fix: only keep stop sequence buffer if we have some

Author: OlivierDehaene

server/text_generation_server/utils/tokens.py

@@ -112,7 +112,7 @@ def __init__(
         self.stop_sequence_criterias = stop_sequence_criterias
         self.max_new_tokens = max_new_tokens
         self.current_tokens = 0
-        self.current_output = "test"
+        self.current_output = ""
         self.ignore_eos_token = ignore_eos_token
 
     def __call__(self, last_token: int, last_output: str) -> Tuple[bool, Optional[str]]:
@@ -123,14 +123,15 @@ def __call__(self, last_token: int, last_output: str) -> Tuple[bool, Optional[st
         if not self.ignore_eos_token and last_token == self.eos_token_id:
             return True, FinishReason.FINISH_REASON_EOS_TOKEN
 
-        self.current_output += last_output
-        # There is no need to keep an output that is too long
-        if len(self.current_output) > 300:
-            # Slice to -200 to avoid doing it all the time
-            self.current_output = self.current_output[-200:]
-        for stop_sequence_criteria in self.stop_sequence_criterias:
-            if stop_sequence_criteria(self.current_output):
-                return True, FinishReason.FINISH_REASON_STOP_SEQUENCE
+        if self.stop_sequence_criterias:
+            self.current_output += last_output
+            # There is no need to keep an output that is too long
+            if len(self.current_output) > 300:
+                # Slice to -200 to avoid doing it all the time
+                self.current_output = self.current_output[-200:]
+            for stop_sequence_criteria in self.stop_sequence_criterias:
+                if stop_sequence_criteria(self.current_output):
+                    return True, FinishReason.FINISH_REASON_STOP_SEQUENCE
 
         return False, None