feat: Auto detect Mixtral's slightly different format (#1214)

Author: lukestanley

llama_cpp/llama_chat_format.py

@@ -29,6 +29,8 @@
 MISTRAL_INSTRUCT_BOS_TOKEN = "<s>"
 MISTRAL_INSTRUCT_EOS_TOKEN = "</s>"
 
+# Source: https://huggingface.co/mistralai/Mixtral-8x7B-Instruct-v0.1/blob/main/tokenizer_config.json
+MIXTRAL_INSTRUCT_CHAT_TEMPLATE = "{{ bos_token }}{% for message in messages %}{% if (message['role'] == 'user') != (loop.index0 % 2 == 0) %}{{ raise_exception('Conversation roles must alternate user/assistant/user/assistant/...') }}{% endif %}{% if message['role'] == 'user' %}{{ '[INST] ' + message['content'] + ' [/INST]' }}{% elif message['role'] == 'assistant' %}{{ message['content'] + eos_token}}{% else %}{{ raise_exception('Only user and assistant roles are supported!') }}{% endif %}{% endfor %}"
 
 ### Chat Completion Handler ###
 
@@ -470,7 +472,8 @@ def guess_chat_format_from_gguf_metadata(metadata: Dict[str, str]) -> Optional[s
     if metadata["tokenizer.chat_template"] == CHATML_CHAT_TEMPLATE:
         return "chatml"
 
-    if metadata["tokenizer.chat_template"] == MISTRAL_INSTRUCT_CHAT_TEMPLATE:
+    if (metadata["tokenizer.chat_template"] == MISTRAL_INSTRUCT_CHAT_TEMPLATE or
+            metadata["tokenizer.chat_template"] == MIXTRAL_INSTRUCT_CHAT_TEMPLATE):
         return "mistral-instruct"
 
     return None