Files
changedetection.io/changedetectionio/notification/task_queue/file_storage.py
T
2026-01-06 18:21:09 +01:00

385 lines
13 KiB
Python

"""
FileStorage backend task manager for Huey notifications.
This is the default backend, optimized for NAS/CIFS compatibility.
INDUSTRIAL-GRADE ENHANCEMENTS:
- Atomic file writes (prevents corruption on crash/power failure)
- JSON corruption detection and recovery
- Lost-found directory for corrupted files
"""
from loguru import logger
from .base import HueyTaskManager
import os
def _atomic_json_write(filepath, data):
"""
Atomic JSON write - never leaves partial/corrupted files.
Critical for aerospace-grade reliability:
- Writes to temp file first
- Forces data to disk (fsync)
- Atomic rename (POSIX guarantees atomicity)
If process crashes mid-write, you either get:
- Old complete file (rename didn't happen)
- New complete file (rename succeeded)
Never a partial/corrupted file.
Args:
filepath: Target file path
data: Data to write (will be JSON encoded)
Returns:
True on success
Raises:
Exception on write failure
"""
import tempfile
import json
directory = os.path.dirname(filepath)
# Write to temp file in same directory (same filesystem = atomic rename)
fd, temp_path = tempfile.mkstemp(dir=directory, prefix='.tmp_', suffix='.json')
try:
with os.fdopen(fd, 'w') as f:
json.dump(data, f, indent=2)
f.flush()
os.fsync(f.fileno()) # Force to disk before rename
# Atomic rename (POSIX guarantees atomicity)
# If crash happens here, worst case is orphaned temp file
os.replace(temp_path, filepath)
return True
except Exception as e:
# Clean up temp file on error
try:
os.unlink(temp_path)
except:
pass
raise
def _safe_json_load(filepath, schema_name, storage_path):
"""
Load JSON with corruption detection and recovery.
Corrupted files are moved to lost-found for forensic analysis.
Args:
filepath: JSON file to load
schema_name: Schema type (for lost-found directory)
storage_path: Root storage path
Returns:
Parsed JSON data or None if corrupted
"""
import json
import shutil
import time
try:
with open(filepath, 'r') as f:
return json.load(f)
except (json.JSONDecodeError, EOFError) as e:
# Corrupted or incomplete JSON file
file_size = os.path.getsize(filepath) if os.path.exists(filepath) else 0
filename = os.path.basename(filepath)
logger.warning(f"Corrupted {schema_name} file: {filename} ({file_size} bytes) - moving to lost-found")
try:
lost_found_dir = os.path.join(storage_path, 'lost-found', schema_name)
os.makedirs(lost_found_dir, exist_ok=True)
timestamp = int(time.time())
lost_found_path = os.path.join(lost_found_dir, f"{filename}.{timestamp}.corrupted")
shutil.move(filepath, lost_found_path)
logger.info(f"Moved corrupted {schema_name} file to {lost_found_path}")
except Exception as move_err:
logger.error(f"Unable to move corrupted {schema_name} file: {move_err}")
return None
except Exception as e:
logger.debug(f"Unable to load {schema_name} file {filepath}: {e}")
return None
class FileStorageTaskManager(HueyTaskManager):
"""Task manager for FileStorage backend (default, NAS-safe)."""
def enumerate_results(self):
"""Enumerate results by walking filesystem directories."""
import os
import pickle
import struct
import time
results = {}
if not self.storage_path:
return results
results_dir = os.path.join(self.storage_path, 'results')
if not os.path.exists(results_dir):
return results
# Walk through all subdirectories to find result files
for root, dirs, files in os.walk(results_dir):
for filename in files:
if filename.startswith('.'):
continue
filepath = os.path.join(root, filename)
try:
# Read and unpickle the result
# Huey FileStorage format: 4-byte length + task_id + pickled data
with open(filepath, 'rb') as f:
# Read the task ID header (length-prefixed)
task_id_len_bytes = f.read(4)
if len(task_id_len_bytes) < 4:
raise EOFError("Incomplete header")
task_id_len = struct.unpack('>I', task_id_len_bytes)[0]
task_id_bytes = f.read(task_id_len)
if len(task_id_bytes) < task_id_len:
raise EOFError("Incomplete task ID")
task_id = task_id_bytes.decode('utf-8')
# Now unpickle the result data
result_data = pickle.load(f)
results[task_id] = result_data
except (pickle.UnpicklingError, EOFError) as e:
# Corrupted or incomplete result file
file_size = os.path.getsize(filepath)
logger.warning(f"Corrupted result file {filename} ({file_size} bytes) - moving to lost-found.")
try:
import shutil
lost_found_dir = os.path.join(self.storage_path, 'lost-found', 'results')
os.makedirs(lost_found_dir, exist_ok=True)
timestamp = int(time.time())
lost_found_path = os.path.join(lost_found_dir, f"{filename}.{timestamp}.corrupted")
shutil.move(filepath, lost_found_path)
logger.info(f"Moved corrupted file to {lost_found_path}")
except Exception as move_err:
logger.error(f"Unable to move corrupted file: {move_err}")
except Exception as e:
logger.debug(f"Unable to read result file {filename}: {e}")
return results
def delete_result(self, task_id):
"""Delete result file from filesystem."""
import hashlib
if not self.storage_path:
return False
results_dir = os.path.join(self.storage_path, 'results')
# Huey uses MD5 hash to create subdirectories
task_id_bytes = task_id.encode('utf-8')
hex_hash = hashlib.md5(task_id_bytes).hexdigest()
# FileStorage creates subdirectories based on first 2 chars of hash
subdir = hex_hash[:2]
result_file = os.path.join(results_dir, subdir, task_id)
if os.path.exists(result_file):
os.remove(result_file)
logger.debug(f"Deleted result file for task {task_id}")
return True
else:
logger.debug(f"Result file not found for task {task_id}")
return False
def count_storage_items(self):
"""Count items by walking filesystem directories."""
queue_count = 0
schedule_count = 0
if not self.storage_path:
return queue_count, schedule_count
try:
# Count queue files
queue_dir = os.path.join(self.storage_path, 'queue')
if os.path.exists(queue_dir):
for root, dirs, files in os.walk(queue_dir):
queue_count += len([f for f in files if not f.startswith('.')])
