mirror of
https://github.com/morpheus65535/bazarr
synced 2024-12-27 01:57:33 +00:00
615 lines
21 KiB
Python
615 lines
21 KiB
Python
"""This package contains the "front end" classes and functions
|
|
for Beaker caching.
|
|
|
|
Included are the :class:`.Cache` and :class:`.CacheManager` classes,
|
|
as well as the function decorators :func:`.region_decorate`,
|
|
:func:`.region_invalidate`.
|
|
|
|
"""
|
|
import warnings
|
|
from itertools import chain
|
|
|
|
from beaker._compat import u_, unicode_text, func_signature, bindfuncargs
|
|
import beaker.container as container
|
|
import beaker.util as util
|
|
from beaker.crypto.util import sha1
|
|
from beaker.exceptions import BeakerException, InvalidCacheBackendError
|
|
from beaker.synchronization import _threading
|
|
|
|
import beaker.ext.memcached as memcached
|
|
import beaker.ext.database as database
|
|
import beaker.ext.sqla as sqla
|
|
import beaker.ext.google as google
|
|
import beaker.ext.mongodb as mongodb
|
|
import beaker.ext.redisnm as redisnm
|
|
from functools import wraps
|
|
|
|
# Initialize the cache region dict
|
|
cache_regions = {}
|
|
"""Dictionary of 'region' arguments.
|
|
|
|
A "region" is a string name that refers to a series of cache
|
|
configuration arguments. An application may have multiple
|
|
"regions" - one which stores things in a memory cache, one
|
|
which writes data to files, etc.
|
|
|
|
The dictionary stores string key names mapped to dictionaries
|
|
of configuration arguments. Example::
|
|
|
|
from beaker.cache import cache_regions
|
|
cache_regions.update({
|
|
'short_term':{
|
|
'expire':60,
|
|
'type':'memory'
|
|
},
|
|
'long_term':{
|
|
'expire':1800,
|
|
'type':'dbm',
|
|
'data_dir':'/tmp',
|
|
}
|
|
})
|
|
"""
|
|
|
|
|
|
cache_managers = {}
|
|
|
|
|
|
class _backends(object):
|
|
initialized = False
|
|
|
|
def __init__(self, clsmap):
|
|
self._clsmap = clsmap
|
|
self._mutex = _threading.Lock()
|
|
|
|
def __getitem__(self, key):
|
|
try:
|
|
return self._clsmap[key]
|
|
except KeyError as e:
|
|
if not self.initialized:
|
|
self._mutex.acquire()
|
|
try:
|
|
if not self.initialized:
|
|
self._init()
|
|
self.initialized = True
|
|
|
|
return self._clsmap[key]
|
|
finally:
|
|
self._mutex.release()
|
|
|
|
raise e
|
|
|
|
def _init(self):
|
|
try:
|
|
import pkg_resources
|
|
|
|
# Load up the additional entry point defined backends
|
|
for entry_point in pkg_resources.iter_entry_points('beaker.backends'):
|
|
try:
|
|
namespace_manager = entry_point.load()
|
|
name = entry_point.name
|
|
if name in self._clsmap:
|
|
raise BeakerException("NamespaceManager name conflict,'%s' "
|
|
"already loaded" % name)
|
|
self._clsmap[name] = namespace_manager
|
|
except (InvalidCacheBackendError, SyntaxError):
|
|
# Ignore invalid backends
|
|
pass
|
|
except:
|
|
import sys
|
|
from pkg_resources import DistributionNotFound
|
|
# Warn when there's a problem loading a NamespaceManager
|
|
if not isinstance(sys.exc_info()[1], DistributionNotFound):
|
|
import traceback
|
|
try:
|
|
from StringIO import StringIO # Python2
|
|
except ImportError:
|
|
from io import StringIO # Python3
|
|
|
|
tb = StringIO()
|
|
traceback.print_exc(file=tb)
|
|
warnings.warn(
|
|
"Unable to load NamespaceManager "
|
|
"entry point: '%s': %s" % (
|
|
entry_point,
|
|
tb.getvalue()),
|
|
RuntimeWarning, 2)
|
|
except ImportError:
|
|
pass
|
|
|
|
# Initialize the basic available backends
|
|
clsmap = _backends({
|
|
'memory': container.MemoryNamespaceManager,
|
|
'dbm': container.DBMNamespaceManager,
|
|
'file': container.FileNamespaceManager,
|
|
'ext:memcached': memcached.MemcachedNamespaceManager,
|
|
'ext:database': database.DatabaseNamespaceManager,
|
|
'ext:sqla': sqla.SqlaNamespaceManager,
|
|
'ext:google': google.GoogleNamespaceManager,
|
|
'ext:mongodb': mongodb.MongoNamespaceManager,
|
|
'ext:redis': redisnm.RedisNamespaceManager
|
|
})
|
|
|
|
|
|
def cache_region(region, *args):
|
|
"""Decorate a function such that its return result is cached,
|
|
using a "region" to indicate the cache arguments.
