wehub-resource-sync
c3749daf48
Tests / test-linux (3.13) (push) Failing after 0s
Tests / test-linux (3.11) (push) Failing after 1s
Tests / lint (push) Failing after 0s
Tests / test-linux (3.9) (push) Failing after 1s
Docker / build (push) Failing after 1s
Docker / build-gpu (push) Failing after 2s
Tests / test-windows (push) Has been cancelled
Tests / test-macos (push) Has been cancelled
75 lines
2.8 KiB
Python
75 lines
2.8 KiB
Python
"""Retention pruning for timestamped palace backups.
|
|
|
|
``mempalace migrate`` and ``mempalace repair max-seq-id`` each write a fresh,
|
|
timestamped backup every time they run and historically never deleted the old
|
|
ones. On a machine that mines or repairs on a schedule those full-size copies
|
|
accumulate silently — a real palace was found with hundreds of gigabytes of
|
|
backups sitting beside only a few hundred megabytes of live data, nearly
|
|
filling the disk. This module prunes the backup set down to a bounded count
|
|
after each new backup is written.
|
|
|
|
The retention count comes from ``MempalaceConfig.max_backups`` (default 10).
|
|
"""
|
|
|
|
import glob
|
|
import os
|
|
import shutil
|
|
|
|
|
|
def prune_backups(pattern, max_backups, *, log=None):
|
|
"""Delete the oldest backups matching ``pattern`` so at most ``max_backups`` remain.
|
|
|
|
Args:
|
|
pattern: A glob pattern matching the backup paths (files or
|
|
directories). The caller is responsible for ``glob.escape``-ing
|
|
any literal, non-wildcard portion that can contain glob
|
|
metacharacters — palace paths sometimes do (e.g. a ``[``).
|
|
max_backups: Number of most-recent backups to keep. ``None`` or any
|
|
value ``<= 0`` disables pruning and returns immediately, so a
|
|
backup set is never touched when the user has opted out.
|
|
log: Optional callable (e.g. ``print``) for human-readable progress.
|
|
|
|
Returns:
|
|
The list of paths that were successfully removed.
|
|
|
|
Recency is determined by filesystem mtime rather than by parsing the
|
|
timestamp out of the name, so it stays correct even when two backup
|
|
producers use different timestamp formats. Deletion failures are logged
|
|
and skipped: pruning is best-effort cleanup and must never abort the
|
|
migrate/repair operation that just completed successfully.
|
|
"""
|
|
if max_backups is None or max_backups <= 0:
|
|
return []
|
|
|
|
scored = []
|
|
for path in glob.glob(pattern):
|
|
try:
|
|
scored.append((os.path.getmtime(path), path))
|
|
except OSError:
|
|
# Vanished between glob and stat (concurrent prune / cleanup);
|
|
# nothing for us to remove.
|
|
continue
|
|
|
|
if len(scored) <= max_backups:
|
|
return []
|
|
|
|
# Newest first; the path breaks mtime ties so ordering is deterministic.
|
|
scored.sort(key=lambda item: (item[0], item[1]), reverse=True)
|
|
|
|
removed = []
|
|
for _mtime, path in scored[max_backups:]:
|
|
try:
|
|
if os.path.isdir(path) and not os.path.islink(path):
|
|
shutil.rmtree(path)
|
|
else:
|
|
os.remove(path)
|
|
except OSError as exc:
|
|
if log:
|
|
log(f" Backup prune: could not remove {path}: {exc}")
|
|
continue
|
|
removed.append(path)
|
|
if log:
|
|
log(f" Backup prune: removed old backup {path}")
|
|
|
|
return removed
|