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- import os
- from datetime import datetime
- from urllib.parse import urljoin
-
- 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 import timezone
- from django.utils._os import safe_join
- from django.utils.crypto import get_random_string
- from django.utils.deconstruct import deconstructible
- from django.utils.encoding import filepath_to_uri
- from django.utils.functional import LazyObject, cached_property
- from django.utils.module_loading import import_string
- from django.utils.text import get_valid_filename
-
- __all__ = (
- 'Storage', 'FileSystemStorage', 'DefaultStorage', 'default_storage',
- 'get_storage_class',
- )
-
-
- class Storage:
- """
- 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'):
- """Retrieve the specified file from storage."""
- return self._open(name, mode)
-
- def save(self, name, content, max_length=None):
- """
- Save 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 = content.name
-
- if not hasattr(content, 'chunks'):
- content = File(content, name)
-
- name = self.get_available_name(name, max_length=max_length)
- return self._save(name, content)
-
- # These methods are part of the public API, with default implementations.
-
- def get_valid_name(self, name):
- """
- Return 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):
- """
- Return 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:
- continue
- # 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 generate_filename(self, filename):
- """
- Validate the filename by calling get_valid_name() and return a filename
- to be passed to the save() method.
- """
- # `filename` may include a path as returned by FileField.upload_to.
- dirname, filename = os.path.split(filename)
- return os.path.normpath(os.path.join(dirname, self.get_valid_name(filename)))
-
- def path(self, name):
- """
- Return 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):
- """
- Delete the specified file from the storage system.
- """
- raise NotImplementedError('subclasses of Storage must provide a delete() method')
-
- def exists(self, name):
- """
- Return 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):
- """
- List the contents of the specified path. Return 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):
- """
- Return 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):
- """
- Return 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 get_accessed_time(self, name):
- """
- Return the last accessed time (as a datetime) of the file specified by
- name. The datetime will be timezone-aware if USE_TZ=True.
- """
- raise NotImplementedError('subclasses of Storage must provide a get_accessed_time() method')
-
- def get_created_time(self, name):
- """
- Return the creation time (as a datetime) of the file specified by name.
- The datetime will be timezone-aware if USE_TZ=True.
- """
- raise NotImplementedError('subclasses of Storage must provide a get_created_time() method')
-
- def get_modified_time(self, name):
- """
- Return the last modified time (as a datetime) of the file specified by
- name. The datetime will be timezone-aware if USE_TZ=True.
- """
- raise NotImplementedError('subclasses of Storage must provide a get_modified_time() method')
-
-
- @deconstructible
- class FileSystemStorage(Storage):
- """
- Standard filesystem storage
- """
- # The combination of O_CREAT and O_EXCL makes os.open() raise OSError if
- # the file already exists before it's opened.
- OS_OPEN_FLAGS = os.O_WRONLY | os.O_CREAT | os.O_EXCL | getattr(os, 'O_BINARY', 0)
-
- def __init__(self, location=None, base_url=None, file_permissions_mode=None,
- directory_permissions_mode=None):
- self._location = location
- self._base_url = base_url
- self._file_permissions_mode = file_permissions_mode
- self._directory_permissions_mode = directory_permissions_mode
- setting_changed.connect(self._clear_cached_properties)
-
- 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)
- elif setting == 'FILE_UPLOAD_DIRECTORY_PERMISSIONS':
- self.__dict__.pop('directory_permissions_mode', None)
-
- def _value_or_setting(self, value, setting):
- return setting if value is None else value
-
- @cached_property
- def base_location(self):
- return self._value_or_setting(self._location, settings.MEDIA_ROOT)
-
- @cached_property
- def location(self):
- return os.path.abspath(self.base_location)
-
- @cached_property
- def base_url(self):
- if self._base_url is not None and not self._base_url.endswith('/'):
- self._base_url += '/'
- return self._value_or_setting(self._base_url, settings.MEDIA_URL)
-
- @cached_property
- def file_permissions_mode(self):
- return self._value_or_setting(self._file_permissions_mode, settings.FILE_UPLOAD_PERMISSIONS)
-
- @cached_property
- 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.
- directory = os.path.dirname(full_path)
- if not os.path.exists(directory):
- try:
- 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)
- try:
- os.makedirs(directory, self.directory_permissions_mode)
- finally:
- os.umask(old_umask)
- else:
- os.makedirs(directory)
- except FileExistsError:
- # There's a race between os.path.exists() and os.makedirs().
- # If os.makedirs() fails with FileExistsError, the directory
- # was created concurrently.
- pass
- 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:
- try:
- # 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.
- else:
- # The current umask value is masked out by os.open!
- fd = os.open(full_path, self.OS_OPEN_FLAGS, 0o666)
- _file = None
- try:
- 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)
- _file.write(chunk)
- finally:
- locks.unlock(fd)
- if _file is not None:
- _file.close()
- else:
- os.close(fd)
- except FileExistsError:
- # A new name is needed if the file exists.
- name = self.get_available_name(name)
- full_path = self.path(name)
- else:
- # OK, the file save worked. Break out of the loop.
- break
-
- if self.file_permissions_mode is not None:
- os.chmod(full_path, self.file_permissions_mode)
-
- # Store filenames with forward slashes, even on Windows.
- return name.replace('\\', '/')
-
- def delete(self, name):
- assert name, "The name argument is not allowed to be empty."
- name = self.path(name)
- # If the file or directory exists, delete it from the filesystem.
- try:
- if os.path.isdir(name):
- os.rmdir(name)
- else:
- os.remove(name)
- except FileNotFoundError:
- # FileNotFoundError is raised if the file or directory was removed
- # concurrently.
- pass
-
- 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.scandir(path):
- if entry.is_dir():
- directories.append(entry.name)
- else:
- files.append(entry.name)
- 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.")
- url = filepath_to_uri(name)
- if url is not None:
- url = url.lstrip('/')
- return urljoin(self.base_url, url)
-
- def _datetime_from_timestamp(self, ts):
- """
- If timezone support is enabled, make an aware datetime object in UTC;
- otherwise make a naive one in the local timezone.
- """
- if settings.USE_TZ:
- # Safe to use .replace() because UTC doesn't have DST
- return datetime.utcfromtimestamp(ts).replace(tzinfo=timezone.utc)
- else:
- return datetime.fromtimestamp(ts)
-
- def get_accessed_time(self, name):
- return self._datetime_from_timestamp(os.path.getatime(self.path(name)))
-
- def get_created_time(self, name):
- return self._datetime_from_timestamp(os.path.getctime(self.path(name)))
-
- def get_modified_time(self, name):
- return self._datetime_from_timestamp(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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