Files
ComfyAssets-ComfyUI_PromptM…/py/api/jobs.py
T
Vito 28ad3a1a1f feat(system): backup and restore backend (System S8) (#335)
* refactor(database): stage restores before publishing

restore_from_file is now stage_restore + publish_staged (database/
restore_stage.py). The stage lives in a .pm-restore-* folder in the
library's own folder, is migrated, has damaged workflow documents repaired
from an inline copy or cleared, is verified with every document read and is
bound by its SHA-256. Publishing keeps a unique, standalone, 0600 safety
backup (microsecond names), copies the pages through the backup API as
before and then truncates the WAL, which stayed database-sized after a
restore. The safety backup writer moves to database/safety_backup.py so
the database layer and maintenance share it.

* fix(database): read the verify streams one row at a time

The provenance and review-evidence checks iterated their cursors; on a
managed connection iteration prefetches 128 rows, so up to 128 large values
were held at once while the docstrings promised one. Both now use fetchone.

* feat(backup): review a restore, run it as an Activity job, verify backups

- POST /restore/preview stages an upload in the library's folder and
  answers what it holds beside the live library, writing nothing live;
  DELETE discards it; at most two stages are held (429 too-large).
- POST /restore/apply rechecks the live fingerprint (409 plan-changed) and
  starts "Database restore": exclusive, not cancellable, indeterminate. It
  waits for request leases, publishes the exact staged bytes, swaps the
  database, prunes safety backups and logs counts, repairs and the backup.
- The legacy /restore runs the same stage and publish as an exclusive hold
  with its old response, so a restore and the health check, Move library
  and every other job refuse each other.
- JobRegistry.lease: Needs review decisions and maintenance and restore
  previews are refused while an exclusive job runs, and a restore waits
  for them before it switches the file.
- GET /backup holds a guarded slot, verifies a standalone snapshot before
  streaming it and removes the closed temp file; GET /backup/status lists
  the safety backups on disk and this session's verified download.

* docs(testing): backup and restore contract

* test(system): a restore refuses a running health check

The health route test relied on a legacy restore interleaving with a running
check; the restore is now exclusive and refuses it, naming the check. The
diagnostics backup tests follow the backup handler into
py/api/backup_restore.py.

* fix(backup): drop stale restore previews off the event loop

A restore drops the previews reviewed against the old library; their stage
files are now removed in the executor, with the old database's connections.

* test(backup): wait for the backup hold to end before reading its state

CI (py3.11/3.12 on Linux, every macOS) read the registry right after the
client had the last byte, before the handler left its hold and removed its
temp file: the job was still running. The tests now wait on that state.

* test(images): the scan dialog's Back up now leaves a finished backup hold

A backup download now holds a guarded registry slot while it streams
(#249 S8), so the jobs list holds that finished hold after the dialog's
Back up now; the spec still proves Cancel starts no scan.

* fix(backup): final review round for the restore and backup routes

- I1: once the stage's copy replaced the library the restore succeeded:
  pruning, reopening self.db, dropping old previews and closing the old
  object only log, so the job finishes and the legacy /restore answers 200
  instead of "the library was not changed". The generation is always bumped.
- M1: a backup download holds its guarded slot only while the snapshot is
  written; the stream runs outside it, so a stalled download blocks nothing.
- M2: a restore preview leases only its read of the live library, not the
  upload or the staging; a restore whose drain still times out keeps the
  reviewed stage under its token.
- M3: the reviewed-preview store changes only on the event loop; stage
  folders are removed in the executor.
- M4: a document whose body inflates completely while only its recorded
  hash or only its length disagrees is re-keyed (or merged into the
  document holding that text) instead of dropped.
- M5: a backup download is refused only when the snapshot is not SQLite or
  fails integrity_check; a semantic check failure still downloads, logged,
  sent as X-PromptManager-Verify and recorded as not verified.
- M6: a refused, failed or cancelled preview removes its stage, also when
  the cancel lands while a worker still stages; a timer removes expired
  stages without another request.
- M7, N1: repair reads rows one at a time and counts distinct images.
- N3: the live fingerprint never commits a transaction it did not open.

* test(backup): close the old library the close-failure test leaves open

CI (py3.12 Linux and the coverage gate) found the old object's
executor-thread connections still open at teardown: the test patches its
close_all to fail, and once the object is collected close_all_instances no
longer reaches it. The test now closes it itself.

