976 lines
36 KiB
Python
976 lines
36 KiB
Python
# SPDX-License-Identifier: Apache-2.0
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# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
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import contextlib
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import json
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from abc import abstractmethod
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from collections.abc import Sequence
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from dataclasses import dataclass, field
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from functools import cached_property
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from openai.types.responses import ToolChoiceFunction
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from pydantic import TypeAdapter, ValidationError
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from vllm.entrypoints.chat_utils import (
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get_tool_call_id_type,
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make_tool_call_id,
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)
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from vllm.entrypoints.openai.chat_completion.protocol import (
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ChatCompletionNamedToolChoiceParam,
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ChatCompletionRequest,
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)
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from vllm.entrypoints.openai.engine.protocol import (
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DeltaMessage,
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ExtractedToolCallInformation,
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FunctionCall,
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FunctionDefinition,
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)
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from vllm.entrypoints.openai.responses.protocol import ResponsesRequest
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from vllm.logger import init_logger
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from vllm.parser.metrics import record_tool_parser_invocation
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from vllm.parser.utils import count_history_tool_calls
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from vllm.reasoning.abs_reasoning_parsers import ReasoningParser
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from vllm.sampling_params import StructuredOutputsParams
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from vllm.tokenizers import TokenizerLike
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from vllm.tool_parsers.abstract_tool_parser import Tool, ToolParser
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from vllm.tool_parsers.streaming import (
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extract_named_tool_call_streaming,
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extract_required_tool_call_streaming,
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)
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logger = init_logger(__name__)
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@dataclass
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class StreamState:
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"""Mutable state for ``Parser.parse_delta()``. One per stream."""
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reasoning_ended: bool = False
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tool_call_text_started: bool = False
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prompt_reasoning_checked: bool = False
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previous_text: str = ""
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previous_token_ids: list[int] = field(default_factory=list)
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history_tool_call_cnt: int = 0
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history_tool_call_cnt_initialized: bool = False
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tool_call_id_type: str = "random"
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# only used for "required" and "named tool" choices,
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# tracks whether function name has been fully returned in the stream yet
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function_name_returned: bool = False
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engine_based: bool = False
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def advance(
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self,
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delta_text: str,
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delta_token_ids: list[int],
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) -> tuple[str, list[int]]:
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if self.engine_based:
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return delta_text, delta_token_ids
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return (
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self.previous_text + delta_text,
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self.previous_token_ids + delta_token_ids,
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)
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def commit(
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self,
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current_text: str,
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current_token_ids: list[int],
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) -> None:
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if self.engine_based:
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self.previous_text = ""
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self.previous_token_ids = []
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else:
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self.previous_text = current_text
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self.previous_token_ids = current_token_ids
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class Parser:
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"""
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Abstract Parser class that unifies ReasoningParser and ToolParser into
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a single interface for parsing model output.
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This class provides a unified way to handle both reasoning extraction
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(e.g., chain-of-thought content in <think> tags) and tool call extraction
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(e.g., function calls in XML/JSON format) from model outputs.
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Subclasses can either:
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1. Override the abstract methods directly for custom parsing logic
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2. Set `reasoning_parser` and `tool_parser` properties to delegate to
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existing parser implementations
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Class Attributes:
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reasoning_parser_cls: The ReasoningParser class to use (for compatibility
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with code that needs the class, not instance).
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tool_parser_cls: The ToolParser class to use (for compatibility with
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code that needs the class, not instance).
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"""
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# Class-level parser classes for compatibility with existing patterns
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# Subclasses should override these if they use specific parser classes
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reasoning_parser_cls: type[ReasoningParser] | None = None
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tool_parser_cls: type[ToolParser] | None = None
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def __init__(
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self,
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tokenizer: TokenizerLike,
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tools: list[Tool] | None = None,
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*args,
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model_config=None,
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**kwargs,
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):
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self.model_tokenizer = tokenizer
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self._reasoning_parser: ReasoningParser | None = None
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self._tool_parser: ToolParser | None = None
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if self.__class__.reasoning_parser_cls is not None:
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self._reasoning_parser = self.__class__.reasoning_parser_cls(
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tokenizer, *args, **kwargs
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)
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if self.__class__.tool_parser_cls is not None:
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self._tool_parser = self.__class__.tool_parser_cls(tokenizer, tools)
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self._engine_based = (
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self._reasoning_parser is None
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or self._reasoning_parser.engine_based_streaming
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) and (self._tool_parser is None or self._tool_parser.engine_based_streaming)
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self._stream_state = StreamState(
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tool_call_id_type=(
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get_tool_call_id_type(model_config)
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if model_config is not None
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else "random"
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),
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engine_based=self._engine_based,
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)
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@cached_property
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def vocab(self) -> dict[str, int]:
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"""Get the vocabulary mapping from tokens to IDs."""
