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backends.py
288 lines | 8.3 KiB | text/x-python | PythonLexer
# -*- coding: utf-8 -*-
# Copyright (C) 2015-2019 RhodeCode GmbH
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License, version 3
# (only), as published by the Free Software Foundation.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
#
# This program is dual-licensed. If you wish to learn more about the
# RhodeCode Enterprise Edition, including its added features, Support services,
# and proprietary license terms, please see https://rhodecode.com/licenses/
import time
import errno
import logging
import msgpack
import gevent
import redis
from dogpile.cache.api import CachedValue
from dogpile.cache.backends import memory as memory_backend
from dogpile.cache.backends import file as file_backend
from dogpile.cache.backends import redis as redis_backend
from dogpile.cache.backends.file import NO_VALUE, compat, FileLock
from dogpile.cache.util import memoized_property
from rhodecode.lib.memory_lru_dict import LRUDict, LRUDictDebug
_default_max_size = 1024
log = logging.getLogger(__name__)
class LRUMemoryBackend(memory_backend.MemoryBackend):
key_prefix = 'lru_mem_backend'
pickle_values = False
def __init__(self, arguments):
max_size = arguments.pop('max_size', _default_max_size)
LRUDictClass = LRUDict
if arguments.pop('log_key_count', None):
LRUDictClass = LRUDictDebug
arguments['cache_dict'] = LRUDictClass(max_size)
super(LRUMemoryBackend, self).__init__(arguments)
def delete(self, key):
try:
del self._cache[key]
except KeyError:
# we don't care if key isn't there at deletion
pass
def delete_multi(self, keys):
for key in keys:
self.delete(key)
class PickleSerializer(object):
def _dumps(self, value, safe=False):
try:
return compat.pickle.dumps(value)
except Exception:
if safe:
return NO_VALUE
else:
raise
def _loads(self, value, safe=True):
try:
return compat.pickle.loads(value)
except Exception:
if safe:
return NO_VALUE
else:
raise
class MsgPackSerializer(object):
def _dumps(self, value, safe=False):
try:
return msgpack.packb(value)
except Exception:
if safe:
return NO_VALUE
else:
raise
def _loads(self, value, safe=True):
"""
pickle maintained the `CachedValue` wrapper of the tuple
msgpack does not, so it must be added back in.
"""
try:
value = msgpack.unpackb(value, use_list=False)
return CachedValue(*value)
except Exception:
if safe:
return NO_VALUE
else:
raise
import fcntl
flock_org = fcntl.flock
class CustomLockFactory(FileLock):
@memoized_property
def _module(self):
def gevent_flock(fd, operation):
"""
Gevent compatible flock
"""
# set non-blocking, this will cause an exception if we cannot acquire a lock
operation |= fcntl.LOCK_NB
start_lock_time = time.time()
timeout = 60 * 15 # 15min
while True:
try:
flock_org(fd, operation)
# lock has been acquired
break
except (OSError, IOError) as e:
# raise on other errors than Resource temporarily unavailable
if e.errno != errno.EAGAIN:
raise
elif (time.time() - start_lock_time) > timeout:
# waited to much time on a lock, better fail than loop for ever
log.error('Failed to acquire lock on `%s` after waiting %ss',
self.filename, timeout)
raise
wait_timeout = 0.03
log.debug('Failed to acquire lock on `%s`, retry in %ss',
self.filename, wait_timeout)
gevent.sleep(wait_timeout)
fcntl.flock = gevent_flock
return fcntl
class FileNamespaceBackend(PickleSerializer, file_backend.DBMBackend):
key_prefix = 'file_backend'
def __init__(self, arguments):
arguments['lock_factory'] = CustomLockFactory
super(FileNamespaceBackend, self).__init__(arguments)
def __repr__(self):
return '{} `{}`'.format(self.__class__, self.filename)
def list_keys(self, prefix=''):
prefix = '{}:{}'.format(self.key_prefix, prefix)
def cond(v):
if not prefix:
return True
if v.startswith(prefix):
return True
return False
with self._dbm_file(True) as dbm:
return filter(cond, dbm.keys())
def get_store(self):
return self.filename
def get(self, key):
with self._dbm_file(False) as dbm:
if hasattr(dbm, 'get'):
value = dbm.get(key, NO_VALUE)
else:
# gdbm objects lack a .get method
try:
value = dbm[key]
except KeyError:
value = NO_VALUE
if value is not NO_VALUE:
value = self._loads(value)
return value
def set(self, key, value):
with self._dbm_file(True) as dbm:
dbm[key] = self._dumps(value)
def set_multi(self, mapping):
with self._dbm_file(True) as dbm:
for key, value in mapping.items():
dbm[key] = self._dumps(value)
class BaseRedisBackend(redis_backend.RedisBackend):
def _create_client(self):
args = {}
if self.url is not None:
args.update(url=self.url)
else:
args.update(
host=self.host, password=self.password,
port=self.port, db=self.db
)
connection_pool = redis.ConnectionPool(**args)
return redis.StrictRedis(connection_pool=connection_pool)
def list_keys(self, prefix=''):
prefix = '{}:{}*'.format(self.key_prefix, prefix)
return self.client.keys(prefix)
def get_store(self):
return self.client.connection_pool
def get(self, key):
value = self.client.get(key)
if value is None:
return NO_VALUE
return self._loads(value)
def get_multi(self, keys):
if not keys:
return []
values = self.client.mget(keys)
loads = self._loads
return [
loads(v) if v is not None else NO_VALUE
for v in values]
def set(self, key, value):
if self.redis_expiration_time:
self.client.setex(key, self.redis_expiration_time,
self._dumps(value))
else:
self.client.set(key, self._dumps(value))
def set_multi(self, mapping):
dumps = self._dumps
mapping = dict(
(k, dumps(v))
for k, v in mapping.items()
)
if not self.redis_expiration_time:
self.client.mset(mapping)
else:
pipe = self.client.pipeline()
for key, value in mapping.items():
pipe.setex(key, self.redis_expiration_time, value)
pipe.execute()
def get_mutex(self, key):
u = redis_backend.u
if self.distributed_lock:
lock_key = u('_lock_{0}').format(key)
log.debug('Trying to acquire Redis lock for key %s', lock_key)
return self.client.lock(lock_key, self.lock_timeout, self.lock_sleep)
else:
return None
class RedisPickleBackend(PickleSerializer, BaseRedisBackend):
key_prefix = 'redis_pickle_backend'
pass
class RedisMsgPackBackend(MsgPackSerializer, BaseRedisBackend):
key_prefix = 'redis_msgpack_backend'
pass