frigate/frigate/util/file.py
leccelecce cedf85fffa Fixes
2026-03-10 22:57:53 +00:00

494 lines
15 KiB
Python

"""Path and file utilities."""
import base64
import fcntl
import logging
import os
import time
from datetime import datetime
from pathlib import Path
from typing import Any, Optional
import cv2
from numpy import ndarray
from frigate.const import CLIPS_DIR, THUMB_DIR
from frigate.models import Event
from frigate.util.image import get_snapshot_bytes, relative_box_to_absolute
logger = logging.getLogger(__name__)
def get_event_thumbnail_bytes(event: Event) -> bytes | None:
if event.thumbnail:
return base64.b64decode(event.thumbnail)
else:
try:
with open(
os.path.join(THUMB_DIR, event.camera, f"{event.id}.webp"), "rb"
) as f:
return f.read()
except Exception:
return None
def get_event_snapshot(event: Event) -> ndarray | None:
image, _ = load_event_snapshot_image(event)
return image
def _load_snapshot_image(image_path: str) -> ndarray | None:
image = cv2.imread(image_path, cv2.IMREAD_UNCHANGED)
if image is None:
return None
if len(image.shape) == 2:
return cv2.cvtColor(image, cv2.COLOR_GRAY2BGR)
if len(image.shape) == 3 and image.shape[2] == 4:
return cv2.cvtColor(image, cv2.COLOR_BGRA2BGR)
return image
def _event_snapshot_is_clean(event: Event) -> bool:
return bool(event.data and event.data.get("snapshot_clean"))
def get_event_snapshot_path(
event: Event, *, clean_only: bool = False
) -> tuple[str | None, bool]:
clean_snapshot_paths = [
os.path.join(CLIPS_DIR, f"{event.camera}-{event.id}-clean.webp"),
os.path.join(CLIPS_DIR, f"{event.camera}-{event.id}-clean.png"),
]
for image_path in clean_snapshot_paths:
if os.path.exists(image_path):
return image_path, True
snapshot_path = os.path.join(CLIPS_DIR, f"{event.camera}-{event.id}.jpg")
if not os.path.exists(snapshot_path):
return None, False
is_clean_snapshot = _event_snapshot_is_clean(event)
if clean_only and not is_clean_snapshot:
return None, False
return snapshot_path, is_clean_snapshot
def load_event_snapshot_image(
event: Event, *, clean_only: bool = False
) -> tuple[ndarray | None, bool]:
image_path, is_clean_snapshot = get_event_snapshot_path(
event, clean_only=clean_only
)
if image_path is None:
return None, False
image = _load_snapshot_image(image_path)
if image is None:
logger.warning("Unable to load snapshot from %s", image_path)
return None, False
return image, is_clean_snapshot
def _get_event_snapshot_overlay_boxes(
frame_shape: tuple[int, ...], event: Event
) -> list[dict[str, Any]]:
overlay_boxes: list[dict[str, Any]] = []
draw_data = event.data.get("draw") if event.data else {}
draw_boxes = draw_data.get("boxes", []) if isinstance(draw_data, dict) else []
for draw_box in draw_boxes:
box = relative_box_to_absolute(frame_shape, draw_box.get("box"))
if box is None:
continue
draw_color = draw_box.get("color", (255, 0, 0))
color = (
tuple(draw_color) if isinstance(draw_color, (list, tuple)) else (255, 0, 0)
)
overlay_boxes.append(
{
"box": box,
"label": event.label,
"score": draw_box.get("score"),
"color": color,
}
)
return overlay_boxes
def get_event_snapshot_bytes(
event: Event,
*,
ext: str,
timestamp: bool = False,
bounding_box: bool = False,
crop: bool = False,
height: int | None = None,
quality: int | None = None,
timestamp_style: Any | None = None,
colormap: dict[str, tuple[int, int, int]] | None = None,
) -> tuple[bytes | None, float]:
best_frame, is_clean_snapshot = load_event_snapshot_image(event)
if best_frame is None:
return None, 0
frame_time = _get_event_snapshot_frame_time(event)
box = relative_box_to_absolute(
best_frame.shape,
event.data.get("box") if event.data else None,
)
overlay_boxes = _get_event_snapshot_overlay_boxes(best_frame.shape, event)
if (bounding_box or crop or timestamp) and not is_clean_snapshot:
logger.warning(
"Unable to fully honor snapshot query parameters for completed event %s because the clean snapshot is unavailable.",
event.id,
)
return get_snapshot_bytes(
best_frame,
frame_time,
ext=ext,
timestamp=timestamp and is_clean_snapshot,
