Source code for bocoel.models.lms.huggingface.generative

# Copyright (c) RenChu Wang - All Rights Reserved

from collections.abc import Sequence

import torch

from bocoel.models.lms.interfaces import GenerativeModel

from .causal import HuggingfaceCausalLM




class HuggingfaceGenerativeLM(HuggingfaceCausalLM, GenerativeModel):
    """
    The generative model backed by huggingface's transformers library.

    Since huggingface's tokenizer needs padding to the left to work,
    padding doesn't guarantee the same positional embeddings, and thus, results.
    If sameness with generating one by one is desired, batch size should be 1.
    """



    def __init__(
        self, model_path: str, batch_size: int, device: str, add_sep_token: bool = False
    ) -> None:
        """
        Parameters:
            model_path: The path to the model.
            batch_size: The batch size to use.
            device: The device to use.
            add_sep_token: Whether to add the sep token.
        """

        super().__init__(
            model_path=model_path,
            batch_size=batch_size,
            device=device,
            add_sep_token=add_sep_token,
        )




    @torch.no_grad()
    def generate(self, prompts: Sequence[str], /) -> Sequence[str]:
        results: list[str] = []
        for idx in range(0, len(prompts), self._batch_size):
            results.extend(self._generate_batch(prompts[idx : idx + self._batch_size]))
        return results


    def _generate_batch(self, prompts: Sequence[str]) -> list[str]:
        inputs = self._tokenizer(prompts)
        outputs = self._model.generate(**inputs)
        outputs = self._tokenizer.batch_decode(outputs)
        return outputs