Files
hermes-agent/hermes_cli/gitlock.py

98 lines
4.5 KiB
Python

"""Stale git lock-file and aborted-fetch pack-debris recovery for update/check paths.
A killed ``git fetch`` can leave ``.git/shallow.lock`` behind (every later fetch fails with "Unable to
create '.../shallow.lock': File exists") and ``tmp_pack_*`` files git itself never cleans up."""
from __future__ import annotations
import logging
import os
import subprocess
import time
from pathlib import Path
from typing import Callable, Iterable, List, Optional
logger = logging.getLogger(__name__)
# Files younger than this are presumed live (a fetch may be in flight) and are never removed. Lock
# files live for seconds and a healthy fetch completes in minutes; 10 minutes is abandoned.
STALE_LOCK_MIN_AGE_SECONDS = 10 * 60
STALE_TMP_PACK_MIN_AGE_SECONDS = STALE_LOCK_MIN_AGE_SECONDS
# ``shallow.lock`` is the one observed in the wild; the others are the same class of failure
# (interrupted git operation). Locks held by a live git process are protected by the process guard.
LOCK_NAMES = ("shallow.lock", "index.lock", "HEAD.lock", "MERGE_HEAD.lock")
# Temp-file prefixes git writes into .git/objects/pack during a transfer and renames away on
# success; anything left with these names after a fetch died is garbage by definition.
_TMP_PACK_PREFIXES = ("tmp_pack_", "tmp_idx_", "tmp_rev_", "tmp_mtimes_")
def _git_proc_running() -> bool:
"""True when a ``git`` process is running — the check that stops us yanking a lock a live fetch holds.
A failed probe logs and returns False; the age floor in the sweep still applies.
"""
try:
if os.name == "nt":
proc = subprocess.run(["tasklist", "/FI", "IMAGENAME eq git.exe", "/FO", "CSV"],
capture_output=True, text=True, timeout=10)
return "git.exe" in proc.stdout.lower()
proc = subprocess.run(["pgrep", "-x", "git"], capture_output=True, text=True, timeout=10)
return proc.returncode == 0
except Exception:
logger.debug("git process probe failed; assuming no git running", exc_info=True)
return False
def _sweep_stale(directory: Path, candidates: Callable[[], Iterable[Path]], *, min_age_seconds: Optional[int],
default_age: int, skip_msg: str, log_removed: Callable[[Path, int], None]) -> List[str]:
"""Shared guard + age-floor sweep. Never raises; skips anything it cannot stat/unlink."""
if not directory.is_dir():
return []
if _git_proc_running():
logger.debug(skip_msg)
return []
cutoff = time.time() - (min_age_seconds if min_age_seconds is not None else default_age)
removed: List[str] = []
for entry in candidates():
try:
if entry.is_file() and (st := entry.stat()).st_mtime < cutoff:
entry.unlink()
removed.append(str(entry))
log_removed(entry, st.st_size)
except OSError:
logger.debug("Could not clear %s (skipping)", entry, exc_info=True)
return removed
def clear_stale_git_locks(repo_root: Path, *, min_age_seconds: Optional[int] = None) -> List[str]:
"""Remove abandoned ``.git`` lock files under ``repo_root``; returns the removed paths.
Removes only when older than the age floor AND no git process is running. Never raises: a lock we cannot
stat/unlink is skipped (it may have been re-created between the age check and the unlink; skipping is safe).
"""
git_dir = Path(repo_root) / ".git"
return _sweep_stale(
git_dir, lambda: [git_dir / name for name in LOCK_NAMES],
min_age_seconds=min_age_seconds, default_age=STALE_LOCK_MIN_AGE_SECONDS,
skip_msg="git process running; skipping stale-lock sweep",
log_removed=lambda p, _size: logger.info("Removed stale git lock %s", p),
)
def clear_stale_tmp_packs(repo_root: Path, *, min_age_seconds: Optional[int] = None) -> List[str]:
"""Remove aborted-fetch temp pack files under ``.git/objects/pack``; same contract as clear_stale_git_locks."""
pack_dir = Path(repo_root) / ".git" / "objects" / "pack"
def _candidates():
try:
return [e for e in pack_dir.iterdir() if e.name.startswith(_TMP_PACK_PREFIXES)]
except OSError:
return []
return _sweep_stale(
pack_dir, _candidates,
min_age_seconds=min_age_seconds, default_age=STALE_TMP_PACK_MIN_AGE_SECONDS,
skip_msg="git process running; skipping tmp-pack sweep",
log_removed=lambda p, size: logger.info("Removed aborted-fetch pack debris %s (%d bytes)", p, size),
)