Fix chat template and message list bug (#549)

openllm-python/src/openllm/_conversation.py

@@ -6,7 +6,8 @@ from enum import auto
 
 import attr
 
-if t.TYPE_CHECKING: import openllm_core
+if t.TYPE_CHECKING:
+  import openllm_core
 
 _object_setattr = object.__setattr__
 
@@ -41,7 +42,7 @@ class Conversation:
   # The names of two roles
   roles: t.Tuple[str, str] = ('User', 'Assistant')
   # All messages. Each item is (role, message).
-  messages: t.List[t.List[str]] = []
+  messages: t.List[t.List[str]] = attr.Factory(list)
   # The number of few shot examples
   offset: int = 0
   # The separator style and configurations
@@ -114,7 +115,7 @@ class Conversation:
       if self.system_message:
         ret = system_prompt
       else:
-        ret = '[INST] '
+        ret = '<s>[INST] '
       for i, (role, message) in enumerate(self.messages):
         tag = self.roles[i % 2]
         if message:
@@ -175,7 +176,9 @@ class Conversation:
       raise ValueError(f'Invalid style: {self.sep_style}')
     return ret
 
-  def set_system_message(self, system_message: str) -> None: _object_setattr(self, 'system_message', system_message)
+  def set_system_message(self, system_message: str) -> None:
+    _object_setattr(self, 'system_message', system_message)
+
   def append_message(self, role: str, message: str) -> None:
     '''Append a new message.'''
     self.messages.append([role, message])
@@ -199,6 +202,19 @@ class Conversation:
         ret.append({'role': 'assistant', 'content': msg})
     return ret
 
+  def copy(self) -> Conversation:
+    return Conversation(name=self.name,
+                        system_template=self.system_template,
+                        system_message=self.system_message,
+                        roles=self.roles,
+                        messages=self.messages,
+                        offset=self.offset,
+                        sep_style=self.sep_style,
+                        sep=self.sep,
+                        sep2=self.sep2,
+                        stop_str=self.stop_str,
+                        stop_token_ids=self.stop_token_ids)
+
 # A global registry for all conversation templates for OpenLLM models
 conv_templates: t.Dict[str, Conversation] = {}
 
@@ -208,7 +224,7 @@ def register_conv_template(template: Conversation) -> None:
 
 def get_conv_template(name: str, llm_config: openllm_core.LLMConfig) -> Conversation:
   if name not in conv_templates: raise ValueError(f'Failed to find conversation templates for {name}')
-  template = conv_templates[name]
+  template = conv_templates[name].copy()
   if hasattr(llm_config, 'default_system_message'): template.set_system_message(llm_config.default_system_message)
   return template
 
@@ -217,7 +233,9 @@ register_conv_template(Conversation(name='raw', system_message='', roles=('', ''
 
 # Llama template
 # source: https://huggingface.co/blog/codellama#conversational-instructions
-register_conv_template(Conversation(name='llama', system_template='[INST] <<SYS>>\n{system_message}\n<</SYS>>\n\n', roles=('[INST]', '[/INST]'), sep_style=SeparatorStyle.LLAMA, sep=' ', sep2=' </s><s>',))
+register_conv_template(
+    Conversation(name='llama', system_template='<s>[INST] <<SYS>>\n{system_message}\n<</SYS>>\n\n', roles=('[INST]', '[/INST]'), sep_style=SeparatorStyle.LLAMA, sep=' ', sep2=' </s><s>',
+                 ))
 
 # ChatGLM template
 register_conv_template(Conversation(name='chatglm', roles=('问', '答'), sep_style=SeparatorStyle.CHATGLM, sep='\n',))

openllm-python/src/openllm/protocol/openai.py

@@ -138,4 +138,5 @@ def messages_to_prompt(messages: list[Message], model: str, llm_config: openllm_
   for message in messages:
     if message['role'] == 'system': conv_template.set_system_message(message['content'])
     else: conv_template.append_message(message['role'], message['content'])
+  conv_template.append_message('assistant', '')
   return conv_template.get_prompt()