Fixed #20536 -- rewrite of the file based cache backend

 * Safer for use in multiprocess environments
 * Better random culling
 * Cache files use less disk space
 * Safer delete behavior

Also fixed #15806, fixed #15825.

1 files changed, 24 insertions, 22 deletions

diff --git a/tests/cache/tests.py b/tests/cache/tests.py
index 053ee14a58..e4ef951295 100644
--- a/tests/cache/tests.py
+++ b/tests/cache/tests.py
@@ -1076,32 +1076,34 @@ class FileBasedCacheTests(unittest.TestCase, BaseCacheTests):
 
     def tearDown(self):
         self.cache.clear()
+        os.rmdir(self.dirname)
 
-    def test_hashing(self):
-        """Test that keys are hashed into subdirectories correctly"""
-        self.cache.set("foo", "bar")
-        key = self.cache.make_key("foo")
-        keyhash = hashlib.md5(key.encode()).hexdigest()
-        keypath = os.path.join(self.dirname, keyhash[:2], keyhash[2:4], keyhash[4:])
-        self.assertTrue(os.path.exists(keypath))
+    def test_cull(self):
+        self.perform_cull_test(50, 29)
 
-    def test_subdirectory_removal(self):
-        """
-        Make sure that the created subdirectories are correctly removed when empty.
-        """
-        self.cache.set("foo", "bar")
-        key = self.cache.make_key("foo")
-        keyhash = hashlib.md5(key.encode()).hexdigest()
-        keypath = os.path.join(self.dirname, keyhash[:2], keyhash[2:4], keyhash[4:])
-        self.assertTrue(os.path.exists(keypath))
+    def test_ignores_non_cache_files(self):
+        fname = os.path.join(self.dirname, 'not-a-cache-file')
+        with open(fname, 'w'):
+            os.utime(fname, None)
+        self.cache.clear()
+        self.assertTrue(os.path.exists(fname),
+                        'Expected cache.clear to ignore non cache files')
+        os.remove(fname)
 
-        self.cache.delete("foo")
-        self.assertTrue(not os.path.exists(keypath))
-        self.assertTrue(not os.path.exists(os.path.dirname(keypath)))
-        self.assertTrue(not os.path.exists(os.path.dirname(os.path.dirname(keypath))))
+    def test_clear_does_not_remove_cache_dir(self):
+        self.cache.clear()
+        self.assertTrue(os.path.exists(self.dirname),
+                        'Expected cache.clear to keep the cache dir')
 
-    def test_cull(self):
-        self.perform_cull_test(50, 29)
+    def test_creates_cache_dir_if_nonexistent(self):
+        os.rmdir(self.dirname)
+        self.cache.set('foo', 'bar')
+        os.path.exists(self.dirname)
+
+    def test_zero_cull(self):
+        # Regression test for #15806
+        self.cache = get_cache(self.backend_name, LOCATION=self.dirname, OPTIONS={'MAX_ENTRIES': 30, 'CULL_FREQUENCY': 0})
+        self.perform_cull_test(50, 19)
 
 
 class CustomCacheKeyValidationTests(unittest.TestCase):