[Core] Factor out input preprocessing to a separate class

vllm/engine/async_llm_engine.py

@@ -5,22 +5,18 @@
                     Optional, Set, Tuple, Type, Union)
 
 from transformers import PreTrainedTokenizer
-from typing_extensions import assert_never
 
 import vllm.envs as envs
 from vllm.config import (DecodingConfig, EngineConfig, LoRAConfig, ModelConfig,
                          ParallelConfig, SchedulerConfig)
 from vllm.core.scheduler import SchedulerOutputs
 from vllm.engine.arg_utils import AsyncEngineArgs
 from vllm.engine.async_timeout import asyncio_timeout
-from vllm.engine.llm_engine import (DecoderPromptComponents, LLMEngine,
-                                    PromptComponents)
+from vllm.engine.llm_engine import LLMEngine
 from vllm.engine.metrics import StatLoggerBase
 from vllm.executor.executor_base import ExecutorAsyncBase
 from vllm.executor.ray_utils import initialize_ray_cluster, ray
-from vllm.inputs import (EncoderDecoderLLMInputs, LLMInputs, PromptInputs,
-                         SingletonPromptInputs)
-from vllm.inputs.parse import is_explicit_encoder_decoder_prompt
+from vllm.inputs import PromptInputs
 from vllm.logger import init_logger
 from vllm.lora.request import LoRARequest
 from vllm.outputs import EmbeddingRequestOutput, RequestOutput
@@ -297,139 +293,6 @@ async def stop_remote_worker_execution_loop_async(self) -> None:
         """Stop the remote worker execution loop."""
         await self.model_executor.stop_remote_worker_execution_loop_async()
 
-    async def _tokenize_prompt_async(
-        self,
-        prompt: str,
-        request_id: str,
-        lora_request: Optional[LoRARequest],
-    ) -> List[int]:
-        """Async version of :meth:`_tokenize_prompt`."""
-        tokenizer = self.get_tokenizer_group("prompts must be None if "
-                                             "skip_tokenizer_init is True")
-
-        return await tokenizer.encode_async(request_id=request_id,
-                                            prompt=prompt,
-                                            lora_request=lora_request)
-
-    async def _extract_prompt_components_async(
-        self,
-        inputs: SingletonPromptInputs,
-        request_id: str,
-        lora_request: Optional[LoRARequest] = None,
-    ) -> PromptComponents:
-        """Async version of :meth:`_extract_prompt_components`."""
-        if isinstance(inputs, str):
-            prompt = inputs
-            prompt_token_ids = await self._tokenize_prompt_async(
-                prompt,
-                request_id=request_id,
-                lora_request=lora_request,
-            )
-            multi_modal_data = None
-        elif isinstance(inputs, dict):
-            if "prompt_token_ids" in inputs:
-                prompt = None
-                prompt_token_ids = inputs["prompt_token_ids"]
-            else:
-                # NOTE: This extra assignment is required to pass mypy
-                prompt = parsed_prompt = inputs["prompt"]
-                prompt_token_ids = await self._tokenize_prompt_async(
-                    parsed_prompt,
-                    request_id=request_id,
-                    lora_request=lora_request,
-                )
-
-            multi_modal_data = inputs.get("multi_modal_data")
-        else:
-            assert_never(inputs)
-
-        return prompt, prompt_token_ids, multi_modal_data
-
-    async def _process_encoder_decoder_prompt_async(
-        self,
-        inputs: PromptInputs,
-        request_id: str,
-    ) -> EncoderDecoderLLMInputs:
-        """Async version of :meth:`_process_encoder_decoder_prompt`."""
-        encoder_comps: PromptComponents
-        decoder_comps: DecoderPromptComponents
-
-        if is_explicit_encoder_decoder_prompt(inputs):
-            encoder_task = self._extract_prompt_components_async(
-                inputs["encoder_prompt"],
-                request_id=request_id,
-            )
-
-            if (decoder_input := inputs["decoder_prompt"]) is None:
-                encoder_comps = await encoder_task
-                decoder_comps = None, None, None
-            else:
-                decoder_task = self._extract_prompt_components_async(
-                    decoder_input,
-                    request_id=request_id,
-                )
-
-                encoder_comps, decoder_comps = await asyncio.gather(
-                    encoder_task, decoder_task)
-        else:
-            encoder_comps = await self._extract_prompt_components_async(
-                inputs,
-                request_id=request_id,
-            )
-
-            decoder_comps = None, None, None
-
-        return self._build_enc_dec_llm_inputs(encoder_comps, decoder_comps)
-
-    async def _process_decoder_only_prompt_async(
-        self,
-        inputs: SingletonPromptInputs,
-        request_id: str,
-        lora_request: Optional[LoRARequest] = None,
-        prompt_adapter_request: Optional[PromptAdapterRequest] = None,
-    ) -> LLMInputs:
-        """Async version of :meth:`_process_decoder_only_prompt`."""
-        prompt_comps = await self._extract_prompt_components_async(
-            inputs,
-            request_id=request_id,
-            lora_request=lora_request,
-        )
-
-        return self._build_decoder_only_llm_inputs(
-            prompt_comps,
-            prompt_adapter_request=prompt_adapter_request,
-        )
-
-    async def process_model_inputs_async(
-        self,
-        inputs: PromptInputs,
-        request_id: str,
-        lora_request: Optional[LoRARequest] = None,
-        prompt_adapter_request: Optional[PromptAdapterRequest] = None,
-    ) -> Union[LLMInputs, EncoderDecoderLLMInputs]:
-        """Async version of :meth:`process_model_inputs`."""
-        if self.is_encoder_decoder_model():
-            # Encoder-decoder model requires special mapping of
-            # input prompts to encoder & decoder
-            model_inputs = await self._process_encoder_decoder_prompt_async(
-                inputs,
-                request_id=request_id,
-            )
-        else:
-            if is_explicit_encoder_decoder_prompt(inputs):
-                raise ValueError("Cannot pass encoder-decoder prompt "
-                                 "to decoder-only models")
-
-            # Decoder-only operation
-            model_inputs = await self._process_decoder_only_prompt_async(
-                inputs,
-                request_id=request_id,
-                lora_request=lora_request,
-                prompt_adapter_request=prompt_adapter_request,
-            )
-
-        return self.input_processor(model_inputs)
-
     async def add_request_async(
         self,
         request_id: str,
@@ -447,12 +310,13 @@ async def add_request_async(
         if arrival_time is None:
             arrival_time = time.time()
 
-        processed_inputs = await self.process_model_inputs_async(
+        preprocessed_inputs = await self.input_preprocessor.preprocess_async(
             inputs,
             request_id=request_id,
             lora_request=lora_request,
             prompt_adapter_request=prompt_adapter_request,
         )
+        processed_inputs = self.input_processor(preprocessed_inputs)
 
         self._add_processed_request(
             request_id=request_id,