| 1 | package session |
| 2 | |
| 3 | import ( |
| 4 | "context" |
| 5 | "encoding/json" |
| 6 | "errors" |
| 7 | "fmt" |
| 8 | "os" |
| 9 | "path/filepath" |
| 10 | "sort" |
| 11 | "strings" |
| 12 | "sync" |
| 13 | "time" |
| 14 | ) |
| 15 | |
| 16 | // VisitCommits streams the complete durable commit prefix from one canonical |
| 17 | // session directory. It is intended for exports and diagnostics that must not |
| 18 | // materialize the cumulative event log. |
| 19 | func VisitCommits(ctx context.Context, dir string, visit func(Commit) error) error { |
| 20 | if err := ctx.Err(); err != nil { |
| 21 | return err |
| 22 | } |
| 23 | manifest, err := readStoredManifest(filepath.Join(dir, "manifest.json")) |
| 24 | if err != nil { |
| 25 | return err |
| 26 | } |
| 27 | file, err := os.Open(logPathForManifest(dir, manifest)) |
| 28 | if os.IsNotExist(err) { |
| 29 | return nil |
| 30 | } |
| 31 | if err != nil { |
| 32 | return err |
| 33 | } |
| 34 | defer file.Close() |
| 35 | var visitErr error |
| 36 | adapter := func(_ int64, commit Commit) bool { |
| 37 | if visit != nil { |
| 38 | visitErr = visit(commit) |
| 39 | } |
| 40 | return visitErr == nil |
| 41 | } |
| 42 | if manifest.Codec == Codec { |
| 43 | err = scanV4CommitFile(ctx, file, 0, 1, contentStoreForSessionDir(dir), nil, adapter) |
| 44 | } else { |
| 45 | err = scanCommitFileCodec(file, 0, 1, manifest.Codec, nil, adapter) |
| 46 | } |
| 47 | return errors.Join(err, visitErr) |
| 48 | } |
| 49 | |
| 50 | // AccessMode separates cold readers from the single leased writer. Read-only |
| 51 | // access never repairs, migrates, truncates, or advances writer generation. |
| 52 | type AccessMode string |
| 53 | |
| 54 | const ( |
| 55 | ReadOnly AccessMode = "read" |
| 56 | ReadWrite AccessMode = "write" |
| 57 | ) |
| 58 | |
| 59 | type CreateOptions struct { |
| 60 | SessionID string |
| 61 | CWD string |
| 62 | ParentSessionID string |
| 63 | Origin SessionOrigin |
| 64 | } |
| 65 | |
| 66 | type SessionInfo struct { |
| 67 | SessionID string |
| 68 | Ref SessionRef |
| 69 | Codec string |
| 70 | Title string |
| 71 | TitleSequence uint64 |
| 72 | ModelRef string |
| 73 | ModelIdentity string |
| 74 | Turns int |
| 75 | CreatedAt time.Time |
| 76 | UpdatedAt time.Time |
| 77 | EventSequence uint64 |
| 78 | ResultSequence uint64 |
| 79 | Preview string |
| 80 | MetadataStatus string |
| 81 | CWD string |
| 82 | ParentSessionID string |
| 83 | Origin SessionOrigin |
| 84 | Path string |
| 85 | Error string |
| 86 | } |
| 87 | |
| 88 | type SessionPage struct { |
| 89 | Sessions []SessionInfo |
| 90 | NextCursor string |
| 91 | } |
| 92 | |
| 93 | type EventPage struct { |
| 94 | Commits []Commit |
| 95 | Next uint64 |
| 96 | Truncated bool |
| 97 | } |
| 98 | |
| 99 | // eventPageReader is the paged durable read surface shared by the physical |
| 100 | // handle and a cold Session, so catalog rebuilds never depend on replaying a |
| 101 | // whole in-memory log. |
| 102 | type eventPageReader interface { |
| 103 | Read(context.Context, uint64, int) (EventPage, error) |
| 104 | } |
| 105 | |
| 106 | // SessionHandle is the physical persistence contract. It reads and writes |
| 107 | // bytes for one session identity and owns the writer lease; it holds no |
| 108 | // projection, operation table, or accepted commit list. |
| 109 | type SessionHandle interface { |
| 110 | ID() string |
| 111 | Manifest() Manifest |
| 112 | Read(context.Context, uint64, int) (EventPage, error) |
| 113 | Append(context.Context, []Commit) error |
