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import errno
import os
from datetime import datetime
from django.conf import settings
from django.core.exceptions import SuspiciousFileOperation
from django.core.files import File, locks
from django.core.files.move import file_move_safe
from django.core.signals import setting_changed
from django.utils._os import abspathu, safe_join
from django.utils.crypto import get_random_string
from django.utils.deconstruct import deconstructible
from django.utils.encoding import filepath_to_uri, force_text
from django.utils.functional import LazyObject, cached_property
from django.utils.module_loading import import_string
from django.utils.six.moves.urllib.parse import urljoin
from django.utils.text import get_valid_filename
__all__ = ('Storage', 'FileSystemStorage', 'DefaultStorage', 'default_storage')
class Storage(object):
A base storage class, providing some default behaviors that all other
storage systems can inherit or override, as necessary.
# The following methods represent a public interface to private methods.
# These shouldn't be overridden by subclasses unless absolutely necessary.
def open(self, name, mode='rb'):
Retrieves the specified file from storage.
return self._open(name, mode)
def save(self, name, content, max_length=None):
Saves new content to the file specified by name. The content should be
a proper File object or any python file-like object, ready to be read
from the beginning.
# Get the proper name for the file, as it will actually be saved.
if name is None:
name =
if not hasattr(content, 'chunks'):
content = File(content)
name = self.get_available_name(name, max_length=max_length)
name = self._save(name, content)
# Store filenames with forward slashes, even on Windows
return force_text(name.replace('\\', '/'))
# These methods are part of the public API, with default implementations.
def get_valid_name(self, name):
Returns a filename, based on the provided filename, that's suitable for
use in the target storage system.
return get_valid_filename(name)
def get_available_name(self, name, max_length=None):
Returns a filename that's free on the target storage system, and
available for new content to be written to.
dir_name, file_name = os.path.split(name)
file_root, file_ext = os.path.splitext(file_name)
# If the filename already exists, add an underscore and a random 7
# character alphanumeric string (before the file extension, if one
# exists) to the filename until the generated filename doesn't exist.
# Truncate original name if required, so the new filename does not
# exceed the max_length.
while self.exists(name) or (max_length and len(name) > max_length):
# file_ext includes the dot.
name = os.path.join(dir_name, "%s_%s%s" % (file_root, get_random_string(7), file_ext))
if max_length is None:
# Truncate file_root if max_length exceeded.
truncation = len(name) - max_length
if truncation > 0:
file_root = file_root[:-truncation]
# Entire file_root was truncated in attempt to find an available filename.
if not file_root:
raise SuspiciousFileOperation(
'Storage can not find an available filename for "%s". '
'Please make sure that the corresponding file field '
'allows sufficient "max_length".' % name
name = os.path.join(dir_name, "%s_%s%s" % (file_root, get_random_string(7), file_ext))
return name
def path(self, name):
Returns a local filesystem path where the file can be retrieved using
Python's built-in open() function. Storage systems that can't be
accessed using open() should *not* implement this method.
raise NotImplementedError("This backend doesn't support absolute paths.")
# The following methods form the public API for storage systems, but with
# no default implementations. Subclasses must implement *all* of these.
def delete(self, name):
Deletes the specified file from the storage system.
raise NotImplementedError('subclasses of Storage must provide a delete() method')
def exists(self, name):
Returns True if a file referenced by the given name already exists in the
storage system, or False if the name is available for a new file.
raise NotImplementedError('subclasses of Storage must provide an exists() method')
def listdir(self, path):
Lists the contents of the specified path, returning a 2-tuple of lists;
the first item being directories, the second item being files.
raise NotImplementedError('subclasses of Storage must provide a listdir() method')
def size(self, name):
Returns the total size, in bytes, of the file specified by name.
raise NotImplementedError('subclasses of Storage must provide a size() method')
def url(self, name):
Returns an absolute URL where the file's contents can be accessed
directly by a Web browser.
raise NotImplementedError('subclasses of Storage must provide a url() method')
def accessed_time(self, name):
Returns the last accessed time (as datetime object) of the file
specified by name.
raise NotImplementedError('subclasses of Storage must provide an accessed_time() method')
def created_time(self, name):
Returns the creation time (as datetime object) of the file
specified by name.
raise NotImplementedError('subclasses of Storage must provide a created_time() method')
def modified_time(self, name):
Returns the last modified time (as datetime object) of the file
specified by name.
raise NotImplementedError('subclasses of Storage must provide a modified_time() method')
class FileSystemStorage(Storage):
Standard filesystem storage
def __init__(self, location=None, base_url=None, file_permissions_mode=None,
self._location = location
if base_url is not None and not base_url.endswith('/'):
base_url += '/'
self._base_url = base_url
self._file_permissions_mode = file_permissions_mode
self._directory_permissions_mode = directory_permissions_mode
def _clear_cached_properties(self, setting, **kwargs):
"""Reset setting based property values."""