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return self.model_tokenizer.get_vocab()
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@property
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def reasoning_parser(self) -> ReasoningParser | None:
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"""The underlying reasoning parser, if any."""
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return self._reasoning_parser
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@reasoning_parser.setter
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def reasoning_parser(self, parser: ReasoningParser | None) -> None:
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self._reasoning_parser = parser
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@property
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def tool_parser(self) -> ToolParser | None:
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"""The underlying tool parser, if any."""
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return self._tool_parser
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@tool_parser.setter
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def tool_parser(self, parser: ToolParser | None) -> None:
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self._tool_parser = parser
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def _initialize_history_tool_call_cnt(
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self,
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request: ChatCompletionRequest | ResponsesRequest,
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) -> None:
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state = self._stream_state
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if state.history_tool_call_cnt_initialized:
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return
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if state.tool_call_id_type != "kimi_k2":
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state.history_tool_call_cnt_initialized = True
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return
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state.history_tool_call_cnt = count_history_tool_calls(request)
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state.history_tool_call_cnt_initialized = True
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# ========== Reasoning Parser Methods ==========
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@abstractmethod
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def is_reasoning_end(self, input_ids: list[int]) -> bool:
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"""
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Check if the reasoning content ends in the input_ids.
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Used by structured engines like `xgrammar` to check if the
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reasoning content ends in the model output.
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Args:
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input_ids: The token IDs of the model output.
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Returns:
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True if the reasoning content ends in the input_ids.
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"""
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def is_reasoning_end_streaming(
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self, input_ids: list[int], delta_ids: list[int]
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) -> bool:
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"""
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Check if the reasoning content ends during a decode step.
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Args:
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input_ids: The entire model output token IDs.
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delta_ids: The last few computed tokens at the current decode step.
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Returns:
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True if the reasoning content ends in the delta_ids.
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"""
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return self.is_reasoning_end(input_ids)
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@abstractmethod
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def extract_content_ids(self, input_ids: list[int]) -> list[int]:
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"""
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Extract content token IDs from the input_ids.
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This extracts the non-reasoning content (e.g., everything after
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the </think> tag).
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Args:
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input_ids: The token IDs of the model output.
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Returns:
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The extracted content token IDs.
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"""
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@abstractmethod
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def extract_reasoning(
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self,
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model_output: str,
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request: ChatCompletionRequest | ResponsesRequest,
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) -> tuple[str | None, str | None]:
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"""
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Extract reasoning content from a complete model-generated string.
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Used for non-streaming responses where we have the entire model
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response available before sending to the client.
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Args:
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model_output: The complete model-generated string.
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request: The request object used to generate the output.
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Returns:
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A tuple of (reasoning, response_content).
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"""
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@abstractmethod
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def extract_reasoning_streaming(
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self,
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previous_text: str,
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current_text: str,
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delta_text: str,
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previous_token_ids: Sequence[int],
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current_token_ids: Sequence[int],
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delta_token_ids: Sequence[int],
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) -> DeltaMessage | None:
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"""
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Extract reasoning content from a streaming delta message.
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Args:
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previous_text: Text from all previous tokens.
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current_text: Text including the current delta.
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delta_text: The new text in this delta.
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previous_token_ids: Token IDs from previous generation.
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current_token_ids: All token IDs including current.
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delta_token_ids: The new token IDs in this delta.
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Returns:
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A DeltaMessage with reasoning and/or content fields, or None.
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"""
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# ========== Tool Parser Methods ==========
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def adjust_request(
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self, request: ChatCompletionRequest | ResponsesRequest
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) -> ChatCompletionRequest | ResponsesRequest:
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"""
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Adjust the request parameters for tool calling.
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Can be overridden by subclasses to modify request parameters
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(e.g., setting structured output schemas for tool calling).
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Args:
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request: The original request.
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Returns:
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The adjusted request.
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"""
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return request
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@abstractmethod
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def extract_tool_calls(
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self,
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model_output: str,
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request: ChatCompletionRequest | ResponsesRequest,
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) -> ExtractedToolCallInformation:
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"""
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Extract tool calls from a complete model-generated string.
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Used for non-streaming responses.
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Args:
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model_output: The complete model-generated string.
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request: The request object used to generate the output.
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Returns:
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ExtractedToolCallInformation containing the tool calls.