| 114 | Sync(context.Context) (DurableReceipt, error) |
| 115 | Close(context.Context) error |
| 116 | } |
| 117 | |
| 118 | // WritableSessionHandle is the leased physical handle. Byte-level maintenance |
| 119 | // operations such as fork, export, and interrupted-turn recovery are Session |
| 120 | // operations because they read or extend the in-memory log; this contract only |
| 121 | // distinguishes a leased writer from a cold reader. |
| 122 | type WritableSessionHandle interface { |
| 123 | SessionHandle |
| 124 | SessionID() string |
| 125 | } |
| 126 | |
| 127 | type SessionPersistence interface { |
| 128 | Create(CreateOptions) (*Session, error) |
| 129 | Open(sessionID string, mode AccessMode) (*Session, error) |
| 130 | Stat(context.Context, string) (SessionInfo, error) |
| 131 | List(context.Context, string, int) (SessionPage, error) |
| 132 | } |
| 133 | |
| 134 | // FilesystemPersistence owns a versioned sessions-v4 root. |
| 135 | type FilesystemPersistence struct{ Root string } |
| 136 | |
| 137 | func NewFilesystemPersistence(root string) *FilesystemPersistence { |
| 138 | return &FilesystemPersistence{Root: filepath.Clean(root)} |
| 139 | } |
| 140 | |
| 141 | // RootForLegacyDir maps a host's legacy transcript catalog to the sibling |
| 142 | // final-format store. The mapping lives in the persistence package so Boot and |
| 143 | // controllers never derive a v3 identity from a transcript path. |
| 144 | func RootForLegacyDir(sessionDir string) string { |
| 145 | dir := filepath.Clean(strings.TrimSpace(sessionDir)) |
| 146 | if dir == "." || dir == "" { |
| 147 | return "" |
| 148 | } |
| 149 | if filepath.Base(dir) == "sessions" { |
| 150 | return filepath.Join(filepath.Dir(dir), "sessions-v4") |
| 151 | } |
| 152 | return filepath.Join(dir, "sessions-v4") |
| 153 | } |
| 154 | |
| 155 | func (p *FilesystemPersistence) Create(options CreateOptions) (*Session, error) { |
| 156 | id := strings.TrimSpace(options.SessionID) |
| 157 | if id == "" { |
| 158 | id = randomID() |
| 159 | } |
| 160 | if err := validateSessionID(id); err != nil { |
| 161 | return nil, err |
| 162 | } |
| 163 | dir, err := p.sessionDir(id, false) |
| 164 | if err != nil { |
| 165 | return nil, err |
| 166 | } |
| 167 | options.SessionID = id |
| 168 | header, err := headerForCreate(options) |
| 169 | if err != nil { |
| 170 | return nil, err |
| 171 | } |
| 172 | return createWithOptions(dir, id, OpenOptions{ExternalHistory: true}, header) |
| 173 | } |
| 174 | |
| 175 | func (p *FilesystemPersistence) Open(sessionID string, mode AccessMode) (*Session, error) { |
| 176 | id := strings.TrimSpace(sessionID) |
| 177 | if err := validateSessionID(id); err != nil { |
| 178 | return nil, err |
| 179 | } |
| 180 | dir, err := p.sessionDir(id, true) |
| 181 | if err != nil { |
| 182 | return nil, err |
| 183 | } |
| 184 | if _, _, err := readSessionHeader(dir, id); err != nil { |
| 185 | return nil, err |
| 186 | } |
| 187 | if mode == ReadOnly { |
| 188 | return openReadSession(dir, id, filepath.Join(p.Root, ".query-cache", filepath.Base(id))) |
| 189 | } |
| 190 | if mode != ReadWrite { |
| 191 | return nil, fmt.Errorf("session: unsupported access mode %q", mode) |
| 192 | } |
| 193 | if _, err := os.Stat(dir); os.IsNotExist(err) { |
| 194 | return nil, fmt.Errorf("%w: %s", ErrSessionNotFound, id) |
| 195 | } else if err != nil { |
| 196 | return nil, err |
| 197 | } |
| 198 | return OpenWithOptions(dir, id, OpenOptions{ExternalHistory: true}) |
| 199 | } |
| 200 | |