* fix(backup): re-review round for restore repair, apply and backup cleanup

- R1: when re-keying merges an intact body into a holder whose own body was
  damaged, the rewritten holder leaves the damaged list, so the clear pass
  no longer deletes it and unlinks the images just moved to it.
- R2: a losing duplicate apply removes a stage only when the store still
  held it, never one another apply's job has taken.
- R3: a restore that times out waiting for requests keeps its review only
  while it is unexpired and its slot is free; otherwise the stage goes and
  the job says to try again.
- R4: a backup download cancelled while its snapshot is written removes
  the snapshot once the worker finishes.
2026-10-25 10:17:07 -07:00

668 lines
26 KiB
Python

"""The session job registry: every long operation as one tracked job.
A job runs as an asyncio task that outlives the HTTP request that started it,
so an accidental tab close never abandons half-finished work. Each job keeps
its counters, a capped list of file outcomes per outcome group and a capped
log, and fans its progress out to SSE subscribers: the request that started
it, a reconnecting page, a second tab. A subscriber receives the latest event
as a snapshot and then every event published after it, until the job ends.
Jobs live only in server memory and are gone after a restart. The registry
keeps the running jobs and this session's last ``MAX_FINISHED_JOBS`` finished
ones. One job of a kind runs at a time, and each job has an admission class
(``ADMISSIONS``) that decides what may run beside it:
- ``records`` changes library records or files (the metadata scan, bulk image
tagging, and the legacy restore, maintenance, cleanup, duplicate delete,
LoRA import and batch auto-tag routes). It is refused while any
``records`` or ``guarded`` job runs.
- ``guarded`` must not overlap record changes but may overlap other guarded
work (thumbnail generation and clearing, later backup). It is refused while
a ``records`` job runs.
- ``read`` only reads; it is refused only by a running job of its own kind
or an ``exclusive`` one.
- ``exclusive`` runs alone (Optimize's VACUUM, which rewrites the whole
database under the write lock): it is refused while any job runs, and every
job is refused while it runs.
A short legacy-page operation takes a ``hold``: a running, non-cancellable
job that lasts as long as the request, so the Activity page lists it and a
workspace job is refused while it runs (and the other way round).
Short request-scoped work that reads or writes the library beside any
ordinary job (a Needs review decision, a maintenance or restore preview)
takes a ``lease`` instead: it is not listed (so quick requests never push
real jobs out of the finished history, and two of them never refuse each
other), but it is refused while an ``exclusive`` job runs, and an
``exclusive`` job that replaces the database (a restore) awaits
``drain_leases`` before it switches the file, so no lease's connection is
open across the switch (#249 S8).
"""
import asyncio
import itertools
import logging
import re
import time
import uuid
from pathlib import PurePosixPath, PureWindowsPath
logger = logging.getLogger(__name__)
# Start and finish order: wall-clock times can tie (coarse Windows clocks).
_sequence = itertools.count()
JOB_STATES = ("running", "finished", "cancelled", "failed")
FINAL_STATES = JOB_STATES[1:]
MAX_OUTCOME_ROWS = 200 # rows listed per outcome group; counters stay exact
MAX_LOG_LINES = 2000
LOG_CAP_LINE = "[Log capped at 2,000 lines]"
MAX_FINISHED_JOBS = 20 # finished jobs this session keeps
# The longest an exclusive job waits for running leases to end (a ceiling a
# hung request reaches, not a pacing timer: leases end with their request).
LEASE_DRAIN_SECONDS = 60
# The metadata scan's outcome groups, in counter-tile order of the spec's
# mapping, and the per-file scan status each group collects. Files without
# usable metadata have no status and go to "no_metadata".
# Which files a scan reads (#249 Activity-2): "new" skips the files the Library
# already links with a resolved link (get_known_resolved_paths) before reading
# them, so new, unlinked, unresolved and ambiguous files are read; "all" reads
# every file again. The workspace job defaults to "new"; legacy /scan is "all".
SCAN_SCOPES = ("new", "all")
DEFAULT_SCAN_SCOPE = "new"
SCAN_GROUP_NAMES = ("added", "known", "review", "no_metadata", "errors")
