[Bugfix] pr conflict fix, bugfix ignore mm data from stages to async omni (vllm-project#1025)

Signed-off-by: dengyunyang <584797741@qq.com>

Author: Bounty-hunter

vllm_omni/entrypoints/omni_stage.py

@@ -1467,7 +1467,7 @@ async def generation_single_request(task: dict[str, Any]):
             batch_request_ids, batch_request_outputs, _gen_ms_list, batch_metrics
         ):
             try:
-                r_outputs = [output]
+                r_outputs = [output_strip(output, omni_stage)]
                 use_shm, payload = maybe_dump_to_shm(r_outputs, shm_threshold_bytes)
                 if use_shm:
                     out_q.put(
@@ -1553,3 +1553,32 @@ def make_stage_stats(_agg_total_tokens: int, _agg_total_gen_time_ms: float):
     from vllm_omni.entrypoints.log_utils import StageStats
 
     return StageStats(total_token=_agg_total_tokens, total_gen_time=_agg_total_gen_time_ms)
+
+
+def output_strip(r_output: RequestOutput | OmniRequestOutput, omni_stage: OmniStage):
+    """
+    Strip unnecessary multimodal outputs from stages results,
+    in order to:
+    - reduce memory usage
+    - reduce transfer & serialization overhead
+    """
+
+    # check multimodal data is required by stage output config.
+    if omni_stage.final_output and omni_stage.final_output_type != "text":
+        return r_output
+
+    # If the request has already finished, should not be altered.
+    if getattr(r_output, "finished", False):
+        return r_output
+
+    mm_output = getattr(r_output, "multimodal_output", None)
+    if mm_output is not None:
+        r_output.multimodal_output = {}
+
+    outputs = getattr(r_output, "outputs", None)
+    if outputs is not None:
+        for out in outputs:
+            if getattr(out, "multimodal_output", None):
+                out.multimodal_output = {}
+
+    return r_output