| 201 | func (p *FilesystemPersistence) Stat(ctx context.Context, sessionID string) (SessionInfo, error) { |
| 202 | if err := ctx.Err(); err != nil { |
| 203 | return SessionInfo{}, err |
| 204 | } |
| 205 | id := strings.TrimSpace(sessionID) |
| 206 | if err := validateSessionID(id); err != nil { |
| 207 | return SessionInfo{}, err |
| 208 | } |
| 209 | dir, err := p.sessionDir(id, true) |
| 210 | if err != nil { |
| 211 | return SessionInfo{}, err |
| 212 | } |
| 213 | manifest, err := readCatalogManifest(filepath.Join(dir, "manifest.json")) |
| 214 | if err != nil { |
| 215 | if os.IsNotExist(err) { |
| 216 | return SessionInfo{}, fmt.Errorf("%w: %s", ErrSessionNotFound, id) |
| 217 | } |
| 218 | return SessionInfo{}, err |
| 219 | } |
| 220 | if manifest.SessionID != id { |
| 221 | return SessionInfo{}, fmt.Errorf("%w: manifest belongs to %q", ErrDamagedStore, manifest.SessionID) |
| 222 | } |
| 223 | header, hasHeader, err := readSessionHeader(dir, id) |
| 224 | if err != nil { |
| 225 | return SessionInfo{}, err |
| 226 | } |
| 227 | // Listing reads the manifest, log metadata, and rebuildable catalog cache. |
| 228 | // It never opens event bodies; Query refreshes missing display metadata in |
| 229 | // the background. |
| 230 | revision, err := revisionOfLog(dir) |
| 231 | if err != nil { |
| 232 | return SessionInfo{}, err |
| 233 | } |
| 234 | updatedAt := manifest.CreatedAt |
| 235 | if revision.Exists { |
| 236 | if stat, statErr := os.Stat(logPathForManifest(dir, manifest)); statErr == nil && stat.ModTime().After(updatedAt) { |
| 237 | updatedAt = stat.ModTime() |
| 238 | } |
| 239 | } |
| 240 | info := SessionInfo{SessionID: manifest.SessionID, Codec: manifest.Codec, CreatedAt: manifest.CreatedAt, UpdatedAt: updatedAt, MetadataStatus: MetadataPending, Path: dir} |
| 241 | if hasHeader { |
| 242 | info.CWD, info.ParentSessionID, info.Origin = header.CWD, header.ParentSessionID, header.Origin |
| 243 | } |
| 244 | cacheDir := filepath.Join(p.Root, ".query-cache", filepath.Base(id)) |
| 245 | if metadata, metadataErr := readCatalogMetadata(cacheDir, manifest, revision); metadataErr == nil { |
| 246 | info.Title, info.TitleSequence = metadata.Title, metadata.TitleSequence |
| 247 | info.ModelRef, info.ModelIdentity = metadata.ModelRef, metadata.ModelIdentity |
| 248 | info.Turns, info.Preview, info.MetadataStatus = metadata.Turns, metadata.Preview, MetadataReady |
| 249 | info.EventSequence, info.ResultSequence = metadata.Sequence, metadata.ResultSequence |
| 250 | } |
| 251 | return info, nil |
| 252 | } |
| 253 | |
| 254 | func readCatalogManifest(path string) (Manifest, error) { |
| 255 | data, err := os.ReadFile(path) |
| 256 | if err != nil { |
| 257 | return Manifest{}, err |
| 258 | } |
| 259 | var manifest Manifest |
| 260 | if err := json.Unmarshal(data, &manifest); err != nil { |
| 261 | return Manifest{}, err |
| 262 | } |
| 263 | if !supportedStoredManifest(manifest) { |
| 264 | return Manifest{}, fmt.Errorf("%w: manifest schema or codec", ErrUnsupportedVersion) |
| 265 | } |
| 266 | return manifest, nil |
| 267 | } |
| 268 | |
| 269 | func (p *FilesystemPersistence) sessionDir(id string, mustExist bool) (string, error) { |
| 270 | if err := validateSessionID(id); err != nil { |
| 271 | return "", err |
| 272 | } |
| 273 | if !mustExist { |
| 274 | if err := os.MkdirAll(p.Root, 0o700); err != nil { |
| 275 | return "", err |
| 276 | } |
| 277 | } |
| 278 | root, err := os.OpenRoot(p.Root) |
| 279 | if os.IsNotExist(err) { |
| 280 | return "", fmt.Errorf("%w: %s", ErrSessionNotFound, id) |
| 281 | } |