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"""
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@abstractmethod
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def extract_tool_calls_streaming(
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self,
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previous_text: str,
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current_text: str,
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delta_text: str,
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previous_token_ids: Sequence[int],
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current_token_ids: Sequence[int],
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delta_token_ids: Sequence[int],
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request: ChatCompletionRequest | ResponsesRequest,
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) -> DeltaMessage | None:
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"""
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Extract tool calls from a streaming delta message.
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Args:
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previous_text: Text from all previous tokens.
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current_text: Text including the current delta.
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delta_text: The new text in this delta.
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previous_token_ids: Token IDs from previous generation.
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current_token_ids: All token IDs including current.
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delta_token_ids: The new token IDs in this delta.
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request: The request object.
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Returns:
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A DeltaMessage with tool_calls field, or None.
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"""
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@abstractmethod
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def parse(
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self,
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model_output: str,
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request: ChatCompletionRequest | ResponsesRequest,
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enable_auto_tools: bool = False,
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model_output_token_ids: Sequence[int] = (),
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) -> tuple[str | None, str | None, list[FunctionCall] | None]:
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"""Parse a complete model output, extracting reasoning and tool calls.
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Args:
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model_output: The complete model-generated string.
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request: The request object used to generate the output.
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enable_auto_tools: Whether to enable automatic tool call parsing.
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model_output_token_ids: The generated raw output token IDs.
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Returns:
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A tuple of (reasoning, content, tool_calls).
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"""
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@abstractmethod
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def parse_delta(
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self,
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delta_text: str,
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delta_token_ids: list[int],
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request: ChatCompletionRequest | ResponsesRequest,
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prompt_token_ids: list[int] | None = None,
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*,
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finished: bool,
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) -> DeltaMessage | None:
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"""Parse a single streaming delta, orchestrating reasoning then
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tool call extraction via internal stream state.
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"""
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class DelegatingParser(Parser):
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"""
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A Parser implementation that delegates to separate ReasoningParser and
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ToolParser instances.
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This is the recommended base class for creating model-specific parsers
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that combine existing reasoning and tool parser implementations.
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Subclasses should set `self._reasoning_parser` and `self._tool_parser`
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in their `__init__` method.
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If either parser is None, the corresponding methods will return default
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values (no reasoning extraction, no tool calls).
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"""
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def extract_reasoning(
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self,
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model_output: str,
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request: ChatCompletionRequest | ResponsesRequest,
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) -> tuple[str | None, str | None]:
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if self._reasoning_parser is None:
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return None, model_output
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return self._reasoning_parser.extract_reasoning(model_output, request)
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def _get_function_name(
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self, request: ChatCompletionRequest | ResponsesRequest
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) -> str:
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if request.tool_choice and isinstance(request.tool_choice, ToolChoiceFunction):
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return request.tool_choice.name
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if request.tool_choice and isinstance(
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request.tool_choice, ChatCompletionNamedToolChoiceParam
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):
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return request.tool_choice.function.name
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raise ValueError("Invalid tool_choice for function name extraction.")
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def _make_tool_call_id(self, function_name: str) -> str | None:
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state = self._stream_state
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if state.tool_call_id_type != "kimi_k2":
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return None
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tool_call_id = make_tool_call_id(
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id_type=state.tool_call_id_type,
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func_name=function_name,
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idx=state.history_tool_call_cnt,
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)
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state.history_tool_call_cnt += 1
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return tool_call_id
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def _extract_tool_calls(
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self,
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content: str | None,
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request: ChatCompletionRequest | ResponsesRequest,
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enable_auto_tools: bool = False,
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) -> tuple[list[FunctionCall] | None, str | None]:
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tool_parser = self._tool_parser
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if tool_parser is None:
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return [], content
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if request.tool_choice == "none":
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if self._engine_based:
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result = self.extract_tool_calls(content or "", request=request)
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return [], result.content
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return [], content
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supports_required_and_named = tool_parser.supports_required_and_named
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is_named_tool_choice = request.tool_choice and isinstance(
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request.tool_choice,
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(ToolChoiceFunction, ChatCompletionNamedToolChoiceParam),
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)
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is_required_tool_choice = request.tool_choice == "required"
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is_auto_tool_choice = enable_auto_tools and (
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request.tool_choice == "auto"
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or request.tool_choice is None
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or (
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not supports_required_and_named
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and (is_named_tool_choice or is_required_tool_choice)
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)
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)
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tool_calls = list[FunctionCall]()
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if is_named_tool_choice and supports_required_and_named:
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if content is None or (isinstance(content, str) and not content.strip()):
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return [], None
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function_name = self._get_function_name(request)
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tool_calls.append(
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FunctionCall(
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id=self._make_tool_call_id(function_name),
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name=function_name,
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arguments=content,
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)
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)
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content = None
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elif is_required_tool_choice and supports_required_and_named:
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# "required" with standard JSON-based parsing
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parsed_calls = []
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with contextlib.suppress(ValidationError):
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content = content or ""
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parsed_calls = TypeAdapter(list[FunctionDefinition]).validate_json(
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content
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)
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for tc in parsed_calls:
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tool_calls.append(
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FunctionCall(
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id=self._make_tool_call_id(tc.name),
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name=tc.name,
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arguments=json.dumps(tc.parameters, ensure_ascii=False),
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)
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)
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content = None
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elif is_auto_tool_choice:
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# Automatic Tool Call Parsing (also used as fallback for
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# required/named when supports_required_and_named=False)
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tool_call_info = self.extract_tool_calls(
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content if content is not None else "",
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request=request,
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)
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if tool_call_info is not None and tool_call_info.tools_called:
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tool_calls.extend(
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FunctionCall(
|
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id=tc.id,
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name=tc.function.name,
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arguments=tc.function.arguments,
|
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)
|
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for tc in tool_call_info.tool_calls
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)
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content = tool_call_info.content
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if content and content.strip() == "":
|
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content = None
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else:
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# No tool calls.
