From 7729d97a418c37db8eab6e9b022e5d3d1379368c Mon Sep 17 00:00:00 2001
From: Roman Mogilatov <rmogilatov@gmail.com>
Date: Sun, 22 May 2016 15:37:39 +0300
Subject: [PATCH] Make injections 2 times faster

---
 dependency_injector/injections.py           | 28 +++++++--------------
 dependency_injector/providers/callable.py   |  4 +--
 dependency_injector/providers/creational.py |  6 ++---
 tests/test_injections.py                    |  6 ++---
 4 files changed, 17 insertions(+), 27 deletions(-)

diff --git a/dependency_injector/injections.py b/dependency_injector/injections.py
index fe526715..2387c63c 100644
--- a/dependency_injector/injections.py
+++ b/dependency_injector/injections.py
@@ -38,7 +38,7 @@ class Injection(object):
     """
 
     __IS_INJECTION__ = True
-    __slots__ = ('injectable', 'call_injectable')
+    __slots__ = ('injectable', 'get_value')
 
     def __init__(self, injectable):
         """Initializer.
@@ -49,24 +49,14 @@ class Injection(object):
                           :py:class:`dependency_injector.providers.Provider`
         """
         self.injectable = injectable
-        self.call_injectable = (is_provider(injectable) and
-                                not is_delegated_provider(injectable))
+
+        if not is_provider(injectable) or is_delegated_provider(injectable):
+            def injectable():
+                return self.injectable
+        self.get_value = injectable
+
         super(Injection, self).__init__()
 
-    @property
-    def value(self):
-        """Read-only property that represents injectable value.
-
-        Injectable values and delegated providers are provided "as is".
-        Other providers will be called every time, when injection needs to
-        be done.
-
-        :rtype: object
-        """
-        if self.call_injectable:
-            return self.injectable.provide()
-        return self.injectable
-
     def __str__(self):
         """Return string representation of provider.
 
@@ -229,11 +219,11 @@ def inject(*args, **kwargs):
         def decorated(*args, **kwargs):
             """Decorated with dependency injection callback."""
             if decorated.args:
-                args = tuple(arg.value for arg in decorated.args) + args
+                args = tuple(arg.get_value() for arg in decorated.args) + args
 
             for kwarg in decorated.kwargs:
                 if kwarg.name not in kwargs:
-                    kwargs[kwarg.name] = kwarg.value
+                    kwargs[kwarg.name] = kwarg.get_value()
 
             return callback(*args, **kwargs)
 
diff --git a/dependency_injector/providers/callable.py b/dependency_injector/providers/callable.py
index 7caffda5..f2714b3c 100644
--- a/dependency_injector/providers/callable.py
+++ b/dependency_injector/providers/callable.py
@@ -102,11 +102,11 @@ class Callable(Provider):
         :rtype: object
         """
         if self._args:
-            args = tuple(arg.value for arg in self._args) + args
+            args = tuple(arg.get_value() for arg in self._args) + args
 
         for kwarg in self._kwargs:
             if kwarg.name not in kwargs:
-                kwargs[kwarg.name] = kwarg.value
+                kwargs[kwarg.name] = kwarg.get_value()
 
         return self._provides(*args, **kwargs)
 
diff --git a/dependency_injector/providers/creational.py b/dependency_injector/providers/creational.py
index 785c3471..4a307ed1 100644
--- a/dependency_injector/providers/creational.py
+++ b/dependency_injector/providers/creational.py
@@ -120,16 +120,16 @@ class Factory(Callable):
         :rtype: object
         """
         if self._args:
-            args = tuple(arg.value for arg in self._args) + args
+            args = tuple(arg.get_value() for arg in self._args) + args
 
         for kwarg in self._kwargs:
             if kwarg.name not in kwargs:
-                kwargs[kwarg.name] = kwarg.value
+                kwargs[kwarg.name] = kwarg.get_value()
 
         instance = self._provides(*args, **kwargs)
 
         for attribute in self._attributes:
-            setattr(instance, attribute.name, attribute.value)
+            setattr(instance, attribute.name, attribute.get_value())
 
         return instance
 
diff --git a/tests/test_injections.py b/tests/test_injections.py
index 9fca174f..c9385e18 100644
--- a/tests/test_injections.py
+++ b/tests/test_injections.py
@@ -19,12 +19,12 @@ class InjectionTests(unittest.TestCase):
     def test_value_with_scalar_injectable(self):
         """Test Injection value property with scalar value."""
         injection = injections.Injection('some_value')
-        self.assertEqual(injection.value, 'some_value')
+        self.assertEqual(injection.get_value(), 'some_value')
 
     def test_value_with_provider_injectable(self):
         """Test Injection value property with provider."""
         injection = injections.Injection(providers.Factory(object))
-        self.assertIsInstance(injection.value, object)
+        self.assertIsInstance(injection.get_value(), object)
 
     def test_value_with_catalog_bundle_injectable(self):
         """Test Injection value property with catalog bundle."""
@@ -35,7 +35,7 @@ class InjectionTests(unittest.TestCase):
         injection = injections.Injection(
             TestCatalog.Bundle(TestCatalog.provider))
 
-        self.assertIsInstance(injection.value, TestCatalog.Bundle)
+        self.assertIsInstance(injection.get_value(), TestCatalog.Bundle)
 
     def test_repr(self):
         """Test Injection representation."""