Write handles now hold a durable lease (session.lock.json beside the
log): a random owner token, diagnostic pid, and an expiry. Acquisition
wins by exclusive create; a second process's create or write open rejects
while the record is unrenewed for less than leaseTtlMs (default 5 min),
and takes over after that — a crashed holder is waited out, never
reclaimed by pid. The holder renews every leaseRenewIntervalMs (default
4 min); a renewal that finds a foreign, vanished, or expired record — or
fails outright — marks the lease lost permanently, so every later
append/flush rejects with SessionOwnershipLostError while reads continue.
Close releases the record; read handles never touch it. Takeover of an
expired record is eventually exclusive: a replaced holder stops within
one renewal interval.
Refs #3245
`session[.vN].jsonl` was assembled independently by the JSONL provider
(twice), the session-log export archive, and the recorded-session fixture
helpers. `dsh-session-format` now owns `sessionFormatLogFilename` and
`parseSessionFormatLogFilename`; the three consumers append only their
compression suffix, and the migration note names the owner.
`snapshotSessionFormatJson` re-implemented the lossless JSON walk that
`dsh-util-values` already publishes as `snapshotJsonValue` + `deepFreeze`,
and the frozen v0 relationship validator carried a third structural JSON
comparison next to `deepEqualJson`. Both now delegate; the format package
reports one `is not lossless JSON` diagnostic per labelled subject instead
of ten member-specific ones, and enumerable accessors whose values survive
a JSON round trip are accepted like `JSON.stringify` accepts them.
`ensureJsonlGenerationCurrent` returned a live Zstandard body iterator that
every production caller disposed unread before decoding the same bytes again;
the header read now decodes only the first frame and owns no decoder past its
return. The JSONL backend reuses the generation module's stable-revision read
instead of keeping a second copy, `encodeCurrent` encodes the validated
current artifact it is documented to receive instead of re-running the
migration chain on it, and the test-only `inspectVersion` catalog method and
the `migrateSessionSnapshotFixture` duplicate of
`prepareSessionSnapshotFixtureForComparison` are removed.
The persistence seam is now create/open/stat/list returning per-session
SessionHandles (read/append/flush/close); every log read and write flows
through the owning handle. The seam package exports only the service and
handle contracts, consumer-visible errors, and pure durable-data
validation helpers; each backend owns its complete storage runtime, and
the shared contract suites pin equivalent observable behavior. The
backend routes published sessions' live events by id into the active
write handle; agent-loop only acquires, seeds, and closes the handle.
Resume appends interruptedTurnClosers through its write handle;
session-query owns the revision-keyed cold cache. Legacy-only surfaces
are removed in the same swap: locate/readRaw/supportsRawArtifacts, the
legacy event-shape read migration, zstd torn-frame salvage,
DSH_SESSION_JSONL, and hook transcript_path population; a torn final
zstd frame is discarded whole; the session-list cold blank probe returns
on stat metadata (eventCount derived from the last physical row,
sizeBytes). The WebUI ZIP export serializes the logical log from a read
handle, so both backends export identically.
Refs #3245
`JsonlSessionPersistence.exists` treats ENOENT as absence and stats the
path's parent first, so a session directory blocked by a regular file
stays a storage fault. Only Windows needs that: it reports ENOENT rather
than ENOTDIR for `regular-file/child`, while POSIX open reports ENOTDIR
before the branch is reached.
The stat ran on every platform and every absent probe. findLog issues
four probes per project directory and the coordinator resolves an id
twice per inspect, so nearly every probe paid it. Counting fs calls
against a five-project store, loading an existing session drops from
40 open + 41 stat to 40 open + 3 stat.
The product model has no cross-process writer exclusion (the coordinator
serializes per-session operations in-process; the README documents one
live writer per session), so the wx-created .lock sibling only guarded
byte-level races while adding two failure modes: a crash leaves a stale
lock that permanently wedges that log's appends/repairs/replacements, and
a post-commit lock cleanup failure makes a committed append look failed,
so the retained write-behind batch retries into duplicate seqs.
Remove withLogLock and keep replaceStored's revision compare-and-swap at
the commit boundary (recheck immediately before the atomic rename).
A present zero-byte .jsonl.zstd file was treated as though no artifact existed because readRaw returned undefined when frame scanning found nothing. That contradicted both the plaintext path and the logical zstd reader, and it made the export endpoint answer 404 for on-disk corruption.
Treat a present artifact without a complete header frame as corruption and reuse the zstd reader's existing diagnostic. The regression test now distinguishes an existing empty file from an absent path, and the bilingual JSONL storage contract records that zero-frame artifacts reject alongside other header and frame failures.
SessionPersistence.readRaw previously used undefined for two unrelated states: a supported backend could not find the requested session, or the backend had no per-session artifact concept at all. The export endpoint consequently reported an existing SQLite-backed session as HTTP 404, which falsely diagnosed storage capability as session absence.
Make raw-artifact support an explicit backend capability. Unsupported backends now fail their inherited readRaw path loudly and the host answers 501 before reading, while undefined retains the single meaning of an absent artifact on a supporting backend. First-party backends, test providers, generated API catalogs, bilingual persistence docs, and export error contracts now state that distinction; focused tests cover both the 501 and the inherited rejection.
Rescope nothing new: drop the needless async from the inherited readRaw
default (reject explicitly on abort), fix the void arrow shorthand in
downloadBlob, and share one revision-stable file-read loop between readRaw
and readPrefix in the JSONL backend.
Review round: the JSONL backend now refuses a foreign header version straight
from the raw header line, before validating today's header shape or decoding
any event row, so a structurally different future format reports the upgrade
direction instead of corruption (shared message builder
sessionFormatVersionRefusal). HMR live-prefix adoption runs the unknown-type
guard like the other read paths. The appendCore comment now states why the
unknown-type guard is read-side only, the loadStoredFrom JSDoc and README pin
the seek-vs-sequential refusal-scope divergence, and the generated catalog
preamble lists the ignorable envelope field.
Machine-produced by `pnpm run rescope-vendor --apply` plus the regeneration it
prints: `pnpm install` for the lockfile, `pnpm run gen-third-party-notices`,
`verify-translation-pairing --write` for the touched bilingual pairs,
`gen-doc-graphs`, and one typert snapshot whose ids embed character offsets.
`pnpm run rescope-vendor --check` verifies the result.
Renames nine vendored packages (cordis, cosmokit, schemastery and the six
@cordisjs plugins) and every reference that resolves them: manifest names and
dependency keys, module specifiers including declare-module merges, cordis.yml
plugin names, tsconfig paths, every Markdown fence, and `docs/` prose.
Directory names, upstream versions, and dependency ranges are unchanged, so
vendor/README.md still reads as an upstream snapshot; its manifest table gains
an upstream-name column so THIRD_PARTY_NOTICES keeps MIT attribution pointed
at each fork's origin.
The tutorial tier follows the rename end to end: its yaml fences named plugins
the Loader can no longer resolve, its `ts ignore-check` fences disagreed with
the compiled fences beside them, and its prose quoted both. The contracts that
told readers to keep upstream names — the root convention and the vendoring
cookbook's tree comment and manifest invariant — now say to rescope instead.
Two rules read `@deepseek-ai/` as "another workspace plugin": the client bundle
purity gate now names the vendored libraries a browser bundle inlines, and the
files where a bare `cordis` is an agent-preset id keep that product data.
The persistence contract gains a concrete readRaw default (undefined for
backends without a per-session artifact) and the JSONL backend overrides it
with the decode of its physical zstd frames, so a consumer can read the
stored artifact text verbatim — the session-log export depends on it.
imccyu