support vllm

src/llmtuner/chat/vllm_engine.py

@@ -0,0 +1,144 @@
+import uuid
+from typing import TYPE_CHECKING, AsyncGenerator, AsyncIterator, Dict, List, Optional, Sequence
+
+from transformers.utils.versions import require_version
+
+from ..data import get_template_and_fix_tokenizer
+from ..extras.misc import get_device_count
+from ..extras.packages import is_vllm_available
+from ..model import load_tokenizer
+from .base_engine import BaseEngine, Response
+
+
+if is_vllm_available():
+    from vllm import AsyncEngineArgs, AsyncLLMEngine, RequestOutput, SamplingParams
+
+if TYPE_CHECKING:
+    from ..hparams import DataArguments, FinetuningArguments, GeneratingArguments, ModelArguments
+
+
+class VllmEngine(BaseEngine):
+    def __init__(
+        self,
+        model_args: "ModelArguments",
+        data_args: "DataArguments",
+        finetuning_args: "FinetuningArguments",
+        generating_args: "GeneratingArguments",
+    ) -> None:
+        require_version("vllm>=0.3.3", "To fix: pip install vllm>=0.3.3")
+        self.can_generate = finetuning_args.stage == "sft"
+        engine_args = AsyncEngineArgs(
+            model=model_args.model_name_or_path,
+            trust_remote_code=True,
+            max_model_len=model_args.vllm_maxlen,
+            tensor_parallel_size=get_device_count(),
+            disable_log_stats=True,
+            disable_log_requests=True,
+        )
+        self.model = AsyncLLMEngine.from_engine_args(engine_args)
+        self.tokenizer = load_tokenizer(model_args)
+        self.tokenizer.padding_side = "left"
+        self.template = get_template_and_fix_tokenizer(self.tokenizer, data_args.template)
+        self.generating_args = generating_args.to_dict()
+
+    async def _generate(
+        self,
+        messages: Sequence[Dict[str, str]],
+        system: Optional[str] = None,
+        tools: Optional[str] = None,
+        **input_kwargs,
+    ) -> AsyncIterator["RequestOutput"]:
+        request_id = "chatcmpl-{}".format(uuid.uuid4().hex)
+        paired_messages = messages + [{"role": "assistant", "content": ""}]
+        prompt_ids, _ = self.template.encode_oneturn(
+            tokenizer=self.tokenizer, messages=paired_messages, system=system, tools=tools
+        )
+        prompt_length = len(prompt_ids)
+
+        temperature = input_kwargs.pop("temperature", None)
+        top_p = input_kwargs.pop("top_p", None)
+        top_k = input_kwargs.pop("top_k", None)
+        num_return_sequences = input_kwargs.pop("num_return_sequences", None)
+        repetition_penalty = input_kwargs.pop("repetition_penalty", None)
+        max_length = input_kwargs.pop("max_length", None)
+        max_new_tokens = input_kwargs.pop("max_new_tokens", None)
+
+        generating_args = self.generating_args.copy()
+        generating_args.update(
+            dict(
+                temperature=temperature or generating_args["temperature"],
+                top_p=top_p or generating_args["top_p"],
+                top_k=top_k or generating_args["top_k"],
+                num_return_sequences=num_return_sequences or 1,
+                repetition_penalty=repetition_penalty or generating_args["repetition_penalty"],
+            )
+        )
+
+        if max_length:
+            generating_args["max_new_tokens"] = max_length - prompt_length
+
+        if max_new_tokens:
+            generating_args["max_new_tokens"] = max_new_tokens
+
+        sampling_params = SamplingParams(
+            n=generating_args["num_return_sequences"],
+            repetition_penalty=generating_args["repetition_penalty"],
+            temperature=generating_args["temperature"],
+            top_p=generating_args["top_p"],
+            top_k=generating_args["top_k"],
+            use_beam_search=generating_args["num_beams"] > 1,
+            length_penalty=generating_args["length_penalty"],
+            stop_token_ids=[self.tokenizer.eos_token_id] + self.tokenizer.additional_special_tokens_ids,
+            max_tokens=generating_args["max_new_tokens"],
+            skip_special_tokens=True,
+        )
+        result_generator = self.model.generate(
+            prompt=None, sampling_params=sampling_params, request_id=request_id, prompt_token_ids=prompt_ids
+        )
+        return result_generator
+
+    async def chat(
+        self,
+        messages: Sequence[Dict[str, str]],
+        system: Optional[str] = None,
+        tools: Optional[str] = None,
+        **input_kwargs,
+    ) -> List["Response"]:
+        final_output = None
+        generator = await self._generate(messages, system, tools, **input_kwargs)
+        async for request_output in generator:
+            final_output = request_output
+
+        results = []
+        for output in final_output.outputs:
+            results.append(
+                Response(
+                    response_text=output.text,
+                    response_length=len(output.token_ids),
+                    prompt_length=len(final_output.prompt_token_ids),
+                    finish_reason=output.finish_reason,
+                )
+            )
+
+        return results
+
+    async def stream_chat(
+        self,
+        messages: Sequence[Dict[str, str]],
+        system: Optional[str] = None,
+        tools: Optional[str] = None,
+        **input_kwargs,
+    ) -> AsyncGenerator[str, None]:
+        generated_text = ""
+        generator = await self._generate(messages, system, tools, **input_kwargs)
+        async for result in generator:
+            delta_text = result.outputs[0].text[len(generated_text) :]
+            generated_text = result.outputs[0].text
+            yield delta_text
+
+    async def get_scores(
+        self,
+        batch_input: List[str],
+        **input_kwargs,
+    ) -> List[float]:
+        raise NotImplementedError("vLLM engine does not support get_scores.")