Error in how FileSystemCache counts number of files #188

flask_caching/backends/filesystemcache.py

@@ -165,7 +165,7 @@ def get(self, key):
                 pickle_time = pickle.load(f)
                 expired = pickle_time != 0 and pickle_time < time()
                 if expired:
-                    os.remove(filename)
+                    self.delete(key)
                 else:
                     hit_or_miss = "hit"
                     result = pickle.load(f)
@@ -207,6 +207,7 @@ def set(self, key, value, timeout=None, mgmt_element=False):
             with os.fdopen(fd, "wb") as f:
                 pickle.dump(timeout, f, 1)
                 pickle.dump(value, f, pickle.HIGHEST_PROTOCOL)
+            is_new_file = not os.path.exists(filename)
             os.replace(tmp, filename)
             os.chmod(filename, self._mode)
         except (IOError, OSError) as exc:
@@ -215,7 +216,7 @@ def set(self, key, value, timeout=None, mgmt_element=False):
             result = True
             logger.debug("set key %r", key)
             # Management elements should not count towards threshold
-            if not mgmt_element:
+            if not mgmt_element and is_new_file:
                 self._update_count(delta=1)
         return result
 
@@ -244,7 +245,7 @@ def has(self, key):
                 pickle_time = pickle.load(f)
                 expired = pickle_time != 0 and pickle_time < time()
                 if expired:
-                    os.remove(filename)
+                    self.delete(key)
                 else:
                     result = True
         except FileNotFoundError:

tests/test_backend_cache.py

@@ -193,6 +193,28 @@ def test_no_threshold(self, make_cache):
         nof_cache_files = c.get(c._fs_count_file)
         assert nof_cache_files is None
 
+    def test_filecount_caching_none(self, make_cache):
+        c = make_cache()
+        for i in range(3):
+            assert c.set("a", None)
+            assert c.get(c._fs_count_file) == 1
+
+    def test_filecount_after_deletion_in_has(self, make_cache):
+        c = make_cache()
+        assert c.set("foo", "bar", timeout=0.01)
+        assert c.get(c._fs_count_file) == 1
+        time.sleep(0.1)
+        assert c.has("foo") in (False, 0)
+        assert c.get(c._fs_count_file) == 0
+
+    def test_filecount_after_deletion_in_get(self, make_cache):
+        c = make_cache()
+        assert c.set("foo", "bar", timeout=0.01)
+        assert c.get(c._fs_count_file) == 1
+        time.sleep(0.1)
+        assert c.get("foo") is None
+        assert c.get(c._fs_count_file) == 0
+
     def test_count_file_accuracy(self, c):
         assert c.set("foo", "bar")
         assert c.set("moo", "car")