API: Don't do a second re-render when tool calling

Re-rendering the template is an expensive operation when it's possible
to just concatenate the prompt and current generation text together.

Signed-off-by: kingbri <8082010+kingbri1@users.noreply.github.com>

endpoints/OAI/utils/chat_completion.py

@@ -361,6 +361,8 @@ async def stream_generate_chat_completion(
             if tool_start:
                 if "stop_str" in generation:
                     generations = await generate_tool_calls(
+                        prompt,
+                        embeddings,
                         data,
                         [generation],
                         request,
@@ -442,7 +444,9 @@ async def generate_chat_completion(
 
         # Check all the generations and see if a tool call is required
         if tool_start:
-            generations = await generate_tool_calls(data, generations, request)
+            generations = await generate_tool_calls(
+                prompt, embeddings, data, generations, request
+            )
 
         response = _create_response(request.state.id, generations, model_path.name)
 
@@ -461,6 +465,8 @@ async def generate_chat_completion(
 
 
 async def generate_tool_calls(
+    prompt: str,
+    embeddings: MultimodalEmbeddingWrapper,
     data: ChatCompletionRequest,
     generations: List[str],
     request: Request,
@@ -482,12 +488,10 @@ async def generate_tool_calls(
 
         logger.info(f"Detected tool call in chat completion request {request.state.id}")
 
-        # Append the existing generation as part of the response prefix
+        # Append the existing generation text if present
         precursor_text = current_generation_text or gen.get("text")
         if precursor_text:
-            tool_data.response_prefix = precursor_text
-
-        pre_tool_prompt, embeddings = await apply_chat_template(tool_data)
+            prompt = prompt + precursor_text
 
         gen_request_id = _parse_gen_request_id(data.n, request.state.id, idx)
         tool_request_id = f"{gen_request_id}-tool"
@@ -496,7 +500,7 @@ async def generate_tool_calls(
             asyncio.create_task(
                 model.container.generate(
                     tool_request_id,
-                    pre_tool_prompt,
+                    prompt,
                     tool_data,
                     mm_embeddings=embeddings,
                 )