Add cache metrics (#119)

python/sglang/srt/constrained/fsm_cache.py

@@ -1,21 +1,14 @@
+from sglang.srt.constrained.base_cache import BaseCache
 from sglang.srt.constrained.fsm import RegexFSM
 from sglang.srt.constrained.tokenizer import TransformerTokenizer
 
-_enable_memory_cache = True
 
-
-class FSMCache:
-    def __init__(self, tokenizer_path, tokenizer_args_dict):
-        self.cache = {}
+class FSMCache(BaseCache):
+    def __init__(self, tokenizer_path, tokenizer_args_dict, enable=True):
+        super().__init__(enable=enable)
         self.outlines_tokenizer = TransformerTokenizer(
             tokenizer_path, **tokenizer_args_dict
         )
 
-    def init_fsm(self, regex):
-        if _enable_memory_cache:
-            if regex not in self.cache:
-                fsm = RegexFSM(regex, self.outlines_tokenizer)
-                self.cache[regex] = fsm
-            return self.cache[regex]
-
+    def init_value(self, regex):
         return RegexFSM(regex, self.outlines_tokenizer)