fix cache

app/utils/string.py

@@ -229,7 +229,7 @@ class StringUtils:
                 size = float(size)
                 d = [(1024 - 1, 'K'), (1024 ** 2 - 1, 'M'), (1024 ** 3 - 1, 'G'), (1024 ** 4 - 1, 'T')]
                 s = [x[0] for x in d]
-                index = bisect.bisect_left(s, size) - 1 # noqa
+                index = bisect.bisect_left(s, size) - 1  # noqa
                 if index == -1:
                     return str(size) + "B"
                 else:
@@ -925,3 +925,16 @@ class StringUtils:
         if re.match(r'^[a-zA-Z0-9.-]+(\.[a-zA-Z]{2,})?$', text):
             return True
         return False
+
+    @staticmethod
+    def is_magnet_link(content: Union[str, bytes]) -> bool:
+        """
+        判断内容是否为磁力链接
+        """
+        if not content:
+            return False
+        if isinstance(content, str) and content.startswith("magnet:"):
+            return True
+        if isinstance(content, bytes) and content.startswith(b"magnet:"):
+            return True
+        return False