SCAN_GROUPS = {
"added": "added",
"linked": "added",
"enriched": "added",
"unchanged": "known",
"skipped": "known", # "new" scope: known and resolved, not read again
"ambiguous": "review",
"conflict": "review",
"unresolved": "review",
"failed": "errors",
}
# Bulk image tagging (#249 D1): Add tags and Auto-tag over selected images.
# Record-changing: it writes image tag sets and new vocabulary names.
IMAGE_TAG_JOB_KIND = "image-tags"
IMAGE_TAG_GROUP_NAMES = ("tagged", "unchanged", "skipped", "errors")
# Thumbnail generation (#249 System S5): previews written, already fresh, failed.
THUMBNAIL_GROUP_NAMES = ("generated", "skipped", "errors")
ADMISSIONS = ("read", "guarded", "records", "exclusive")
# What each admission class is refused beside (besides its own kind).
# ``exclusive`` (Optimize's VACUUM) runs alone: beside no job of any class.
_REFUSED_BESIDE = {
"read": frozenset({"exclusive"}),
"guarded": frozenset({"records", "exclusive"}),
"records": frozenset({"records", "guarded", "exclusive"}),
"exclusive": frozenset(ADMISSIONS),
}
# Kinds of the legacy-page operations that hold the registry (D80; titles in
# their handlers end in "(admin page)", "(gallery page)" or "(legacy page)").
RESTORE_JOB_KIND = "restore"
MAINTENANCE_JOB_KIND = "maintenance"
DUPLICATE_CLEANUP_JOB_KIND = "duplicate_cleanup"
THUMBNAILS_JOB_KIND = "thumbnails"
LORA_IMPORT_JOB_KIND = "lora_import"
AUTOTAG_BATCH_JOB_KIND = "autotag"
# Duplicate image files (#249 System S6, py/api/duplicate_files.py): the
# find is a cancellable ``read`` job; the reviewed removal is ``records``.
DUPLICATES_JOB_KIND = "duplicates"
DUPLICATE_GROUP_NAMES = ("groups_found",)
DUPLICATE_CLEANUP_GROUP_NAMES = ("removed", "kept", "errors")
# The System health check (py/api/system.py): a read-only ``read`` job with
# no file outcomes, so it may run beside a scan.
HEALTH_JOB_KIND = "health"
def resolve_admission(admission=None, record_changing=None) -> str:
"""The admission class for a start call; ``record_changing`` is an alias.
``record_changing=True`` means ``records`` and ``False`` means ``read``;
with neither given the class is ``read``. Raises ValueError for an
unknown class or one that contradicts ``record_changing``.
"""
if admission is None:
return "records" if record_changing else "read"
if admission not in ADMISSIONS:
raise ValueError(f"Unknown job admission {admission!r}")
if record_changing is not None and record_changing != (admission == "records"):
raise ValueError(
f"record_changing={record_changing!r} contradicts admission {admission!r}"
)
return admission
def _relative_path(path) -> str:
"""``path`` as a root-relative POSIX path; an absolute one keeps its name."""
text = str(path or "")
if (
PurePosixPath(text).is_absolute()
or PureWindowsPath(text).is_absolute()
or PureWindowsPath(text).drive
):
return re.split(r"[\\/]", text)[-1]
return text.replace("\\", "/")
class JobBusy(Exception):
"""A job could not start because ``running`` holds its slot."""
def __init__(self, running):
super().__init__(f"{running.title} is already running")
self.running = running
class Job:
"""One tracked operation: state, counters, outcomes, log and subscribers."""
def __init__(
self,
kind,
title,
*,
admission=None,
record_changing=None,
cancellable=True,
scope=None,
groups=(),
clock=None,
):
self._clock = clock or time.time
self.id = uuid.uuid4().hex
self.kind = kind
self.title = title
self.admission = resolve_admission(admission, record_changing)
self.cancellable = bool(cancellable)
self.scope = dict(scope or {})
self.state = "running"
self.started_at = self._clock()
self._started_seq = next(_sequence)
self._finished_seq = None
self.finished_at = None
self.progress = 0
self.status_line = ""
self.processed = 0
self.total = 0
self.counters = dict.fromkeys(groups, 0)
self.outcomes = {group: [] for group in groups}
self.log = []
self.cancelled = False
self.last_event = None
self.task = None
self._subscribers = set()
@property
def record_changing(self):
return self.admission == "records"
@property
def running(self):
return self.state == "running"
@property
def finished(self):
return not self.running
@property
def subscriber_count(self):
return len(self._subscribers)
# ── progress ──────────────────────────────────────────────────────
def update(self, *, progress=None, status_line=None, processed=None, total=None):
"""Set the summary's progress fields; ``None`` leaves one unchanged."""
if progress is not None:
