vllm.parser.engine.adapters ¶

class ParserEngineReasoningAdapter(ReasoningParser):
    """Adapts a :class:`ParserEngine` to the :class:`ReasoningParser`
    interface so parser engines can be used as reasoning parsers in the
    existing serving code.

    Subclasses set :attr:`_parser_engine_cls` to the concrete
    :class:`ParserEngine` class.
    """

    _parser_engine_cls: type[ParserEngine]
    engine_based_streaming: bool = True

    def __init__(self, tokenizer: TokenizerLike, *args, **kwargs) -> None:
        super().__init__(tokenizer, *args, **kwargs)
        self._parser_engine = self._parser_engine_cls(tokenizer, **kwargs)  # type: ignore[call-arg]
        self._parser_engine_kwargs = kwargs
        self._counting_parser_engine: ParserEngine | None = None
        # TODO: Remove once Responses finalization reuses accumulated streaming
        # parser results instead of reparsing the complete output.
        self._streaming_count_valid = False

    @contextmanager
    def _skip_tool_parsing(self) -> Iterator[None]:
        saved = self._parser_engine.skip_tool_parsing
        self._parser_engine.skip_tool_parsing = True
        try:
            yield
        finally:
            self._parser_engine.skip_tool_parsing = saved

    def is_reasoning_end(self, input_ids: Sequence[int]) -> bool:
        return self._parser_engine.is_reasoning_end(list(input_ids))

    def adjust_initial_state_from_prompt(self, prompt_token_ids: Sequence[int]) -> None:
        self._parser_engine.adjust_initial_state_from_prompt(prompt_token_ids)

    def extract_content_ids(self, input_ids: list[int]) -> list[int]:
        return self._parser_engine.extract_content_ids(input_ids)

    def extract_reasoning(
        self,
        model_output: str,
        request: ChatCompletionRequest | ResponsesRequest,
    ) -> tuple[str | None, str | None]:
        self._streaming_count_valid = False
        with self._skip_tool_parsing():
            return self._parser_engine.extract_reasoning(model_output, request)

    def extract_reasoning_streaming(
        self,
        previous_text: str,
        current_text: str,
        delta_text: str,
        previous_token_ids: Sequence[int],
        current_token_ids: Sequence[int],
        delta_token_ids: Sequence[int],
    ) -> DeltaMessage | None:
        self._streaming_count_valid = True
        with self._skip_tool_parsing():
            return self._parser_engine.extract_reasoning_streaming(
                previous_text,
                current_text,
                delta_text,
                previous_token_ids,
                current_token_ids,
                delta_token_ids,
            )

    @property
    def reasoning_start_str(self) -> str | None:
        return self._parser_engine.reasoning_start_str

    @property
    def reasoning_end_str(self) -> str | None:
        return self._parser_engine.reasoning_end_str

    def adjust_request(
        self,
        request: ChatCompletionRequest | ResponsesRequest,
    ) -> ChatCompletionRequest | ResponsesRequest:
        return self._parser_engine.adjust_request(request)

    def has_engine_confirmed_reasoning_end(self) -> bool:
        return self._parser_engine.reasoning_ended

    def finish_streaming(self) -> DeltaMessage | None:
        with self._skip_tool_parsing():
            return self._parser_engine.finish_streaming()

    def get_streaming_fallback_content(
        self,
        text: str,
        request: ChatCompletionRequest | ResponsesRequest,
    ) -> str | None:
        return self._parser_engine.get_streaming_fallback_content(text, request)

    def count_reasoning_tokens(self, token_ids: Sequence[int]) -> int:
        if self._streaming_count_valid:
            return self._parser_engine.count_reasoning_tokens(token_ids)
        if not token_ids:
            return 0
        if self._counting_parser_engine is None:
            self._counting_parser_engine = self._parser_engine_cls(
                self.model_tokenizer, **self._parser_engine_kwargs
            )  # type: ignore[call-arg]
        self._counting_parser_engine._single_pass_parse(
            self.model_tokenizer.decode(token_ids), token_ids
        )
        return self._counting_parser_engine.count_reasoning_tokens(token_ids)

class ParserEngineToolAdapter(ToolParser):
    """Adapts a :class:`ParserEngine` to the :class:`ToolParser` interface.

    :meth:`extract_tool_calls` starts the parser engine in ``CONTENT``
    state so it can parse reasoning-stripped content (i.e. the output of
    :meth:`ReasoningParser.extract_reasoning`).

    Subclasses set :attr:`_parser_engine_cls` to the concrete
    :class:`ParserEngine` class.
    """

    _parser_engine_cls: type[ParserEngine]
    engine_based_streaming: bool = True

    def __init__(
        self,
        tokenizer: TokenizerLike,
        tools: list[Tool] | None = None,
        **kwargs,
    ) -> None:
        super().__init__(tokenizer, tools)
        self._parser_engine = self._parser_engine_cls(tokenizer, tools, **kwargs)  # type: ignore[call-arg]

    def adjust_request(
        self,
        request: ChatCompletionRequest | ResponsesRequest,
    ) -> ChatCompletionRequest | ResponsesRequest:
        request = super().adjust_request(request)
        return self._parser_engine.adjust_request(request)

    def extract_tool_calls(
        self,
        model_output: str,
        request: ChatCompletionRequest,
    ) -> ExtractedToolCallInformation:
        return self._parser_engine.extract_tool_calls_from_content(
            model_output, request
        )

    def extract_tool_calls_streaming(
        self,
        previous_text: str,
        current_text: str,
        delta_text: str,
        previous_token_ids: Sequence[int],
        current_token_ids: Sequence[int],
        delta_token_ids: Sequence[int],
        request: ChatCompletionRequest,
    ) -> DeltaMessage | None:
        engine = self._parser_engine
        engine.initialize_streaming(initial_state=ParserState.CONTENT)
        return engine.extract_tool_calls_streaming(
            previous_text,
            current_text,
            delta_text,
            previous_token_ids,
            current_token_ids,
            delta_token_ids,
            request,
        )

    def finish_streaming(self) -> DeltaMessage | None:
        return self._parser_engine.finish_streaming()