| 1 | package checkpoint |
| 2 | |
| 3 | import ( |
| 4 | "encoding/json" |
| 5 | "errors" |
| 6 | "fmt" |
| 7 | "log/slog" |
| 8 | "os" |
| 9 | "path/filepath" |
| 10 | "slices" |
| 11 | "sort" |
| 12 | "strings" |
| 13 | "time" |
| 14 | ) |
| 15 | |
| 16 | // InjectFail is a test seam. When set, CommitRewind fails at the named phase |
| 17 | // after optionally publishing the first N files. Empty = disabled. |
| 18 | // |
| 19 | // Known phases: "publish_file", "delete_file", "conversation", "truncate", |
| 20 | // "after_conversation_before_finalize", "finalize". |
| 21 | type InjectFail struct { |
| 22 | Phase string |
| 23 | AfterFiles int // fail after successfully handling this many file targets |
| 24 | } |
| 25 | |
| 26 | // ConversationApplier applies conversation truncation during commit and restores |
| 27 | // forward conversation on compensate. Implemented by the control layer. |
| 28 | type ConversationApplier interface { |
| 29 | // ApplyConversationTruncate replaces the live message log with msgs[:boundary]. |
| 30 | // forward is the full pre-truncate snapshot for later restore. |
| 31 | ApplyConversationTruncate(boundary int, forward []byte) error |
| 32 | // RestoreConversation reinstalls the forward snapshot. |
| 33 | RestoreConversation(forward []byte) error |
| 34 | // TruncateCheckpoints drops checkpoints at or after turn. |
| 35 | TruncateCheckpoints(fromTurn int) error |
| 36 | // RestoreCheckpoints reinstalls backed-up future checkpoints. |
| 37 | RestoreCheckpoints(backup []byte) error |
| 38 | } |
| 39 | |
| 40 | // PrepareRewind builds a plan and optionally a prepared transaction without |
| 41 | // mutating workspace or conversation. Conflict detection uses last-owned after |
| 42 | // fingerprints when available. |
| 43 | func (s *Store) PrepareRewind(turn int, scope RewindScope, sessionRev int64, boundary int, hasBound bool) (RewindPlan, error) { |
| 44 | if s == nil { |
| 45 | return RewindPlan{}, fmt.Errorf("checkpoints unavailable") |
| 46 | } |
| 47 | plan := RewindPlan{ |
| 48 | PlanID: newID("plan"), |
| 49 | Turn: turn, |
| 50 | Scope: scope, |
| 51 | SessionRevision: sessionRev, |
| 52 | BoundaryIndex: boundary, |
| 53 | HasBoundary: hasBound, |
| 54 | CreatedAt: time.Now(), |
| 55 | WorkspaceToken: fmt.Sprintf("%d", s.barrier.Generation()), |
| 56 | } |
| 57 | |
| 58 | s.mu.Lock() |
| 59 | writers := append([]ActiveWriter(nil), s.activeWriters...) |
| 60 | plan.ActiveWriters = writers |
| 61 | cov, gaps, legacy, expired := s.coverageFromTurnLocked(turn) |
| 62 | plan.Coverage = cov |
| 63 | plan.CoverageGaps = gaps |
| 64 | plan.Legacy = legacy |
| 65 | plan.ExpiredFilePayload = expired |
| 66 | files := s.filesFromTurnLocked(turn) |
| 67 | plan.Files = files |
| 68 | plan.FileCount = len(files) |
| 69 | s.mu.Unlock() |
| 70 | |
| 71 | wantFiles := scope == RewindCode || scope == RewindBoth |
| 72 | wantConv := scope == RewindConversation || scope == RewindBoth |
| 73 | |
| 74 | if len(writers) > 0 { |
| 75 | plan.CanFiles = false |
| 76 | plan.CanConversation = false |
| 77 | plan.DisabledReason = "active background writer" |
| 78 | for _, w := range writers { |
| 79 | plan.Conflicts = append(plan.Conflicts, RewindConflict{ |
| 80 | Path: "", |
| 81 | Reason: ConflictBusyWriter, |
| 82 | }) |
| 83 | _ = w |
| 84 | } |
| 85 | return plan, nil |
| 86 | } |
| 87 | |
| 88 | if wantConv { |
| 89 | if !hasBound { |
| 90 | plan.CanConversation = false |
| 91 | if scope == RewindConversation || scope == RewindBoth { |
| 92 | plan.DisabledReason = "conversation boundary unavailable" |
| 93 | } |
| 94 | } else { |
| 95 | plan.CanConversation = true |
| 96 | } |
| 97 | } |
| 98 | |
| 99 | if wantFiles { |
| 100 | if len(files) == 0 && scope == RewindBoth { |
| 101 | // The file half of a combined rewind is an atomic no-op when this |
| 102 | // conversation range never touched a tracked file. |
| 103 | plan.CanFiles = true |
| 104 | } else if cov == CoverageNone { |
| 105 | plan.CanFiles = false |
| 106 | plan.DisabledReason = "no file captures" |
| 107 | } else if expired { |
| 108 | plan.CanFiles = false |
| 109 | plan.DisabledReason = "file recovery payload expired" |
| 110 | plan.Conflicts = append(plan.Conflicts, RewindConflict{Reason: ConflictExpired}) |
| 111 | } else if legacy { |
| 112 | // Legacy: files can be restored only with explicit warning; batch |
| 113 | // overwrite without prompt is forbidden. Prepare still reports files |
| 114 | // but CanFiles stays false for the unprompted path. |
| 115 | plan.CanFiles = false |
| 116 | plan.DisabledReason = "legacy checkpoint cannot verify later manual edits" |
| 117 | plan.Conflicts = append(plan.Conflicts, RewindConflict{Reason: ConflictCoverageLegacy}) |
| 118 | } else { |
| 119 | conflicts := s.precheckFiles(turn) |
| 120 | plan.Conflicts = append(plan.Conflicts, conflicts...) |
| 121 | plan.CanFiles = len(conflicts) == 0 && len(files) > 0 |
| 122 | if len(conflicts) > 0 { |
| 123 | plan.DisabledReason = "file conflicts detected" |
| 124 | } |
| 125 | } |
| 126 | } |
| 127 | |
| 128 | // both requires both sides to pass precheck. |
| 129 | if scope == RewindBoth { |
| 130 | if !plan.CanFiles || !plan.CanConversation { |
| 131 | if plan.DisabledReason == "" { |
| 132 | plan.DisabledReason = "both scope requires file and conversation precheck" |
| 133 | } |
| 134 | } |
| 135 | } |
| 136 | |
| 137 | // Persist plan token so Commit can verify freshness. |
| 138 | s.mu.Lock() |
| 139 | if s.plans == nil { |
| 140 | s.plans = map[string]preparedPlan{} |
| 141 | } |
| 142 | s.plans[plan.PlanID] = preparedPlan{plan: plan, created: time.Now()} |
| 143 | // Drop stale plans older than 10 minutes. |
| 144 | for id, p := range s.plans { |
| 145 | if time.Since(p.created) > 10*time.Minute { |
| 146 | delete(s.plans, id) |
| 147 | } |
| 148 | } |
| 149 | s.mu.Unlock() |
| 150 | return plan, nil |
| 151 | } |
| 152 | |
| 153 | type preparedPlan struct { |
| 154 | plan RewindPlan |
| 155 | created time.Time |
| 156 | previewFingerprint *Fingerprint |
| 157 | } |
| 158 | |
| 159 | // ValidatePlanSessionRevision binds a preview to the controller's exact |
| 160 | // conversation revision. The controller holds its rotation gate while calling |
| 161 | // this and committing, so no turn can slip between validation and mutation. |
| 162 | func (s *Store) ValidatePlanSessionRevision(planID string, current int64) error { |
| 163 | if s == nil { |
| 164 | return fmt.Errorf("checkpoints unavailable") |
| 165 | } |
| 166 | s.mu.Lock() |
| 167 | defer s.mu.Unlock() |
| 168 | prepared, ok := s.plans[planID] |
| 169 | if !ok { |
| 170 | return fmt.Errorf("unknown or expired plan %q", planID) |
| 171 | } |
| 172 | if prepared.plan.SessionRevision != current { |
| 173 | return fmt.Errorf("conversation changed since preview") |
| 174 | } |
| 175 | return nil |
| 176 | } |
| 177 | |
| 178 | // CommitRewind executes a previously prepared plan under exclusive barrier. |
| 179 | // conversation/checkpoints are applied via applier when non-nil. |
| 180 | func (s *Store) CommitRewind(planID string, applier ConversationApplier, inject *InjectFail) (RewindResult, error) { |
| 181 | if s == nil { |
| 182 | return RewindResult{}, fmt.Errorf("checkpoints unavailable") |
| 183 | } |
| 184 | s.mu.Lock() |
| 185 | pp, ok := s.plans[planID] |
| 186 | if ok { |
| 187 | delete(s.plans, planID) |
| 188 | } |
| 189 | s.mu.Unlock() |
| 190 | if !ok { |
| 191 | return RewindResult{OK: false, Error: "unknown or expired plan"}, fmt.Errorf("unknown or expired plan %q", planID) |
| 192 | } |
| 193 | plan := pp.plan |
| 194 | |
| 195 | // Re-validate gate conditions before any mutation. |
| 196 | if plan.Scope == RewindBoth && (!plan.CanFiles || !plan.CanConversation) { |
| 197 | return RewindResult{OK: false, Error: plan.DisabledReason, Conflicts: plan.Conflicts, Coverage: plan.Coverage}, fmt.Errorf("%s", plan.DisabledReason) |
| 198 | } |
| 199 | if (plan.Scope == RewindCode || plan.Scope == RewindBoth) && !plan.CanFiles && plan.Scope != RewindConversation { |
| 200 | if plan.Scope == RewindCode || plan.Scope == RewindBoth { |
| 201 | return RewindResult{OK: false, Error: plan.DisabledReason, Conflicts: plan.Conflicts, Coverage: plan.Coverage}, fmt.Errorf("%s", plan.DisabledReason) |
| 202 | } |
| 203 | } |
| 204 | if (plan.Scope == RewindConversation || plan.Scope == RewindBoth) && !plan.CanConversation { |
| 205 | return RewindResult{OK: false, Error: plan.DisabledReason}, fmt.Errorf("%s", plan.DisabledReason) |
| 206 | } |
| 207 | |
| 208 | // Workspace exclusive barrier. |
| 209 | if !s.barrier.TryEnterExclusive() { |
| 210 | err := fmt.Errorf("workspace mutation in progress") |
| 211 | return RewindResult{OK: false, Error: err.Error(), Conflicts: []RewindConflict{{Reason: ConflictBusyWriter}}}, err |
| 212 | } |
| 213 | defer s.barrier.ExitExclusive() |
| 214 | if conflicts := s.activeWriterConflicts(); len(conflicts) > 0 { |
| 215 | err := fmt.Errorf("active background writer") |
| 216 | return RewindResult{OK: false, Error: err.Error(), Conflicts: conflicts, Coverage: plan.Coverage}, err |
| 217 | } |
| 218 | |