| 282 | if err != nil { |
| 283 | return "", err |
| 284 | } |
| 285 | defer root.Close() |
| 286 | // Root.Lstat rejects traversal and follows the platform's reparse-point |
| 287 | // boundary rules. The single-segment validation above also keeps lock and |
| 288 | // cache names portable on Windows. |
| 289 | info, err := root.Lstat(id) |
| 290 | if os.IsNotExist(err) && !mustExist { |
| 291 | return filepath.Join(p.Root, id), nil |
| 292 | } |
| 293 | if os.IsNotExist(err) { |
| 294 | return "", fmt.Errorf("%w: %s", ErrSessionNotFound, id) |
| 295 | } |
| 296 | if err != nil { |
| 297 | return "", err |
| 298 | } |
| 299 | if info.Mode()&os.ModeSymlink != 0 || !info.IsDir() { |
| 300 | return "", fmt.Errorf("session: session identity %q is not a confined directory", id) |
| 301 | } |
| 302 | // Resolve the physical path through the rooted handle. This keeps protocol |
| 303 | // input out of the path propagated through the storage stack. |
| 304 | child, err := root.OpenRoot(id) |
| 305 | if err != nil { |
| 306 | return "", err |
| 307 | } |
| 308 | dir := child.Name() |
| 309 | if err := child.Close(); err != nil { |
| 310 | return "", err |
| 311 | } |
| 312 | return dir, nil |
| 313 | } |
| 314 | |
| 315 | func (p *FilesystemPersistence) List(ctx context.Context, cursor string, limit int) (SessionPage, error) { |
| 316 | if err := ctx.Err(); err != nil { |
| 317 | return SessionPage{}, err |
| 318 | } |
| 319 | if limit == 0 { |
| 320 | limit = 50 |
| 321 | } |
| 322 | if limit < 1 || limit > 100 { |
| 323 | return SessionPage{}, fmt.Errorf("session: list limit must be 1..100") |
| 324 | } |
| 325 | entries, err := os.ReadDir(p.Root) |
| 326 | if os.IsNotExist(err) { |
| 327 | return SessionPage{Sessions: []SessionInfo{}}, nil |
| 328 | } |
| 329 | if err != nil { |
| 330 | return SessionPage{}, err |
| 331 | } |
| 332 | ids := make([]string, 0, len(entries)) |
| 333 | for _, entry := range entries { |
| 334 | if err := ctx.Err(); err != nil { |
| 335 | return SessionPage{}, err |
| 336 | } |
| 337 | if entry.IsDir() && !strings.HasPrefix(entry.Name(), ".") && entry.Name() > cursor { |
| 338 | ids = append(ids, entry.Name()) |
| 339 | } |
| 340 | } |
| 341 | sort.Strings(ids) |
| 342 | page := SessionPage{Sessions: []SessionInfo{}} |
| 343 | for _, id := range ids { |
| 344 | info, statErr := p.Stat(ctx, id) |
| 345 | if statErr != nil { |
| 346 | info = SessionInfo{SessionID: id, Path: filepath.Join(p.Root, id), Error: statErr.Error()} |
| 347 | } |
| 348 | if len(page.Sessions) == limit { |
| 349 | page.NextCursor = page.Sessions[len(page.Sessions)-1].SessionID |
| 350 | break |
| 351 | } |
| 352 | page.Sessions = append(page.Sessions, info) |
| 353 | } |
| 354 | return page, nil |
| 355 | } |
| 356 | |
| 357 | func validateSessionID(id string) error { |
| 358 | id = strings.TrimSpace(id) |
| 359 | if len(id) == 0 || len(id) > 255 || strings.HasPrefix(id, ".") || strings.HasSuffix(id, ".") || |
| 360 | !filepath.IsLocal(id) || id == "." || filepath.Base(id) != id || strings.ContainsAny(id, `/\\<>:"|?*`) { |
| 361 | return fmt.Errorf("session: invalid session id %q", id) |
| 362 | } |
| 363 | for _, char := range id { |
| 364 | if char < 0x20 { |
| 365 | return fmt.Errorf("session: invalid session id %q", id) |
| 366 | } |
| 367 | } |
| 368 | base := strings.ToUpper(strings.SplitN(id, ".", 2)[0]) |
| 369 | if base == "CON" || base == "PRN" || base == "AUX" || base == "NUL" || |
| 370 | (len(base) == 4 && (strings.HasPrefix(base, "COM") || strings.HasPrefix(base, "LPT")) && base[3] >= '1' && base[3] <= '9') { |