|
|
|
|
Example::
|
|
|
|
from beaker.cache import cache_regions, cache_region
|
|
|
|
# configure regions
|
|
cache_regions.update({
|
|
'short_term':{
|
|
'expire':60,
|
|
'type':'memory'
|
|
}
|
|
})
|
|
|
|
@cache_region('short_term', 'load_things')
|
|
def load(search_term, limit, offset):
|
|
'''Load from a database given a search term, limit, offset.'''
|
|
return database.query(search_term)[offset:offset + limit]
|
|
|
|
The decorator can also be used with object methods. The ``self``
|
|
argument is not part of the cache key. This is based on the
|
|
actual string name ``self`` being in the first argument
|
|
position (new in 1.6)::
|
|
|
|
class MyThing(object):
|
|
@cache_region('short_term', 'load_things')
|
|
def load(self, search_term, limit, offset):
|
|
'''Load from a database given a search term, limit, offset.'''
|
|
return database.query(search_term)[offset:offset + limit]
|
|
|
|
Classmethods work as well - use ``cls`` as the name of the class argument,
|
|
and place the decorator around the function underneath ``@classmethod``
|
|
(new in 1.6)::
|
|
|
|
class MyThing(object):
|
|
@classmethod
|
|
@cache_region('short_term', 'load_things')
|
|
def load(cls, search_term, limit, offset):
|
|
'''Load from a database given a search term, limit, offset.'''
|
|
return database.query(search_term)[offset:offset + limit]
|
|
|
|
:param region: String name of the region corresponding to the desired
|
|
caching arguments, established in :attr:`.cache_regions`.
|
|
|
|
:param \*args: Optional ``str()``-compatible arguments which will uniquely
|
|
identify the key used by this decorated function, in addition
|
|
to the positional arguments passed to the function itself at call time.
|
|
This is recommended as it is needed to distinguish between any two functions
|
|
or methods that have the same name (regardless of parent class or not).
|
|
|
|
.. note::
|
|
|
|
The function being decorated must only be called with
|
|
positional arguments, and the arguments must support
|
|
being stringified with ``str()``. The concatenation
|
|
of the ``str()`` version of each argument, combined
|
|
with that of the ``*args`` sent to the decorator,
|
|
forms the unique cache key.
|
|
|
|
.. note::
|
|
|
|
When a method on a class is decorated, the ``self`` or ``cls``
|
|
argument in the first position is
|
|
not included in the "key" used for caching. New in 1.6.
|
|
|
|
"""
|
|
return _cache_decorate(args, None, None, region)
|
|
|
|
|
|
def region_invalidate(namespace, region, *args):
|
|
"""Invalidate a cache region corresponding to a function
|
|
decorated with :func:`.cache_region`.
|
|
|
|
:param namespace: The namespace of the cache to invalidate. This is typically
|
|
a reference to the original function (as returned by the :func:`.cache_region`
|
|
decorator), where the :func:`.cache_region` decorator applies a "memo" to
|
|
the function in order to locate the string name of the namespace.
|
|
|
|
:param region: String name of the region used with the decorator. This can be
|
|
``None`` in the usual case that the decorated function itself is passed,
|
|
not the string name of the namespace.
|
|
|
|
:param args: Stringifyable arguments that are used to locate the correct
|
|
key. This consists of the ``*args`` sent to the :func:`.cache_region`
|
|
decorator itself, plus the ``*args`` sent to the function itself
|
|
at runtime.
|
|
|
|
Example::
|
|
|
|
from beaker.cache import cache_regions, cache_region, region_invalidate
|
|
|
|
# configure regions
|
|
cache_regions.update({
|
|
'short_term':{
|
|
'expire':60,
|
|
'type':'memory'
|
|
}
|
|
})
|
|
|
|
@cache_region('short_term', 'load_data')
|
|
def load(search_term, limit, offset):
|
|
'''Load from a database given a search term, limit, offset.'''
|
|
return database.query(search_term)[offset:offset + limit]
|
|
|
|
def invalidate_search(search_term, limit, offset):
|
|
'''Invalidate the cached storage for a given search term, limit, offset.'''
