mirror of
https://github.com/SickGear/SickGear.git
synced 2024-11-21 20:35:05 +00:00
134 lines
4.5 KiB
Python
134 lines
4.5 KiB
Python
# -*- coding: utf-8 -*-
|
|
# Copyright 2012 Nicolas Wack <wackou@gmail.com>
|
|
#
|
|
# This file is part of subliminal.
|
|
#
|
|
# subliminal is free software; you can redistribute it and/or modify it under
|
|
# the terms of the GNU Lesser General Public License as published by
|
|
# the Free Software Foundation; either version 3 of the License, or
|
|
# (at your option) any later version.
|
|
#
|
|
# subliminal 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 Lesser General Public License for more details.
|
|
#
|
|
# You should have received a copy of the GNU Lesser General Public License
|
|
# along with subliminal. If not, see <http://www.gnu.org/licenses/>.
|
|
from collections import defaultdict
|
|
from functools import wraps
|
|
import logging
|
|
import os.path
|
|
import threading
|
|
try:
|
|
import cPickle as pickle
|
|
except ImportError:
|
|
import pickle
|
|
|
|
|
|
__all__ = ['Cache', 'cachedmethod']
|
|
logger = logging.getLogger("subliminal")
|
|
|
|
|
|
class Cache(object):
|
|
"""A Cache object contains cached values for methods. It can have
|
|
separate internal caches, one for each service
|
|
|
|
"""
|
|
def __init__(self, cache_dir):
|
|
self.cache_dir = cache_dir
|
|
self.cache = defaultdict(dict)
|
|
self.lock = threading.RLock()
|
|
|
|
def __del__(self):
|
|
for service_name in self.cache:
|
|
self.save(service_name)
|
|
|
|
def cache_location(self, service_name):
|
|
return os.path.join(self.cache_dir, 'subliminal_%s.cache' % service_name)
|
|
|
|
def load(self, service_name):
|
|
with self.lock:
|
|
if service_name in self.cache:
|
|
# already loaded
|
|
return
|
|
|
|
self.cache[service_name] = defaultdict(dict)
|
|
filename = self.cache_location(service_name)
|
|
logger.debug(u'Cache: loading cache from %s' % filename)
|
|
try:
|
|
self.cache[service_name] = pickle.load(open(filename, 'rb'))
|
|
except IOError:
|
|
logger.info('Cache: Cache file "%s" doesn\'t exist, creating it' % filename)
|
|
except EOFError:
|
|
logger.error('Cache: cache file "%s" is corrupted... Removing it.' % filename)
|
|
os.remove(filename)
|
|
|
|
def save(self, service_name):
|
|
filename = self.cache_location(service_name)
|
|
logger.debug(u'Cache: saving cache to %s' % filename)
|
|
with self.lock:
|
|
pickle.dump(self.cache[service_name], open(filename, 'wb'))
|
|
|
|
def clear(self, service_name):
|
|
try:
|
|
os.remove(self.cache_location(service_name))
|
|
except OSError:
|
|
pass
|
|
self.cache[service_name] = defaultdict(dict)
|
|
|
|
def cached_func_key(self, func, cls=None):
|
|
try:
|
|
cls = func.im_class
|
|
except:
|
|
pass
|
|
return ('%s.%s' % (cls.__module__, cls.__name__), func.__name__)
|
|
|
|
def function_cache(self, service_name, func):
|
|
func_key = self.cached_func_key(func)
|
|
return self.cache[service_name][func_key]
|
|
|
|
def cache_for(self, service_name, func, args, result):
|
|
# no need to lock here, dict ops are atomic
|
|
self.function_cache(service_name, func)[args] = result
|
|
|
|
def cached_value(self, service_name, func, args):
|
|
"""Raises KeyError if not found"""
|
|
# no need to lock here, dict ops are atomic
|
|
return self.function_cache(service_name, func)[args]
|
|
|
|
|
|
def cachedmethod(function):
|
|
"""Decorator to make a method use the cache.
|
|
|
|
.. note::
|
|
|
|
This can NOT be used with static functions, it has to be used on
|
|
methods of some class
|
|
|
|
"""
|
|
@wraps(function)
|
|
def cached(*args):
|
|
c = args[0].config.cache
|
|
service_name = args[0].__class__.__name__
|
|
func_key = c.cached_func_key(function, cls=args[0].__class__)
|
|
func_cache = c.cache[service_name][func_key]
|
|
|
|
# we need to remove the first element of args for the key, as it is the
|
|
# instance pointer and we don't want the cache to know which instance
|
|
# called it, it is shared among all instances of the same class
|
|
key = args[1:]
|
|
|
|
if key in func_cache:
|
|
result = func_cache[key]
|
|
logger.debug(u'Using cached value for %s(%s), returns: %s' % (func_key, key, result))
|
|
return result
|
|
|
|
result = function(*args)
|
|
|
|
# note: another thread could have already cached a value in the
|
|
# meantime, but that's ok as we prefer to keep the latest value in
|
|
# the cache
|
|
func_cache[key] = result
|
|
return result
|
|
return cached
|