Add tests for CyCache.

Cython/Build/Tests/TestCyCache.py

+import glob
+import gzip
+import os
+import tempfile
+
+import Cython.Build.Dependencies
+import Cython.Utils
+#from Cython.Build.Dependencies import cythonize
+from Cython.TestUtils import CythonTest
+
+
+class TestInline(CythonTest):
+
+    def setUp(self):
+        CythonTest.setUp(self)
+        self.temp_dir = tempfile.mkdtemp(
+            prefix='cycache-test',
+            dir='TEST_TMP' if os.path.isdir('TEST_TMP') else None)
+        self.src_dir = tempfile.mkdtemp(prefix='src', dir=self.temp_dir)
+        self.cache_dir = tempfile.mkdtemp(prefix='cache', dir=self.temp_dir)
+
+    def cache_files(self, file_glob):
+        return glob.glob(os.path.join(self.cache_dir, file_glob))
+
+    def fresh_cythonize(self, *args, **kwargs):
+        Cython.Utils.clear_function_caches()
+        Cython.Build.Dependencies._dep_tree = None  # discard method caches
+        Cython.Build.Dependencies.cythonize(*args, **kwargs)
+
+    def test_cycache_switch(self):
+        content1 = 'value = 1\n'
+        content2 = 'value = 2\n'
+        a_pyx = os.path.join(self.src_dir, 'a.pyx')
+        a_c = a_pyx[:-4] + '.c'
+
+        open(a_pyx, 'w').write(content1)
+        self.fresh_cythonize(a_pyx, cache=self.cache_dir)
+        self.fresh_cythonize(a_pyx, cache=self.cache_dir)
+        self.assertEqual(1, len(self.cache_files('a.c*')))
+        a_contents1 = open(a_c).read()
+
+        open(a_pyx, 'w').write(content2)
+        self.fresh_cythonize(a_pyx, cache=self.cache_dir)
+        a_contents2 = open(a_c).read()
+
+        self.assertNotEqual(a_contents1, a_contents2)
+        self.assertEqual(2, len(self.cache_files('a.c*')))
+
+        open(a_pyx, 'w').write(content1)
+        self.fresh_cythonize(a_pyx, cache=self.cache_dir)
+        self.assertEqual(2, len(self.cache_files('a.c*')))
+        a_contents = open(a_c).read()
+        self.assertEqual(a_contents, a_contents1)
+
+    def test_cycache_uses_cache(self):
+        a_pyx = os.path.join(self.src_dir, 'a.pyx')
+        a_c = a_pyx[:-4] + '.c'
+        open(a_pyx, 'w').write("pass")
+        self.fresh_cythonize(a_pyx, cache=self.cache_dir)
+        a_cache = os.path.join(self.cache_dir, os.listdir(self.cache_dir)[0])
+        gzip.GzipFile(a_cache, 'wb').write('fake stuff')
+        os.unlink(a_c)
+        self.fresh_cythonize(a_pyx, cache=self.cache_dir)
+        a_contents = open(a_c).read()
+        self.assertEqual(a_contents, 'fake stuff')

Cython/Utils.py

@@ -20,9 +20,14 @@ from contextlib import contextmanager
 
 modification_time = os.path.getmtime
 
+_function_caches = []
+def clear_function_caches():
+    for cache in _function_caches:
+        cache.clear()
 
 def cached_function(f):
     cache = {}
+    _function_caches.append(cache)
     uncomputed = object()
     def wrapper(*args):
         res = cache.get(args, uncomputed)