Fix eagle radix cache (#10846)

python/sglang/srt/managers/schedule_batch.py

@@ -547,6 +547,8 @@ class Req:
         self.host_hit_length = 0
         # The node to lock until for swa radix tree lock ref
         self.swa_uuid_for_lock: Optional[int] = None
+        # The prefix length of the last prefix matching
+        self.last_matched_prefix_len: int = 0
 
         # Whether or not if it is chunked. It increments whenever
         # it is chunked, and decrement whenever chunked request is
@@ -701,6 +703,7 @@ class Req:
                     token_ids=self.adjust_max_prefix_ids(), extra_key=self.extra_key
                 ),
             )
+            self.last_matched_prefix_len = len(self.prefix_indices)
         self.extend_input_len = len(self.fill_ids) - len(self.prefix_indices)
 
     def adjust_max_prefix_ids(self):