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author | ttt | 2017-05-13 00:29:47 +0530 |
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committer | ttt | 2017-05-13 00:29:47 +0530 |
commit | abf599be33b383a6a5baf9493093b2126a622ac8 (patch) | |
tree | 4c5ab6e0d935d5e65fabcf0258e4a00dd20a5afa /lib/python2.7/site-packages/django/contrib/sessions/backends/file.py | |
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added all server files
Diffstat (limited to 'lib/python2.7/site-packages/django/contrib/sessions/backends/file.py')
-rw-r--r-- | lib/python2.7/site-packages/django/contrib/sessions/backends/file.py | 202 |
1 files changed, 202 insertions, 0 deletions
diff --git a/lib/python2.7/site-packages/django/contrib/sessions/backends/file.py b/lib/python2.7/site-packages/django/contrib/sessions/backends/file.py new file mode 100644 index 0000000..f47aa2d --- /dev/null +++ b/lib/python2.7/site-packages/django/contrib/sessions/backends/file.py @@ -0,0 +1,202 @@ +import datetime +import errno +import logging +import os +import shutil +import tempfile + +from django.conf import settings +from django.contrib.sessions.backends.base import SessionBase, CreateError, VALID_KEY_CHARS +from django.core.exceptions import SuspiciousOperation, ImproperlyConfigured +from django.utils import timezone +from django.utils.encoding import force_text + +from django.contrib.sessions.exceptions import InvalidSessionKey + +class SessionStore(SessionBase): + """ + Implements a file based session store. + """ + def __init__(self, session_key=None): + self.storage_path = type(self)._get_storage_path() + self.file_prefix = settings.SESSION_COOKIE_NAME + super(SessionStore, self).__init__(session_key) + + @classmethod + def _get_storage_path(cls): + try: + return cls._storage_path + except AttributeError: + storage_path = getattr(settings, "SESSION_FILE_PATH", None) + if not storage_path: + storage_path = tempfile.gettempdir() + + # Make sure the storage path is valid. + if not os.path.isdir(storage_path): + raise ImproperlyConfigured( + "The session storage path %r doesn't exist. Please set your" + " SESSION_FILE_PATH setting to an existing directory in which" + " Django can store session data." % storage_path) + + cls._storage_path = storage_path + return storage_path + + def _key_to_file(self, session_key=None): + """ + Get the file associated with this session key. + """ + if session_key is None: + session_key = self._get_or_create_session_key() + + # Make sure we're not vulnerable to directory traversal. Session keys + # should always be md5s, so they should never contain directory + # components. + if not set(session_key).issubset(set(VALID_KEY_CHARS)): + raise InvalidSessionKey( + "Invalid characters in session key") + + return os.path.join(self.storage_path, self.file_prefix + session_key) + + def _last_modification(self): + """ + Return the modification time of the file storing the session's content. + """ + modification = os.stat(self._key_to_file()).st_mtime + if settings.USE_TZ: + modification = datetime.datetime.utcfromtimestamp(modification) + modification = modification.replace(tzinfo=timezone.utc) + else: + modification = datetime.datetime.fromtimestamp(modification) + return modification + + def load(self): + session_data = {} + try: + with open(self._key_to_file(), "rb") as session_file: + file_data = session_file.read() + # Don't fail if there is no data in the session file. + # We may have opened the empty placeholder file. + if file_data: + try: + session_data = self.decode(file_data) + except (EOFError, SuspiciousOperation) as e: + if isinstance(e, SuspiciousOperation): + logger = logging.getLogger('django.security.%s' % + e.__class__.__name__) + logger.warning(force_text(e)) + self.create() + + # Remove expired sessions. + expiry_age = self.get_expiry_age( + modification=self._last_modification(), + expiry=session_data.get('_session_expiry')) + if expiry_age < 0: + session_data = {} + self.delete() + self.create() + except (IOError, SuspiciousOperation): + self.create() + return session_data + + def create(self): + while True: + self._session_key = self._get_new_session_key() + try: + self.save(must_create=True) + except CreateError: + continue + self.modified = True + self._session_cache = {} + return + + def save(self, must_create=False): + # Get the session data now, before we start messing + # with the file it is stored within. + session_data = self._get_session(no_load=must_create) + + session_file_name = self._key_to_file() + + try: + # Make sure the file exists. If it does not already exist, an + # empty placeholder file is created. + flags = os.O_WRONLY | os.O_CREAT | getattr(os, 'O_BINARY', 0) + if must_create: + flags |= os.O_EXCL + fd = os.open(session_file_name, flags) + os.close(fd) + + except OSError as e: + if must_create and e.errno == errno.EEXIST: + raise CreateError + raise + + # Write the session file without interfering with other threads + # or processes. By writing to an atomically generated temporary + # file and then using the atomic os.rename() to make the complete + # file visible, we avoid having to lock the session file, while + # still maintaining its integrity. + # + # Note: Locking the session file was explored, but rejected in part + # because in order to be atomic and cross-platform, it required a + # long-lived lock file for each session, doubling the number of + # files in the session storage directory at any given time. This + # rename solution is cleaner and avoids any additional overhead + # when reading the session data, which is the more common case + # unless SESSION_SAVE_EVERY_REQUEST = True. + # + # See ticket #8616. + dir, prefix = os.path.split(session_file_name) + + try: + output_file_fd, output_file_name = tempfile.mkstemp(dir=dir, + prefix=prefix + '_out_') + renamed = False + try: + try: + os.write(output_file_fd, self.encode(session_data).encode()) + finally: + os.close(output_file_fd) + + # This will atomically rename the file (os.rename) if the OS + # supports it. Otherwise this will result in a shutil.copy2 + # and os.unlink (for example on Windows). See #9084. + shutil.move(output_file_name, session_file_name) + renamed = True + finally: + if not renamed: + os.unlink(output_file_name) + + except (OSError, IOError, EOFError): + pass + + def exists(self, session_key): + return os.path.exists(self._key_to_file(session_key)) + + def delete(self, session_key=None): + if session_key is None: + if self.session_key is None: + return + session_key = self.session_key + try: + os.unlink(self._key_to_file(session_key)) + except OSError: + pass + + def clean(self): + pass + + @classmethod + def clear_expired(cls): + storage_path = cls._get_storage_path() + file_prefix = settings.SESSION_COOKIE_NAME + + for session_file in os.listdir(storage_path): + if not session_file.startswith(file_prefix): + continue + session_key = session_file[len(file_prefix):] + session = cls(session_key) + # When an expired session is loaded, its file is removed, and a + # new file is immediately created. Prevent this by disabling + # the create() method. + session.create = lambda: None + session.load() |