Files
DECNET/decnet/logging/inode_aware_handler.py
anti f2b3393669 chore: relicense to AGPL-3.0-or-later and add SPDX headers
Replaces LICENSE (GPLv3 -> AGPLv3) and prepends
`SPDX-License-Identifier: AGPL-3.0-or-later` to every source file
across decnet/, decnet_web/, tests/, scripts/, and tools/.

Rationale: closes the GPLv3 ASP loophole so any party operating a
modified DECNET as a network service must offer their modified
source. Personal copyright (Samuel Paschuan) + inbound=outbound
contributions make a future unilateral relicense infeasible.

- LICENSE: full AGPL-3.0 text (gnu.org/licenses/agpl-3.0.txt)
- COPYRIGHT: project copyright notice
- tools/add_spdx_headers.py: idempotent header injector
  (shebang- and PEP 263-aware)

Touches 1565 source files (.py, .ts, .tsx, .js, .jsx, .css, .sh).
No behavior change; comments only.
2026-05-22 21:04:16 -04:00

62 lines
2.2 KiB
Python

# SPDX-License-Identifier: AGPL-3.0-or-later
"""
RotatingFileHandler that detects external deletion or rotation.
Stdlib ``RotatingFileHandler`` holds an open file descriptor for the
lifetime of the handler. If the target file is deleted (``rm``) or
rotated out (``logrotate`` without ``copytruncate``), the handler keeps
writing to the now-orphaned inode until its own size-based rotation
finally triggers — silently losing every line in between.
Stdlib ``WatchedFileHandler`` solves exactly this problem but doesn't
rotate by size. This subclass combines both: before each emit we stat
the configured path and compare its inode/device to the currently open
file; on mismatch we close and reopen.
Cheap: one ``os.stat`` per log record. Matches the pattern used by
``decnet/collector/worker.py:_reopen_if_needed``.
"""
from __future__ import annotations
import logging
import logging.handlers
import os
class InodeAwareRotatingFileHandler(logging.handlers.RotatingFileHandler):
"""RotatingFileHandler that reopens the target on external rotation/deletion."""
def _should_reopen(self) -> bool:
if self.stream is None:
return True
try:
disk_stat = os.stat(self.baseFilename)
except FileNotFoundError:
return True
except OSError:
return False
try:
open_stat = os.fstat(self.stream.fileno())
except OSError:
return True
return (disk_stat.st_ino != open_stat.st_ino
or disk_stat.st_dev != open_stat.st_dev)
def emit(self, record: logging.LogRecord) -> None:
if self._should_reopen():
try:
if self.stream is not None:
self.close()
except Exception: # nosec B110
pass
try:
self.stream = self._open()
except OSError:
# A logging handler MUST NOT crash its caller. If we can't
# reopen (e.g. file is root-owned after `sudo decnet deploy`
# and the current process is non-root), defer to the stdlib
# error path, which just prints a traceback to stderr.
self.handleError(record)
return
super().emit(record)