|
|
region_invalidate(load, 'short_term', 'load_data', search_term, limit, offset)
|
|
|
|
Note that when a method on a class is decorated, the first argument ``cls``
|
|
or ``self`` is not included in the cache key. This means you don't send
|
|
it to :func:`.region_invalidate`::
|
|
|
|
class MyThing(object):
|
|
@cache_region('short_term', 'some_data')
|
|
def load(self, search_term, limit, offset):
|
|
'''Load from a database given a search term, limit, offset.'''
|
|
return database.query(search_term)[offset:offset + limit]
|
|
|
|
def invalidate_search(self, search_term, limit, offset):
|
|
'''Invalidate the cached storage for a given search term, limit, offset.'''
|
|
region_invalidate(self.load, 'short_term', 'some_data', search_term, limit, offset)
|
|
|
|
"""
|
|
if callable(namespace):
|
|
if not region:
|
|
region = namespace._arg_region
|
|
namespace = namespace._arg_namespace
|
|
|
|
if not region:
|
|
raise BeakerException("Region or callable function "
|
|
"namespace is required")
|
|
else:
|
|
region = cache_regions[region]
|
|
|
|
cache = Cache._get_cache(namespace, region)
|
|
_cache_decorator_invalidate(cache,
|
|
region.get('key_length', util.DEFAULT_CACHE_KEY_LENGTH),
|
|
args)
|
|
|
|
|
|
class Cache(object):
|
|
"""Front-end to the containment API implementing a data cache.
|
|
|
|
:param namespace: the namespace of this Cache
|
|
|
|
:param type: type of cache to use
|
|
|
|
:param expire: seconds to keep cached data
|
|
|
|
:param expiretime: seconds to keep cached data (legacy support)
|
|
|
|
:param starttime: time when cache was cache was
|
|
|
|
"""
|
|
def __init__(self, namespace, type='memory', expiretime=None,
|
|
starttime=None, expire=None, **nsargs):
|
|
try:
|
|
cls = clsmap[type]
|
|
if isinstance(cls, InvalidCacheBackendError):
|
|
raise cls
|
|
except KeyError:
|
|
raise TypeError("Unknown cache implementation %r" % type)
|
|
|
|
if expire is not None:
|
|
expire = int(expire)
|
|
|
|
self.namespace_name = namespace
|
|
self.namespace = cls(namespace, **nsargs)
|
|
self.expiretime = expiretime or expire
|
|
self.starttime = starttime
|
|
self.nsargs = nsargs
|
|
|
|
@classmethod
|
|
def _get_cache(cls, namespace, kw):
|
|
key = namespace + str(kw)
|
|
try:
|
|
return cache_managers[key]
|
|
except KeyError:
|
|
cache_managers[key] = cache = cls(namespace, **kw)
|
|
return cache
|
|
|
|
def put(self, key, value, **kw):
|
|
self._get_value(key, **kw).set_value(value)
|
|
set_value = put
|
|
|
|
def get(self, key, **kw):
|
|
"""Retrieve a cached value from the container"""
|
|
return self._get_value(key, **kw).get_value()
|
|
get_value = get
|
|
|
|
def remove_value(self, key, **kw):
|
|
mycontainer = self._get_value(key, **kw)
|
|
mycontainer.clear_value()
|
|
remove = remove_value
|
|
|
|
def _get_value(self, key, **kw):
|
|
if isinstance(key, unicode_text):
|
|
key = key.encode('ascii', 'backslashreplace')
|
|
|
|
if 'type' in kw:
|
|
return self._legacy_get_value(key, **kw)
|
|
|
|
kw.setdefault('expiretime', self.expiretime)
|
|
kw.setdefault('starttime', self.starttime)
|
|
|
|
return container.Value(key, self.namespace, **kw)
|
|
|
|
@util.deprecated("Specifying a "
|
|
"'type' and other namespace configuration with cache.get()/put()/etc. "
|
|
"is deprecated. Specify 'type' and other namespace configuration to "
|
|
"cache_manager.get_cache() and/or the Cache constructor instead.")