if setting == 'MEDIA_ROOT':
self.__dict__.pop('base_location', None)
self.__dict__.pop('location', None)
elif setting == 'MEDIA_URL':
self.__dict__.pop('base_url', None)
elif setting == 'FILE_UPLOAD_PERMISSIONS':
self.__dict__.pop('file_permissions_mode', None)
self.__dict__.pop('directory_permissions_mode', None)
def _value_or_setting(self, value, setting):
return setting if value is None else value
def base_location(self):
return self._value_or_setting(self._location, settings.MEDIA_ROOT)
def location(self):
return abspathu(self.base_location)
def base_url(self):
return self._value_or_setting(self._base_url, settings.MEDIA_URL)
def file_permissions_mode(self):
return self._value_or_setting(self._file_permissions_mode, settings.FILE_UPLOAD_PERMISSIONS)
def directory_permissions_mode(self):
return self._value_or_setting(self._directory_permissions_mode, settings.FILE_UPLOAD_DIRECTORY_PERMISSIONS)
def _open(self, name, mode='rb'):
return File(open(self.path(name), mode))
def _save(self, name, content):
full_path = self.path(name)
# Create any intermediate directories that do not exist.
# Note that there is a race between os.path.exists and os.makedirs:
# if os.makedirs fails with EEXIST, the directory was created
# concurrently, and we can continue normally. Refs #16082.
directory = os.path.dirname(full_path)
if not os.path.exists(directory):
if self.directory_permissions_mode is not None:
# os.makedirs applies the global umask, so we reset it,
# for consistency with file_permissions_mode behavior.
old_umask = os.umask(0)
os.makedirs(directory, self.directory_permissions_mode)
except OSError as e:
if e.errno != errno.EEXIST:
if not os.path.isdir(directory):
raise IOError("%s exists and is not a directory." % directory)
# There's a potential race condition between get_available_name and
# saving the file; it's possible that two threads might return the
# same name, at which point all sorts of fun happens. So we need to
# try to create the file, but if it already exists we have to go back
# to get_available_name() and try again.
while True:
# This file has a file path that we can move.
if hasattr(content, 'temporary_file_path'):
file_move_safe(content.temporary_file_path(), full_path)
# This is a normal uploadedfile that we can stream.
# This fun binary flag incantation makes throw an
# OSError if the file already exists before we open it.
flags = (os.O_WRONLY | os.O_CREAT | os.O_EXCL |
getattr(os, 'O_BINARY', 0))
# The current umask value is masked out by!
fd =, flags, 0o666)
_file = None
locks.lock(fd, locks.LOCK_EX)
for chunk in content.chunks():
if _file is None:
mode = 'wb' if isinstance(chunk, bytes) else 'wt'
_file = os.fdopen(fd, mode)
if _file is not None:
except OSError as e:
if e.errno == errno.EEXIST:
# Ooops, the file exists. We need a new file name.
name = self.get_available_name(name)
full_path = self.path(name)
# OK, the file save worked. Break out of the loop.
if self.file_permissions_mode is not None:
os.chmod(full_path, self.file_permissions_mode)
return name
def delete(self, name):
assert name, "The name argument is not allowed to be empty."
name = self.path(name)
# If the file exists, delete it from the filesystem.
# Note that there is a race between os.path.exists and os.remove:
# if os.remove fails with ENOENT, the file was removed
# concurrently, and we can continue normally.
if os.path.exists(name):
except OSError as e:
if e.errno != errno.ENOENT:
def exists(self, name):
return os.path.exists(self.path(name))
def listdir(self, path):
path = self.path(path)
directories, files = [], []
for entry in os.listdir(path):
if os.path.isdir(os.path.join(path, entry)):
return directories, files
def path(self, name):
return safe_join(self.location, name)
def size(self, name):
return os.path.getsize(self.path(name))
def url(self, name):
if self.base_url is None:
raise ValueError("This file is not accessible via a URL.")
return urljoin(self.base_url, filepath_to_uri(name))
def accessed_time(self, name):
return datetime.fromtimestamp(os.path.getatime(self.path(name)))
def created_time(self, name):
return datetime.fromtimestamp(os.path.getctime(self.path(name)))
def modified_time(self, name):
return datetime.fromtimestamp(os.path.getmtime(self.path(name)))
def get_storage_class(import_path=None):
return import_string(import_path or settings.DEFAULT_FILE_STORAGE)
class DefaultStorage(LazyObject):
def _setup(self):
self._wrapped = get_storage_class()()
default_storage = DefaultStorage()
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