| 371 | return fmt.Errorf("session: reserved session id %q", id) |
| 372 | } |
| 373 | return nil |
| 374 | } |
| 375 | |
| 376 | // ValidateSessionID applies the canonical session storage identity rules. |
| 377 | // Callers that accept compatibility routes must validate the extracted ID |
| 378 | // before deciding whether the input names a SessionRef or a legacy path. |
| 379 | func ValidateSessionID(id string) error { |
| 380 | return validateSessionID(id) |
| 381 | } |
| 382 | |
| 383 | type readHandle struct { |
| 384 | id string |
| 385 | dir string |
| 386 | cacheDir string |
| 387 | manifest Manifest |
| 388 | mu sync.Mutex |
| 389 | closed bool |
| 390 | } |
| 391 | |
| 392 | // openReadSession returns a cold Session backed only by the durable prefix. It |
| 393 | // performs no replay and takes no writer lease: paged reads remain the only way |
| 394 | // to consume it, which is what keeps catalog and history queries cheap. |
| 395 | func openReadSession(dir, id string, cacheDirs ...string) (*Session, error) { |
| 396 | handle, err := openReadHandle(dir, id, cacheDirs...) |
| 397 | if err != nil { |
| 398 | return nil, err |
| 399 | } |
| 400 | return newReadSession(handle), nil |
| 401 | } |
| 402 | |
| 403 | func openReadHandle(dir, id string, cacheDirs ...string) (*readHandle, error) { |
| 404 | cacheDir := dir |
| 405 | if len(cacheDirs) > 0 && strings.TrimSpace(cacheDirs[0]) != "" { |
| 406 | cacheDir = cacheDirs[0] |
| 407 | } |
| 408 | manifest, err := readStoredManifest(filepath.Join(dir, "manifest.json")) |
| 409 | if err != nil { |
| 410 | if os.IsNotExist(err) { |
| 411 | return nil, fmt.Errorf("%w: %s", ErrSessionNotFound, id) |
| 412 | } |
| 413 | return nil, err |
| 414 | } |
| 415 | if manifest.SessionID != id { |
| 416 | return nil, fmt.Errorf("session: manifest belongs to %q", manifest.SessionID) |
| 417 | } |
| 418 | return &readHandle{id: id, dir: dir, cacheDir: cacheDir, manifest: manifest}, nil |
| 419 | } |
| 420 | |
| 421 | func (h *readHandle) ID() string { return h.id } |
| 422 | |
| 423 | func (h *readHandle) Manifest() Manifest { return h.manifest } |
| 424 | |
| 425 | // Dir reports the directory this cold reader opened. A fork from a session with |
| 426 | // no live runtime still has to locate the parent's owned files, and that must |
| 427 | // not require acquiring the writer lease the cold reader deliberately avoids. |
| 428 | func (h *readHandle) Dir() string { |
| 429 | if h == nil { |
| 430 | return "" |
| 431 | } |
| 432 | return h.dir |
| 433 | } |
| 434 | |
| 435 | func (h *readHandle) Read(ctx context.Context, offset uint64, limit int) (EventPage, error) { |
| 436 | if h == nil { |
| 437 | return EventPage{}, os.ErrClosed |
| 438 | } |
| 439 | h.mu.Lock() |
| 440 | closed := h.closed |
| 441 | dir, cacheDir := h.dir, h.cacheDir |
| 442 | h.mu.Unlock() |
| 443 | if closed { |
| 444 | return EventPage{}, os.ErrClosed |
| 445 | } |
| 446 | return readCommitPageWithCache(ctx, dir, cacheDir, offset, limit) |
| 447 | } |
| 448 | |
| 449 | func (h *readHandle) Append(context.Context, []Commit) error { |
| 450 | return ErrReadOnly |
| 451 | } |
| 452 | |
| 453 | func (h *readHandle) Sync(context.Context) (DurableReceipt, error) { |
| 454 | if h == nil { |
| 455 | return DurableReceipt{}, os.ErrClosed |
| 456 | } |
| 457 | h.mu.Lock() |
| 458 | closed := h.closed |
| 459 | dir := h.dir |
| 460 | h.mu.Unlock() |
| 461 | if closed { |
| 462 | return DurableReceipt{}, os.ErrClosed |
| 463 | } |
| 464 | sequence, err := lastDurableSequence(dir) |