|
|
def _legacy_get_value(self, key, type, **kw):
|
|
expiretime = kw.pop('expiretime', self.expiretime)
|
|
starttime = kw.pop('starttime', None)
|
|
createfunc = kw.pop('createfunc', None)
|
|
kwargs = self.nsargs.copy()
|
|
kwargs.update(kw)
|
|
c = Cache(self.namespace.namespace, type=type, **kwargs)
|
|
return c._get_value(key, expiretime=expiretime, createfunc=createfunc,
|
|
starttime=starttime)
|
|
|
|
def clear(self):
|
|
"""Clear all the values from the namespace"""
|
|
self.namespace.remove()
|
|
|
|
# dict interface
|
|
def __getitem__(self, key):
|
|
return self.get(key)
|
|
|
|
def __contains__(self, key):
|
|
return self._get_value(key).has_current_value()
|
|
|
|
def has_key(self, key):
|
|
return key in self
|
|
|
|
def __delitem__(self, key):
|
|
self.remove_value(key)
|
|
|
|
def __setitem__(self, key, value):
|
|
self.put(key, value)
|
|
|
|
|
|
class CacheManager(object):
|
|
def __init__(self, **kwargs):
|
|
"""Initialize a CacheManager object with a set of options
|
|
|
|
Options should be parsed with the
|
|
:func:`~beaker.util.parse_cache_config_options` function to
|
|
ensure only valid options are used.
|
|
|
|
"""
|
|
self.kwargs = kwargs
|
|
self.regions = kwargs.pop('cache_regions', {})
|
|
|
|
# Add these regions to the module global
|
|
cache_regions.update(self.regions)
|
|
|
|
def get_cache(self, name, **kwargs):
|
|
kw = self.kwargs.copy()
|
|
kw.update(kwargs)
|
|
return Cache._get_cache(name, kw)
|
|
|
|
def get_cache_region(self, name, region):
|
|
if region not in self.regions:
|
|
raise BeakerException('Cache region not configured: %s' % region)
|
|
kw = self.regions[region]
|
|
return Cache._get_cache(name, kw)
|
|
|
|
def region(self, region, *args):
|
|
"""Decorate a function to cache itself using a cache region
|
|
|
|
The region decorator requires arguments if there are more than
|
|
two of the same named function, in the same module. This is
|
|
because the namespace used for the functions cache is based on
|
|
the functions name and the module.
|
|
|
|
|
|
Example::
|
|
|
|
# Assuming a cache object is available like:
|
|
cache = CacheManager(dict_of_config_options)
|
|
|
|
|
|
def populate_things():
|
|
|
|
@cache.region('short_term', 'some_data')
|
|
def load(search_term, limit, offset):
|
|
return load_the_data(search_term, limit, offset)
|
|
|
|
return load('rabbits', 20, 0)
|
|
|
|
.. note::
|
|
|
|
The function being decorated must only be called with
|
|
positional arguments.
|
|
|
|
"""
|
|
return cache_region(region, *args)
|
|
|
|
def region_invalidate(self, namespace, region, *args):
|
|
"""Invalidate a cache region namespace or decorated function
|
|
|
|
This function only invalidates cache spaces created with the
|
|
cache_region decorator.
|
|
|
|
:param namespace: Either the namespace of the result to invalidate, or the
|
|
cached function
|
|
|
|
:param region: The region the function was cached to. If the function was
|
|
cached to a single region then this argument can be None
|
|
|
|
:param args: Arguments that were used to differentiate the cached
|
|
function as well as the arguments passed to the decorated
|
|
function
|
|
|
|
Example::
|
|
|
|
# Assuming a cache object is available like:
|
|
cache = CacheManager(dict_of_config_options)
|
|
|
|
def populate_things(invalidate=False):
|
|
|
|
@cache.region('short_term', 'some_data')
|
|
def load(search_term, limit, offset):
|
|
return load_the_data(search_term, limit, offset)
|
|
|
|
# If the results should be invalidated first
|
|
if invalidate:
|
|
cache.region_invalidate(load, None, 'some_data',
|
|
'rabbits', 20, 0)
|
|
return load('rabbits', 20, 0)
|
|
|
|
|
|
"""
|
|
return region_invalidate(namespace, region, *args)
|
|
|
|
def cache(self, *args, **kwargs):
|
|
"""Decorate a function to cache itself with supplied parameters
|
|
|
|
:param args: Used to make the key unique for this function, as in region()
|
|
above.
|
|
|
|
:param kwargs: Parameters to be passed to get_cache(), will override defaults
|
|
|
|
Example::
|
|
|
|
# Assuming a cache object is available like:
|
|
cache = CacheManager(dict_of_config_options)
|
|
|
|
|
|
def populate_things():
|
|
|
|
@cache.cache('mycache', expire=15)
|
|
def load(search_term, limit, offset):
|
|
return load_the_data(search_term, limit, offset)
|
|
|
|
return load('rabbits', 20, 0)
|
|
|
|
.. note::
|
|
|
|
The function being decorated must only be called with
|
|
positional arguments.
|
|
|
|
"""
|
|
return _cache_decorate(args, self, kwargs, None)
|
|
|
|
def invalidate(self, func, *args, **kwargs):
|
|
"""Invalidate a cache decorated function
|
|
|
|
This function only invalidates cache spaces created with the
|
|
cache decorator.