| 219 | if plan.Scope == RewindCode || plan.Scope == RewindBoth { |
| 220 | if plan.WorkspaceToken != fmt.Sprintf("%d", s.barrier.Generation()) { |
| 221 | conflict := RewindConflict{Reason: ConflictStalePlan} |
| 222 | return RewindResult{OK: false, Error: "workspace changed since preview", Conflicts: []RewindConflict{conflict}, Coverage: plan.Coverage}, fmt.Errorf("workspace changed since preview") |
| 223 | } |
| 224 | conflicts := s.precheckFiles(plan.Turn) |
| 225 | if len(conflicts) > 0 { |
| 226 | return RewindResult{OK: false, Error: "file conflicts detected", Conflicts: conflicts, Coverage: plan.Coverage}, fmt.Errorf("file conflicts detected") |
| 227 | } |
| 228 | } |
| 229 | |
| 230 | tx, err := s.prepareTransaction(plan, applier) |
| 231 | if err != nil { |
| 232 | return RewindResult{OK: false, Error: err.Error()}, err |
| 233 | } |
| 234 | |
| 235 | result, err := s.commitTransaction(tx, applier, inject) |
| 236 | return result, err |
| 237 | } |
| 238 | |
| 239 | // UndoRewind reverses a committed transaction when still available. |
| 240 | func (s *Store) UndoRewind(transactionID string, applier ConversationApplier) (RewindResult, error) { |
| 241 | if s == nil { |
| 242 | return RewindResult{}, fmt.Errorf("checkpoints unavailable") |
| 243 | } |
| 244 | s.mu.Lock() |
| 245 | last := s.lastUndo |
| 246 | s.mu.Unlock() |
| 247 | if last == nil || last.ID != transactionID || last.State != TxCommitted { |
| 248 | return RewindResult{OK: false, Error: "undo not available"}, fmt.Errorf("undo not available for %q", transactionID) |
| 249 | } |
| 250 | |
| 251 | if !s.barrier.TryEnterExclusive() { |
| 252 | err := fmt.Errorf("workspace mutation in progress") |
| 253 | return RewindResult{OK: false, Error: err.Error(), Conflicts: []RewindConflict{{Reason: ConflictBusyWriter}}}, err |
| 254 | } |
| 255 | defer s.barrier.ExitExclusive() |
| 256 | if conflicts := s.activeWriterConflicts(); len(conflicts) > 0 { |
| 257 | err := fmt.Errorf("active background writer") |
| 258 | return RewindResult{OK: false, Error: err.Error(), Conflicts: conflicts}, err |
| 259 | } |
| 260 | |
| 261 | // Precheck that current disk still matches what we published (targets' restore state). |
| 262 | for _, t := range last.Targets { |
| 263 | fp, err := FingerprintPath(s.root, t.AbsPath) |
| 264 | if err != nil && !os.IsNotExist(err) { |
| 265 | return RewindResult{OK: false, Error: err.Error()}, fmt.Errorf("fingerprint %s before undo: %w", t.Path, err) |
| 266 | } |
| 267 | // After commit, disk should match restore image. If it doesn't, refuse. |
| 268 | if t.Action == "delete" { |
| 269 | if fp.Existed { |
| 270 | return RewindResult{OK: false, Error: "file changed since rewind", Conflicts: []RewindConflict{{ |
| 271 | Path: t.Path, Reason: ConflictManualEdit, CurrentSHA: fp.SHA256, |
| 272 | }}}, fmt.Errorf("file changed since rewind: %s", t.Path) |
| 273 | } |
| 274 | } else { |
| 275 | if !fingerprintMatches(fp, t.RestoreExisted, t.RestoreSHA, t.RestoreMode) { |
| 276 | restoreExisted := t.RestoreExisted |
| 277 | return RewindResult{OK: false, Error: "file changed since rewind", Conflicts: []RewindConflict{{ |
| 278 | Path: t.Path, Reason: CompareIdentity(fp, t.RestoreSHA, &restoreExisted, t.RestoreMode), |
| 279 | CurrentSHA: fp.SHA256, LastOwnedSHA: t.RestoreSHA, CurrentMode: fp.Mode, CheckpointMode: t.RestoreMode, |
| 280 | }}}, fmt.Errorf("file changed since rewind: %s", t.Path) |
| 281 | } |
| 282 | } |
| 283 | } |
| 284 | |
| 285 | // Build inverse transaction: restore forward images. |
| 286 | undo := &TransactionManifest{ |
| 287 | SchemaVersion: SchemaV2, |
| 288 | ID: newID("tx"), |
| 289 | SessionID: last.SessionID, |
| 290 | WorkspaceRoot: last.WorkspaceRoot, |
| 291 | State: TxPrepared, |
| 292 | Kind: "undo", |
| 293 | Turn: last.Turn, |
| 294 | Scope: last.Scope, |
| 295 | CreatedAt: time.Now(), |
| 296 | UpdatedAt: time.Now(), |
| 297 | SessionRevision: last.SessionRevision, |
| 298 | ParentTransaction: last.ID, |
| 299 | HasBoundary: last.HasBoundary, |
| 300 | BoundaryIndex: last.BoundaryIndex, |
| 301 | ConversationForward: last.ConversationForward, |
| 302 | CheckpointBackup: last.CheckpointBackup, |
| 303 | TruncateFrom: last.TruncateFrom, |
| 304 | } |
| 305 | for _, t := range last.Targets { |
| 306 | inv := TransactionTarget{ |
| 307 | Path: t.Path, |
| 308 | AbsPath: t.AbsPath, |
| 309 | RestoreExisted: t.ForwardExisted, |
| 310 | RestoreMode: t.ForwardMode, |
| 311 | RestoreSHA: t.ForwardSHA, |
| 312 | RestoreBlob: t.ForwardBlob, |
| 313 | RestoreInline: clonePayload(t.ForwardInline), |
| 314 | ForwardExisted: t.RestoreExisted, |
| 315 | ForwardMode: t.RestoreMode, |
| 316 | ForwardSHA: t.RestoreSHA, |
| 317 | ForwardBlob: t.RestoreBlob, |
| 318 | ForwardInline: clonePayload(t.RestoreInline), |
| 319 | } |
| 320 | if t.ForwardExisted { |
| 321 | inv.Action = "write" |
| 322 | } else { |
| 323 | inv.Action = "delete" |
| 324 | } |
| 325 | inv.PublishTmp, inv.BackupPath = transactionSiblingPaths(inv.AbsPath, undo.ID, len(undo.Targets)) |
| 326 | if inv.Action != "write" { |
| 327 | inv.PublishTmp = "" |
| 328 | } |
| 329 | undo.Targets = append(undo.Targets, inv) |
| 330 | } |
| 331 | if err := s.persistTransaction(undo); err != nil { |
| 332 | return RewindResult{OK: false, Error: err.Error()}, err |
| 333 | } |
| 334 | |
| 335 | // Stage publish temps for write targets. |
| 336 | for i := range undo.Targets { |
| 337 | t := &undo.Targets[i] |
| 338 | if t.Action != "write" { |
| 339 | continue |
| 340 | } |
| 341 | data, err := s.loadBlobOrInline(t.RestoreBlob, t.RestoreInline) |
| 342 | if err != nil { |
| 343 | s.cleanupPublishTemps(undo.Targets) |
| 344 | _ = s.abortTransaction(undo, err) |
| 345 | return RewindResult{OK: false, Error: err.Error()}, err |
| 346 | } |
| 347 | mode := os.FileMode(0o644) |
| 348 | if t.RestoreMode != 0 { |
| 349 | mode = os.FileMode(t.RestoreMode) |
| 350 | } |
| 351 | if err := s.writePublishTemp(t.PublishTmp, data, mode); err != nil { |
| 352 | s.cleanupPublishTemps(undo.Targets) |
| 353 | _ = s.abortTransaction(undo, err) |
| 354 | return RewindResult{OK: false, Error: err.Error()}, err |
| 355 | } |
| 356 | } |
| 357 | undo.State = TxPrepared |
| 358 | if err := s.persistTransaction(undo); err != nil { |
| 359 | err = s.failTransaction(undo, undo.Targets, nil, err) |
| 360 | return RewindResult{OK: false, Error: err.Error()}, err |
| 361 | } |
| 362 | |
| 363 | // For undo of conversation: restore forward conversation and checkpoints. |
| 364 | // Commit path for undo: publish files, then restore conversation/checkpoints. |
| 365 | result, err := s.commitUndoTransaction(undo, last, applier) |
| 366 | return result, err |
| 367 | } |
| 368 | |
| 369 | func (s *Store) commitUndoTransaction(undo, original *TransactionManifest, applier ConversationApplier) (RewindResult, error) { |
| 370 | undo.State = TxCommitting |
| 371 | undo.UpdatedAt = time.Now() |
| 372 | if err := s.persistTransaction(undo); err != nil { |
| 373 | err = s.failTransaction(undo, undo.Targets, nil, err) |
| 374 | return RewindResult{OK: false, Error: err.Error()}, err |
| 375 | } |
| 376 | |
| 377 | result := RewindResult{TransactionID: undo.ID, Coverage: CoverageComplete} |
| 378 | var stages []FileStage |
| 379 | |
| 380 | // Publish files (inverse). |
| 381 | for i := range undo.Targets { |
| 382 | t := &undo.Targets[i] |
| 383 | st := FileStage{Path: t.Path, Phase: "commit", Action: t.Action} |
| 384 | t.Published = true |
| 385 | undo.UpdatedAt = time.Now() |
| 386 | if err := s.persistTransaction(undo); err != nil { |
| 387 | t.Published = false |
| 388 | st.Error = err.Error() |
| 389 | stages = append(stages, st) |
| 390 | err = s.failTransaction(undo, undo.Targets, stages, err) |
| 391 | result.Error = err.Error() |
| 392 | result.Files = stages |
| 393 | return result, err |
| 394 | } |
| 395 | if err := s.publishTarget(t); err != nil { |
| 396 | st.Error = err.Error() |
| 397 | stages = append(stages, st) |
| 398 | err = s.failTransaction(undo, undo.Targets[:i+1], stages, err) |
| 399 | result.OK = false |
| 400 | result.Error = err.Error() |
| 401 | result.Files = stages |
| 402 | return result, err |
| 403 | } |
| 404 | undo.UpdatedAt = time.Now() |
| 405 | if err := s.persistTransaction(undo); err != nil { |
| 406 | st.Error = err.Error() |
| 407 | stages = append(stages, st) |
| 408 | err = s.failTransaction(undo, undo.Targets[:i+1], stages, err) |
| 409 | result.Error = err.Error() |
| 410 | result.Files = stages |
| 411 | return result, err |
| 412 | } |
| 413 | st.Phase = "done" |
| 414 | stages = append(stages, st) |
| 415 | if t.Action == "write" { |
| 416 | result.Written = append(result.Written, t.Path) |
| 417 | } else { |
| 418 | result.Deleted = append(result.Deleted, t.Path) |
| 419 | } |
| 420 | } |
| 421 | |
| 422 | // Restore conversation and checkpoints to pre-rewind state. |
| 423 | if applier != nil && len(original.ConversationForward) > 0 { |
| 424 | if err := applier.RestoreConversation(original.ConversationForward); err != nil { |
| 425 | restoreErr := s.restoreOriginalRewind(original, applier) |
| 426 | err = s.failTransactionAfterStateCompensation(undo, undo.Targets, stages, err, restoreErr) |
