Add clean_cache method

jsoncache/ApplicationCache.py

@@ -59,6 +59,17 @@ class ApplicationCache():
     def gen_key(cls, cache_id: str, args: list, kwargs: dict) -> str:
         return cls.get_hash(args, kwargs, cache_id)
 
+    def clean_cache(self, max_age: int = None) -> int:
+        max_age = max_age or self.default_max_age
+        cleaned_count = 0
+        for cache_path in self.cache_dir.iterdir():
+            if cache_path.is_file():
+                cache_stat = cache_path.stat()
+                if cache_stat.st_mtime + max_age <= time.time():
+                    cache_path.unlink()
+                    cleaned_count += 1
+        return cleaned_count
+
     def compress(self, data: str) -> bytes:
         bin_data = data.encode(self.encoding)
         if self.compress_data and len(bin_data) > self.compress_threshold: