Performance improvements (#13)

* Compute argspec for serialisation functions only once

* mocked_get_context -> mocked_inspect_getargspec

* Bump version to 1.3.2

Author: youtux

CHANGES.rst

@@ -1,6 +1,12 @@
 Changelog
 =========
 
+1.3.2
+-----
+
+* Improve serialization performance (youtux)
+
+
 1.3.1
 -----
 

halogen/__init__.py

@@ -1,6 +1,6 @@
 """halogen public API."""
 
-__version__ = '1.3.1'
+__version__ = '1.3.2'
 
 try:
     from halogen.schema import Schema, attr, Attr, Link, Curie, Embedded, Accessor

halogen/schema.py

@@ -26,14 +26,13 @@ def BYPASS(value):
     return value
 
 
-def _get_context(func, kwargs):
+def _get_context(argspec, kwargs):
     """Prepare a context for the serialization.
 
-    :param func: Function which needs or does not need kwargs.
+    :param argspec: The argspec of the serialization function.
     :param kwargs: Dict with context
     :return: Keywords arguments that function can accept.
     """
-    argspec = inspect.getargspec(func)
     if argspec.keywords is not None:
         return kwargs
     return dict((arg, kwargs[arg]) for arg in argspec.args if arg in kwargs)
@@ -48,6 +47,10 @@ def __init__(self, getter=None, setter=None):
         self.getter = getter
         self.setter = setter
 
+    @cached_property
+    def _getter_argspec(self):
+        return inspect.getargspec(self.getter)
+
     def get(self, obj, **kwargs):
         """Get an attribute from a value.
 
@@ -56,7 +59,7 @@ def get(self, obj, **kwargs):
         """
         assert self.getter is not None, "Getter accessor is not specified."
         if callable(self.getter):
-            return self.getter(obj, **_get_context(self.getter, kwargs))
+            return self.getter(obj, **_get_context(self._getter_argspec, kwargs))
 
         assert isinstance(self.getter, string_types), "Accessor must be a function or a dot-separated string."
 
@@ -153,6 +156,10 @@ def accessor(self):
         attr = self.attr or self.name
         return Accessor(getter=attr, setter=attr)
 
+    @cached_property
+    def _attr_type_serialize_argspec(self):
+        return inspect.getargspec(self.attr_type.serialize)
+
     def serialize(self, value, **kwargs):
         """Serialize the attribute of the input data.
 
@@ -172,7 +179,7 @@ def serialize(self, value, **kwargs):
                     raise
                 value = self.default() if callable(self.default) else self.default
 
-            return self.attr_type.serialize(value, **_get_context(self.attr_type.serialize, kwargs))
+            return self.attr_type.serialize(value, **_get_context(self._attr_type_serialize_argspec, kwargs))
 
         return self.attr_type
 

setup.py

@@ -73,8 +73,10 @@ def run_tests(self):
         "Topic :: Software Development :: Libraries",
         "Topic :: Utilities",
         "Programming Language :: Python :: 2",
-        "Programming Language :: Python :: 3"
-    ] + [("Programming Language :: Python :: %s" % x) for x in "2.7 3.4".split()],
+        "Programming Language :: Python :: 2.7",
+        "Programming Language :: Python :: 3",
+        "Programming Language :: Python :: 3.4",
+    ],
     cmdclass={"test": ToxTestCommand},
     packages=["halogen"],
     install_requires=install_requires,

tests/conftest.py

@@ -1,4 +1,5 @@
 """Test configuration."""
+import inspect
 
 import halogen
 import mock
@@ -7,8 +8,13 @@
 
 
 @pytest.fixture(scope="session")
-def mocked_get_context():
+def mocked_inspect_getargspec(request):
     """Mock halogen.schema._get_context for returning empty dict."""
-    patcher = mock.patch("halogen.schema._get_context")
+    def f():
+        return None
+
+    patcher = mock.patch("inspect.getargspec")
+    patcher.return_value = inspect.getargspec(f)
+
     patcher.start()
-    patcher.return_value = {}
+    request.addfinalizer(patcher.stop)

tests/unit/schema/accessor/test_get.py

@@ -32,7 +32,7 @@ def test_get_object_callable(basic_object_value, basic_object):
     assert acc.get(basic_object) == basic_object_value
 
 
-def test_get_object_callable_called(mocked_get_context, basic_object):
+def test_get_object_callable_called(mocked_inspect_getargspec, basic_object):
     """Test if Accessor.get() calls Accessor.getter() if getter is callable."""
     acc = Accessor()
     acc.getter = mock.Mock()

tests/unit/schema/attr/test_serialize.py

@@ -5,7 +5,7 @@
 from halogen.types import Type
 
 
-def test_serialize_type(mocked_get_context):
+def test_serialize_type(mocked_inspect_getargspec):
     """Test if serialization of a "type" works.
 
     Test if serialization of an Attr with an attr_type that is a "type" correctly calls the serialization function.

tox.ini

@@ -1,6 +1,6 @@
 [tox]
 distshare = {homedir}/.tox/distshare
-envlist = py27,py34
+envlist = py27,py34,py35,py36
 
 [testenv]
 commands = py.test --junitxml={envlogdir}/junit-{envname}.xml halogen tests