You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
761 lines
24 KiB
761 lines
24 KiB
"""Container and Namespace classes"""
|
|
import errno
|
|
|
|
from ._compat import pickle, anydbm, add_metaclass, PYVER, unicode_text
|
|
|
|
import beaker.util as util
|
|
import logging
|
|
import os
|
|
import time
|
|
|
|
from beaker.exceptions import CreationAbortedError, MissingCacheParameter
|
|
from beaker.synchronization import _threading, file_synchronizer, \
|
|
mutex_synchronizer, NameLock, null_synchronizer
|
|
|
|
__all__ = ['Value', 'Container', 'ContainerContext',
|
|
'MemoryContainer', 'DBMContainer', 'NamespaceManager',
|
|
'MemoryNamespaceManager', 'DBMNamespaceManager', 'FileContainer',
|
|
'OpenResourceNamespaceManager',
|
|
'FileNamespaceManager', 'CreationAbortedError']
|
|
|
|
|
|
logger = logging.getLogger('beaker.container')
|
|
if logger.isEnabledFor(logging.DEBUG):
|
|
debug = logger.debug
|
|
else:
|
|
def debug(message, *args):
|
|
pass
|
|
|
|
|
|
class NamespaceManager(object):
|
|
"""Handles dictionary operations and locking for a namespace of
|
|
values.
|
|
|
|
:class:`.NamespaceManager` provides a dictionary-like interface,
|
|
implementing ``__getitem__()``, ``__setitem__()``, and
|
|
``__contains__()``, as well as functions related to lock
|
|
acquisition.
|
|
|
|
The implementation for setting and retrieving the namespace data is
|
|
handled by subclasses.
|
|
|
|
NamespaceManager may be used alone, or may be accessed by
|
|
one or more :class:`.Value` objects. :class:`.Value` objects provide per-key
|
|
services like expiration times and automatic recreation of values.
|
|
|
|
Multiple NamespaceManagers created with a particular name will all
|
|
share access to the same underlying datasource and will attempt to
|
|
synchronize against a common mutex object. The scope of this
|
|
sharing may be within a single process or across multiple
|
|
processes, depending on the type of NamespaceManager used.
|
|
|
|
The NamespaceManager itself is generally threadsafe, except in the
|
|
case of the DBMNamespaceManager in conjunction with the gdbm dbm
|
|
implementation.
|
|
|
|
"""
|
|
|
|
@classmethod
|
|
def _init_dependencies(cls):
|
|
"""Initialize module-level dependent libraries required
|
|
by this :class:`.NamespaceManager`."""
|
|
|
|
def __init__(self, namespace):
|
|
self._init_dependencies()
|
|
self.namespace = namespace
|
|
|
|
def get_creation_lock(self, key):
|
|
"""Return a locking object that is used to synchronize
|
|
multiple threads or processes which wish to generate a new
|
|
cache value.
|
|
|
|
This function is typically an instance of
|
|
:class:`.FileSynchronizer`, :class:`.ConditionSynchronizer`,
|
|
or :class:`.null_synchronizer`.
|
|
|
|
The creation lock is only used when a requested value
|
|
does not exist, or has been expired, and is only used
|
|
by the :class:`.Value` key-management object in conjunction
|
|
with a "createfunc" value-creation function.
|
|
|
|
"""
|
|
raise NotImplementedError()
|
|
|
|
def do_remove(self):
|
|
"""Implement removal of the entire contents of this
|
|
:class:`.NamespaceManager`.
|
|
|
|
e.g. for a file-based namespace, this would remove
|
|
all the files.
|
|
|
|
The front-end to this method is the
|
|
:meth:`.NamespaceManager.remove` method.
|
|
|
|
"""
|
|
raise NotImplementedError()
|
|
|
|
def acquire_read_lock(self):
|
|
"""Establish a read lock.
|
|
|
|
This operation is called before a key is read. By
|
|
default the function does nothing.
|
|
|
|
"""
|
|
|
|
def release_read_lock(self):
|
|
"""Release a read lock.
|
|
|
|
This operation is called after a key is read. By
|
|
default the function does nothing.
|
|
|
|
"""
|
|
|
|
def acquire_write_lock(self, wait=True, replace=False):
|
|
"""Establish a write lock.
|
|
|
|
This operation is called before a key is written.
|
|
A return value of ``True`` indicates the lock has
|
|
been acquired.
|
|
|
|
By default the function returns ``True`` unconditionally.
