Benchmark serving structured output (#10880)

Signed-off-by: Chendi Xue <chendi.xue@intel.com>
Co-authored-by: Michael Goin <michael@neuralmagic.com>

benchmarks/backend_request_func.py

@@ -24,6 +24,7 @@ class RequestFuncInput:
     model: str
     best_of: int = 1
     logprobs: Optional[int] = None
+    extra_body: Optional[dict] = None
     multi_modal_content: Optional[dict] = None
     ignore_eos: bool = False
 
@@ -36,6 +37,7 @@ class RequestFuncOutput:
     ttft: float = 0.0  # Time to first token
     itl: List[float] = field(
         default_factory=list)  # List of inter-token latencies
+    tpot: float = 0.0  # avg next-token latencies
     prompt_len: int = 0
     error: str = ""
 
@@ -242,6 +244,8 @@ async def async_request_openai_completions(
             "stream": True,
             "ignore_eos": request_func_input.ignore_eos,
         }
+        if request_func_input.extra_body:
+            payload.update(request_func_input.extra_body)
         headers = {
             "Authorization": f"Bearer {os.environ.get('OPENAI_API_KEY')}"
         }
@@ -336,6 +340,8 @@ async def async_request_openai_chat_completions(
             "stream": True,
             "ignore_eos": request_func_input.ignore_eos,
         }
+        if request_func_input.extra_body:
+            payload.update(request_func_input.extra_body)
         headers = {
             "Content-Type": "application/json",
             "Authorization": f"Bearer {os.environ.get('OPENAI_API_KEY')}",