allow custom cache objects (#4)

allow custom cache objects

* update changelog

* cosmetics

CHANGES.txt

@@ -4,8 +4,9 @@ CHANGES
 2.2 (unreleased)
 ----------------
 
-- Nothing changed yet.
-
+- The caching option to searchResults now accepts a dict-like value and it
+  will use that to allow for caching results over multiple searchResults()
+  calls. The cache invalidation then is the responsibility of the caller.
 
 2.1 (2017-02-07)
 ----------------
@@ -19,7 +20,6 @@ CHANGES
 
 - Fix log line in Text term for invalid text search.
 
-
 2.0 (2016-09-07)
 ----------------
 
@@ -48,7 +48,6 @@ CHANGES
 
 * Add support for an All query.
 
-
 1.1.1 (2012-06-22)
 ------------------
 

src/hurry/query/interfaces.py

@@ -42,7 +42,16 @@ def searchResults(
         result in set to the given start position.
 
         Optionally provide a `caching` parameter to cache terms result
-        across multiple search queries.
+        across multiple search queries. Accepted parameter values are:
+
+            `True` for `threading.local` based and transaction boundary-aware
+            caching. The cache for multiple `searchResults()` calls is
+            invalidated at the end of the transaction.
+
+            `False` to cache only for individual `searchResults()` calls.
+
+            Or a `dict`-like object where invalidation is handled by the
+            caller of the multiple `searchResults()` call.
         """
 
 

src/hurry/query/query.py

@@ -130,7 +130,6 @@ def __iter__(self):
             yield self.get(uid)
 
 
-
 class Timing(object):
 
     def __init__(self, key=None, order=0):
@@ -215,10 +214,14 @@ def searchResults(
             context = getSiteManager()
         else:
             context = IComponentLookup(context)
-        if caching:
+
+        if caching is True:
             cache = transaction_cache.use(context)
-        else:
+        elif caching is False:
             cache = {}
+        else:
+            # A custom cache object was injected, use it.
+            cache = caching
 
         timer = None
         if timing is not False: