/usr/lib/python2.7/dist-packages/tg/caching.py is in python-turbogears2 2.3.7-2.
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 | """Caching decorator, took as is from pylons"""
import tg, inspect, time
from tg.support.converters import asbool
from tg.support import NoDefault, EmptyContext
from tg._compat import im_func, im_class
from functools import wraps
class cached_property(object):
"""
Works like python @property but the decorated function only gets
executed once, successive accesses to the property will just
return the value previously stored into the object.
The ``@cached_property`` decorator can be executed within a
provided context, for example to make the cached property
thread safe a Lock can be provided::
from threading import Lock
from tg.caching import cached_property
class MyClass(object):
@cached_property
def my_property(self):
return 'Value!'
my_property.context = Lock()
"""
def __init__(self, func):
self.__name__ = func.__name__
self.__module__ = func.__module__
self.__doc__ = func.__doc__
self.func = func
self.context = EmptyContext()
def _get_value(self, obj):
value = obj.__dict__.get(self.__name__, NoDefault)
if value is NoDefault:
value = self.func(obj)
obj.__dict__[self.__name__] = value
return value
def __get__(self, obj, type=None):
if obj is None:
return self
with self.context:
return self._get_value(obj)
def _cached_call(func, args, kwargs, namespace, cache_key,
expire="never", type=None, starttime=None,
cache_headers=('content-type', 'content-length'),
cache_response=True, cache_extra_args=None):
"""
Optional arguments:
``key_func``
Function used to genereate the cache key, the function name
and class will be used as the base for the cache key. If None
the ``func`` itself will be used. It's usually handy when
creating caches for decorated functions, for which we want the
cache key to be generated on the decorated function and not on
the decorator.
``key_dict``
Arguments used to generate the cache key, only the arguments
listed into this dictionary will be used to generate the
cache key together with the key_func.
``expire``
Time in seconds before cache expires, or the string "never".
Defaults to "never"
``type``
Type of cache to use: dbm, memory, file, memcached, or None for
Beaker's default
``cache_headers``
A tuple of header names indicating response headers that
will also be cached.
``invalidate_on_startup``
If True, the cache will be invalidated each time the application
starts or is restarted.
``cache_response``
Determines whether the response at the time beaker_cache is used
should be cached or not, defaults to True.
.. note::
When cache_response is set to False, the cache_headers
argument is ignored as none of the response is cached.
If cache.enabled is set to False in the .ini file, then cache is
disabled globally.
"""
tg_locals = tg.request.environ['tg.locals']
enabled = asbool(tg_locals.config.get("cache.enabled", True))
if not enabled:
return func(*args, **kwargs)
cache_extra_args = cache_extra_args or {}
if type:
cache_extra_args['type'] = type
cache_obj = getattr(tg_locals, 'cache', None)
if not cache_obj: # pragma: no cover
raise Exception('TurboGears Cache object not found, ensure cache.enabled=True')
my_cache = cache_obj.get_cache(namespace, **cache_extra_args)
if expire == "never":
cache_expire = None
else:
cache_expire = expire
def create_func():
result = func(*args, **kwargs)
glob_response = tg_locals.response
headers = glob_response.headerlist
status = glob_response.status
full_response = dict(headers=headers, status=status,
cookies=None, content=result)
return full_response
response = my_cache.get_value(cache_key,
createfunc=create_func,
expiretime=cache_expire,
starttime=starttime)
if cache_response:
glob_response = tg_locals.response
glob_response.headerlist = [header for header in response['headers']
if header[0].lower() in cache_headers]
glob_response.status = response['status']
return response['content']
def beaker_cache(key="cache_default", expire="never", type=None,
query_args=False,
cache_headers=('content-type', 'content-length'),
invalidate_on_startup=False,
cache_response=True, **b_kwargs):
"""Cache decorator utilizing Beaker. Caches a
function that returns a pickle-able object as a result.
Optional arguments:
``key``
None - No variable key, uses function name as key
"cache_default" - Uses all function arguments as the key
string - Use kwargs[key] as key
list - Use [kwargs[k] for k in list] as key
``expire``
Time in seconds before cache expires, or the string "never".
Defaults to "never"
``type``
Type of cache to use: dbm, memory, file, memcached, or None for
Beaker's default
``query_args``
Uses the query arguments as the key, defaults to False
``cache_headers``
A tuple of header names indicating response headers that
will also be cached.
``invalidate_on_startup``
If True, the cache will be invalidated each time the application
starts or is restarted.
``cache_response``
Determines whether the response at the time beaker_cache is used
should be cached or not, defaults to True.
.. note::
When cache_response is set to False, the cache_headers
argument is ignored as none of the response is cached.
If cache.enabled is set to False in the .ini file, then cache is
disabled globally.
"""
if invalidate_on_startup:
starttime = time.time()
else:
starttime = None
cache_headers = set(cache_headers)
def beaker_cache_decorate(func):
@wraps(func)
def beaker_cached_call(*args, **kwargs):
if key:
key_dict = kwargs.copy()
key_dict.update(_make_dict_from_args(func, args, kwargs))
if query_args:
key_dict.update(tg.request.GET.mixed())
if key != 'cache_default':
if isinstance(key, list):
key_dict = dict((k, key_dict[k]) for k in key)
else:
key_dict = {key: key_dict[key]}
else:
key_dict = None
self = None
if args:
self = args[0]
namespace, cache_key = create_cache_key(func, key_dict, self)
return _cached_call(func, args, kwargs, namespace, cache_key,
expire, type, starttime,
cache_headers, cache_response,
b_kwargs)
return beaker_cached_call
return beaker_cache_decorate
def create_cache_key(func, key_dict=None, self=None):
"""Get a cache namespace and key used by the beaker_cache decorator.
Example::
from tg import cache
from tg.caching import create_cache_key
namespace, key = create_cache_key(MyController.some_method)
cache.get_cache(namespace).remove(key)
"""
kls = None
imfunc = im_func(func)
if imfunc:
kls = im_class(func)
func = imfunc
cache_key = func.__name__
else:
cache_key = func.__name__
if key_dict:
cache_key += " " + " ".join("%s=%s" % (k, v)
for k, v in key_dict.items())
if not kls and self:
kls = getattr(self, '__class__', None)
if kls:
return '%s.%s' % (kls.__module__, kls.__name__), cache_key
else:
return func.__module__, cache_key
def _make_dict_from_args(func, args, kwargs):
"""Inspects function for name of args"""
args_keys = {}
for i, arg in enumerate(inspect.getargspec(func)[0]):
if arg != "self":
try:
args_keys[arg] = args[i]
except IndexError:
args_keys[arg] = kwargs[arg]
return args_keys
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