| 427 | result.OK = false |
| 428 | result.Error = err.Error() |
| 429 | result.Files = stages |
| 430 | return result, err |
| 431 | } |
| 432 | result.ConversationOK = true |
| 433 | } |
| 434 | if applier != nil && len(original.CheckpointBackup) > 0 { |
| 435 | if err := applier.RestoreCheckpoints(original.CheckpointBackup); err != nil { |
| 436 | // Return every side to the original rewind state before compensating |
| 437 | // the inverse file publish. Re-restoring the forward conversation here |
| 438 | // would leave conversation and files at opposite endpoints. |
| 439 | restoreErr := s.restoreOriginalRewind(original, applier) |
| 440 | err = s.failTransactionAfterStateCompensation(undo, undo.Targets, stages, err, restoreErr) |
| 441 | result.OK = false |
| 442 | result.Error = err.Error() |
| 443 | result.Files = stages |
| 444 | return result, err |
| 445 | } |
| 446 | } |
| 447 | |
| 448 | // Controller appliers restore this same store and then rebuild their boundary |
| 449 | // index. Only the store-only path needs a direct restore here. |
| 450 | if applier == nil && len(original.CheckpointBackup) > 0 { |
| 451 | if err := s.restoreCheckpointBackup(original.CheckpointBackup); err != nil { |
| 452 | err = s.failTransactionAfterStateCompensation(undo, undo.Targets, stages, err, nil) |
| 453 | result.OK = false |
| 454 | result.Error = err.Error() |
| 455 | result.Files = stages |
| 456 | return result, err |
| 457 | } |
| 458 | } |
| 459 | |
| 460 | undo.State = TxCommitted |
| 461 | undo.UpdatedAt = time.Now() |
| 462 | if err := s.persistTransaction(undo); err != nil { |
| 463 | restoreErr := s.restoreOriginalRewind(original, applier) |
| 464 | err = s.failTransactionAfterStateCompensation(undo, undo.Targets, stages, err, restoreErr) |
| 465 | result.OK = false |
| 466 | result.Error = err.Error() |
| 467 | result.Files = stages |
| 468 | return result, err |
| 469 | } |
| 470 | |
| 471 | // Mark original as undone; clear lastUndo. |
| 472 | original.State = TxUndone |
| 473 | original.UpdatedAt = time.Now() |
| 474 | if err := s.persistTransaction(original); err != nil { |
| 475 | // The committed undo manifest durably names its parent, so startup will |
| 476 | // suppress the stale parent even if this secondary write failed. |
| 477 | slog.Warn("checkpoint: persist original transaction as undone", "err", err) |
| 478 | } |
| 479 | s.mu.Lock() |
| 480 | s.lastUndo = nil |
| 481 | s.mu.Unlock() |
| 482 | |
| 483 | result.OK = true |
| 484 | result.UndoAvailable = false |
| 485 | result.Files = stages |
| 486 | return result, nil |
| 487 | } |
| 488 | |
| 489 | func (s *Store) restoreOriginalRewind(original *TransactionManifest, applier ConversationApplier) error { |
| 490 | if original == nil || applier == nil { |
| 491 | return nil |
| 492 | } |
| 493 | if original.Scope != RewindConversation && original.Scope != RewindBoth { |
| 494 | return nil |
| 495 | } |
| 496 | var err error |
| 497 | if original.HasBoundary { |
| 498 | err = errors.Join(err, applier.ApplyConversationTruncate(original.BoundaryIndex, original.ConversationForward)) |
| 499 | } |
| 500 | err = errors.Join(err, applier.TruncateCheckpoints(original.TruncateFrom)) |
| 501 | return err |
| 502 | } |
| 503 | |
| 504 | func (s *Store) prepareTransaction(plan RewindPlan, applier ConversationApplier) (*TransactionManifest, error) { |
| 505 | tx := newRewindTransaction(s.root, plan) |
| 506 | prepared := false |
| 507 | defer func() { |
| 508 | if !prepared { |
| 509 | s.cleanupPublishTemps(tx.Targets) |
| 510 | } |
| 511 | }() |
| 512 | |
| 513 | if plan.Scope == RewindCode || plan.Scope == RewindBoth { |
| 514 | earliest := s.earliestRevisions(plan.Turn) |
| 515 | // Stable order for deterministic inject tests. |
| 516 | paths := make([]string, 0, len(earliest)) |
| 517 | for p := range earliest { |
| 518 | paths = append(paths, p) |
| 519 | } |
| 520 | sort.Strings(paths) |
| 521 | for targetIndex, p := range paths { |
| 522 | rev := earliest[p] |
| 523 | abs, err := safePath(s.root, p) |
| 524 | if err != nil { |
| 525 | return nil, err |
| 526 | } |
| 527 | // Capture forward image. |
| 528 | fwd, gap, err := CapturePath(abs, CaptureOptions{WorkspaceRoot: s.root, ReadContent: true}) |
| 529 | if err != nil && gap != nil { |
| 530 | return nil, fmt.Errorf("capture forward %s: %w", p, err) |
| 531 | } |
| 532 | t := TransactionTarget{ |
| 533 | Path: p, |
| 534 | AbsPath: abs, |
| 535 | RestoreExisted: rev.Existed, |
| 536 | RestoreMode: rev.Mode, |
| 537 | RestoreSHA: rev.SHA256, |
| 538 | RestoreBlob: rev.BlobRef, |
| 539 | RestoreEncoding: rev.Encoding, |
| 540 | ForwardExisted: fwd.Existed, |
| 541 | ForwardMode: fwd.Mode, |
| 542 | ForwardSHA: fwd.SHA256, |
| 543 | } |
| 544 | if rev.Existed { |
| 545 | t.Action = "write" |
| 546 | if t.RestoreBlob == "" && rev.Content == nil { |
| 547 | return nil, fmt.Errorf("missing restore payload for %s", p) |
| 548 | } |
| 549 | // Stage publish temp. Blobs hold raw on-disk bytes; inline |
| 550 | // Content is decoded text and must be re-encoded. Legacy v1 |
| 551 | // snapshots often omit Encoding — fall back to the current |
| 552 | // file's encoding (same as the pre-v2 RestoreCode path). |
| 553 | var data []byte |
| 554 | if rev.BlobRef != "" { |
| 555 | var lerr error |
| 556 | data, lerr = s.loadRevisionBytes(rev) |
| 557 | if lerr != nil { |
| 558 | return nil, lerr |
| 559 | } |
| 560 | } else if rev.Content != nil { |
| 561 | var eerr error |
| 562 | if data, eerr = s.encodeRevisionContent(rev, abs); eerr != nil { |
| 563 | return nil, eerr |
| 564 | } |
| 565 | } else { |
| 566 | return nil, fmt.Errorf("missing restore payload for %s", p) |
| 567 | } |
| 568 | mode := os.FileMode(0o644) |
| 569 | if rev.Mode != 0 { |
| 570 | mode = os.FileMode(rev.Mode) |
| 571 | } |
| 572 | if t.RestoreBlob == "" && s.blobs != nil { |
| 573 | ref, err := s.blobs.Put(data) |
| 574 | if err != nil { |
| 575 | return nil, err |
| 576 | } |
| 577 | t.RestoreBlob = ref |
| 578 | } else if t.RestoreBlob == "" { |
| 579 | t.RestoreInline = clonePayload(data) |
| 580 | } |
| 581 | t.PublishTmp, t.BackupPath = transactionSiblingPaths(abs, tx.ID, targetIndex) |
| 582 | if err := s.writePublishTemp(t.PublishTmp, data, mode); err != nil { |
| 583 | return nil, err |
| 584 | } |
| 585 | } else { |
| 586 | t.Action = "delete" |
| 587 | _, t.BackupPath = transactionSiblingPaths(abs, tx.ID, targetIndex) |
| 588 | } |
| 589 | if fwd.Existed && s.blobs != nil { |
| 590 | ref, err := s.blobs.Put(fwd.Content) |
| 591 | if err != nil { |
| 592 | if t.PublishTmp != "" { |
| 593 | _ = secureRemove(s.root, t.PublishTmp) |
| 594 | } |
| 595 | return nil, err |
| 596 | } |
| 597 | t.ForwardBlob = ref |
| 598 | } else if fwd.Existed { |
| 599 | t.ForwardInline = clonePayload(fwd.Content) |
| 600 | } |
| 601 | // Backup existing file for delete path (move later at commit). |
| 602 | tx.Targets = append(tx.Targets, t) |
| 603 | } |
| 604 | } |
| 605 | |
| 606 | if shouldTruncateConversation(tx) && applier != nil { |
| 607 | // Backup future checkpoints for undo. |
| 608 | backup, err := s.backupCheckpointsFrom(plan.Turn) |
| 609 | if err != nil { |
| 610 | return nil, err |
| 611 | } |
| 612 | tx.CheckpointBackup = backup |
| 613 | } |
| 614 | |
| 615 | if err := s.persistTransaction(tx); err != nil { |
| 616 | return nil, err |
| 617 | } |
| 618 | prepared = true |
| 619 | return tx, nil |
| 620 | } |
| 621 | |
| 622 | func transactionSiblingPaths(absPath, transactionID string, index int) (publish, backup string) { |
| 623 | dir := filepath.Dir(absPath) |
| 624 | base := filepath.Base(absPath) |
| 625 | prefix := fmt.Sprintf(".%s.reasonix-%s-%d", base, transactionID, index) |
| 626 | return filepath.Join(dir, prefix+".tmp"), filepath.Join(dir, prefix+".bak") |
| 627 | } |
| 628 | |
| 629 | func (s *Store) writePublishTemp(path string, data []byte, mode os.FileMode) error { |
| 630 | if err := secureWriteNew(s.root, path, data, mode); err != nil { |
| 631 | return fmt.Errorf("create publish temp: %w", err) |
| 632 | } |
| 633 | return nil |
| 634 | } |
| 635 | |
| 636 | func (s *Store) cleanupPublishTemps(targets []TransactionTarget) { |
| 637 | for _, target := range targets { |
| 638 | if target.PublishTmp != "" { |
| 639 | _ = secureRemove(s.root, target.PublishTmp) |
| 640 | } |
| 641 | } |
| 642 | } |
| 643 | |
| 644 | func (s *Store) commitTransaction(tx *TransactionManifest, applier ConversationApplier, inject *InjectFail) (RewindResult, error) { |
| 645 | tx.State = TxCommitting |
| 646 | tx.UpdatedAt = time.Now() |
| 647 | if err := s.persistTransaction(tx); err != nil { |
| 648 | err = s.failTransaction(tx, tx.Targets, nil, err) |
| 649 | return RewindResult{OK: false, Error: err.Error()}, err |
| 650 | } |
| 651 | |
| 652 | result := RewindResult{TransactionID: tx.ID, Coverage: tx.Coverage, CoverageGaps: append([]CoverageGap(nil), tx.CoverageGaps...)} |
| 653 | stages := make([]FileStage, 0, len(tx.Targets)) |
| 654 | filesDone := 0 |
| 655 | |
| 656 | for i := range tx.Targets { |
| 657 | t := &tx.Targets[i] |
| 658 | st := FileStage{Path: t.Path, Phase: "commit", Action: t.Action} |
