def __init__(self, name, create=True, timeout=None, version=None):
super(Cache, self).__init__(_Table,
name,
create=create,
timeout=timeout,
version=version)
lock_name = '__lock__'
self._restricted = set([lock_name])
self._tables = {}
self._metadata = None
self._start = persistent_cache_base.Now()
self._lock_path = os.path.join(self.name, lock_name)
self._lock = None
self._persistent = False
if not os.path.exists(self.name):
if not create:
raise exceptions.CacheNotFound(
'Persistent cache [{}] not found.'.format(self.name))
elif not os.path.exists(self._lock_path):
raise exceptions.CacheInvalid(
'[{}] is not a persistent cache.'.format(self.name))
else:
# self.name exists and is a directory, and self._lock_path exists.
self._persistent = True
self._lock = files.FileLock(self._lock_path, timeout_secs=2)
self._lock.Lock()
try:
self.InitializeMetadata()
except exceptions.Error:
# Make sure we clean up any dangling resources.
self.Close(commit=False)
raise
def Commit(self):
"""Commits all operations up to this point."""
if not self._lock:
os.mkdir(self.name, 0700)
self._persistent = True
self._lock = files.FileLock(self._lock_path, timeout_secs=2)
self._lock.Lock()
# Update the changed tables.
for table in list([x for x in self._tables.values() if x.changed]):
table._Commit() # pylint: disable=protected-access
if self._metadata.changed:
self._metadata._Commit() # pylint: disable=protected-access
