Remove useless computation during model calls using liteLLM (#171)

Author: mandel

src/pdl/pdl_interpreter.py

@@ -1112,9 +1112,9 @@ def generate_client_response_streaming(
     model_input: Messages,
 ) -> Generator[YieldMessage, Any, tuple[Message, Any]]:
     msg_stream: Generator[Message, Any, Any]
-    model_input_str = messages_to_str(block.model, model_input)
     match block:
         case BamModelBlock():
+            model_input_str = messages_to_str(block.model, model_input)
             msg_stream = BamModel.generate_text_stream(
                 model_id=block.model,
                 prompt_id=block.prompt_id,
@@ -1172,9 +1172,9 @@ def generate_client_response_single(
     model_input: Messages,
 ) -> Generator[YieldMessage, Any, tuple[Message, Any]]:
     msg: Message
-    model_input_str = messages_to_str(block.model, model_input)
     match block:
         case BamModelBlock():
+            model_input_str = messages_to_str(block.model, model_input)
             msg, raw_result = BamModel.generate_text(
                 model_id=block.model,
                 prompt_id=block.prompt_id,
@@ -1203,9 +1203,9 @@ def generate_client_response_batching(  # pylint: disable=too-many-arguments
     # model: str,
     model_input: Messages,
 ) -> Generator[YieldMessage, Any, Message]:
-    model_input_str = messages_to_str(block.model, model_input)
     match block:
         case BamModelBlock():
+            model_input_str = messages_to_str(block.model, model_input)
             msg = yield ModelCallMessage(
                 model_id=block.model,
                 prompt_id=block.prompt_id,

src/pdl/pdl_utils.py

@@ -39,7 +39,7 @@ def messages_to_str(model_id: str, messages: Messages) -> str:
         "".join(
             [
                 (
-                    msg["content"]
+                    str(msg["content"])
                     if msg["role"] is None
                     # else f"<|{msg['role']}|>{msg['content']}"
                     else f"<|start_of_role|>{msg['role']}<|end_of_role|>{msg['content']}<|end_of_text|>\n"