| 659 | phase := "publish_file" |
| 660 | if t.Action == "delete" { |
| 661 | phase = "delete_file" |
| 662 | } |
| 663 | if inject != nil && inject.Phase == phase && filesDone >= inject.AfterFiles { |
| 664 | err := fmt.Errorf("injected failure at %s after %d files", inject.Phase, inject.AfterFiles) |
| 665 | st.Error = err.Error() |
| 666 | stages = append(stages, st) |
| 667 | err = s.failTransaction(tx, tx.Targets[:i], stages, err) |
| 668 | result.OK = false |
| 669 | result.Error = err.Error() |
| 670 | result.Files = stages |
| 671 | return result, err |
| 672 | } |
| 673 | // Persist a conservative "may have published" intent before the first |
| 674 | // filesystem rename. Recovery can safely compensate even if the crash |
| 675 | // happened just before publish. |
| 676 | t.Published = true |
| 677 | tx.UpdatedAt = time.Now() |
| 678 | if err := s.persistTransaction(tx); err != nil { |
| 679 | t.Published = false |
| 680 | st.Error = err.Error() |
| 681 | stages = append(stages, st) |
| 682 | err = s.failTransaction(tx, tx.Targets, stages, err) |
| 683 | result.Error = err.Error() |
| 684 | result.Files = stages |
| 685 | return result, err |
| 686 | } |
| 687 | if err := s.publishTarget(t); err != nil { |
| 688 | st.Error = err.Error() |
| 689 | stages = append(stages, st) |
| 690 | err = s.failTransaction(tx, tx.Targets[:i+1], stages, err) |
| 691 | result.OK = false |
| 692 | result.Error = err.Error() |
| 693 | result.Files = stages |
| 694 | return result, err |
| 695 | } |
| 696 | if inject != nil && inject.Phase == "after_publish_before_progress" && filesDone >= inject.AfterFiles { |
| 697 | // Deliberately leave the durable state as committing to simulate a |
| 698 | // process crash at the narrowest progress-persistence window. |
| 699 | err := fmt.Errorf("injected crash after publish before progress") |
| 700 | result.Error = err.Error() |
| 701 | result.Files = append(stages, st) |
| 702 | return result, err |
| 703 | } |
| 704 | tx.UpdatedAt = time.Now() |
| 705 | if err := s.persistTransaction(tx); err != nil { |
| 706 | st.Error = err.Error() |
| 707 | stages = append(stages, st) |
| 708 | err = s.failTransaction(tx, tx.Targets[:i+1], stages, err) |
| 709 | result.Error = err.Error() |
| 710 | result.Files = stages |
| 711 | return result, err |
| 712 | } |
| 713 | st.Phase = "done" |
| 714 | stages = append(stages, st) |
| 715 | filesDone++ |
| 716 | if t.Action == "write" { |
| 717 | result.Written = append(result.Written, t.Path) |
| 718 | } else { |
| 719 | result.Deleted = append(result.Deleted, t.Path) |
| 720 | } |
| 721 | } |
| 722 | if err := s.persistTransaction(tx); err != nil { |
| 723 | err = s.failTransaction(tx, tx.Targets, stages, err) |
| 724 | result.Error = err.Error() |
| 725 | result.Files = stages |
| 726 | return result, err |
| 727 | } |
| 728 | |
| 729 | if shouldTruncateConversation(tx) { |
| 730 | if inject != nil && inject.Phase == "conversation" { |
| 731 | err := fmt.Errorf("injected failure at conversation") |
| 732 | err = s.failTransaction(tx, tx.Targets, stages, err) |
| 733 | result.OK = false |
| 734 | result.Error = err.Error() |
| 735 | result.Files = stages |
| 736 | return result, err |
| 737 | } |
| 738 | if applier != nil && tx.HasBoundary { |
| 739 | if err := applier.ApplyConversationTruncate(tx.BoundaryIndex, tx.ConversationForward); err != nil { |
| 740 | restoreErr := s.restoreTransactionConversation(tx, applier) |
| 741 | err = s.failTransactionAfterStateCompensation(tx, tx.Targets, stages, err, restoreErr) |
| 742 | result.OK = false |
| 743 | result.Error = err.Error() |
| 744 | result.Files = stages |
| 745 | return result, err |
| 746 | } |
| 747 | result.ConversationOK = true |
| 748 | } |
| 749 | if inject != nil && inject.Phase == "truncate" { |
| 750 | err := fmt.Errorf("injected failure at truncate") |
| 751 | restoreErr := s.restoreTransactionConversation(tx, applier) |
| 752 | err = s.failTransactionAfterStateCompensation(tx, tx.Targets, stages, err, restoreErr) |
| 753 | result.OK = false |
| 754 | result.Error = err.Error() |
| 755 | result.Files = stages |
| 756 | return result, err |
| 757 | } |
| 758 | if applier != nil { |
| 759 | if err := applier.TruncateCheckpoints(tx.TruncateFrom); err != nil { |
| 760 | restoreErr := s.restoreTransactionConversation(tx, applier) |
| 761 | err = s.failTransactionAfterStateCompensation(tx, tx.Targets, stages, err, restoreErr) |
| 762 | result.OK = false |
| 763 | result.Error = err.Error() |
| 764 | result.Files = stages |
| 765 | return result, err |
| 766 | } |
| 767 | } else if err := s.TruncateFrom(tx.TruncateFrom); err != nil { |
| 768 | restoreErr := s.restoreTransactionConversation(tx, applier) |
| 769 | err = s.failTransactionAfterStateCompensation(tx, tx.Targets, stages, err, restoreErr) |
| 770 | result.OK = false |
| 771 | result.Error = err.Error() |
| 772 | result.Files = stages |
| 773 | return result, err |
| 774 | } |
| 775 | } |
| 776 | |
| 777 | if inject != nil && inject.Phase == "finalize" { |
| 778 | err := fmt.Errorf("injected failure at finalize") |
| 779 | restoreErr := s.restoreTransactionConversation(tx, applier) |
| 780 | err = s.failTransactionAfterStateCompensation(tx, tx.Targets, stages, err, restoreErr) |
| 781 | result.OK = false |
| 782 | result.Error = err.Error() |
| 783 | result.Files = stages |
| 784 | return result, err |
| 785 | } |
| 786 | if inject != nil && inject.Phase == "after_conversation_before_finalize" { |
| 787 | // Simulate process death after both conversation mutations are durable but |
| 788 | // before the transaction can be marked committed. Startup must restore the |
| 789 | // forward transcript/checkpoints before compensating files. |
| 790 | err := fmt.Errorf("injected crash after conversation before finalize") |
| 791 | result.Error = err.Error() |
| 792 | result.Files = stages |
| 793 | return result, err |
| 794 | } |
| 795 | |
| 796 | tx.State = TxCommitted |
| 797 | tx.UpdatedAt = time.Now() |
| 798 | if err := s.persistTransaction(tx); err != nil { |
| 799 | restoreErr := s.restoreTransactionConversation(tx, applier) |
| 800 | err = s.failTransactionAfterStateCompensation(tx, tx.Targets, stages, err, restoreErr) |
| 801 | result.OK = false |
| 802 | result.Error = err.Error() |
| 803 | result.Files = stages |
| 804 | return result, err |
| 805 | } |
| 806 | s.mu.Lock() |
| 807 | s.lastUndo = tx |
| 808 | s.mu.Unlock() |
| 809 | |
| 810 | result.OK = true |
| 811 | result.UndoAvailable = true |
| 812 | result.Files = stages |
| 813 | return result, nil |
| 814 | } |
| 815 | |
| 816 | func (s *Store) restoreTransactionConversation(tx *TransactionManifest, applier ConversationApplier) error { |
| 817 | if tx == nil { |
| 818 | return nil |
| 819 | } |
| 820 | var restoreErr error |
| 821 | if applier != nil { |
| 822 | if len(tx.ConversationForward) > 0 { |
| 823 | restoreErr = errors.Join(restoreErr, applier.RestoreConversation(tx.ConversationForward)) |
| 824 | } |
| 825 | if len(tx.CheckpointBackup) > 0 { |
| 826 | restoreErr = errors.Join(restoreErr, applier.RestoreCheckpoints(tx.CheckpointBackup)) |
| 827 | } |
| 828 | } else if len(tx.CheckpointBackup) > 0 { |
| 829 | restoreErr = errors.Join(restoreErr, s.restoreCheckpointBackup(tx.CheckpointBackup)) |
| 830 | } |
| 831 | return restoreErr |
| 832 | } |
| 833 | |
| 834 | // SetConversationForward attaches the pre-truncate conversation snapshot to a |
| 835 | // prepared transaction before commit. The controller calls this after Prepare. |
| 836 | func (s *Store) SetConversationForward(txID string, forward []byte) error { |
| 837 | path := s.txManifestPath(txID) |
| 838 | var tx TransactionManifest |
| 839 | if err := readJSONFile(path, &tx); err != nil { |
| 840 | // Also check in-memory last prepare path: store plans don't hold tx yet. |
| 841 | // Commit builds tx fresh; controller should pass forward via Commit options. |
| 842 | return err |
| 843 | } |
| 844 | setTransactionConversationForward(&tx, forward) |
| 845 | tx.UpdatedAt = time.Now() |
| 846 | return s.persistTransaction(&tx) |
| 847 | } |
| 848 | |
| 849 | // CommitRewindWithForward is CommitRewind plus conversation forward payload. |
| 850 | func (s *Store) CommitRewindWithForward(planID string, forward []byte, applier ConversationApplier, inject *InjectFail) (RewindResult, error) { |
| 851 | if s == nil { |
| 852 | return RewindResult{}, fmt.Errorf("checkpoints unavailable") |
| 853 | } |
| 854 | s.mu.Lock() |
| 855 | pp, ok := s.plans[planID] |
| 856 | if ok { |
| 857 | delete(s.plans, planID) |
| 858 | } |
| 859 | s.mu.Unlock() |
| 860 | if !ok { |
| 861 | return RewindResult{OK: false, Error: "unknown or expired plan"}, fmt.Errorf("unknown or expired plan %q", planID) |
| 862 | } |
| 863 | plan := pp.plan |
| 864 | |
| 865 | if plan.Scope == RewindBoth && (!plan.CanFiles || !plan.CanConversation) { |
| 866 | return RewindResult{OK: false, Error: plan.DisabledReason, Conflicts: plan.Conflicts}, fmt.Errorf("%s", plan.DisabledReason) |
| 867 | } |
| 868 | if plan.Scope == RewindCode && !plan.CanFiles { |