|
|
|
|
'replace' is a hint indicating the full contents
|
|
of the namespace may be safely discarded. Some backends
|
|
may implement this (i.e. file backend won't unpickle the
|
|
current contents).
|
|
|
|
"""
|
|
return True
|
|
|
|
def release_write_lock(self):
|
|
"""Release a write lock.
|
|
|
|
This operation is called after a new value is written.
|
|
By default this function does nothing.
|
|
|
|
"""
|
|
|
|
def has_key(self, key):
|
|
"""Return ``True`` if the given key is present in this
|
|
:class:`.Namespace`.
|
|
"""
|
|
return self.__contains__(key)
|
|
|
|
def __getitem__(self, key):
|
|
raise NotImplementedError()
|
|
|
|
def __setitem__(self, key, value):
|
|
raise NotImplementedError()
|
|
|
|
def set_value(self, key, value, expiretime=None):
|
|
"""Sets a value in this :class:`.NamespaceManager`.
|
|
|
|
This is the same as ``__setitem__()``, but
|
|
also allows an expiration time to be passed
|
|
at the same time.
|
|
|
|
"""
|
|
self[key] = value
|
|
|
|
def __contains__(self, key):
|
|
raise NotImplementedError()
|
|
|
|
def __delitem__(self, key):
|
|
raise NotImplementedError()
|
|
|
|
def keys(self):
|
|
"""Return the list of all keys.
|
|
|
|
This method may not be supported by all
|
|
:class:`.NamespaceManager` implementations.
|
|
|
|
"""
|
|
raise NotImplementedError()
|
|
|
|
def remove(self):
|
|
"""Remove the entire contents of this
|
|
:class:`.NamespaceManager`.
|
|
|
|
e.g. for a file-based namespace, this would remove
|
|
all the files.
|
|
"""
|
|
self.do_remove()
|
|
|
|
|
|
class OpenResourceNamespaceManager(NamespaceManager):
|
|
"""A NamespaceManager where read/write operations require opening/
|
|
closing of a resource which is possibly mutexed.
|
|
|
|
"""
|
|
def __init__(self, namespace):
|
|
NamespaceManager.__init__(self, namespace)
|
|
self.access_lock = self.get_access_lock()
|
|
self.openers = 0
|
|
self.mutex = _threading.Lock()
|
|
|
|
def get_access_lock(self):
|
|
raise NotImplementedError()
|
|
|
|
def do_open(self, flags, replace):
|
|
raise NotImplementedError()
|
|
|
|
def do_close(self):
|
|
raise NotImplementedError()
|
|
|
|
def acquire_read_lock(self):
|
|
self.access_lock.acquire_read_lock()
|
|
try:
|
|
self.open('r', checkcount=True)
|
|
except:
|
|
self.access_lock.release_read_lock()
|
|
raise
|
|
|
|
def release_read_lock(self):
|
|
try:
|
|
self.close(checkcount=True)
|
|
finally:
|
|
self.access_lock.release_read_lock()
|
|
|
|
def acquire_write_lock(self, wait=True, replace=False):
|
|
r = self.access_lock.acquire_write_lock(wait)
|
|
try:
|
|
if (wait or r):
|
|
self.open('c', checkcount=True, replace=replace)
|
|
return r
|
|
except:
|
|
self.access_lock.release_write_lock()
|
|
raise
|
|
|
|
def release_write_lock(self):
|
|
try:
|
|
self.close(checkcount=True)
|
|
finally:
|
|
self.access_lock.release_write_lock()
|
|
|
|
def open(self, flags, checkcount=False, replace=False):
|
|
self.mutex.acquire()
|
|
try:
|
|
if checkcount:
|
|
if self.openers == 0:
|
|
self.do_open(flags, replace)
|
|
self.openers += 1
|
|
else:
|
|
self.do_open(flags, replace)
|
|
self.openers = 1
|
|
finally:
|
|
self.mutex.release()
|
|
|
|
def close(self, checkcount=False):
|
|
self.mutex.acquire()
|
|
try:
|
|
if checkcount:
|
|
self.openers -= 1
|
|
if self.openers == 0:
|
|
self.do_close()
|
|
else:
|
|
if self.openers > 0:
|
|
self.do_close()
|
|
self.openers = 0
|
|
finally:
|
|
self.mutex.release()
|
|
|
|
def remove(self):
|
|
self.access_lock.acquire_write_lock()
|
|
try:
|
|
self.close(checkcount=False)
|
|
self.do_remove()
|
|
finally:
|
|
self.access_lock.release_write_lock()
|
|
|
|
|
|
class Value(object):
|
|
"""Implements synchronization, expiration, and value-creation logic
|
|
for a single value stored in a :class:`.NamespaceManager`.