self.progress = max(0, min(100, int(progress)))
if status_line is not None:
self.status_line = status_line
if processed is not None:
self.processed = processed
if total is not None:
self.total = total
def publish(self, payload):
"""Record ``payload`` as the latest event and hand it to every subscriber."""
if isinstance(payload.get("progress"), (int, float)):
self.update(progress=payload["progress"])
self.last_event = payload
for queue in list(self._subscribers):
queue.put_nowait(payload)
def log_line(self, text):
"""Append a timestamped log line, up to MAX_LOG_LINES and one cap line."""
if len(self.log) > MAX_LOG_LINES:
return
if len(self.log) == MAX_LOG_LINES:
self.log.append(LOG_CAP_LINE)
return
stamp = time.strftime("%H:%M:%S", time.localtime(self._clock()))
self.log.append(f"{stamp} {text}")
def record(self, group, row, log_line):
"""Count one file outcome in ``group``, list its row and log it.
``row`` is ``{path, root, root_index, detail}``: the path relative to
its output root, the root's public label and its listing index (the
identity Images opens it by; None when unknown). An absolute path is
cut to its file name, so a row never reveals the server's layout.
"""
if group not in self.counters:
raise ValueError(f"Unknown outcome group {group!r} for {self.kind}")
self.counters[group] += 1
raw = str(row.get("path") or "")
path = _relative_path(raw)
if raw and raw != path:
log_line = log_line.replace(raw, path)
rows = self.outcomes[group]
index = row.get("root_index")
if isinstance(index, bool) or not isinstance(index, int) or index < 0:
index = None
if len(rows) < MAX_OUTCOME_ROWS:
rows.append(
{
"path": path,
"root": str(row.get("root") or ""),
"root_index": index,
"detail": str(row.get("detail") or ""),
}
)
self.log_line(log_line)
def record_counted(self, group, count, rows=()):
"""Count ``count`` outcomes in ``group`` at once, listing ``rows``.
For outcomes that need no log line each (a thumbnail job's already
fresh previews): the counter is exact, ``rows`` (``record``'s row
shape) are listed up to MAX_OUTCOME_ROWS, and nothing is logged.
"""
if group not in self.counters:
raise ValueError(f"Unknown outcome group {group!r} for {self.kind}")
self.counters[group] += max(0, int(count))
listed = self.outcomes[group]
for row in rows:
if len(listed) >= MAX_OUTCOME_ROWS:
break
index = row.get("root_index")
if isinstance(index, bool) or not isinstance(index, int) or index < 0:
index = None
listed.append(
{
"path": _relative_path(row.get("path")),
"root": str(row.get("root") or ""),
"root_index": index,
"detail": str(row.get("detail") or ""),
}
)
def finish(self, state="finished"):
"""End the job in ``state`` and release every subscriber.
Each subscriber still gets the events queued before the release. A
second finish is a no-op, so the first final state stands.
"""
if state not in FINAL_STATES:
raise ValueError(f"{state!r} is not a final job state")
if self.finished:
return
self.state = state
self.finished_at = self._clock()
self._finished_seq = next(_sequence)
for queue in list(self._subscribers):
queue.put_nowait(None)
async def events(self, lead=None):
"""Yield the latest event, then each later one, until the job finishes.
``lead``, when given, is yielded first, after the subscription is in
place, so nothing published while the consumer sends it is missed.
Consume it under ``contextlib.aclosing`` so a consumer that stops early
(a closed socket) drops its queue at once instead of at garbage collection.
"""
queue = asyncio.Queue()
self._subscribers.add(queue)
# As of the subscription: a later event or the end reaches the queue.
snapshot, ended = self.last_event, self.finished
try:
if lead is not None:
yield lead
if snapshot is not None:
yield snapshot
if ended:
return
while True:
payload = await queue.get()
if payload is None:
return
yield payload
finally:
self._subscribers.discard(queue)
# ── views ─────────────────────────────────────────────────────────
def summary(self):
"""The job as the Activity list and pill show it."""
return {
"id": self.id,
"kind": self.kind,
"title": self.title,
"state": self.state,
"started_at": self.started_at,
"finished_at": self.finished_at,
"progress": self.progress,
"status_line": self.status_line,
"processed": self.processed,
"total": self.total,
"counters": dict(self.counters),
"scope": dict(self.scope),
# What detail() lists, so a view re-reads it only when it changed.
"listed": {group: len(rows) for group, rows in self.outcomes.items()},