| 869 | return RewindResult{OK: false, Error: plan.DisabledReason, Conflicts: plan.Conflicts}, fmt.Errorf("%s", plan.DisabledReason) |
| 870 | } |
| 871 | if (plan.Scope == RewindConversation || plan.Scope == RewindBoth) && !plan.CanConversation { |
| 872 | return RewindResult{OK: false, Error: plan.DisabledReason}, fmt.Errorf("%s", plan.DisabledReason) |
| 873 | } |
| 874 | |
| 875 | if !s.barrier.TryEnterExclusive() { |
| 876 | err := fmt.Errorf("workspace mutation in progress") |
| 877 | return RewindResult{OK: false, Error: err.Error(), Conflicts: []RewindConflict{{Reason: ConflictBusyWriter}}}, err |
| 878 | } |
| 879 | defer s.barrier.ExitExclusive() |
| 880 | if conflicts := s.activeWriterConflicts(); len(conflicts) > 0 { |
| 881 | err := fmt.Errorf("active background writer") |
| 882 | return RewindResult{OK: false, Error: err.Error(), Conflicts: conflicts, Coverage: plan.Coverage}, err |
| 883 | } |
| 884 | |
| 885 | if plan.Scope == RewindCode || plan.Scope == RewindBoth { |
| 886 | if plan.WorkspaceToken != fmt.Sprintf("%d", s.barrier.Generation()) { |
| 887 | conflict := RewindConflict{Reason: ConflictStalePlan} |
| 888 | return RewindResult{OK: false, Error: "workspace changed since preview", Conflicts: []RewindConflict{conflict}, Coverage: plan.Coverage}, fmt.Errorf("workspace changed since preview") |
| 889 | } |
| 890 | if conflicts := s.precheckFiles(plan.Turn); len(conflicts) > 0 { |
| 891 | return RewindResult{OK: false, Error: "file conflicts detected", Conflicts: conflicts}, fmt.Errorf("file conflicts detected") |
| 892 | } |
| 893 | } |
| 894 | |
| 895 | tx, err := s.prepareTransaction(plan, applier) |
| 896 | if err != nil { |
| 897 | return RewindResult{OK: false, Error: err.Error()}, err |
| 898 | } |
| 899 | setTransactionConversationForward(tx, forward) |
| 900 | if err := s.persistTransaction(tx); err != nil { |
| 901 | return RewindResult{OK: false, Error: err.Error()}, err |
| 902 | } |
| 903 | return s.commitTransaction(tx, applier, inject) |
| 904 | } |
| 905 | |
| 906 | func (s *Store) publishTarget(t *TransactionTarget) error { |
| 907 | if t.BackupPath == "" { |
| 908 | return fmt.Errorf("missing transaction backup path for %s", t.Path) |
| 909 | } |
| 910 | backupExists, err := securePathExists(s.root, t.BackupPath) |
| 911 | if err != nil { |
| 912 | return err |
| 913 | } |
| 914 | if backupExists { |
| 915 | return fmt.Errorf("transaction backup already exists for %s", t.Path) |
| 916 | } |
| 917 | targetExists, err := securePathExists(s.root, t.AbsPath) |
| 918 | if err != nil { |
| 919 | return err |
| 920 | } |
| 921 | if targetExists { |
| 922 | if err := secureRename(s.root, t.AbsPath, t.BackupPath); err != nil { |
| 923 | return fmt.Errorf("backup %s: %w", t.Path, err) |
| 924 | } |
| 925 | } |
| 926 | if t.Action == "delete" { |
| 927 | return nil |
| 928 | } |
| 929 | if t.PublishTmp == "" { |
| 930 | return fmt.Errorf("missing publish tmp for %s", t.Path) |
| 931 | } |
| 932 | if err := secureRename(s.root, t.PublishTmp, t.AbsPath); err != nil { |
| 933 | restoreErr := error(nil) |
| 934 | if exists, statErr := securePathExists(s.root, t.BackupPath); statErr == nil && exists { |
| 935 | restoreErr = secureRename(s.root, t.BackupPath, t.AbsPath) |
| 936 | } |
| 937 | return errors.Join(fmt.Errorf("publish %s: %w", t.Path, err), restoreErr) |
| 938 | } |
| 939 | if t.RestoreMode != 0 { |
| 940 | if err := secureChmod(s.root, t.AbsPath, os.FileMode(t.RestoreMode)); err != nil { |
| 941 | return fmt.Errorf("chmod restored %s: %w", t.Path, err) |
| 942 | } |
| 943 | } |
| 944 | return nil |
| 945 | } |
| 946 | |
| 947 | func (s *Store) compensatePublished(targets []TransactionTarget, stages []FileStage) error { |
| 948 | var first error |
| 949 | for _, v := range slices.Backward(targets) { |
| 950 | t := v |
| 951 | if !t.Published { |
| 952 | if t.PublishTmp != "" { |
| 953 | _ = secureRemove(s.root, t.PublishTmp) |
| 954 | } |
| 955 | continue |
| 956 | } |
| 957 | // Published is a durable intent. If the target still exactly matches its |
| 958 | // forward image, the crash happened before publish and compensation is a |
| 959 | // no-op. Any other unrelated state is preserved with a recovery copy. |
| 960 | var err error |
| 961 | cur, fpErr := FingerprintPath(s.root, t.AbsPath) |
| 962 | if fpErr != nil { |
| 963 | markCompensationStage(stages, t.Path, fpErr) |
| 964 | if first == nil { |
| 965 | first = fpErr |
| 966 | } |
| 967 | continue |
| 968 | } else if fingerprintMatches(cur, t.ForwardExisted, t.ForwardSHA, t.ForwardMode) { |
| 969 | if t.PublishTmp != "" { |
| 970 | _ = secureRemove(s.root, t.PublishTmp) |
| 971 | } |
| 972 | markCompensationStage(stages, t.Path, nil) |
| 973 | continue |
| 974 | } |
| 975 | // Crash window: publishTarget durably records Published before moving the |
| 976 | // target to its backup. A process death after that first rename leaves the |
| 977 | // target absent, the forward image in BackupPath, and (for writes) the |
| 978 | // publish temp still present. Recognize that owned intermediate state before |
| 979 | // classifying the absent target as an external modification. |
| 980 | if t.ForwardExisted && !cur.Existed && t.BackupPath != "" { |
| 981 | backup, backupErr := FingerprintPath(s.root, t.BackupPath) |
| 982 | publishPending := t.Action == "delete" |
| 983 | if t.Action == "write" && t.PublishTmp != "" { |
| 984 | publishPending, _ = securePathExists(s.root, t.PublishTmp) |
| 985 | } |
| 986 | if backupErr == nil && publishPending && fingerprintMatches(backup, true, t.ForwardSHA, t.ForwardMode) { |
| 987 | err = secureRename(s.root, t.BackupPath, t.AbsPath) |
| 988 | if err == nil && t.PublishTmp != "" { |
| 989 | if removeErr := secureRemove(s.root, t.PublishTmp); removeErr != nil && !os.IsNotExist(removeErr) { |
| 990 | err = removeErr |
| 991 | } |
| 992 | } |
| 993 | markCompensationStage(stages, t.Path, err) |
| 994 | if err != nil && first == nil { |
| 995 | first = err |
| 996 | } |
| 997 | continue |
| 998 | } |
| 999 | } |
| 1000 | if t.ForwardExisted { |
| 1001 | data, lerr := s.loadBlobOrInline(t.ForwardBlob, t.ForwardInline) |
| 1002 | if lerr != nil && t.BackupPath != "" { |
| 1003 | data, lerr = secureReadFile(s.root, t.BackupPath) |
| 1004 | } |
| 1005 | if !fingerprintMatches(cur, t.RestoreExisted, t.RestoreSHA, t.RestoreMode) { |
| 1006 | if lerr == nil { |
| 1007 | suffix := t.RestoreSHA |
| 1008 | if len(suffix) > 8 { |
| 1009 | suffix = suffix[:8] |
| 1010 | } |
| 1011 | if suffix == "" { |
| 1012 | suffix = "unknown" |
| 1013 | } |
| 1014 | recov := t.AbsPath + ".reasonix-recovery-" + suffix |
| 1015 | _ = secureWriteNew(s.root, recov, data, os.FileMode(t.ForwardMode)) |
| 1016 | err = fmt.Errorf("external modification after publish; recovery copy at %s", recov) |
| 1017 | } else { |
| 1018 | err = lerr |
| 1019 | } |
| 1020 | } else if backupExists, backupErr := securePathExists(s.root, t.BackupPath); backupErr == nil && backupExists { |
| 1021 | if cur.Existed { |
| 1022 | err = secureRemove(s.root, t.AbsPath) |
| 1023 | } |
| 1024 | if err == nil { |
| 1025 | err = secureRename(s.root, t.BackupPath, t.AbsPath) |
| 1026 | } |
| 1027 | } else if lerr != nil { |
| 1028 | err = lerr |
| 1029 | } else { |
| 1030 | mode := os.FileMode(0o644) |
| 1031 | if t.ForwardMode != 0 { |
| 1032 | mode = os.FileMode(t.ForwardMode) |
| 1033 | } |
| 1034 | if cur.Existed { |
| 1035 | if werr := secureRemove(s.root, t.AbsPath); werr != nil { |
| 1036 | err = werr |
| 1037 | } |
| 1038 | } |
| 1039 | tmp, _ := transactionSiblingPaths(t.AbsPath, newID("compensate"), 0) |
| 1040 | if werr := s.writePublishTemp(tmp, data, mode); werr != nil { |
| 1041 | err = werr |
| 1042 | } else if err == nil { |
| 1043 | if werr := secureRename(s.root, tmp, t.AbsPath); werr != nil { |
| 1044 | err = werr |
| 1045 | } |
| 1046 | } |
| 1047 | } |
| 1048 | } else { |
| 1049 | // Forward did not exist — remove what we published. |
| 1050 | if !fingerprintMatches(cur, t.RestoreExisted, t.RestoreSHA, t.RestoreMode) { |
| 1051 | // External rewrite of a file we restored then someone changed — |
| 1052 | // for compensate of delete action inverse: leave it. |
| 1053 | err = fmt.Errorf("external modification; not removing %s", t.AbsPath) |
| 1054 | } else { |
| 1055 | err = secureRemove(s.root, t.AbsPath) |
| 1056 | if os.IsNotExist(err) { |
| 1057 | err = nil |
| 1058 | } |
| 1059 | } |
| 1060 | } |
| 1061 | markCompensationStage(stages, t.Path, err) |
| 1062 | if err != nil && first == nil { |
| 1063 | first = err |
| 1064 | } |
| 1065 | } |
| 1066 | return first |
| 1067 | } |
| 1068 | |
| 1069 | func fingerprintMatches(fp Fingerprint, existed bool, sha string, mode uint32) bool { |
| 1070 | if fp.Existed != existed { |
| 1071 | return false |
| 1072 | } |
| 1073 | if !existed { |
| 1074 | return true |
| 1075 | } |
| 1076 | if sha != "" && fp.SHA256 != sha { |
| 1077 | return false |
| 1078 | } |
| 1079 | return mode == 0 || fp.Mode == 0 || fp.Mode == mode |
| 1080 | } |
| 1081 | |
| 1082 | func markCompensationStage(stages []FileStage, path string, err error) { |
| 1083 | for i := range stages { |
| 1084 | if stages[i].Path != path { |
| 1085 | continue |