| 465 | return DurableReceipt{DurableSequence: sequence}, err |
| 466 | } |
| 467 | |
| 468 | func (h *readHandle) Close(context.Context) error { |
| 469 | if h == nil { |
| 470 | return nil |
| 471 | } |
| 472 | h.mu.Lock() |
| 473 | h.closed = true |
| 474 | h.mu.Unlock() |
| 475 | return nil |
| 476 | } |
| 477 | |
| 478 | func (s *Store) Read(ctx context.Context, offset uint64, limit int) (EventPage, error) { |
| 479 | if s == nil { |
| 480 | return EventPage{}, os.ErrClosed |
| 481 | } |
| 482 | s.mu.Lock() |
| 483 | closed := s.closed |
| 484 | dir := s.dir |
| 485 | s.mu.Unlock() |
| 486 | if closed { |
| 487 | return EventPage{}, os.ErrClosed |
| 488 | } |
| 489 | return readCommitPage(ctx, dir, offset, limit) |
| 490 | } |
| 491 | |
| 492 | func readCommitPage(ctx context.Context, dir string, offset uint64, limit int) (EventPage, error) { |
| 493 | return readCommitPageWithCache(ctx, dir, dir, offset, limit) |
| 494 | } |
| 495 | |
| 496 | func readCommitPageWithCache(ctx context.Context, dir, cacheDir string, offset uint64, limit int) (EventPage, error) { |
| 497 | if err := ctx.Err(); err != nil { |
| 498 | return EventPage{}, err |
| 499 | } |
| 500 | if limit == 0 { |
| 501 | limit = 100 |
| 502 | } |
| 503 | if limit < 1 || limit > 1000 { |
| 504 | return EventPage{}, fmt.Errorf("session: read limit must be 1..1000 commits") |
| 505 | } |
| 506 | index, err := loadOrBuildSparseIndex(ctx, dir, cacheDir) |
| 507 | if err != nil { |
| 508 | return EventPage{}, err |
| 509 | } |
| 510 | page := EventPage{Commits: []Commit{}} |
| 511 | if index.LastSequence <= offset { |
| 512 | return page, nil |
| 513 | } |
| 514 | checkpoint := index.checkpoint(offset) |
| 515 | manifest, err := readStoredManifest(filepath.Join(dir, "manifest.json")) |
| 516 | if err != nil { |
| 517 | return EventPage{}, err |
| 518 | } |
| 519 | file, err := os.Open(logPathForManifest(dir, manifest)) |
| 520 | if err != nil { |
| 521 | return EventPage{}, err |
| 522 | } |
| 523 | defer file.Close() |
| 524 | visit := func(_ int64, commit Commit) bool { |
| 525 | if ctx.Err() != nil { |
| 526 | return false |
| 527 | } |
| 528 | if commit.LastSequence() <= offset { |
| 529 | return true |
| 530 | } |
| 531 | if len(page.Commits) == limit { |
| 532 | page.Truncated = true |
| 533 | return false |
| 534 | } |
| 535 | page.Commits = append(page.Commits, commit) |
| 536 | page.Next = commit.LastSequence() |
| 537 | return true |
| 538 | } |
| 539 | if manifest.Codec == Codec { |
| 540 | err = scanV4CommitFile(ctx, file, checkpoint.Offset, checkpoint.FirstSequence, contentStoreForSessionDir(dir), nil, visit) |
| 541 | } else { |
| 542 | err = scanCommitFileCodec(file, checkpoint.Offset, checkpoint.FirstSequence, manifest.Codec, nil, visit) |
| 543 | } |
| 544 | if err != nil { |
| 545 | return EventPage{}, err |
| 546 | } |
| 547 | if err := ctx.Err(); err != nil { |
| 548 | return EventPage{}, err |
| 549 | } |
| 550 | return page, nil |
| 551 | } |
| 552 | |
| 553 | func lastDurableSequence(dir string) (uint64, error) { |
| 554 | return lastDurableSequenceWithCache(dir, dir) |
| 555 | } |
| 556 | |
| 557 | func lastDurableSequenceWithCache(dir, cacheDir string) (uint64, error) { |
| 558 | index, err := loadOrBuildSparseIndex(context.Background(), dir, cacheDir) |
| 559 | return index.LastSequence, err |
| 560 | } |
| 561 | |
| 562 | var _ SessionPersistence = (*FilesystemPersistence)(nil) |
| 563 | var _ SessionHandle = (*Store)(nil) |
| 564 | var _ SessionHandle = (*readHandle)(nil) |
| 565 |