bounding_box=bounding_box and is_clean_snapshot,
crop=crop and is_clean_snapshot,
height=height,
quality=quality,
label=event.label,
box=box,
score=_get_event_snapshot_score(event),
area=_get_event_snapshot_area(event),
attributes=_get_event_snapshot_attributes(
best_frame.shape,
event.data.get("attributes") if event.data else None,
),
color=(colormap or {}).get(event.label, (255, 255, 255)),
overlay_boxes=overlay_boxes,
timestamp_style=timestamp_style,
estimated_speed=_get_event_snapshot_estimated_speed(event),
)
def _as_timestamp(value: Any) -> float:
if isinstance(value, datetime):
return value.timestamp()
return float(value)
def _get_event_snapshot_frame_time(event: Event) -> float:
if event.data:
snapshot_frame_time = event.data.get("snapshot_frame_time")
if snapshot_frame_time is not None:
return _as_timestamp(snapshot_frame_time)
frame_time = event.data.get("frame_time")
if frame_time is not None:
return _as_timestamp(frame_time)
return _as_timestamp(event.start_time)
def _get_event_snapshot_attributes(
frame_shape: tuple[int, ...], attributes: list[dict[str, Any]] | None
) -> list[dict[str, Any]]:
absolute_attributes: list[dict[str, Any]] = []
for attribute in attributes or []:
box = relative_box_to_absolute(frame_shape, attribute.get("box"))
if box is None:
continue
absolute_attributes.append(
{
"box": box,
"label": attribute.get("label", "attribute"),
"score": attribute.get("score", 0),
}
)
return absolute_attributes
def _get_event_snapshot_score(event: Event) -> float:
if event.data:
score = event.data.get("score")
if score is not None:
return score
top_score = event.data.get("top_score")
if top_score is not None:
return top_score
return event.top_score or event.score or 0
def _get_event_snapshot_area(event: Event) -> int | None:
if event.data:
area = event.data.get("snapshot_area")
if area is not None:
return int(area)
return None
def _get_event_snapshot_estimated_speed(event: Event) -> float:
if event.data:
estimated_speed = event.data.get("snapshot_estimated_speed")
if estimated_speed is not None:
return float(estimated_speed)
average_speed = event.data.get("average_estimated_speed")
if average_speed is not None:
return float(average_speed)
return 0
### Deletion
def delete_event_images(event: Event) -> bool:
return delete_event_snapshot(event) and delete_event_thumbnail(event)
def delete_event_snapshot(event: Event) -> bool:
media_name = f"{event.camera}-{event.id}"
media_path = Path(f"{os.path.join(CLIPS_DIR, media_name)}.jpg")
try:
media_path.unlink(missing_ok=True)
media_path = Path(f"{os.path.join(CLIPS_DIR, media_name)}-clean.webp")
media_path.unlink(missing_ok=True)
# also delete clean.png (legacy) for backward compatibility
media_path = Path(f"{os.path.join(CLIPS_DIR, media_name)}-clean.png")
media_path.unlink(missing_ok=True)
return True
except OSError:
return False
def delete_event_thumbnail(event: Event) -> bool:
if event.thumbnail:
return True
else:
Path(os.path.join(THUMB_DIR, event.camera, f"{event.id}.webp")).unlink(
missing_ok=True
)
return True
### File Locking
class FileLock:
"""
A file-based lock for coordinating access to resources across processes.
Uses fcntl.flock() for proper POSIX file locking on Linux. Supports timeouts,
stale lock detection, and can be used as a context manager.
Example:
```python
# Using as a context manager (recommended)
with FileLock("/path/to/resource.lock", timeout=60):
# Critical section
do_something()
# Manual acquisition and release
lock = FileLock("/path/to/resource.lock")
if lock.acquire(timeout=60):
try:
do_something()
finally:
lock.release()
```
Attributes:
lock_path: Path to the lock file
timeout: Maximum time to wait for lock acquisition (seconds)
poll_interval: Time to wait between lock acquisition attempts (seconds)
stale_timeout: Time after which a lock is considered stale (seconds)
"""
def __init__(
self,
lock_path: str | Path,
timeout: int = 300,
poll_interval: float = 1.0,
stale_timeout: int = 600,
cleanup_stale_on_init: bool = False,
):
"""
Initialize a FileLock.