| 1086 | } |
| 1087 | stages[i].Compensated = err == nil |
| 1088 | if err != nil { |
| 1089 | stages[i].CompError = err.Error() |
| 1090 | } |
| 1091 | } |
| 1092 | } |
| 1093 | |
| 1094 | func (s *Store) failTransaction(tx *TransactionManifest, targets []TransactionTarget, stages []FileStage, cause error) error { |
| 1095 | return s.failTransactionAfterStateCompensation(tx, targets, stages, cause, nil) |
| 1096 | } |
| 1097 | |
| 1098 | // failTransactionAfterStateCompensation compensates files and records whether |
| 1099 | // the conversation/checkpoint side was also restored. Any incomplete side keeps |
| 1100 | // the manifest committing so startup can retry the whole compensation. |
| 1101 | func (s *Store) failTransactionAfterStateCompensation(tx *TransactionManifest, targets []TransactionTarget, stages []FileStage, cause, stateCompensationErr error) error { |
| 1102 | if tx != nil { |
| 1103 | targets = tx.Targets |
| 1104 | } |
| 1105 | compensationErr := s.compensatePublished(targets, stages) |
| 1106 | combined := errors.Join(cause, stateCompensationErr) |
| 1107 | if compensationErr != nil { |
| 1108 | combined = errors.Join(combined, fmt.Errorf("compensation failed: %w", compensationErr)) |
| 1109 | } |
| 1110 | if compensationErr != nil || stateCompensationErr != nil { |
| 1111 | // Do not make a failed compensation terminal. Startup recovery retries |
| 1112 | // committing manifests; marking this aborted would strand a half-applied |
| 1113 | // workspace permanently. |
| 1114 | tx.State = TxCommitting |
| 1115 | tx.Error = combined.Error() |
| 1116 | tx.UpdatedAt = time.Now() |
| 1117 | if persistErr := s.persistTransaction(tx); persistErr != nil { |
| 1118 | combined = errors.Join(combined, fmt.Errorf("persist pending compensation: %w", persistErr)) |
| 1119 | } |
| 1120 | return combined |
| 1121 | } |
| 1122 | if abortErr := s.abortTransaction(tx, combined); abortErr != nil { |
| 1123 | combined = errors.Join(combined, fmt.Errorf("persist aborted transaction: %w", abortErr)) |
| 1124 | } |
| 1125 | return combined |
| 1126 | } |
| 1127 | |
| 1128 | func (s *Store) abortTransaction(tx *TransactionManifest, cause error) error { |
| 1129 | tx.State = TxAborted |
| 1130 | tx.Error = cause.Error() |
| 1131 | tx.UpdatedAt = time.Now() |
| 1132 | return s.persistTransaction(tx) |
| 1133 | } |
| 1134 | |
| 1135 | func (s *Store) persistTransaction(tx *TransactionManifest) error { |
| 1136 | if s.dir == "" { |
| 1137 | return nil |
| 1138 | } |
| 1139 | return writeJSONAtomic(s.txManifestPath(tx.ID), tx) |
| 1140 | } |
| 1141 | |
| 1142 | func (s *Store) txDir() string { |
| 1143 | if s.dir == "" { |
| 1144 | return filepath.Join(os.TempDir(), "reasonix-ckpt-tx") |
| 1145 | } |
| 1146 | return filepath.Join(s.dir, "transactions") |
| 1147 | } |
| 1148 | |
| 1149 | func (s *Store) txManifestPath(id string) string { |
| 1150 | return filepath.Join(s.txDir(), id+".json") |
| 1151 | } |
| 1152 | |
| 1153 | // RecoverTransactions scans for incomplete file-only transactions. Conversation |
| 1154 | // transactions are intentionally deferred until the controller has installed the |
| 1155 | // resumed session and can provide a ConversationApplier. |
| 1156 | func (s *Store) RecoverTransactions() []string { |
| 1157 | return s.recoverTransactions(nil) |
| 1158 | } |
| 1159 | |
| 1160 | // RecoverTransactionsWithApplier finishes startup recovery after the resumed |
| 1161 | // conversation is live. A committing rewind first restores its forward |
| 1162 | // transcript/checkpoints, then compensates files; a committing undo first |
| 1163 | // reapplies its parent rewind, then compensates files. The manifest remains |
| 1164 | // committing if either side fails so a later startup can retry idempotently. |
| 1165 | func (s *Store) RecoverTransactionsWithApplier(applier ConversationApplier) []string { |
| 1166 | return s.recoverTransactions(applier) |
| 1167 | } |
| 1168 | |
| 1169 | func (s *Store) recoverTransactions(applier ConversationApplier) []string { |
| 1170 | if s == nil || s.dir == "" { |
| 1171 | return nil |
| 1172 | } |
| 1173 | dir := s.txDir() |
| 1174 | ents, err := os.ReadDir(dir) |
| 1175 | if err != nil { |
| 1176 | return nil |
| 1177 | } |
| 1178 | undoneParents := map[string]bool{} |
| 1179 | for _, entry := range ents { |
| 1180 | if entry.IsDir() || !strings.HasSuffix(entry.Name(), ".json") { |
| 1181 | continue |
| 1182 | } |
| 1183 | var tx TransactionManifest |
| 1184 | if readJSONFile(filepath.Join(dir, entry.Name()), &tx) == nil && tx.State == TxCommitted && tx.Kind == "undo" && tx.ParentTransaction != "" { |
| 1185 | undoneParents[tx.ParentTransaction] = true |
| 1186 | } |
| 1187 | } |
| 1188 | var notes []string |
| 1189 | for _, e := range ents { |
| 1190 | if e.IsDir() || !strings.HasSuffix(e.Name(), ".json") { |
| 1191 | continue |
| 1192 | } |
| 1193 | var tx TransactionManifest |
| 1194 | if err := readJSONFile(filepath.Join(dir, e.Name()), &tx); err != nil { |
| 1195 | continue |
| 1196 | } |
| 1197 | switch tx.State { |
| 1198 | case TxPrepared: |
| 1199 | // Never published — safe to discard. |
| 1200 | for _, target := range tx.Targets { |
| 1201 | if target.PublishTmp != "" { |
| 1202 | _ = secureRemove(s.root, target.PublishTmp) |
| 1203 | } |
| 1204 | } |
| 1205 | tx.State = TxAborted |
| 1206 | tx.Error = "abandoned prepared transaction on recovery" |
| 1207 | tx.UpdatedAt = time.Now() |
| 1208 | _ = s.persistTransaction(&tx) |
| 1209 | notes = append(notes, fmt.Sprintf("aborted prepared %s", tx.ID)) |
| 1210 | case TxCommitting: |
| 1211 | needsConversation := tx.Scope == RewindConversation || tx.Scope == RewindBoth |
| 1212 | if needsConversation && applier == nil { |
| 1213 | notes = append(notes, fmt.Sprintf("deferred conversation recovery %s", tx.ID)) |
| 1214 | continue |
| 1215 | } |
| 1216 | if needsConversation { |
| 1217 | var restoreErr error |
| 1218 | if tx.Kind != "undo" && tx.HasBoundary && len(tx.ConversationForward) == 0 { |
| 1219 | restoreErr = fmt.Errorf("missing forward conversation payload") |
| 1220 | } else if tx.Kind == "undo" { |
| 1221 | if tx.HasBoundary { |
| 1222 | restoreErr = errors.Join(restoreErr, applier.ApplyConversationTruncate(tx.BoundaryIndex, tx.ConversationForward)) |
| 1223 | } |
| 1224 | restoreErr = errors.Join(restoreErr, applier.TruncateCheckpoints(tx.TruncateFrom)) |
| 1225 | } else { |
| 1226 | restoreErr = s.restoreTransactionConversation(&tx, applier) |
| 1227 | } |
| 1228 | if restoreErr != nil { |
| 1229 | notes = append(notes, fmt.Sprintf("conversation recovery %s pending: %v", tx.ID, restoreErr)) |
| 1230 | tx.Error = fmt.Sprintf("crash recovery conversation compensation pending: %v", restoreErr) |
| 1231 | tx.UpdatedAt = time.Now() |
| 1232 | _ = s.persistTransaction(&tx) |
| 1233 | continue |
| 1234 | } |
| 1235 | } |
| 1236 | // Compensate published files back to forward images. |
| 1237 | stages := make([]FileStage, len(tx.Targets)) |
| 1238 | for i, t := range tx.Targets { |
| 1239 | stages[i] = FileStage{Path: t.Path, Phase: "compensate"} |
| 1240 | } |
| 1241 | if err := s.compensatePublished(tx.Targets, stages); err != nil { |
| 1242 | notes = append(notes, fmt.Sprintf("compensate %s: %v", tx.ID, err)) |
| 1243 | tx.Error = fmt.Sprintf("crash recovery compensation pending: %v", err) |
| 1244 | tx.UpdatedAt = time.Now() |
| 1245 | _ = s.persistTransaction(&tx) |
| 1246 | } else { |
| 1247 | notes = append(notes, fmt.Sprintf("compensated committing %s", tx.ID)) |
| 1248 | tx.State = TxAborted |
| 1249 | tx.Error = "compensated after crash during commit" |
| 1250 | tx.UpdatedAt = time.Now() |
| 1251 | _ = s.persistTransaction(&tx) |
| 1252 | } |
| 1253 | case TxCommitted: |
| 1254 | if tx.Kind == "undo" || undoneParents[tx.ID] { |
| 1255 | continue |
| 1256 | } |
| 1257 | // Keep as last undo if newer. |
| 1258 | s.mu.Lock() |
| 1259 | if s.lastUndo == nil || s.lastUndo.UpdatedAt.Before(tx.UpdatedAt) { |
| 1260 | cp := tx |
| 1261 | s.lastUndo = &cp |
| 1262 | } |
| 1263 | s.mu.Unlock() |
| 1264 | } |
| 1265 | } |
| 1266 | return notes |
| 1267 | } |
| 1268 | |
| 1269 | func (s *Store) precheckFiles(fromTurn int) []RewindConflict { |
| 1270 | earliest := s.earliestRevisions(fromTurn) |
| 1271 | var conflicts []RewindConflict |
| 1272 | for p, rev := range earliest { |
| 1273 | abs, err := safePath(s.root, p) |
| 1274 | if err != nil { |
| 1275 | conflicts = append(conflicts, RewindConflict{Path: p, Reason: ConflictPathUnsafe}) |
| 1276 | continue |
| 1277 | } |
| 1278 | if rev.BlobRef == "" && rev.Content == nil && rev.Existed { |
| 1279 | if rev.SHA256 != "" && s.blobs != nil && !s.blobs.Has(rev.SHA256) && (rev.BlobRef == "" || !s.blobs.Has(rev.BlobRef)) { |
| 1280 | conflicts = append(conflicts, RewindConflict{Path: p, Reason: ConflictMissingPayload, CheckpointSHA: rev.SHA256}) |
| 1281 | continue |
| 1282 | } |
| 1283 | if rev.Content == nil && rev.BlobRef == "" { |
| 1284 | conflicts = append(conflicts, RewindConflict{Path: p, Reason: ConflictMissingPayload}) |
| 1285 | continue |
| 1286 | } |
| 1287 | } |
| 1288 | fp, err := FingerprintPath(s.root, abs) |
| 1289 | if err != nil { |