"log_length": len(self.log),
# A view offers Cancel only when the server can stop the job.
"cancellable": self.cancellable,
"admission": self.admission,
}
def detail(self):
"""The summary plus the listed outcome rows and the log."""
return {
**self.summary(),
"outcomes": {
group: [dict(row) for row in rows]
for group, rows in self.outcomes.items()
},
"log": list(self.log),
}
def report(self):
"""The downloadable report: the summary, every outcome group and the log.
Each group carries its exact count, its listed rows (at most
MAX_OUTCOME_ROWS) and whether the list is cut short. Rows and log lines
already hold root-relative paths only.
"""
summary = self.summary()
summary.pop("listed", None)
summary.pop("log_length", None)
return {
"report_version": 1,
"generated_at": self._clock(),
"job": summary,
"outcomes": {
group: {
"count": self.counters.get(group, len(rows)),
"rows": [dict(row) for row in rows],
"truncated": self.counters.get(group, len(rows)) > len(rows),
}
for group, rows in self.outcomes.items()
},
"log": list(self.log),
}
def report_filename(self):
"""The download name: prompt-manager-KIND-YYYYMMDD-HHMM.json (local time)."""
stamp = time.strftime("%Y%m%d-%H%M", time.localtime(self._clock()))
return f"prompt-manager-{self.kind}-{stamp}.json"
class JobRegistry:
"""Every job of this server session, running and recently finished."""
def __init__(self, logger_=None):
self._logger = logger_ or logger
self._jobs = {}
self._leases = {} # title -> running count
self._drain_waiters = []
# ── leases ────────────────────────────────────────────────────────
def lease(self, title):
"""An async context manager for short request-scoped library work.
Entering raises JobBusy, naming the job, while an ``exclusive`` job
runs; otherwise the lease is counted until the block exits. Leases
are never listed and never refuse one another or any job.
"""
return _Lease(self, title)
def lease_blocker(self):
"""The running ``exclusive`` job a new lease is refused for, or None."""
for job in self.running():
if job.admission == "exclusive":
return job
return None
@property
def leases(self):
"""Running leases by title (a copy)."""
return dict(self._leases)
def _take_lease(self, title):
blocker = self.lease_blocker()
if blocker is not None:
raise JobBusy(blocker)
self._leases[title] = self._leases.get(title, 0) + 1
def _release_lease(self, title):
count = self._leases.get(title, 0) - 1
if count > 0:
self._leases[title] = count
else:
self._leases.pop(title, None)
if not self._leases:
waiters, self._drain_waiters = self._drain_waiters, []
for waiter in waiters:
if not waiter.done():
waiter.set_result(True)
async def drain_leases(self, timeout=None):
"""Wait until no lease runs; False when ``timeout`` ended the wait.
For an ``exclusive`` job about to switch the database: once it runs
no new lease is admitted, so the count only goes down.
"""
if not self._leases:
return True
waiter = asyncio.get_running_loop().create_future()
self._drain_waiters.append(waiter)
try:
await asyncio.wait_for(
asyncio.shield(waiter),
LEASE_DRAIN_SECONDS if timeout is None else timeout,
)
return True
except asyncio.TimeoutError:
self._logger.warning(
"Still running after the wait: " + ", ".join(sorted(self._leases))
)
return False
finally:
if waiter in self._drain_waiters:
self._drain_waiters.remove(waiter)
def start(
self,
kind,
title,
*,
admission=None,
record_changing=None,
cancellable=True,
scope=None,
runner,
groups=(),
) -> Job:
"""Create a job and run ``runner(job)`` as a task.
``admission`` is one of ``ADMISSIONS``; ``record_changing=True`` is
the older spelling of ``records`` and ``False`` of ``read``. One of
the two is required (TypeError otherwise), so no new job runs as
``read`` beside a scan by omission. Raises JobBusy, naming the job in
the way, when the admission class refuses it (see the module
docstring). Must be called from the event loop.
"""
if admission is None and record_changing is None:
raise TypeError(
f"JobRegistry.start({kind!r}) needs an admission class "
"(admission= or record_changing=)"
)
job = self._admit(
kind,
title,
admission=admission,
record_changing=record_changing,
cancellable=cancellable,
scope=scope,
groups=groups,
)
job.task = asyncio.ensure_future(self._run(job, runner))
return job
def hold(self, kind, title, *, admission, scope=None):
"""A running, non-cancellable job for a legacy-page operation.
Returns an async context manager. Entering it registers the job and
