[Frontend] Separate pooling APIs in offline inference (#11129)

Signed-off-by: DarkLight1337 <tlleungac@connect.ust.hk>

vllm/engine/llm_engine.py

@@ -46,11 +46,10 @@ from vllm.outputs import (PoolingRequestOutput, RequestOutput,
 from vllm.pooling_params import PoolingParams
 from vllm.prompt_adapter.request import PromptAdapterRequest
 from vllm.sampling_params import RequestOutputKind, SamplingParams
-from vllm.sequence import (EmbeddingSequenceGroupOutput, ExecuteModelRequest,
-                           ParallelSampleSequenceGroup, Sequence,
-                           SequenceGroup, SequenceGroupBase,
-                           SequenceGroupMetadata, SequenceGroupOutput,
-                           SequenceStatus)
+from vllm.sequence import (ExecuteModelRequest, ParallelSampleSequenceGroup,
+                           PoolingSequenceGroupOutput, Sequence, SequenceGroup,
+                           SequenceGroupBase, SequenceGroupMetadata,
+                           SequenceGroupOutput, SequenceStatus)
 from vllm.tracing import (SpanAttributes, SpanKind, extract_trace_context,
                           init_tracer)
 from vllm.transformers_utils.config import try_get_generation_config
@@ -966,9 +965,9 @@ class LLMEngine:
     @staticmethod
     def _process_sequence_group_outputs(
         seq_group: SequenceGroup,
-        outputs: List[EmbeddingSequenceGroupOutput],
+        outputs: List[PoolingSequenceGroupOutput],
     ) -> None:
-        seq_group.embeddings = outputs[0].embeddings
+        seq_group.pooled_data = outputs[0].data
 
         for seq in seq_group.get_seqs():
             seq.status = SequenceStatus.FINISHED_STOPPED
@@ -1784,8 +1783,8 @@ class LLMEngine:
                                num_prompt_tokens_iter)
         # Spec decode, if enabled, emits specialized metrics from the worker in
         # sampler output.
-        if model_output and (model_output[0].spec_decode_worker_metrics
-                             is not None):
+        if model_output and isinstance(model_output[0], SamplerOutput) and (
+                model_output[0].spec_decode_worker_metrics is not None):
             spec_decode_metrics = model_output[0].spec_decode_worker_metrics
         else:
             spec_decode_metrics = None