Исходный код django.core.files.storage.base

import os
import pathlib

from django.core.exceptions import SuspiciousFileOperation
from django.core.files import File
from django.core.files.utils import validate_file_name
from django.utils.crypto import get_random_string
from django.utils.text import get_valid_filename


[документация]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.
[документация] def open(self, name, mode="rb"): """Retrieve the specified file from storage.""" return self._open(name, mode)
[документация] 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) name = self._save(name, content) # Ensure that the name returned from the storage system is still valid. validate_file_name(name, allow_relative_path=True) return name
# These methods are part of the public API, with default implementations.
[документация] 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)
[документация] def get_alternative_name(self, file_root, file_ext): """ Return an alternative filename, by adding an underscore and a random 7 character alphanumeric string (before the file extension, if one exists) to the filename. """ return "%s_%s%s" % (file_root, get_random_string(7), file_ext)
[документация] 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. """ name = str(name).replace("\\", "/") dir_name, file_name = os.path.split(name) if ".." in pathlib.PurePath(dir_name).parts: raise SuspiciousFileOperation( "Detected path traversal attempt in '%s'" % dir_name ) validate_file_name(file_name) file_root, file_ext = os.path.splitext(file_name) # If the filename already exists, generate an alternative filename # until it 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, self.get_alternative_name(file_root, 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, self.get_alternative_name(file_root, file_ext) ) return name
[документация] 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 = str(filename).replace("\\", "/") # `filename` may include a path as returned by FileField.upload_to. dirname, filename = os.path.split(filename) if ".." in pathlib.PurePath(dirname).parts: raise SuspiciousFileOperation( "Detected path traversal attempt in '%s'" % dirname ) return os.path.normpath(os.path.join(dirname, self.get_valid_name(filename)))
[документация] 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.
[документация] def delete(self, name): """ Delete the specified file from the storage system. """ raise NotImplementedError( "subclasses of Storage must provide a delete() method" )
[документация] 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" )
[документация] 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" )
[документация] 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")
[документация] 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")
[документация] 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" )
[документация] 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" )
[документация] 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" )
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