| 1290 | // unreadable etc. |
| 1291 | conflicts = append(conflicts, RewindConflict{Path: p, Reason: ConflictExternalChange, CheckpointSHA: rev.SHA256}) |
| 1292 | continue |
| 1293 | } |
| 1294 | if MatchesRestoreImage(fp, rev.SHA256, rev.Existed) { |
| 1295 | continue |
| 1296 | } |
| 1297 | // Prefer after fingerprint for conflict detection. |
| 1298 | reason := CompareIdentity(fp, rev.AfterSHA256, rev.AfterExisted, rev.AfterMode) |
| 1299 | if reason == ConflictCoverageLegacy { |
| 1300 | // Legacy handled at plan level; skip per-file for batch. |
| 1301 | continue |
| 1302 | } |
| 1303 | if reason != "" { |
| 1304 | conflicts = append(conflicts, RewindConflict{ |
| 1305 | Path: p, |
| 1306 | Reason: reason, |
| 1307 | CheckpointSHA: rev.SHA256, |
| 1308 | LastOwnedSHA: rev.AfterSHA256, |
| 1309 | CurrentSHA: fp.SHA256, |
| 1310 | CheckpointMode: rev.Mode, |
| 1311 | CurrentMode: fp.Mode, |
| 1312 | CurrentExisted: fp.Existed, |
| 1313 | CheckpointExist: rev.Existed, |
| 1314 | }) |
| 1315 | } |
| 1316 | } |
| 1317 | sort.Slice(conflicts, func(i, j int) bool { return conflicts[i].Path < conflicts[j].Path }) |
| 1318 | return conflicts |
| 1319 | } |
| 1320 | |
| 1321 | func (s *Store) earliestRevisions(fromTurn int) map[string]FileRevision { |
| 1322 | s.mu.Lock() |
| 1323 | defer s.mu.Unlock() |
| 1324 | return s.earliestRevisionsLocked(fromTurn) |
| 1325 | } |
| 1326 | |
| 1327 | func (s *Store) earliestRevisionsLocked(fromTurn int) map[string]FileRevision { |
| 1328 | earliest := map[string]FileRevision{} |
| 1329 | for _, c := range s.all() { |
| 1330 | if c.Turn < fromTurn { |
| 1331 | continue |
| 1332 | } |
| 1333 | for _, rev := range c.revisions() { |
| 1334 | pathKey := NormalizeRelPath(s.root, rev.Path) |
| 1335 | if first, ok := earliest[pathKey]; ok { |
| 1336 | // Preserve the earliest preimage, but carry forward the final |
| 1337 | // mutation's ownership identity. Missing final identity deliberately |
| 1338 | // clears an older proof instead of authorizing an unsafe restore. |
| 1339 | first.AfterExisted = rev.AfterExisted |
| 1340 | first.AfterSHA256 = rev.AfterSHA256 |
| 1341 | first.AfterMode = rev.AfterMode |
| 1342 | earliest[pathKey] = first |
| 1343 | continue |
| 1344 | } |
| 1345 | rev.Path = pathKey |
| 1346 | earliest[pathKey] = rev |
| 1347 | } |
| 1348 | } |
| 1349 | return earliest |
| 1350 | } |
| 1351 | |
| 1352 | func (s *Store) filesFromTurnLocked(fromTurn int) []string { |
| 1353 | seen := map[string]bool{} |
| 1354 | var out []string |
| 1355 | for _, c := range s.all() { |
| 1356 | if c.Turn < fromTurn { |
| 1357 | continue |
| 1358 | } |
| 1359 | for _, rev := range c.revisions() { |
| 1360 | pathKey := NormalizeRelPath(s.root, rev.Path) |
| 1361 | if seen[pathKey] { |
| 1362 | continue |
| 1363 | } |
| 1364 | seen[pathKey] = true |
| 1365 | out = append(out, pathKey) |
| 1366 | } |
| 1367 | } |
| 1368 | sort.Strings(out) |
| 1369 | return out |
| 1370 | } |
| 1371 | |
| 1372 | func (s *Store) coverageFromTurnLocked(fromTurn int) (Coverage, []CoverageGap, bool, bool) { |
| 1373 | var gaps []CoverageGap |
| 1374 | legacy := false |
| 1375 | expired := false |
| 1376 | hasFiles := false |
| 1377 | partial := false |
| 1378 | for _, c := range s.all() { |
| 1379 | if c.Turn < fromTurn { |
| 1380 | continue |
| 1381 | } |
| 1382 | if c.SchemaVersion < SchemaV2 && c.SchemaVersion != 0 { |
| 1383 | legacy = true |
| 1384 | } |
| 1385 | if c.SchemaVersion == 0 { |
| 1386 | // v1 had no schemaVersion field |
| 1387 | legacy = true |
| 1388 | } |
| 1389 | if c.Coverage == CoverageLegacy || c.Legacy { |
| 1390 | legacy = true |
| 1391 | } |
| 1392 | if c.ExpiredFilePayload { |
| 1393 | expired = true |
| 1394 | } |
| 1395 | if c.Coverage == CoveragePartial { |
| 1396 | partial = true |
| 1397 | } |
| 1398 | gaps = append(gaps, c.CoverageGaps...) |
| 1399 | if len(c.revisions()) > 0 { |
| 1400 | hasFiles = true |
| 1401 | } |
| 1402 | } |
| 1403 | if legacy { |
| 1404 | return CoverageLegacy, append(gaps, CoverageGap{Reason: GapLegacyUnverified}), true, expired |
| 1405 | } |
| 1406 | if expired { |
| 1407 | return CoveragePartial, append(gaps, CoverageGap{Reason: GapExpiredPayload}), false, true |
| 1408 | } |
| 1409 | if !hasFiles { |
| 1410 | if len(gaps) > 0 { |
| 1411 | return CoverageNone, gaps, false, false |
| 1412 | } |
| 1413 | return CoverageNone, nil, false, false |
| 1414 | } |
| 1415 | if partial || len(gaps) > 0 { |
| 1416 | return CoveragePartial, gaps, false, false |
| 1417 | } |
| 1418 | return CoverageComplete, nil, false, false |
| 1419 | } |
| 1420 | |
| 1421 | func (s *Store) loadRevisionBytes(rev FileRevision) ([]byte, error) { |
| 1422 | if rev.BlobRef != "" && s.blobs != nil { |
| 1423 | return s.blobs.Get(rev.BlobRef) |
| 1424 | } |
| 1425 | if rev.Content != nil { |
| 1426 | return []byte(*rev.Content), nil |
| 1427 | } |
| 1428 | if rev.SHA256 != "" && s.blobs != nil && s.blobs.Has(rev.SHA256) { |
| 1429 | return s.blobs.Get(rev.SHA256) |
| 1430 | } |
| 1431 | return nil, fmt.Errorf("missing payload for %s", rev.Path) |
| 1432 | } |
| 1433 | |
| 1434 | func (s *Store) loadBlobOrInline(ref string, inline []byte) ([]byte, error) { |
| 1435 | if ref != "" && s.blobs != nil { |
| 1436 | return s.blobs.Get(ref) |
| 1437 | } |
| 1438 | if inline != nil { |
| 1439 | return inline, nil |
| 1440 | } |
| 1441 | return nil, fmt.Errorf("missing blob %q", ref) |
| 1442 | } |
| 1443 | |
| 1444 | func (s *Store) backupCheckpointsFrom(fromTurn int) ([]byte, error) { |
| 1445 | s.mu.Lock() |
| 1446 | defer s.mu.Unlock() |
| 1447 | var future []*Checkpoint |
| 1448 | for _, c := range s.all() { |
| 1449 | if c.Turn >= fromTurn { |
| 1450 | cp := *c |
| 1451 | future = append(future, &cp) |
| 1452 | } |
| 1453 | } |
| 1454 | return json.Marshal(future) |
| 1455 | } |
| 1456 | |
| 1457 | func (s *Store) restoreCheckpointBackup(backup []byte) error { |
| 1458 | var future []*Checkpoint |
| 1459 | if err := json.Unmarshal(backup, &future); err != nil { |
| 1460 | return err |
| 1461 | } |
| 1462 | s.mu.Lock() |
| 1463 | defer s.mu.Unlock() |
| 1464 | // Merge future checkpoints back (by turn). |
| 1465 | byTurn := map[int]*Checkpoint{} |
| 1466 | for _, c := range s.done { |
| 1467 | byTurn[c.Turn] = c |
| 1468 | } |
| 1469 | if s.cur != nil { |
| 1470 | byTurn[s.cur.Turn] = s.cur |
| 1471 | } |
| 1472 | for _, c := range future { |
| 1473 | byTurn[c.Turn] = c |
| 1474 | if err := s.persist(c); err != nil { |
| 1475 | return fmt.Errorf("persist restored checkpoint turn %d: %w", c.Turn, err) |
| 1476 | } |
| 1477 | counterpart := filepath.Join(s.expiredDir(), fmt.Sprintf("turn-%d.json", c.Turn)) |
| 1478 | if c.ExpiredFilePayload { |
| 1479 | counterpart = filepath.Join(s.dir, fmt.Sprintf("turn-%d.json", c.Turn)) |
| 1480 | } |
| 1481 | if err := os.Remove(counterpart); err != nil && !os.IsNotExist(err) { |
| 1482 | return fmt.Errorf("remove stale checkpoint counterpart turn %d: %w", c.Turn, err) |
| 1483 | } |
| 1484 | } |
| 1485 | // Rebuild done/cur: highest turn as cur if it was cur; else all in done. |
| 1486 | turns := make([]int, 0, len(byTurn)) |
| 1487 | for t := range byTurn { |
| 1488 | turns = append(turns, t) |
| 1489 | } |
| 1490 | sort.Ints(turns) |
| 1491 | s.done = nil |
| 1492 | s.cur = nil |
| 1493 | for _, t := range turns { |
| 1494 | s.done = append(s.done, byTurn[t]) |
| 1495 | } |
| 1496 | return nil |
| 1497 | } |
| 1498 | |
| 1499 | func newID(prefix string) string { |
| 1500 | return fmt.Sprintf("%s-%d-%s", prefix, time.Now().UnixNano(), Digest(fmt.Appendf(nil, "%d", time.Now().UnixNano()))[:8]) |
| 1501 | } |
| 1502 | |
| 1503 | // RestoreCheckpointBackupPublic reloads backed-up checkpoints after an undo. |
| 1504 | func (s *Store) RestoreCheckpointBackupPublic(backup []byte) error { |
| 1505 | return s.restoreCheckpointBackup(backup) |
| 1506 | } |
| 1507 | |
| 1508 | // PrepareFileRevert prepares a single-file restore to the earliest session preimage. |
| 1509 | func (s *Store) PrepareFileRevert(path string, sessionRev int64) (RewindPlan, error) { |
| 1510 | if s == nil { |
| 1511 | return RewindPlan{}, fmt.Errorf("checkpoints unavailable") |
| 1512 | } |
| 1513 | plan := RewindPlan{ |
| 1514 | PlanID: newID("plan"), |
| 1515 | Scope: RewindCode, |
| 1516 | Path: path, |
| 1517 | SessionRevision: sessionRev, |
| 1518 | CreatedAt: time.Now(), |
| 1519 | WorkspaceToken: fmt.Sprintf("%d", s.barrier.Generation()), |
| 1520 | Files: []string{path}, |
| 1521 | FileCount: 1, |
| 1522 | } |
| 1523 | state, ok := s.FileState(path) |
| 1524 | if !ok { |
| 1525 | plan.CanFiles = false |
| 1526 | plan.DisabledReason = "file is not session-owned" |
| 1527 | return plan, nil |
| 1528 | } |
| 1529 | _ = state |
| 1530 | abs, err := safePath(s.root, path) |
| 1531 | if err != nil { |
| 1532 | plan.CanFiles = false |
| 1533 | plan.DisabledReason = "path unsafe" |
| 1534 | plan.Conflicts = []RewindConflict{{Path: path, Reason: ConflictPathUnsafe}} |
| 1535 | return plan, nil |
| 1536 | } |
| 1537 | revs := s.earliestRevisions(0) |
| 1538 | rev, has := revs[path] |
| 1539 | if !has { |
| 1540 | for p, r := range revs { |