Args:
lock_path: Path to the lock file
timeout: Maximum time to wait for lock acquisition in seconds (default: 300)
poll_interval: Time to wait between lock attempts in seconds (default: 1.0)
stale_timeout: Time after which a lock is considered stale in seconds (default: 600)
cleanup_stale_on_init: Whether to clean up stale locks on initialization (default: False)
"""
self.lock_path = Path(lock_path)
self.timeout = timeout
self.poll_interval = poll_interval
self.stale_timeout = stale_timeout
self._fd: Optional[int] = None
self._acquired = False
if cleanup_stale_on_init:
self._cleanup_stale_lock()
def _cleanup_stale_lock(self) -> bool:
"""
Clean up a stale lock file if it exists and is old.
Returns:
True if lock was cleaned up, False otherwise
"""
try:
if self.lock_path.exists():
# Check if lock file is older than stale_timeout
lock_age = time.time() - self.lock_path.stat().st_mtime
if lock_age > self.stale_timeout:
logger.warning(
f"Removing stale lock file: {self.lock_path} (age: {lock_age:.1f}s)"
)
self.lock_path.unlink()
return True
except Exception as e:
logger.error(f"Error cleaning up stale lock: {e}")
return False
def is_stale(self) -> bool:
"""
Check if the lock file is stale (older than stale_timeout).
Returns:
True if lock is stale, False otherwise
"""
try:
if self.lock_path.exists():
lock_age = time.time() - self.lock_path.stat().st_mtime
return lock_age > self.stale_timeout
except Exception:
pass
return False
def acquire(self, timeout: Optional[int] = None) -> bool:
"""
Acquire the file lock using fcntl.flock().
Args:
timeout: Maximum time to wait for lock in seconds (uses instance timeout if None)
Returns:
True if lock acquired, False if timeout or error
"""
if self._acquired:
logger.warning(f"Lock already acquired: {self.lock_path}")
return True
if timeout is None:
timeout = self.timeout
# Ensure parent directory exists
self.lock_path.parent.mkdir(parents=True, exist_ok=True)
# Clean up stale lock before attempting to acquire
self._cleanup_stale_lock()
try:
self._fd = os.open(self.lock_path, os.O_CREAT | os.O_RDWR)
start_time = time.time()
while time.time() - start_time < timeout:
try:
fcntl.flock(self._fd, fcntl.LOCK_EX | fcntl.LOCK_NB)
self._acquired = True
logger.debug(f"Acquired lock: {self.lock_path}")
return True
except (OSError, IOError):
# Lock is held by another process
if time.time() - start_time >= timeout:
logger.warning(f"Timeout waiting for lock: {self.lock_path}")
os.close(self._fd)
self._fd = None
return False
time.sleep(self.poll_interval)
# Timeout reached
if self._fd is not None:
os.close(self._fd)
self._fd = None
return False
except Exception as e:
logger.error(f"Error acquiring lock: {e}")
if self._fd is not None:
try:
os.close(self._fd)
except Exception:
pass
self._fd = None
return False
def release(self) -> None:
"""
Release the file lock.
This closes the file descriptor and removes the lock file.
"""
if not self._acquired:
return
try:
# Close file descriptor and release fcntl lock
if self._fd is not None:
try:
fcntl.flock(self._fd, fcntl.LOCK_UN)
os.close(self._fd)
except Exception as e:
logger.warning(f"Error closing lock file descriptor: {e}")
finally:
self._fd = None
# Remove lock file
if self.lock_path.exists():
self.lock_path.unlink()
logger.debug(f"Released lock: {self.lock_path}")
except FileNotFoundError:
# Lock file already removed, that's fine
pass
except Exception as e:
logger.error(f"Error releasing lock: {e}")
finally:
self._acquired = False
def __enter__(self):
"""Context manager entry - acquire the lock."""
if not self.acquire():
raise TimeoutError(f"Failed to acquire lock: {self.lock_path}")
return self
def __exit__(self, exc_type, exc_val, exc_tb):
"""Context manager exit - release the lock."""
self.release()
return False
def __del__(self):
"""Destructor - ensure lock is released."""
if self._acquired:
self.release()