refactor api_server: implement asynchronous file I/O using asyncio.to_thread for JSON operations, add global python-magic instance for MIME type detection, and enhance delayed file deletion documentation

This commit is contained in:
vvzvlad
2025-09-12 23:50:52 +03:00
parent 43516d6dab
commit 778aa04904
+31 -24
View File
@@ -38,6 +38,9 @@ from rss_generator import generate_channel_rss, generate_channel_html
from post_parser import PostParser
from url_signer import verify_media_digest, generate_media_digest
# Global python-magic instance for MIME type detection
magic_mime = magic.Magic(mime=True)
# Define custom exception for zero-size files
class ZeroSizeFileError(Exception):
"""Custom exception for zero-size files found or downloaded."""
@@ -178,6 +181,7 @@ def delayed_delete_file(file_path: str, delay: int = 300) -> None:
"""
Delete temporary file after a delay to ensure complete file delivery.
Delay is set to 5 minutes by default.
NOTE: Runs in a background thread via Starlette BackgroundTask.
"""
time.sleep(delay)
try:
@@ -192,8 +196,8 @@ async def prepare_file_response(file_path: str, delete_after: bool = False) -> F
if not os.path.exists(file_path): raise HTTPException(status_code=404, detail="File not found")
try:
mime = magic.Magic(mime=True) # Try to determine MIME type using python-magic first
media_type = mime.from_file(file_path)
# Determine MIME type using python-magic in a thread to avoid blocking the event loop
media_type = await asyncio.to_thread(magic_mime.from_file, file_path)
except Exception as e:
logger.warning(f"Failed to determine MIME type using python-magic: {str(e)}")
media_type = None
@@ -272,16 +276,14 @@ async def download_media_file(channel: Union[str, int], post_id: int, file_uniqu
file_ids_path = os.path.join(os.path.abspath("./data"), 'media_file_ids.json')
try:
if os.path.exists(file_ids_path):
with open(file_ids_path, 'r', encoding='utf-8') as f:
media_files = json.load(f)
media_files = await asyncio.to_thread(read_json_file_sync, file_ids_path)
for file_data in media_files:
if (file_data.get('channel') == str(channel) and # Ensure channel is string for comparison
file_data.get('post_id') == post_id and
file_data.get('file_unique_id') == file_unique_id):
file_data['added'] = datetime.now().timestamp()
break
with open(file_ids_path, 'w', encoding='utf-8') as f:
json.dump(media_files, f, ensure_ascii=False, indent=2)
await asyncio.to_thread(write_json_file_sync, file_ids_path, media_files)
except Exception as e:
logger.error(f"Failed to update timestamp for {channel}/{post_id}/{file_unique_id}: {str(e)}")
return cache_path, False
@@ -291,13 +293,11 @@ async def download_media_file(channel: Union[str, int], post_id: int, file_uniqu
error_message = f"Media with file_unique_id {file_unique_id} not found in message {post_id} for channel {channel}"
logger.error(error_message)
# Attempt to remove the invalid entry from media_file_ids.json
# Attempt to remove the invalid entry from media_file_ids.json using threadpool I/O
file_ids_path = os.path.join(os.path.abspath("./data"), 'media_file_ids.json')
try:
if os.path.exists(file_ids_path):
with open(file_ids_path, 'r', encoding='utf-8') as f:
media_files = json.load(f)
media_files = await asyncio.to_thread(read_json_file_sync, file_ids_path)
initial_count = len(media_files)
media_files_updated = [
f_data for f_data in media_files
@@ -307,10 +307,8 @@ async def download_media_file(channel: Union[str, int], post_id: int, file_uniqu
f_data.get('file_unique_id') == file_unique_id
)
]
if len(media_files_updated) < initial_count:
with open(file_ids_path, 'w', encoding='utf-8') as f:
json.dump(media_files_updated, f, ensure_ascii=False, indent=2)
await asyncio.to_thread(write_json_file_sync, file_ids_path, media_files_updated)
logger.info(f"Removed invalid entry for {channel}/{post_id}/{file_unique_id} from media_file_ids.json")
else:
logger.warning(f"Entry for {channel}/{post_id}/{file_unique_id} not found in media_file_ids.json for removal")
@@ -340,7 +338,7 @@ async def download_media_file(channel: Union[str, int], post_id: int, file_uniqu
return file_path, False
async def remove_old_cached_files(media_files: list, cache_dir: str) -> tuple[list, int]:
def remove_old_cached_files_sync(media_files: list, cache_dir: str) -> tuple[list, int]:
"""
Remove files that haven't been accessed for more than 20 days
Returns tuple of (updated media files list, number of removed files)
@@ -501,26 +499,23 @@ async def cache_media_files() -> None:
continue
try:
with open(file_path, 'r', encoding='utf-8') as f:
media_files = json.load(f)
media_files = await asyncio.to_thread(read_json_file_sync, file_path)
except json.JSONDecodeError:
logger.error(f"JSON decode error in {file_path}, attempting to fix")
media_files = fix_corrupted_json(file_path)
media_files = await asyncio.to_thread(fix_corrupted_json, file_path)
if media_files:
with open(file_path, 'w', encoding='utf-8') as f:
json.dump(media_files, f, ensure_ascii=False, indent=2)
await asyncio.to_thread(write_json_file_sync, file_path, media_files)
else:
logger.error("Failed to fix JSON file, skipping cache update")
await asyncio.sleep(delay)
continue
cache_dir = os.path.abspath("./data/cache")
updated_media_files, files_removed = await remove_old_cached_files(media_files, cache_dir)
updated_media_files, files_removed = await asyncio.to_thread(remove_old_cached_files_sync, media_files, cache_dir)
if files_removed > 0:
try:
with open(file_path, 'w', encoding='utf-8') as f:
json.dump(updated_media_files, f, ensure_ascii=False, indent=2)
await asyncio.to_thread(write_json_file_sync, file_path, updated_media_files)
logger.info(f"Removed {files_removed} old files from cache")
except Exception as e:
logger.error(f"Failed to update media_file_ids.json: {str(e)}")
@@ -596,6 +591,17 @@ def calculate_cache_stats() -> dict[str, Any]:
"channels": channels_stats
}
# Synchronous JSON helpers to be used via asyncio.to_thread
def read_json_file_sync(file_path: str) -> list:
with open(file_path, 'r', encoding='utf-8') as f:
return json.load(f)
def write_json_file_sync(file_path: str, data: list) -> None:
temp_path = f"{file_path}.tmp"
with open(temp_path, 'w', encoding='utf-8') as f:
json.dump(data, f, ensure_ascii=False, indent=2)
os.replace(temp_path, file_path)
def is_local_request(request: Request) -> bool:
local_hosts = ["127.0.0.1", "localhost"]
if request and request.client and request.client.host:
@@ -699,8 +705,9 @@ async def health_check(request: Request, token: str | None = None) -> Response:
try:
me = await client.client.get_me()
cache_stats = calculate_cache_stats()
# Offload heavy filesystem scanning to threadpool
cache_stats = await asyncio.to_thread(calculate_cache_stats)
config_info = {}
for config_key, config_value in Config.items():