You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
240 lines
7.5 KiB
240 lines
7.5 KiB
# mako/cache.py
|
|
# Copyright 2006-2022 the Mako authors and contributors <see AUTHORS file>
|
|
#
|
|
# This module is part of Mako and is released under
|
|
# the MIT License: http://www.opensource.org/licenses/mit-license.php
|
|
|
|
from mako import util
|
|
|
|
_cache_plugins = util.PluginLoader("mako.cache")
|
|
|
|
register_plugin = _cache_plugins.register
|
|
register_plugin("beaker", "mako.ext.beaker_cache", "BeakerCacheImpl")
|
|
|
|
|
|
class Cache:
|
|
|
|
"""Represents a data content cache made available to the module
|
|
space of a specific :class:`.Template` object.
|
|
|
|
.. versionadded:: 0.6
|
|
:class:`.Cache` by itself is mostly a
|
|
container for a :class:`.CacheImpl` object, which implements
|
|
a fixed API to provide caching services; specific subclasses exist to
|
|
implement different
|
|
caching strategies. Mako includes a backend that works with
|
|
the Beaker caching system. Beaker itself then supports
|
|
a number of backends (i.e. file, memory, memcached, etc.)
|
|
|
|
The construction of a :class:`.Cache` is part of the mechanics
|
|
of a :class:`.Template`, and programmatic access to this
|
|
cache is typically via the :attr:`.Template.cache` attribute.
|
|
|
|
"""
|
|
|
|
impl = None
|
|
"""Provide the :class:`.CacheImpl` in use by this :class:`.Cache`.
|
|
|
|
This accessor allows a :class:`.CacheImpl` with additional
|
|
methods beyond that of :class:`.Cache` to be used programmatically.
|
|
|
|
"""
|
|
|
|
id = None
|
|
"""Return the 'id' that identifies this cache.
|
|
|
|
This is a value that should be globally unique to the
|
|
:class:`.Template` associated with this cache, and can
|
|
be used by a caching system to name a local container
|
|
for data specific to this template.
|
|
|
|
"""
|
|
|
|
starttime = None
|
|
"""Epochal time value for when the owning :class:`.Template` was
|
|
first compiled.
|
|
|
|
A cache implementation may wish to invalidate data earlier than
|
|
this timestamp; this has the effect of the cache for a specific
|
|
:class:`.Template` starting clean any time the :class:`.Template`
|
|
is recompiled, such as when the original template file changed on
|
|
the filesystem.
|
|
|
|
"""
|
|
|
|
def __init__(self, template, *args):
|
|
# check for a stale template calling the
|
|
# constructor
|
|
if isinstance(template, str) and args:
|
|
return
|
|
self.template = template
|
|
self.id = template.module.__name__
|
|
self.starttime = template.module._modified_time
|
|
self._def_regions = {}
|
|
self.impl = self._load_impl(self.template.cache_impl)
|
|
|
|
def _load_impl(self, name):
|
|
return _cache_plugins.load(name)(self)
|
|
|
|
def get_or_create(self, key, creation_function, **kw):
|
|
"""Retrieve a value from the cache, using the given creation function
|
|
to generate a new value."""
|
|
|
|
return self._ctx_get_or_create(key, creation_function, None, **kw)
|
|
|
|
def _ctx_get_or_create(self, key, creation_function, context, **kw):
|
|
"""Retrieve a value from the cache, using the given creation function
|
|
to generate a new value."""
|
|
|
|
if not self.template.cache_enabled:
|
|
return creation_function()
|
|
|
|
return self.impl.get_or_create(
|
|
key, creation_function, **self._get_cache_kw(kw, context)
|
|
)
|
|
|
|
def set(self, key, value, **kw):
|
|
r"""Place a value in the cache.
|
|
|
|
:param key: the value's key.
|
|
:param value: the value.
|
|
:param \**kw: cache configuration arguments.
|
|
|
|
"""
|
|
|
|
self.impl.set(key, value, **self._get_cache_kw(kw, None))
|
|
|
|
put = set
|
|
"""A synonym for :meth:`.Cache.set`.
|
|
|
|
This is here for backwards compatibility.
|
|
|
|
"""
|
|
|
|
def get(self, key, **kw):
|
|
r"""Retrieve a value from the cache.
|
|
|
|
:param key: the value's key.