| 1541 | if ap, e := safePath(s.root, p); e == nil && ap == abs { |
| 1542 | rev, has = r, true |
| 1543 | plan.Path = p |
| 1544 | break |
| 1545 | } |
| 1546 | } |
| 1547 | } |
| 1548 | if !has { |
| 1549 | plan.CanFiles = false |
| 1550 | plan.DisabledReason = "file is not session-owned" |
| 1551 | return plan, nil |
| 1552 | } |
| 1553 | if rev.AfterExisted == nil && rev.AfterSHA256 == "" { |
| 1554 | // A v1 or incomplete capture has a preimage but no evidence that the |
| 1555 | // current file is still the session's last write. Do not turn the |
| 1556 | // generic conflict-overwrite affordance into an unsafe legacy restore. |
| 1557 | plan.PlanID = "" |
| 1558 | plan.CanFiles = false |
| 1559 | plan.Legacy = true |
| 1560 | plan.Coverage = CoverageLegacy |
| 1561 | plan.DisabledReason = "legacy checkpoint cannot verify later manual edits" |
| 1562 | return plan, nil |
| 1563 | } |
| 1564 | fp, fperr := FingerprintPath(s.root, abs) |
| 1565 | if fperr == nil { |
| 1566 | reason := CompareIdentity(fp, rev.AfterSHA256, rev.AfterExisted, rev.AfterMode) |
| 1567 | if reason != "" { |
| 1568 | plan.Conflicts = []RewindConflict{{ |
| 1569 | Path: path, Reason: reason, |
| 1570 | CheckpointSHA: rev.SHA256, LastOwnedSHA: rev.AfterSHA256, CurrentSHA: fp.SHA256, |
| 1571 | CurrentExisted: fp.Existed, CheckpointExist: rev.Existed, |
| 1572 | }} |
| 1573 | plan.CanFiles = true |
| 1574 | plan.DisabledReason = "conflict requires explicit resolution" |
| 1575 | } else { |
| 1576 | plan.CanFiles = true |
| 1577 | } |
| 1578 | } else { |
| 1579 | plan.CanFiles = false |
| 1580 | plan.DisabledReason = "current file identity unavailable" |
| 1581 | plan.Conflicts = []RewindConflict{{Path: path, Reason: ConflictExternalChange}} |
| 1582 | } |
| 1583 | if rev.BlobRef == "" && rev.Content == nil && rev.Existed { |
| 1584 | plan.CanFiles = false |
| 1585 | plan.DisabledReason = "missing file payload" |
| 1586 | plan.Conflicts = append(plan.Conflicts, RewindConflict{Path: path, Reason: ConflictMissingPayload}) |
| 1587 | } |
| 1588 | s.mu.Lock() |
| 1589 | if s.plans == nil { |
| 1590 | s.plans = map[string]preparedPlan{} |
| 1591 | } |
| 1592 | s.plans[plan.PlanID] = preparedPlan{plan: plan, created: time.Now(), previewFingerprint: &fp} |
| 1593 | s.mu.Unlock() |
| 1594 | return plan, nil |
| 1595 | } |
| 1596 | |
| 1597 | // CommitFileRevert commits a single-file restore. |
| 1598 | func (s *Store) CommitFileRevert(planID string, resolution ConflictResolution) (RewindResult, error) { |
| 1599 | if s == nil { |
| 1600 | return RewindResult{}, fmt.Errorf("checkpoints unavailable") |
| 1601 | } |
| 1602 | s.mu.Lock() |
| 1603 | pp, ok := s.plans[planID] |
| 1604 | if ok { |
| 1605 | delete(s.plans, planID) |
| 1606 | } |
| 1607 | s.mu.Unlock() |
| 1608 | if !ok { |
| 1609 | return RewindResult{OK: false, Error: "unknown or expired plan"}, fmt.Errorf("unknown or expired plan") |
| 1610 | } |
| 1611 | plan := pp.plan |
| 1612 | if plan.Path == "" { |
| 1613 | return RewindResult{OK: false, Error: "not a file plan"}, fmt.Errorf("not a file plan") |
| 1614 | } |
| 1615 | if !plan.CanFiles { |
| 1616 | return RewindResult{OK: false, Error: plan.DisabledReason, Conflicts: plan.Conflicts}, fmt.Errorf("%s", plan.DisabledReason) |
| 1617 | } |
| 1618 | if len(plan.Conflicts) > 0 && resolution != ResolveOverwriteCheckpoint { |
| 1619 | if resolution == ResolveKeepCurrent { |
| 1620 | return RewindResult{OK: true, UndoAvailable: false}, nil |
| 1621 | } |
| 1622 | return RewindResult{OK: false, Error: "conflict requires explicit resolution", Conflicts: plan.Conflicts}, fmt.Errorf("conflict requires explicit resolution") |
| 1623 | } |
| 1624 | if !s.barrier.TryEnterExclusive() { |
| 1625 | err := fmt.Errorf("workspace mutation in progress") |
| 1626 | return RewindResult{OK: false, Error: err.Error(), Conflicts: []RewindConflict{{Path: plan.Path, Reason: ConflictBusyWriter}}}, err |
| 1627 | } |
| 1628 | defer s.barrier.ExitExclusive() |
| 1629 | if conflicts := s.activeWriterConflicts(); len(conflicts) > 0 { |
| 1630 | err := fmt.Errorf("active background writer") |
| 1631 | return RewindResult{OK: false, Error: err.Error(), Conflicts: conflicts}, err |
| 1632 | } |
| 1633 | if plan.WorkspaceToken != fmt.Sprintf("%d", s.barrier.Generation()) { |
| 1634 | conflict := RewindConflict{Path: plan.Path, Reason: ConflictStalePlan} |
| 1635 | return RewindResult{OK: false, Error: "workspace changed since preview", Conflicts: []RewindConflict{conflict}}, fmt.Errorf("workspace changed since preview") |
| 1636 | } |
| 1637 | absPreview, err := safePath(s.root, plan.Path) |
| 1638 | if err != nil { |
| 1639 | return RewindResult{OK: false, Error: err.Error()}, err |
| 1640 | } |
| 1641 | current, err := FingerprintPath(s.root, absPreview) |
| 1642 | if err != nil || pp.previewFingerprint == nil || !sameFingerprint(current, *pp.previewFingerprint) { |
| 1643 | conflict := RewindConflict{Path: plan.Path, Reason: ConflictStalePlan, CurrentSHA: current.SHA256, CurrentExisted: current.Existed} |
| 1644 | return RewindResult{OK: false, Error: "file changed since preview; preview again", Conflicts: []RewindConflict{conflict}}, fmt.Errorf("file changed since preview; preview again") |
| 1645 | } |
| 1646 | |
| 1647 | // Restore via restoreCodeLegacy for the single earliest path using turn 0. |
| 1648 | // Build synthetic order of one path. |
| 1649 | revs := s.earliestRevisions(0) |
| 1650 | rev, has := revs[plan.Path] |
| 1651 | if !has { |
| 1652 | abs, _ := safePath(s.root, plan.Path) |
| 1653 | for p, r := range revs { |
| 1654 | if ap, e := safePath(s.root, p); e == nil && ap == abs { |
| 1655 | rev, has = r, true |
| 1656 | plan.Path = p |
| 1657 | break |
| 1658 | } |
| 1659 | } |
| 1660 | } |
| 1661 | if !has { |
| 1662 | return RewindResult{OK: false, Error: "file is not session-owned"}, fmt.Errorf("file is not session-owned") |
| 1663 | } |
| 1664 | |
| 1665 | // Find which turn first touched this path for RestoreCode semantics: |
| 1666 | // restoring one file = write earliest preimage (not all files from a turn). |
| 1667 | abs, err := safePath(s.root, rev.Path) |
| 1668 | if err != nil { |
| 1669 | return RewindResult{OK: false, Error: err.Error()}, err |
| 1670 | } |
| 1671 | fwd, _, _ := CapturePath(abs, CaptureOptions{WorkspaceRoot: s.root, ReadContent: true}) |
| 1672 | tx := &TransactionManifest{ |
| 1673 | SchemaVersion: SchemaV2, |
| 1674 | ID: newID("tx"), |
| 1675 | WorkspaceRoot: s.root, |
| 1676 | State: TxPrepared, |
| 1677 | Kind: "file_revert", |
| 1678 | Scope: RewindCode, |
| 1679 | Path: rev.Path, |
| 1680 | CreatedAt: time.Now(), |
| 1681 | UpdatedAt: time.Now(), |
| 1682 | } |
| 1683 | t := TransactionTarget{ |
| 1684 | Path: rev.Path, AbsPath: abs, |
| 1685 | RestoreExisted: rev.Existed, RestoreMode: rev.Mode, RestoreSHA: rev.SHA256, RestoreBlob: rev.BlobRef, RestoreEncoding: rev.Encoding, |
| 1686 | ForwardExisted: fwd.Existed, ForwardMode: fwd.Mode, ForwardSHA: fwd.SHA256, |
| 1687 | } |
| 1688 | t.PublishTmp, t.BackupPath = transactionSiblingPaths(abs, tx.ID, 0) |
| 1689 | if rev.Existed { |
| 1690 | t.Action = "write" |
| 1691 | data, lerr := s.loadRevisionBytes(rev) |
| 1692 | if lerr != nil && rev.Content != nil { |
| 1693 | data, lerr = s.encodeRevisionContent(rev, abs) |
| 1694 | } |
| 1695 | if lerr != nil { |
| 1696 | return RewindResult{OK: false, Error: lerr.Error()}, lerr |
| 1697 | } |
| 1698 | mode := os.FileMode(0o644) |
| 1699 | if rev.Mode != 0 { |
| 1700 | mode = os.FileMode(rev.Mode) |
| 1701 | } |
| 1702 | if t.RestoreBlob == "" && s.blobs != nil { |
| 1703 | ref, perr := s.blobs.Put(data) |
| 1704 | if perr != nil { |
| 1705 | return RewindResult{OK: false, Error: perr.Error()}, perr |
| 1706 | } |
| 1707 | t.RestoreBlob = ref |
| 1708 | } else if t.RestoreBlob == "" { |
| 1709 | t.RestoreInline = clonePayload(data) |
| 1710 | } |
| 1711 | if err := s.writePublishTemp(t.PublishTmp, data, mode); err != nil { |
| 1712 | return RewindResult{OK: false, Error: err.Error()}, err |
| 1713 | } |
| 1714 | } else { |
| 1715 | t.Action = "delete" |
| 1716 | t.PublishTmp = "" |
| 1717 | } |
| 1718 | if fwd.Existed && s.blobs != nil { |
| 1719 | ref, perr := s.blobs.Put(fwd.Content) |
| 1720 | if perr != nil { |
| 1721 | return RewindResult{OK: false, Error: perr.Error()}, perr |
| 1722 | } |
| 1723 | t.ForwardBlob = ref |
| 1724 | } else if fwd.Existed { |
| 1725 | t.ForwardInline = clonePayload(fwd.Content) |
| 1726 | } |
| 1727 | tx.Targets = []TransactionTarget{t} |
| 1728 | if err := s.persistTransaction(tx); err != nil { |
| 1729 | return RewindResult{OK: false, Error: err.Error()}, err |
| 1730 | } |
| 1731 | return s.commitTransaction(tx, nil, nil) |
| 1732 | } |
| 1733 | |
| 1734 | func sameFingerprint(a, b Fingerprint) bool { |
| 1735 | return a.Existed == b.Existed && a.IsDir == b.IsDir && a.IsSymlink == b.IsSymlink && |
| 1736 | a.Nlink == b.Nlink && a.Mode == b.Mode && a.Size == b.Size && a.SHA256 == b.SHA256 |
| 1737 | } |
| 1738 | |
| 1739 | func clonePayload(data []byte) []byte { |
| 1740 | out := make([]byte, len(data)) |
| 1741 | copy(out, data) |
| 1742 | return out |
| 1743 | } |
| 1744 |