|
|
|
|
"""
|
|
|
|
__slots__ = 'key', 'createfunc', 'expiretime', 'expire_argument', 'starttime', 'storedtime',\
|
|
'namespace'
|
|
|
|
def __init__(self, key, namespace, createfunc=None, expiretime=None, starttime=None):
|
|
self.key = key
|
|
self.createfunc = createfunc
|
|
self.expire_argument = expiretime
|
|
self.starttime = starttime
|
|
self.storedtime = -1
|
|
self.namespace = namespace
|
|
|
|
def has_value(self):
|
|
"""return true if the container has a value stored.
|
|
|
|
This is regardless of it being expired or not.
|
|
|
|
"""
|
|
self.namespace.acquire_read_lock()
|
|
try:
|
|
return self.key in self.namespace
|
|
finally:
|
|
self.namespace.release_read_lock()
|
|
|
|
def can_have_value(self):
|
|
return self.has_current_value() or self.createfunc is not None
|
|
|
|
def has_current_value(self):
|
|
self.namespace.acquire_read_lock()
|
|
try:
|
|
has_value = self.key in self.namespace
|
|
if has_value:
|
|
try:
|
|
stored, expired, value = self._get_value()
|
|
return not self._is_expired(stored, expired)
|
|
except KeyError:
|
|
pass
|
|
return False
|
|
finally:
|
|
self.namespace.release_read_lock()
|
|
|
|
def _is_expired(self, storedtime, expiretime):
|
|
"""Return true if this container's value is expired."""
|
|
return (
|
|
(
|
|
self.starttime is not None and
|
|
storedtime < self.starttime
|
|
)
|
|
or
|
|
(
|
|
expiretime is not None and
|
|
time.time() >= expiretime + storedtime
|
|
)
|
|
)
|
|
|
|
def get_value(self):
|
|
self.namespace.acquire_read_lock()
|
|
try:
|
|
has_value = self.has_value()
|
|
if has_value:
|
|
try:
|
|
stored, expired, value = self._get_value()
|
|
if not self._is_expired(stored, expired):
|
|
return value
|
|
except KeyError:
|
|
# guard against un-mutexed backends raising KeyError
|
|
has_value = False
|
|
|
|
if not self.createfunc:
|
|
raise KeyError(self.key)
|
|
finally:
|
|
self.namespace.release_read_lock()
|
|
|
|
has_createlock = False
|
|
creation_lock = self.namespace.get_creation_lock(self.key)
|
|
if has_value:
|
|
if not creation_lock.acquire(wait=False):
|
|
debug("get_value returning old value while new one is created")
|
|
return value
|
|
else:
|
|
debug("lock_creatfunc (didnt wait)")
|
|
has_createlock = True
|
|
|
|
if not has_createlock:
|
|
debug("lock_createfunc (waiting)")
|
|
creation_lock.acquire()
|
|
debug("lock_createfunc (waited)")
|
|
|
|
try:
|
|
# see if someone created the value already
|
|
self.namespace.acquire_read_lock()
|
|
try:
|
|
if self.has_value():
|
|
try:
|
|
stored, expired, value = self._get_value()
|
|
if not self._is_expired(stored, expired):
|
|
return value
|
|
except KeyError:
|
|
# guard against un-mutexed backends raising KeyError
|
|
pass
|
|
finally:
|
|
self.namespace.release_read_lock()
|
|
|
|
debug("get_value creating new value")
|
|
v = self.createfunc()
|
|
self.set_value(v)
|
|
return v
|
|
finally:
|
|
creation_lock.release()
|
|
debug("released create lock")
|
|
|
|
def _get_value(self):
|
|
value = self.namespace[self.key]
|
|
try:
|
|
stored, expired, value = value
|
|
except ValueError:
|
|
if not len(value) == 2:
|
|
raise
|
|
# Old format: upgrade
|
|
stored, value = value
|
|
expired = self.expire_argument
|
|
debug("get_value upgrading time %r expire time %r", stored, self.expire_argument)
|
|
self.namespace.release_read_lock()
|
|
self.set_value(value, stored)
|
|
self.namespace.acquire_read_lock()
|
|
except TypeError:
|
|
# occurs when the value is None. memcached
|
|
# may yank the rug from under us in which case
|
|
# that's the result
|
|
raise KeyError(self.key)
|
|
return stored, expired, value
|
|
|
|
def set_value(self, value, storedtime=None):
|
|
self.namespace.acquire_write_lock()
|
|
try:
|
|
if storedtime is None:
|
|
storedtime = time.time()
|
|
debug("set_value stored time %r expire time %r", storedtime, self.expire_argument)
|
|
self.namespace.set_value(self.key, (storedtime, self.expire_argument, value),
|
|
expiretime=self.expire_argument)
|
|
finally:
|
|
self.namespace.release_write_lock()
|
|
|
|
def clear_value(self):
|
|
self.namespace.acquire_write_lock()
|
|
try:
|
|
debug("clear_value")
|
|
if self.key in self.namespace:
|
|
try:
|
|
del self.namespace[self.key]
|
|
except KeyError:
|
|
# guard against un-mutexed backends raising KeyError
|
|
pass
|
|
self.storedtime = -1
|
|
finally:
|
|
self.namespace.release_write_lock()
|
|
|
|
|
|
class AbstractDictionaryNSManager(NamespaceManager):
|
|
"""A subclassable NamespaceManager that places data in a dictionary.