|
|
:param \**kw: cache configuration arguments. The
|
|
backend is configured using these arguments upon first request.
|
|
Subsequent requests that use the same series of configuration
|
|
values will use that same backend.
|
|
|
|
"""
|
|
return self.impl.get(key, **self._get_cache_kw(kw, None))
|
|
|
|
def invalidate(self, key, **kw):
|
|
r"""Invalidate a value in the cache.
|
|
|
|
:param key: the value's key.
|
|
:param \**kw: cache configuration arguments. The
|
|
backend is configured using these arguments upon first request.
|
|
Subsequent requests that use the same series of configuration
|
|
values will use that same backend.
|
|
|
|
"""
|
|
self.impl.invalidate(key, **self._get_cache_kw(kw, None))
|
|
|
|
def invalidate_body(self):
|
|
"""Invalidate the cached content of the "body" method for this
|
|
template.
|
|
|
|
"""
|
|
self.invalidate("render_body", __M_defname="render_body")
|
|
|
|
def invalidate_def(self, name):
|
|
"""Invalidate the cached content of a particular ``<%def>`` within this
|
|
template.
|
|
|
|
"""
|
|
|
|
self.invalidate("render_%s" % name, __M_defname="render_%s" % name)
|
|
|
|
def invalidate_closure(self, name):
|
|
"""Invalidate a nested ``<%def>`` within this template.
|
|
|
|
Caching of nested defs is a blunt tool as there is no
|
|
management of scope -- nested defs that use cache tags
|
|
need to have names unique of all other nested defs in the
|
|
template, else their content will be overwritten by
|
|
each other.
|
|
|
|
"""
|
|
|
|
self.invalidate(name, __M_defname=name)
|
|
|
|
def _get_cache_kw(self, kw, context):
|
|
defname = kw.pop("__M_defname", None)
|
|
if not defname:
|
|
tmpl_kw = self.template.cache_args.copy()
|
|
tmpl_kw.update(kw)
|
|
elif defname in self._def_regions:
|
|
tmpl_kw = self._def_regions[defname]
|
|
else:
|
|
tmpl_kw = self.template.cache_args.copy()
|
|
tmpl_kw.update(kw)
|
|
self._def_regions[defname] = tmpl_kw
|
|
if context and self.impl.pass_context:
|
|
tmpl_kw = tmpl_kw.copy()
|
|
tmpl_kw.setdefault("context", context)
|
|
return tmpl_kw
|
|
|
|
|
|
class CacheImpl:
|
|
|
|
"""Provide a cache implementation for use by :class:`.Cache`."""
|
|
|
|
def __init__(self, cache):
|
|
self.cache = cache
|
|
|
|
pass_context = False
|
|
"""If ``True``, the :class:`.Context` will be passed to
|
|
:meth:`get_or_create <.CacheImpl.get_or_create>` as the name ``'context'``.
|
|
"""
|
|
|
|
def get_or_create(self, key, creation_function, **kw):
|
|
r"""Retrieve a value from the cache, using the given creation function
|
|
to generate a new value.
|
|
|
|
This function *must* return a value, either from
|
|
the cache, or via the given creation function.
|
|
If the creation function is called, the newly
|
|
created value should be populated into the cache
|
|
under the given key before being returned.
|
|
|
|
:param key: the value's key.
|
|
:param creation_function: function that when called generates
|
|
a new value.
|
|
:param \**kw: cache configuration arguments.
|
|
|
|
"""
|
|
raise NotImplementedError()
|
|
|
|
def set(self, key, value, **kw):
|
|
r"""Place a value in the cache.
|
|
|
|
:param key: the value's key.
|
|
:param value: the value.
|
|
:param \**kw: cache configuration arguments.
|
|
|
|
"""
|
|
raise NotImplementedError()
|
|
|
|
def get(self, key, **kw):
|
|
r"""Retrieve a value from the cache.
|
|
|
|
:param key: the value's key.
|
|
:param \**kw: cache configuration arguments.
|
|
|
|
"""
|
|
raise NotImplementedError()
|
|
|
|
def invalidate(self, key, **kw):
|
|
r"""Invalidate a value in the cache.
|
|
|
|
:param key: the value's key.
|
|
:param \**kw: cache configuration arguments.
|
|
|
|
"""
|
|
raise NotImplementedError()
|