def trim_dir(directory):
"""
Removed the least accessed file on a given dir
:param directory: Directory to check
"""
access_time = lambda f: os.stat(os.path.join(directory, f)).st_atime
files = sorted(os.listdir(directory), key=access_time)
file_name = os.path.join(directory, files[0])
log.debug('removing least accessed file: %s', file_name)
os.remove(file_name)
def cached_resource(url,
base_dir,
force=False,
max_size=250,
directory='cached_resources'):
"""
Caches a remote resource to local filesystem. Return a tuple of local file name and mime type, use primarily
for API/WebUI.
:param url: Resource URL
:param force: Does not check for existence of cached resource, fetches the remote URL, ignores directory size limit
:param max_size: Maximum allowed size of directory, in MB.
:param directory: Name of directory to use. Default is `cached_resources`
:return: Tuple of file path and mime type
"""
mime_type = None
hashed_name = hashlib.md5(url.encode('utf-8')).hexdigest()
file_path = os.path.join(base_dir, directory, hashed_name)
directory = os.path.dirname(file_path)
if not os.path.exists(file_path) or force:
log.debug('caching %s', url)
response = requests.get(url)
response.raise_for_status()
mime_type = response.headers.get('content-type')
content = response.content
if not os.path.exists(directory):
os.makedirs(directory)
# Checks directory size and trims if necessary.
size = dir_size(directory) / (1024 * 1024.0)
if not force:
while size >= max_size:
log.debug(
'directory %s size is over the allowed limit of %s, trimming',
size, max_size)
trim_dir(directory)
size = dir_size(directory) / (1024 * 1024.0)
with io.open(file_path, 'wb') as file:
file.write(content)
return file_path, mime_type
def cached_resource(url, base_dir, force=False, max_size=250, directory='cached_resources'):
"""
Caches a remote resource to local filesystem. Return a tuple of local file name and mime type, use primarily
for API/WebUI.
:param url: Resource URL
:param force: Does not check for existence of cached resource, fetches the remote URL, ignores directory size limit
:param max_size: Maximum allowed size of directory, in MB.
:param directory: Name of directory to use. Default is `cached_resources`
:return: Tuple of file path and mime type
"""
mime_type = None
hashed_name = hashlib.md5(url.encode('utf-8')).hexdigest()
file_path = os.path.join(base_dir, directory, hashed_name)
directory = os.path.dirname(file_path)
if not os.path.exists(file_path) or force:
log.debug('caching %s', url)
response = requests.get(url)
response.raise_for_status()
mime_type = response.headers.get('content-type')
content = response.content
if not os.path.exists(directory):
os.makedirs(directory)
# Checks directory size and trims if necessary.
size = dir_size(directory) / (1024 * 1024.0)
if not force:
while size >= max_size:
log.debug(
'directory %s size is over the allowed limit of %s, trimming', size, max_size
)
trim_dir(directory)
size = dir_size(directory) / (1024 * 1024.0)
with io.open(file_path, 'wb') as file:
file.write(content)
return file_path, mime_type