|
|
|
|
Subclasses should provide a "dictionary" attribute or descriptor
|
|
which returns a dict-like object. The dictionary will store keys
|
|
that are local to the "namespace" attribute of this manager, so
|
|
ensure that the dictionary will not be used by any other namespace.
|
|
|
|
e.g.::
|
|
|
|
import collections
|
|
cached_data = collections.defaultdict(dict)
|
|
|
|
class MyDictionaryManager(AbstractDictionaryNSManager):
|
|
def __init__(self, namespace):
|
|
AbstractDictionaryNSManager.__init__(self, namespace)
|
|
self.dictionary = cached_data[self.namespace]
|
|
|
|
The above stores data in a global dictionary called "cached_data",
|
|
which is structured as a dictionary of dictionaries, keyed
|
|
first on namespace name to a sub-dictionary, then on actual
|
|
cache key to value.
|
|
|
|
"""
|
|
|
|
def get_creation_lock(self, key):
|
|
return NameLock(
|
|
identifier="memorynamespace/funclock/%s/%s" %
|
|
(self.namespace, key),
|
|
reentrant=True
|
|
)
|
|
|
|
def __getitem__(self, key):
|
|
return self.dictionary[key]
|
|
|
|
def __contains__(self, key):
|
|
return self.dictionary.__contains__(key)
|
|
|
|
def has_key(self, key):
|
|
return self.dictionary.__contains__(key)
|
|
|
|
def __setitem__(self, key, value):
|
|
self.dictionary[key] = value
|
|
|
|
def __delitem__(self, key):
|
|
del self.dictionary[key]
|
|
|
|
def do_remove(self):
|
|
self.dictionary.clear()
|
|
|
|
def keys(self):
|
|
return self.dictionary.keys()
|
|
|
|
|
|
class MemoryNamespaceManager(AbstractDictionaryNSManager):
|
|
""":class:`.NamespaceManager` that uses a Python dictionary for storage."""
|
|
|
|
namespaces = util.SyncDict()
|
|
|
|
def __init__(self, namespace, **kwargs):
|
|
AbstractDictionaryNSManager.__init__(self, namespace)
|
|
self.dictionary = MemoryNamespaceManager.\
|
|
namespaces.get(self.namespace, dict)
|
|
|
|
|
|
class DBMNamespaceManager(OpenResourceNamespaceManager):
|
|
""":class:`.NamespaceManager` that uses ``dbm`` files for storage."""
