def cache_file_at_url(self, url):
""" Caches the remote file or retrieves its cached version if one exists. Returns None if an error occurs. """
filename, extension = os.path.splitext(url)
cache_asset_hash = hash(str(self.channel_id) + filename)
asset = Asset.selectBy(plugin_channel=self.channel_id,
filename=filename,
is_cached=True).getOne(None)
if asset is None:
if CacheManager._get_lock(cache_asset_hash, blocking=False):
try:
asset = Asset(plugin_channel=self.channel_id,
filename=filename,
user=None,
extension=extension if extension is not None
and len(extension) > 0 else None,
is_cached=True)
self.download_manager.enqueue_asset(asset)
except (URLError, OSError):
logger.warning(
'Exception encountered when attempting to cache file at url %s',
url,
exc_info=True)
CacheManager._release_lock(cache_asset_hash)
return None
CacheManager._release_lock(cache_asset_hash)
else:
CacheManager._get_lock(cache_asset_hash, blocking=True)
CacheManager._release_lock(cache_asset_hash)
asset = Asset.selectBy(plugin_channel=self.channel_id,
filename=filename,
is_cached=True).getOne(None)
return asset
def get_cached_file(self, filename):
"""
Returns an Asset if this cache manager has a cached version of the given file for this channel
or None if none exists.
"""
return Asset.selectBy(plugin_channel=self.channel_id,
filename=filename,
is_cached=True).getOne(None)
def cleanup_cache(self):
""" Cleans up the cached assets by deleting all assets not referenced during this day. """
today = datetime.date.today()
unused_assets = Asset.selectBy(is_cached=True).filter(Asset.q.last_reference < sqlbuilder.func.date(str(today)))
total_assets_size = 0
if unused_assets.count() > 0:
total_assets_size = int(unused_assets.sum(Asset.q.file_size))
Asset.deleteMany(AND(Asset.q.last_reference < sqlbuilder.func.date(str(today)), Asset.q.is_cached == True))
logger.info('Ran cache cleanup and deleted %d assets for a total size of %s', unused_assets.count(),
CleanupScheduler._human_readable_size(total_assets_size))
next_cleanup = datetime.datetime.combine(today + datetime.timedelta(days=1), datetime.time(hour=23, minute=55))
self.s.enterabs(time.mktime(next_cleanup.timetuple()), 1, self.cleanup_cache)