- The Beaker import (or attempt thereof)

  is delayed until actually needed;
  this to remove the performance penalty
  from startup, particularly for
  "single execution" environments
  such as shell scripts. [ticket:153]

2 files changed, 21 insertions, 6 deletions

diff --git a/CHANGES b/CHANGES
index 1b4608b..8867314 100644
--- a/CHANGES
+++ b/CHANGES
@@ -5,6 +5,13 @@
   for those who don't use the caching
   as well as to conform to Pyramid 
   deployment practices.  [ticket:154]
+
+- The Beaker import (or attempt thereof)
+  is delayed until actually needed; 
+  this to remove the performance penalty 
+  from startup, particularly for 
+  "single execution" environments
+  such as shell scripts. [ticket:153]
   
 - Fixed missing **extra collection in 
   setup.py which prevented setup.py
diff --git a/mako/cache.py b/mako/cache.py
index 43f7317..595b05f 100644
--- a/mako/cache.py
+++ b/mako/cache.py
@@ -1,10 +1,10 @@
 from mako import exceptions
 
-try:
-    from beaker import cache
-    cache = cache.CacheManager()
-except ImportError:
-    cache = None
+cache = None
+
+class BeakerMissing(object):
+    def get_cache(self, name, **kwargs):
+        raise exceptions.RuntimeException("the Beaker package is required to use cache functionality.")
 
 class Cache(object):
     def __init__(self, id, starttime):
@@ -43,8 +43,16 @@ class Cache(object):
         self.invalidate(name, defname=name)
     
     def _get_cache(self, defname, type=None, **kw):
+        global cache
         if not cache:
-            raise exceptions.RuntimeException("the Beaker package is required to use cache functionality.")
+            try:
+                from beaker import cache as beaker_cache
+                cache = beaker_cache.CacheManager()
+            except ImportError:
+                # keep a fake cache around so subsequent 
+                # calls don't attempt to re-import
+                cache = BeakerMissing()
+
         if type == 'memcached':
             type = 'ext:memcached'
         if not type: