Rewrote arbitrary data cache system

The caching facilities in Bcfg2.Server.Cache provided basically no
features.  This rewrites that to allow for much more powerful cache
expiration, with a particular focus on interoperation between
different components and plugins to let caches be expired as
necessary.  (E.g., the Probes plugin can expire the Metadata cache.)

This does not affect any of the file data cached by Bcfg2, only the
caches that are populated with arbitrary data (Metadata, Packages,
Probes, etc.).

1 files changed, 3 insertions, 17 deletions

diff --git a/src/lib/Bcfg2/Server/Core.py b/src/lib/Bcfg2/Server/Core.py
index 501a78bc0..b0b80e956 100644
--- a/src/lib/Bcfg2/Server/Core.py
+++ b/src/lib/Bcfg2/Server/Core.py
@@ -207,7 +207,7 @@ class Core(object):
 
         #: A :class:`Bcfg2.Server.Cache.Cache` object for caching client
         #: metadata
-        self.metadata_cache = Cache()
+        self.metadata_cache = Cache("Metadata")
 
         #: Whether or not it's possible to use the Django database
         #: backend for plugins that have that capability
@@ -227,20 +227,6 @@ class Core(object):
                 self.logger.error("Updating database %s failed: %s" %
                                   (Bcfg2.Options.setup.db_name, err))
 
-    def expire_caches_by_type(self, base_cls, key=None):
-        """ Expire caches for all
-        :class:`Bcfg2.Server.Plugin.interfaces.Caching` plugins that
-        are instances of ``base_cls``.
-
-        :param base_cls: The base plugin interface class to match (see
-                         :mod:`Bcfg2.Server.Plugin.interfaces`)
-        :type base_cls: type
-        :param key: The cache key to expire
-        """
-        for plugin in self.plugins_by_type(base_cls):
-            if isinstance(plugin, Bcfg2.Server.Plugin.Caching):
-                plugin.expire_cache(key)
-
     def plugins_by_type(self, base_cls):
         """ Return a list of loaded plugins that match the passed type.
 
@@ -683,7 +669,7 @@ class Core(object):
         if event.code2str() == 'deleted':
             return
         Bcfg2.Options.get_parser().reparse()
-        self.expire_caches_by_type(Bcfg2.Server.Plugin.Metadata)
+        self.metadata_cache.expire()
 
     def block_for_fam_events(self, handle_events=False):
         """ Block until all fam events have been handleed, optionally
@@ -1070,7 +1056,7 @@ class Core(object):
             # that's created for RecvProbeData doesn't get cached.
             # I.e., the next metadata object that's built, after probe
             # data is processed, is cached.
-            self.expire_caches_by_type(Bcfg2.Server.Plugin.Metadata)
+            self.metadata_cache.expire(client)
         try:
             xpdata = lxml.etree.XML(probedata.encode('utf-8'),
                                     parser=Bcfg2.Server.XMLParser)