|
|
|
|
def __init__(self, namespace, dbmmodule=None, data_dir=None,
|
|
dbm_dir=None, lock_dir=None,
|
|
digest_filenames=True, **kwargs):
|
|
self.digest_filenames = digest_filenames
|
|
|
|
if not dbm_dir and not data_dir:
|
|
raise MissingCacheParameter("data_dir or dbm_dir is required")
|
|
elif dbm_dir:
|
|
self.dbm_dir = dbm_dir
|
|
else:
|
|
self.dbm_dir = data_dir + "/container_dbm"
|
|
util.verify_directory(self.dbm_dir)
|
|
|
|
if not lock_dir and not data_dir:
|
|
raise MissingCacheParameter("data_dir or lock_dir is required")
|
|
elif lock_dir:
|
|
self.lock_dir = lock_dir
|
|
else:
|
|
self.lock_dir = data_dir + "/container_dbm_lock"
|
|
util.verify_directory(self.lock_dir)
|
|
|
|
self.dbmmodule = dbmmodule or anydbm
|
|
|
|
self.dbm = None
|
|
OpenResourceNamespaceManager.__init__(self, namespace)
|
|
|
|
self.file = util.encoded_path(root=self.dbm_dir,
|
|
identifiers=[self.namespace],
|
|
extension='.dbm',
|
|
digest_filenames=self.digest_filenames)
|
|
|
|
debug("data file %s", self.file)
|
|
self._checkfile()
|
|
|
|
def get_access_lock(self):
|
|
return file_synchronizer(identifier=self.namespace,
|
|
lock_dir=self.lock_dir)
|
|
|
|
def get_creation_lock(self, key):
|
|
return file_synchronizer(
|
|
identifier="dbmcontainer/funclock/%s/%s" % (
|
|
self.namespace, key
|
|
),
|
|
lock_dir=self.lock_dir
|
|
)
|
|
|
|
def file_exists(self, file):
|
|
if os.access(file, os.F_OK):
|
|
return True
|
|
else:
|
|
for ext in ('db', 'dat', 'pag', 'dir'):
|
|
if os.access(file + os.extsep + ext, os.F_OK):
|
|
return True
|
|
|
|
return False
|
|
|
|
def _ensuredir(self, filename):
|
|
dirname = os.path.dirname(filename)
|
|
if not os.path.exists(dirname):
|
|
util.verify_directory(dirname)
|
|
|
|
def _checkfile(self):
|
|
if not self.file_exists(self.file):
|
|
self._ensuredir(self.file)
|
|
g = self.dbmmodule.open(self.file, 'c')
|
|
g.close()
|
|
|
|
def get_filenames(self):
|
|
list = []
|
|
if os.access(self.file, os.F_OK):
|
|
list.append(self.file)
|
|
|
|
for ext in ('pag', 'dir', 'db', 'dat'):
|
|
if os.access(self.file + os.extsep + ext, os.F_OK):
|
|
list.append(self.file + os.extsep + ext)
|
|
return list
|
|
|
|
def do_open(self, flags, replace):
|
|
debug("opening dbm file %s", self.file)
|
|
try:
|
|
self.dbm = self.dbmmodule.open(self.file, flags)
|
|
except:
|
|
self._checkfile()
|
|
self.dbm = self.dbmmodule.open(self.file, flags)
|
|
|
|
def do_close(self):
|
|
if self.dbm is not None:
|
|
debug("closing dbm file %s", self.file)
|
|
self.dbm.close()
|
|
|
|
def do_remove(self):
|
|
for f in self.get_filenames():
|
|
os.remove(f)
|
|
|
|
def __getitem__(self, key):
|
|
return pickle.loads(self.dbm[key])
|
|
|
|
def __contains__(self, key):
|
|
if PYVER == (3, 2):
|
|
# Looks like this is a bug that got solved in PY3.3 and PY3.4
|
|
# http://bugs.python.org/issue19288
|
|
if isinstance(key, unicode_text):
|
|
key = key.encode('UTF-8')
|
|
return key in self.dbm
|
|
|
|
def __setitem__(self, key, value):
|
|
self.dbm[key] = pickle.dumps(value)
|
|
|
|
def __delitem__(self, key):
|
|
del self.dbm[key]
|
|
|
|
def keys(self):
|
|
return self.dbm.keys()
|
|
|
|
|
|
class FileNamespaceManager(OpenResourceNamespaceManager):
|
|
""":class:`.NamespaceManager` that uses binary files for storage.
|
|
|
|
Each namespace is implemented as a single file storing a
|
|
dictionary of key/value pairs, serialized using the Python
|
|
``pickle`` module.
