diff options
Diffstat (limited to 'tg_backup.py')
| -rw-r--r-- | tg_backup.py | 38 |
1 files changed, 32 insertions, 6 deletions
diff --git a/tg_backup.py b/tg_backup.py index 6c77878..382a756 100644 --- a/tg_backup.py +++ b/tg_backup.py @@ -75,6 +75,15 @@ def save_state(archive_dir, state): json.dump(state, f, indent=4) os.replace(tmp_file, state_file) +def record_failure(archive_dir, message_id, filename, error): + # State advances past a permanently failed download on purpose, so without + # this the message ID is lost and the backup silently has a hole in it. + # Append-only log, one JSON object per line: a partial last line costs one + # record, not the whole file. + entry = {'id': message_id, 'file': filename, 'error': str(error)} + with open(archive_dir / "failures.json", 'a') as f: + f.write(json.dumps(entry) + "\n") + def safe_filename(message_id, original_name, ext): # original_name comes from the sender. Strip path components so a name like # "../../.ssh/authorized_keys" resolves to a plain file inside archive_dir. @@ -87,12 +96,14 @@ async def download_with_retry(client, message, filepath): # Download to a .part file so an interrupted run never leaves a truncated # file that the exists() check would mistake for a complete download. partpath = filepath.with_name(filepath.name + ".part") + last_error = f"no attempt made (MAX_RETRIES={MAX_RETRIES})" for attempt in range(MAX_RETRIES): try: await client.download_media(message, file=str(partpath)) os.replace(partpath, filepath) - return True + return None except FloodWaitError as e: + last_error = e print(f"Rate limited on download. Waiting {e.seconds}s... (Attempt {attempt+1}/{MAX_RETRIES})") await asyncio.sleep(e.seconds) except (KeyboardInterrupt, asyncio.CancelledError): @@ -101,6 +112,7 @@ async def download_with_retry(client, message, filepath): except Exception as e: # Network drops, expired file references, disk errors. Backing off # and retrying beats killing an overnight run on one bad socket. + last_error = e delay = 2 ** attempt print(f"Download error on {filepath.name}: {e}. " f"Retrying in {delay}s... (Attempt {attempt+1}/{MAX_RETRIES})") @@ -108,7 +120,8 @@ async def download_with_retry(client, message, filepath): await asyncio.sleep(delay) partpath.unlink(missing_ok=True) print(f"Failed to download {filepath.name} after {MAX_RETRIES} retries.") - return False + # Returns the last error, or None on success: the caller logs it to failures.json. + return last_error def migrate_session(archive_dir): # Sessions used to live per-archive-dir, which forced a fresh login for every @@ -206,11 +219,14 @@ async def run_backup(target, archive_dir): if not filepath.exists(): print(f"Downloading {filename}...") - success = await download_with_retry(client, message, filepath) - if not success: - # If download permanently fails, we still advance state + error = await download_with_retry(client, message, filepath) + if error is not None: + # If download permanently fails, we still advance state # so we don't get stuck on a broken file forever. - print("Skipping file due to max retries.") + # Log it so the gap is auditable instead of silent. + record_failure(archive_dir, message.id, filename, error) + print(f"Skipping file due to max retries " + f"(logged to {archive_dir / 'failures.json'}).") else: print(f"Skipping {filename} (exists).") @@ -292,6 +308,16 @@ def _self_check(): assert load_state(archive).get('target') == '-1001234567890' assert load_state(Path(tempfile.mkdtemp())).get('target') is None + # Failures append, one parseable record per line, and survive an exception + # object being passed straight in. + record_failure(archive, 11, '11_a.jpg', OSError('disk full')) + record_failure(archive, 12, '12_b.mp4', 'timeout') + lines = (archive / 'failures.json').read_text().splitlines() + assert len(lines) == 2, f"expected 2 failure records, got {len(lines)}" + first, second = json.loads(lines[0]), json.loads(lines[1]) + assert first == {'id': 11, 'file': '11_a.jpg', 'error': 'disk full'} + assert second['id'] == 12 and second['error'] == 'timeout' + print("self-check OK") if __name__ == "__main__": |