yields it, or raises JobBusy at once, without waiting, when the
admission class refuses it; nothing is registered until then, so a
hold that is never entered leaves no job behind. The job ends when
the block exits: ``finished``, or ``failed`` when it raised (unless
the body already ended it). A caller that answers a refusal in its
own way checks ``blocker(kind, admission=...)`` first, with no await
before the ``async with``.
"""
resolve_admission(admission) # an unknown class fails at the call
return _Hold(
lambda: self._admit(
kind, title, admission=admission, cancellable=False, scope=scope
)
)
def _admit(self, kind, title, *, admission, record_changing=None, **job_args):
resolved = resolve_admission(admission, record_changing)
blocker = self.blocker(kind, admission=resolved)
if blocker is not None:
raise JobBusy(blocker)
self._prune()
job = Job(kind, title, admission=resolved, **job_args)
self._jobs[job.id] = job
return job
def blocker(self, kind, *, admission=None, record_changing=None, compatible=()):
"""The running job a new ``kind`` job would be refused for, or None.
The same kind refuses first; then the oldest running job whose class
the new job's admission class may not run beside. Running jobs of a
kind in ``compatible`` never refuse it: the caller knows that work
cannot conflict with its own (the monitor's Needs review recording
beside thumbnail work, which writes previews and no records).
"""
same_kind = self.active(kind)
if same_kind is not None:
return same_kind
refused = _REFUSED_BESIDE[resolve_admission(admission, record_changing)]
# A snapshot: the monitor's worker thread asks too (Needs review).
running = [job for job in tuple(self._jobs.values()) if job.running]
running.sort(key=lambda job: job._started_seq)
for job in running:
if job.admission in refused and job.kind not in compatible:
return job
return None
async def _run(self, job, runner):
try:
await runner(job)
except asyncio.CancelledError:
job.finish("cancelled")
raise
except Exception:
self._logger.exception(f"Job {job.kind} failed")
job.finish("failed")
finally:
if job.running:
job.finish("cancelled" if job.cancelled else "finished")
def _prune(self):
"""Drop the oldest finished jobs so a new one keeps the cap."""
finished = [job for job in self._jobs.values() if job.finished]
finished.sort(key=lambda job: job._finished_seq)
for job in finished[: max(0, len(finished) - MAX_FINISHED_JOBS + 1)]:
del self._jobs[job.id]
def get(self, job_id):
return self._jobs.get(job_id)
def running(self):
"""The running jobs, oldest first (a snapshot, safe off the event loop)."""
jobs = [job for job in tuple(self._jobs.values()) if job.running]
jobs.sort(key=lambda job: job._started_seq)
return jobs
def active(self, kind):
"""The running job of ``kind``, or None (safe off the event loop)."""
for job in tuple(self._jobs.values()):
if job.kind == kind and job.running:
return job
return None
def list(self):
"""Running jobs first, then the last finished ones, newest first."""
jobs = list(self._jobs.values())
running = [job for job in jobs if job.running]
finished = [job for job in jobs if job.finished]
running.sort(key=lambda job: job._started_seq, reverse=True)
finished.sort(key=lambda job: job._finished_seq, reverse=True)
return running + finished[:MAX_FINISHED_JOBS]
def cancel(self, job_id) -> bool:
"""Ask a running job to stop at its next safe boundary.
Returns whether a cancellation was requested: False for a finished,
unknown or non-cancellable job, so a cancel after the end is a no-op.
"""
job = self._jobs.get(job_id)
if job is None or job.finished or not job.cancellable:
return False
job.cancelled = True
return True
class _Hold:
"""The async context manager ``JobRegistry.hold`` returns."""
def __init__(self, admit):
self._admit = admit
self._job = None
async def __aenter__(self):
self._job = self._admit()
return self._job
async def __aexit__(self, exc_type, exc, tb):
if self._job.running:
self._job.finish("finished" if exc_type is None else "failed")
return False
class _Lease:
"""The async context manager ``JobRegistry.lease`` returns."""
def __init__(self, registry, title):
self._registry = registry
self._title = title
self._held = False
async def __aenter__(self):
self._registry._take_lease(self._title)
self._held = True
return self
async def __aexit__(self, exc_type, exc, tb):
if self._held:
self._held = False
self._registry._release_lease(self._title)
return False