|
|
|
|
:param func: Decorated function to invalidate
|
|
|
|
:param args: Used to make the key unique for this function, as in region()
|
|
above.
|
|
|
|
:param kwargs: Parameters that were passed for use by get_cache(), note that
|
|
this is only required if a ``type`` was specified for the
|
|
function
|
|
|
|
Example::
|
|
|
|
# Assuming a cache object is available like:
|
|
cache = CacheManager(dict_of_config_options)
|
|
|
|
|
|
def populate_things(invalidate=False):
|
|
|
|
@cache.cache('mycache', type="file", expire=15)
|
|
def load(search_term, limit, offset):
|
|
return load_the_data(search_term, limit, offset)
|
|
|
|
# If the results should be invalidated first
|
|
if invalidate:
|
|
cache.invalidate(load, 'mycache', 'rabbits', 20, 0, type="file")
|
|
return load('rabbits', 20, 0)
|
|
|
|
"""
|
|
namespace = func._arg_namespace
|
|
|
|
cache = self.get_cache(namespace, **kwargs)
|
|
if hasattr(func, '_arg_region'):
|
|
cachereg = cache_regions[func._arg_region]
|
|
key_length = cachereg.get('key_length', util.DEFAULT_CACHE_KEY_LENGTH)
|
|
else:
|
|
key_length = kwargs.pop('key_length', util.DEFAULT_CACHE_KEY_LENGTH)
|
|
_cache_decorator_invalidate(cache, key_length, args)
|
|
|
|
|
|
def _cache_decorate(deco_args, manager, options, region):
|
|
"""Return a caching function decorator."""
|
|
|
|
cache = [None]
|
|
|
|
def decorate(func):
|
|
namespace = util.func_namespace(func)
|
|
skip_self = util.has_self_arg(func)
|
|
signature = func_signature(func)
|
|
|
|
@wraps(func)
|
|
def cached(*args, **kwargs):
|
|
if not cache[0]:
|
|
if region is not None:
|
|
if region not in cache_regions:
|
|
raise BeakerException(
|
|
'Cache region not configured: %s' % region)
|
|
reg = cache_regions[region]
|
|
if not reg.get('enabled', True):
|
|
return func(*args, **kwargs)
|
|
cache[0] = Cache._get_cache(namespace, reg)
|
|
elif manager:
|
|
cache[0] = manager.get_cache(namespace, **options)
|
|
else:
|
|
raise Exception("'manager + kwargs' or 'region' "
|
|
"argument is required")
|
|
|
|
cache_key_kwargs = []
|
|
if kwargs:
|
|
# kwargs provided, merge them in positional args
|
|
# to avoid having different cache keys.
|
|
args, kwargs = bindfuncargs(signature, args, kwargs)
|
|
cache_key_kwargs = [u_(':').join((u_(key), u_(value))) for key, value in kwargs.items()]
|
|
|
|
cache_key_args = args
|
|
if skip_self:
|
|
cache_key_args = args[1:]
|
|
|
|
cache_key = u_(" ").join(map(u_, chain(deco_args, cache_key_args, cache_key_kwargs)))
|
|
|
|
if region:
|
|
cachereg = cache_regions[region]
|
|
key_length = cachereg.get('key_length', util.DEFAULT_CACHE_KEY_LENGTH)
|
|
else:
|
|
key_length = options.pop('key_length', util.DEFAULT_CACHE_KEY_LENGTH)
|
|
|
|
# TODO: This is probably a bug as length is checked before converting to UTF8
|
|
# which will cause cache_key to grow in size.
|
|
if len(cache_key) + len(namespace) > int(key_length):
|
|
cache_key = sha1(cache_key.encode('utf-8')).hexdigest()
|
|
|
|
def go():
|
|
return func(*args, **kwargs)
|
|
# save org function name
|
|
go.__name__ = '_cached_%s' % (func.__name__,)
|
|
|
|
return cache[0].get_value(cache_key, createfunc=go)
|
|
cached._arg_namespace = namespace
|
|
if region is not None:
|
|
cached._arg_region = region
|
|
return cached
|
|
return decorate
|
|
|
|
|
|
def _cache_decorator_invalidate(cache, key_length, args):
|
|
"""Invalidate a cache key based on function arguments."""
|
|
|
|
cache_key = u_(" ").join(map(u_, args))
|
|
if len(cache_key) + len(cache.namespace_name) > key_length:
|
|
cache_key = sha1(cache_key.encode('utf-8')).hexdigest()
|
|
cache.remove_value(cache_key)
|