|
|
|
|
"""
|
|
def __init__(self, namespace, data_dir=None, file_dir=None, lock_dir=None,
|
|
digest_filenames=True, **kwargs):
|
|
self.digest_filenames = digest_filenames
|
|
|
|
if not file_dir and not data_dir:
|
|
raise MissingCacheParameter("data_dir or file_dir is required")
|
|
elif file_dir:
|
|
self.file_dir = file_dir
|
|
else:
|
|
self.file_dir = data_dir + "/container_file"
|
|
util.verify_directory(self.file_dir)
|
|
|
|
if not lock_dir and not data_dir:
|
|
raise MissingCacheParameter("data_dir or lock_dir is required")
|
|
elif lock_dir:
|
|
self.lock_dir = lock_dir
|
|
else:
|
|
self.lock_dir = data_dir + "/container_file_lock"
|
|
util.verify_directory(self.lock_dir)
|
|
OpenResourceNamespaceManager.__init__(self, namespace)
|
|
|
|
self.file = util.encoded_path(root=self.file_dir,
|
|
identifiers=[self.namespace],
|
|
extension='.cache',
|
|
digest_filenames=self.digest_filenames)
|
|
self.hash = {}
|
|
|
|
debug("data file %s", self.file)
|
|
|
|
def get_access_lock(self):
|
|
return file_synchronizer(identifier=self.namespace,
|
|
lock_dir=self.lock_dir)
|
|
|
|
def get_creation_lock(self, key):
|
|
return file_synchronizer(
|
|
identifier="dbmcontainer/funclock/%s/%s" % (
|
|
self.namespace, key
|
|
),
|
|
lock_dir=self.lock_dir
|
|
)
|
|
|
|
def file_exists(self, file):
|
|
return os.access(file, os.F_OK)
|
|
|
|
def do_open(self, flags, replace):
|
|
if not replace and self.file_exists(self.file):
|
|
try:
|
|
with open(self.file, 'rb') as fh:
|
|
self.hash = pickle.load(fh)
|
|
except IOError as e:
|
|
# Ignore EACCES and ENOENT as it just means we are no longer
|
|
# able to access the file or that it no longer exists
|
|
if e.errno not in [errno.EACCES, errno.ENOENT]:
|
|
raise
|
|
|
|
self.flags = flags
|
|
|
|
def do_close(self):
|
|
if self.flags == 'c' or self.flags == 'w':
|
|
pickled = pickle.dumps(self.hash)
|
|
util.safe_write(self.file, pickled)
|
|
|
|
self.hash = {}
|
|
self.flags = None
|
|
|
|
def do_remove(self):
|
|
try:
|
|
os.remove(self.file)
|
|
except OSError:
|
|
# for instance, because we haven't yet used this cache,
|
|
# but client code has asked for a clear() operation...
|
|
pass
|
|
self.hash = {}
|
|
|
|
def __getitem__(self, key):
|
|
return self.hash[key]
|
|
|
|
def __contains__(self, key):
|
|
return key in self.hash
|
|
|
|
def __setitem__(self, key, value):
|
|
self.hash[key] = value
|
|
|
|
def __delitem__(self, key):
|
|
del self.hash[key]
|
|
|
|
def keys(self):
|
|
return self.hash.keys()
|
|
|
|
|
|
#### legacy stuff to support the old "Container" class interface
|
|
|
|
namespace_classes = {}
|
|
|
|
ContainerContext = dict
|
|
|
|
|
|
class ContainerMeta(type):
|
|
def __init__(cls, classname, bases, dict_):
|
|
namespace_classes[cls] = cls.namespace_class
|
|
return type.__init__(cls, classname, bases, dict_)
|
|
|
|
def __call__(self, key, context, namespace, createfunc=None,
|
|
expiretime=None, starttime=None, **kwargs):
|
|
if namespace in context:
|
|
ns = context[namespace]
|
|
else:
|
|
nscls = namespace_classes[self]
|
|
context[namespace] = ns = nscls(namespace, **kwargs)
|
|
return Value(key, ns, createfunc=createfunc,
|
|
expiretime=expiretime, starttime=starttime)
|
|
|
|
@add_metaclass(ContainerMeta)
|
|
class Container(object):
|
|
"""Implements synchronization and value-creation logic
|
|
for a 'value' stored in a :class:`.NamespaceManager`.
|
|
|
|
:class:`.Container` and its subclasses are deprecated. The
|
|
:class:`.Value` class is now used for this purpose.
|
|
|
|
"""
|
|
namespace_class = NamespaceManager
|
|
|
|
|
|
class FileContainer(Container):
|
|
namespace_class = FileNamespaceManager
|
|
|
|
|
|
class MemoryContainer(Container):
|
|
namespace_class = MemoryNamespaceManager
|
|
|
|
|
|
class DBMContainer(Container):
|
|
namespace_class = DBMNamespaceManager
|
|
|
|
DbmContainer = DBMContainer
|