Move common libs to libs/common

libs/common/dogpile/cache/plugins/mako_cache.py

@@ -0,0 +1,90 @@
+"""
+Mako Integration
+----------------
+
+dogpile.cache includes a `Mako <http://www.makotemplates.org>`_ plugin
+that replaces `Beaker <http://beaker.groovie.org>`_
+as the cache backend.
+Setup a Mako template lookup using the "dogpile.cache" cache implementation
+and a region dictionary::
+
+    from dogpile.cache import make_region
+    from mako.lookup import TemplateLookup
+
+    my_regions = {
+        "local":make_region().configure(
+                    "dogpile.cache.dbm",
+                    expiration_time=360,
+                    arguments={"filename":"file.dbm"}
+                ),
+        "memcached":make_region().configure(
+                    "dogpile.cache.pylibmc",
+                    expiration_time=3600,
+                    arguments={"url":["127.0.0.1"]}
+                )
+    }
+
+    mako_lookup = TemplateLookup(
+        directories=["/myapp/templates"],
+        cache_impl="dogpile.cache",
+        cache_args={
+            'regions':my_regions
+        }
+    )
+
+To use the above configuration in a template, use the ``cached=True``
+argument  on any Mako tag which accepts it, in conjunction with the
+name of the desired region as the ``cache_region`` argument::
+
+    <%def name="mysection()" cached="True" cache_region="memcached">
+        some content that's cached
+    </%def>
+
+
+"""
+from mako.cache import CacheImpl
+
+
+class MakoPlugin(CacheImpl):
+    """A Mako ``CacheImpl`` which talks to dogpile.cache."""
+
+    def __init__(self, cache):
+        super(MakoPlugin, self).__init__(cache)
+        try:
+            self.regions = self.cache.template.cache_args['regions']
+        except KeyError:
+            raise KeyError(
+                "'cache_regions' argument is required on the "
+                "Mako Lookup or Template object for usage "
+                "with the dogpile.cache plugin.")
+
+    def _get_region(self, **kw):
+        try:
+            region = kw['region']
+        except KeyError:
+            raise KeyError(
+                "'cache_region' argument must be specified with 'cache=True'"
+                "within templates for usage with the dogpile.cache plugin.")
+        try:
+            return self.regions[region]
+        except KeyError:
+            raise KeyError("No such region '%s'" % region)
+
+    def get_and_replace(self, key, creation_function, **kw):
+        expiration_time = kw.pop("timeout", None)
+        return self._get_region(**kw).get_or_create(
+            key, creation_function,
+            expiration_time=expiration_time)
+
+    def get_or_create(self, key, creation_function, **kw):
+        return self.get_and_replace(key, creation_function, **kw)
+
+    def put(self, key, value, **kw):
+        self._get_region(**kw).put(key, value)
+
+    def get(self, key, **kw):
+        expiration_time = kw.pop("timeout", None)
+        return self._get_region(**kw).get(key, expiration_time=expiration_time)
+
+    def invalidate(self, key, **kw):
+        self._get_region(**kw).delete(key)