implement cython for cache_anon_map, prefix_anon_map

These are small bits where cache_anon_map in particular
is part of the cache key generation scheme which is a key
target for cython.

changing such a tiny element of the cache key gen is
doing basically nothing yet, as the cython impl is
mostly the exact same speed as the python one.  I guess for
cython to be effective we'd need to redo the whole cache key
generation and possibly not use the same kinds of structures,
which might not be very easy to do.

Additionally, some cython runtime import errors are being
observed on jenkins, add an upfront check to the test suite
to indicate if the expected build succeeded when REQUIRE_SQLALCHEMY_CEXT
is set.

Running case CacheAnonMap
Running python .... Done
Running cython .... Done
                    | python      | cython      | cy / py     |
test_get_anon_non_present| 0.301266758 | 0.231203834 | 0.767438915 |
test_get_anon_present| 0.300919362 | 0.227336695 | 0.755473803 |
test_has_key_non_present| 0.152725077 | 0.133191719 | 0.872101171 |
test_has_key_present| 0.152689778 | 0.133673095 | 0.875455428 |
Running case PrefixAnonMap
Running python .. Done
Running cython .. Done
                    | python      | cython      | cy / py     |
test_apply_non_present| 0.358715744 | 0.335245703 | 0.934572034 |
test_apply_present  | 0.354434996 | 0.338579782 | 0.955266229 |

Change-Id: I0d3f1dd285c044afc234479141d831b2ee0455be

1 files changed, 42 insertions, 0 deletions

diff --git a/lib/sqlalchemy/cyextension/util.pyx b/lib/sqlalchemy/cyextension/util.pyx
index ac15ff9de..62ca960b3 100644
--- a/lib/sqlalchemy/cyextension/util.pyx
+++ b/lib/sqlalchemy/cyextension/util.pyx
@@ -41,3 +41,45 @@ def _distill_raw_params(object params):
         return [params]
     else:
         raise exc.ArgumentError("mapping or sequence expected for parameters")
+
+cdef class prefix_anon_map(dict):
+    def __missing__(self, str key):
+        cdef str derived
+        cdef int anonymous_counter
+        cdef dict self_dict = self
+
+        derived = key.split(" ", 1)[1]
+
+        anonymous_counter = self_dict.get(derived, 1)
+        self_dict[derived] = anonymous_counter + 1
+        value = f"{derived}_{anonymous_counter}"
+        self_dict[key] = value
+        return value
+
+
+cdef class cache_anon_map(dict):
+    cdef int _index
+
+    def __init__(self):
+        self._index = 0
+
+    def get_anon(self, obj):
+        cdef long idself
+        cdef str id_
+        cdef dict self_dict = self
+
+        idself = id(obj)
+        if idself in self_dict:
+            return self_dict[idself], True
+        else:
+            id_ = self.__missing__(idself)
+            return id_, False
+
+    def __missing__(self, key):
+        cdef str val
+        cdef dict self_dict = self
+
+        self_dict[key] = val = str(self._index)
+        self._index += 1
+        return val
+