Don't apply aliasing + adaption for simple relationship joins

Identified a performance issue in the system by which a join is constructed
based on a mapped relationship.   The clause adaption system would be used
for the majority of join expressions including in the common case where no
adaptation is needed.   The conditions under which this adaptation occur
have been refined so that average non-aliased joins along a simple
relationship without a "secondary" table use about 70% less function calls.

Change-Id: Ifbe04214576e5a9fac86ca80c1dc7145c27cd50a

1 files changed, 5 insertions, 2 deletions

diff --git a/lib/sqlalchemy/testing/profiling.py b/lib/sqlalchemy/testing/profiling.py
index bfc4997e1..b837d9b5b 100644
--- a/lib/sqlalchemy/testing/profiling.py
+++ b/lib/sqlalchemy/testing/profiling.py
@@ -221,7 +221,7 @@ class ProfileStatsFile(object):
         profile_f.close()
 
 
-def function_call_count(variance=0.05):
+def function_call_count(variance=0.05, times=1):
     """Assert a target for a test case's function call count.
 
     The main purpose of this assertion is to detect changes in
@@ -234,8 +234,11 @@ def function_call_count(variance=0.05):
 
     def decorate(fn):
         def wrap(*args, **kw):
+            timerange = range(times)
             with count_functions(variance=variance):
-                return fn(*args, **kw)
+                for time in timerange:
+                    rv = fn(*args, **kw)
+                return rv
 
         return update_wrapper(wrap, fn)