# Count schedule files
schedule_dir = os.path.join(self.storage_path, 'schedule')
if os.path.exists(schedule_dir):
for root, dirs, files in os.walk(schedule_dir):
schedule_count += len([f for f in files if not f.startswith('.')])
except Exception as e:
logger.debug(f"FileStorage count error: {e}")
return queue_count, schedule_count
def clear_all_notifications(self):
"""Clear all notification files from filesystem."""
cleared = {
'queue': 0,
'schedule': 0,
'results': 0,
'retry_attempts': 0,
'task_metadata': 0,
'delivered': 0
}
if not self.storage_path:
return cleared
# Clear queue
queue_dir = os.path.join(self.storage_path, 'queue')
if os.path.exists(queue_dir):
for root, dirs, files in os.walk(queue_dir):
for f in files:
if not f.startswith('.'):
os.remove(os.path.join(root, f))
cleared['queue'] += 1
# Clear schedule
schedule_dir = os.path.join(self.storage_path, 'schedule')
if os.path.exists(schedule_dir):
for root, dirs, files in os.walk(schedule_dir):
for f in files:
if not f.startswith('.'):
os.remove(os.path.join(root, f))
cleared['schedule'] += 1
# Clear results
results_dir = os.path.join(self.storage_path, 'results')
if os.path.exists(results_dir):
for root, dirs, files in os.walk(results_dir):
for f in files:
if not f.startswith('.'):
os.remove(os.path.join(root, f))
cleared['results'] += 1
# Clear retry attempts
attempts_dir = os.path.join(self.storage_path, 'retry_attempts')
if os.path.exists(attempts_dir):
for f in os.listdir(attempts_dir):
if f.endswith('.json'):
os.remove(os.path.join(attempts_dir, f))
cleared['retry_attempts'] += 1
# Clear task metadata
metadata_dir = os.path.join(self.storage_path, 'task_metadata')
if os.path.exists(metadata_dir):
for f in os.listdir(metadata_dir):
if f.endswith('.json'):
os.remove(os.path.join(metadata_dir, f))
cleared['task_metadata'] += 1
# Clear delivered (success) notifications
success_dir = os.path.join(self.storage_path, 'success')
if os.path.exists(success_dir):
for f in os.listdir(success_dir):
if f.startswith('success-') and f.endswith('.json'):
os.remove(os.path.join(success_dir, f))
cleared['delivered'] += 1
return cleared
def store_task_metadata(self, task_id, metadata):
"""Store task metadata as JSON file with atomic write."""
import time
if not self.storage_path:
return False
try:
metadata_dir = os.path.join(self.storage_path, 'task_metadata')
os.makedirs(metadata_dir, exist_ok=True)
metadata_file = os.path.join(metadata_dir, f"{task_id}.json")
metadata_with_id = {
'task_id': task_id,
'timestamp': time.time(),
**metadata
}
# Use atomic write to prevent corruption
_atomic_json_write(metadata_file, metadata_with_id)
return True
except Exception as e:
logger.debug(f"Unable to store task metadata: {e}")
return False
def get_task_metadata(self, task_id):
"""Retrieve task metadata from JSON file with corruption handling."""
if not self.storage_path:
return None
try:
metadata_dir = os.path.join(self.storage_path, 'task_metadata')
metadata_file = os.path.join(metadata_dir, f"{task_id}.json")
if os.path.exists(metadata_file):
# Use safe JSON load with corruption handling
return _safe_json_load(metadata_file, 'task_metadata', self.storage_path)
except Exception as e:
logger.debug(f"Unable to load task metadata for {task_id}: {e}")
return None
def delete_task_metadata(self, task_id):
"""Delete task metadata JSON file."""
if not self.storage_path:
return False
try:
metadata_dir = os.path.join(self.storage_path, 'task_metadata')
metadata_file = os.path.join(metadata_dir, f"{task_id}.json")
if os.path.exists(metadata_file):
os.remove(metadata_file)
return True
return False
except Exception as e:
logger.debug(f"Unable to delete task metadata for {task_id}: {e}")
return False
def cleanup_old_retry_attempts(self, cutoff_time):
"""Clean up old retry attempt files from filesystem."""
if not self.storage_path:
return 0
deleted_count = 0
try:
attempts_dir = os.path.join(self.storage_path, 'retry_attempts')
if os.path.exists(attempts_dir):
for filename in os.listdir(attempts_dir):
if filename.endswith('.json'):
filepath = os.path.join(attempts_dir, filename)
try:
file_mtime = os.path.getmtime(filepath)
if file_mtime < cutoff_time:
os.remove(filepath)
deleted_count += 1
except Exception as fe:
logger.debug(f"Unable to delete old retry attempt file {filename}: {fe}")
except Exception as e:
logger.debug(f"Error cleaning up old retry attempts: {e}")
return deleted_count