some();
        if self.completed_sequence_fingerprint.is_some()
            == self.aborted_sequence_fingerprint.is_some()
            || self.cleanup_status == ReplayCleanupStatus::Completed
                && self.completed_sequence_fingerprint.is_none()
            || self.cleanup_status == ReplayCleanupStatus::SequenceQuiescent
                && self.aborted_sequence_fingerprint.is_none()
            || self.cleanup_status == ReplayCleanupStatus::CleanupPending
                && self.plan_cleanup_fingerprint.is_some()
            || self.cleanup_status != ReplayCleanupStatus::CleanupPending
                && self.plan_cleanup_fingerprint.is_none()
            || has_static_pool != self.resource_pool_identity_fingerprint.is_some()
            || has_static_pool != self.pool_journal_fingerprint.is_some()
            || has_static_pool != (self.pool_journal_event_count > 0)
        {
            return Err(invalid_event(
                "replay cleanup status differs from its exact sequence disposition",
            ));
        }
        Ok(())
    }

    pub fn terminal_identity(&self) -> &ExecutionIdentityEnvelope {
        &self.terminal_identity
    }

    pub fn resolved_plan_fingerprint(&self) -> &str {
        &self.resolved_plan_fingerprint
    }

    pub fn request_input_fingerprint(&self) -> &str {
        &self.request_input_fingerprint
    }

    pub fn initial_state_fingerprint(&self) -> &str {
        &self.initial_state_fingerprint
    }

    pub const fn random_seed(&self) -> u64 {
        self.random_seed
    }

    pub fn request_journal_fingerprint(&self) -> &str {
        &self.request_journal_fingerprint
    }

    pub fn pool_journal_fingerprint(&self) -> Option<&str> {
        self.pool_journal_fingerprint.as_deref()
    }

    pub fn plan_cleanup_fingerprint(&self) -> Option<&str> {
        self.plan_cleanup_fingerprint.as_deref()
    }

    pub const fn cleanup_status(&self) -> ReplayCleanupStatus {
        self.cleanup_status
    }

    pub fn decode_untrusted(bytes: &[u8]) -> Result<UnvalidatedReplayIdentity, VNextError> {
        if bytes.len() > MAX_REPLAY_IDENTITY_WIRE_BYTES {
            return Err(invalid_event(
                "untrusted replay identity exceeds the wire byte limit",
            ));
        }
        serde_json::from_slice::<ReplayIdentityWire>(bytes)
            .map(Into::into)
            .map_err(|error| VNextError::Serialization {
                context: "decode untrusted replay identity",
                message: error.to_string(),
            })
    }
}

impl UnvalidatedReplayIdentity {
    pub fn revalidate(self, evidence: &ReplayEvidence<'_>) -> Result<ReplayIdentity, VNextError> {
        let rebuilt = ReplayIdentity::from_evidence(evidence)?;
        let supplied_terminal = ExecutionIdentityEnvelope::new(self.terminal_identity.into())?;
        if self.identity_version != rebuilt.identity_version
            || supplied_terminal != rebuilt.terminal_identity
            || self.resolved_plan_fingerprint != rebuilt.resolved_plan_fingerprint
            || self.execution_topology_fingerprint != rebuilt.execution_topology_fingerprint
            || self.request_input_fingerprint != rebuilt.request_input_fingerprint
            || self.initial_state_fingerprint != rebuilt.initial_state_fingerprint
            || self.random_seed != rebuilt.random_seed
            || self.request_journal_event_count != rebuilt.request_journal_event_count
            || self.request_journal_fingerprint != rebuilt.request_journal_fingerprint
            || self.active_sequence_fingerprint != rebuilt.active_sequence_fingerprint
            || self.completed_sequence_fingerprint != rebuilt.completed_sequence_fingerprint
            || self.aborted_sequence_fingerprint != rebuilt.aborted_sequence_fingerprint
            || self.cleanup_status != rebuilt.cleanup_status
            || self.operation_terminal_evidence_count != rebuilt.operation_terminal_evidence_count
            || self.operation_terminal_evidence_fingerprint
                != rebuilt.operation_terminal_evidence_fingerprint
            || self.resource_pool_id != rebuilt.resource_pool_id
            || self.resource_pool_identity_fingerprint != rebuilt.resource_pool_identity_fingerprint
            || self.pool_journal_event_count != rebuilt.pool_journal_event_count
            || self.pool_journal_fingerprint != rebuilt.pool_journal_fingerprint
            || self.plan_cleanup_fingerprint != rebuilt.plan_cleanup_fingerprint
        {
            return Err(invalid_event(
                "serialized replay identity differs from independently rebuilt evidence",
            ));
        }
        rebuilt.validate_fingerprint_shape()?;
        Ok(rebuilt)
    }
}