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# SPDX-FileCopyrightText: Copyright 2023-2024 SGLang Team
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"""Abstract engine interface for runtime entrypoints."""

from abc import ABC, abstractmethod
from collections.abc import Iterator

import torch


class EngineBase(ABC):
    """Abstract base class for engine interfaces.

    This interface covers generation, weight updates, and memory control for
    both HTTP-based adapters and in-process engines.
    """

    @abstractmethod
    def generate(
        self,
        prompt: list[str] | str | None = None,
        sampling_params: list[dict] | dict | None = None,
        input_ids: list[list[int]] | list[int] | None = None,
        return_logprob: list[bool] | bool | None = None,
        logprob_start_len: list[int] | int | None = None,
        top_logprobs_num: list[int] | int | None = None,
        token_ids_logprob: list[list[int]] | list[int] | None = None,
        return_text_in_logprobs: bool = False,
        logprob_format: list[str | None] | str | None = None,
        custom_logit_processor: list[str] | str | None = None,
        return_hidden_states: bool | None = None,
        stream: bool | None = None,
        bootstrap_host: list[str] | str | None = None,
        bootstrap_port: list[int] | int | None = None,
        bootstrap_room: list[int] | int | None = None,
        data_parallel_rank: int | None = None,
    ) -> dict | Iterator[dict]:
        """Generate outputs based on given inputs."""

    @abstractmethod
    def flush_cache(self) -> None:
        """Flush the cache of the engine."""

    @abstractmethod
    def update_weights_from_tensor(
        self,
        named_tensors: list[tuple[str, torch.Tensor]],
        load_format: str | None = None,
        flush_cache: bool = True,
    ) -> None:
        """Update model weights with in-memory tensor data."""

    @abstractmethod
    def release_memory_occupation(self, tags: list[str] | None = None) -> None:
        """Release GPU memory occupation temporarily (optionally by tag)."""

    @abstractmethod
    def resume_memory_occupation(self, tags: list[str] | None = None) -> None:
        """Resume GPU memory occupation previously released (optionally by tag)."""

    @abstractmethod
    def is_sleeping(self) -> bool:
        """Return whether any GPU memory is currently released."""

    @abstractmethod
    def shutdown(self) -> None:
        """Shutdown the engine and clean up resources."""