def __init__(self, name, create=True, timeout=None, version=None):
super(Cache, self).__init__(
_Table, name, create=create, timeout=timeout, version=version)
self._persistent = False
# Check if the db file exists and is an sqlite3 db.
# Surprise, we have to do the heavy lifting.
# That stops here.
try:
with open(name, 'r') as f:
actual_magic = f.read(len(self._EXPECTED_MAGIC))
if actual_magic != self._EXPECTED_MAGIC:
raise exceptions.CacheInvalid(
'[{}] is not a persistent cache.'.format(self.name))
self._persistent = True
except IOError as e:
if e.errno in (errno.EISDIR, errno.EACCES):
raise exceptions.CacheInvalid(
'[{}] is not a persistent cache.'.format(self.name))
elif e.errno != errno.ENOENT:
raise
elif not create:
raise exceptions.CacheNotFound(
'Persistent cache [{}] not found.'.format(self.name))
self._db = sqlite3.connect(name)
self.cursor = self._db.cursor()
self._restricted = set(['__lock__'])
self._tables = {}
self._metadata = None
self._start = persistent_cache_base.Now()
try:
self.InitializeMetadata()
except exceptions.Error:
# Make sure we clean up any dangling resources.
self.Close(commit=False)
raise
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