fix: kimi k2 xgrammar crash (#8367)

Co-authored-by: cicirori <32845984+cicirori@users.noreply.github.com>
Co-authored-by: gongwei-130 <56567052+gongwei-130@users.noreply.github.com>

python/sglang/srt/managers/schedule_batch.py

@@ -431,6 +431,7 @@ class Req:
         bootstrap_port: Optional[int] = None,
         bootstrap_room: Optional[int] = None,
         data_parallel_rank: Optional[int] = None,
+        vocab_size: Optional[int] = None,
     ):
         # Input and output info
         self.rid = rid
@@ -480,6 +481,7 @@ class Req:
         self.to_abort_message: str = None
         self.stream = stream
         self.eos_token_ids = eos_token_ids
+        self.vocab_size = vocab_size
 
         # For incremental decoding
         # ----- | --------- read_ids -------|
@@ -713,6 +715,14 @@ class Req:
                 self.finished_reason = FINISH_MATCHED_TOKEN(matched=last_token_id)
                 return
 
+        if last_token_id > self.vocab_size or last_token_id < 0:
+            if self.sampling_params.stop_token_ids:
+                self.output_ids[-1] = next(iter(self.sampling_params.stop_token_ids))
+            if self.eos_token_ids:
+                self.output_ids[-1] = next(iter(self.eos_token_ids))
+            self.finished_reason = FINISH_MATCHED_STR(matched="NaN happened")
+            return
+
         # Check stop strings
         if len(self.sampling_params.stop_strs) > 0:
             tail_str = self.tokenizer.decode(

python/sglang/srt/managers/scheduler.py

@@ -1129,6 +1129,7 @@ class Scheduler(
                 bootstrap_port=recv_req.bootstrap_port,
                 bootstrap_room=recv_req.bootstrap_room,
                 data_parallel_rank=recv_req.data_parallel_rank,
+                vocab_size=self.model_config.vocab_size,
             )
             req.tokenizer = self.tokenizer
 
@@ -1395,8 +1396,10 @@ class Scheduler(
         logger.info(f)
 
         if self.enable_metrics:
-            cache_hit_rate = adder.log_hit_tokens / (
-                adder.log_input_tokens + adder.log_hit_tokens
+            total_tokens = adder.log_input_tokens + adder.log_hit_tokens
+
+            cache_hit_rate = (
+                adder.log_hit_tokens / total_tokens if total_tokens > 0 else 0.0
             )
             self.stats.num_running_reqs = running_bs
             self.stats.num_used_tokens = num_used