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# For required/named tool choice (when falling back to auto
|
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# parsing), if content is empty or whitespace-only, return
|
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# empty list with None content.
|
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if (is_required_tool_choice or is_named_tool_choice) and (
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content is None
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or (isinstance(content, str) and not content.strip())
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):
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return [], None
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return None, content
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return tool_calls, content
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|
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def adjust_request(
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self, request: ChatCompletionRequest | ResponsesRequest
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) -> ChatCompletionRequest | ResponsesRequest:
|
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if self._reasoning_parser is not None:
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request = self._reasoning_parser.adjust_request(request)
|
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if self._tool_parser is not None:
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request = self._apply_structural_tag(request)
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if self._tool_parser is not None:
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request = self._tool_parser.adjust_request(request)
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return request
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|
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def _apply_structural_tag(
|
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self, request: ChatCompletionRequest | ResponsesRequest
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) -> ChatCompletionRequest | ResponsesRequest:
|
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if (
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self._tool_parser is None
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or self._tool_parser.structural_tag_model is None
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or not request.tools
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):
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return request
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|
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need_tool_calling = (
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request.tool_choice == "auto"
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or request.tool_choice == "required"
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or isinstance(
|
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request.tool_choice,
|
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(ChatCompletionNamedToolChoiceParam, ToolChoiceFunction),
|
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)
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)
|
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if not need_tool_calling:
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return request
|
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|
|
structure_tag = self._tool_parser.get_structural_tag(
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request,
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reasoning=False,
|
|
)
|
|
if structure_tag is None:
|
|
return request
|
|
|
|
structural_tag = json.dumps(structure_tag.model_dump())
|
|
request.structured_outputs = StructuredOutputsParams(
|
|
structural_tag=structural_tag,
|
|
)
|
|
if isinstance(request, ResponsesRequest):
|
|
request.text = None
|
|
else:
|
|
request.response_format = None
|
|
return 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:
|
|
if self._reasoning_parser is None:
|
|
return DeltaMessage(content=delta_text)
|
|
return self._reasoning_parser.extract_reasoning_streaming(
|
|
previous_text,
|
|
current_text,
|
|
delta_text,
|
|
previous_token_ids,
|
|
current_token_ids,
|
|
delta_token_ids,
|
|
)
|
|
|
|
def extract_tool_calls(
|
|
self,
|
|
model_output: str,
|
|
request: ChatCompletionRequest | ResponsesRequest,
|
|
) -> ExtractedToolCallInformation:
|
|
if self._tool_parser is None:
|
|
return ExtractedToolCallInformation(
|
|
tools_called=False, tool_calls=[], content=model_output
|
|
)
|
|
result = None
|
|
is_tool_called: bool | Exception = False
|
|
try:
|
|
result = self._tool_parser.extract_tool_calls(
|
|
model_output,
|
|
request=request, # type: ignore[arg-type]
|
|
)
|
|
is_tool_called = bool(result.tools_called)
|
|
except Exception as e:
|
|
is_tool_called = e
|
|
raise
|
|
finally:
|
|
record_tool_parser_invocation(
|
|
is_tool_called=is_tool_called,
|
|
is_streaming=False,
|
|
request=request,
|
|
)
|
|
return result
|
|
|
|
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 | ResponsesRequest,
|
|
) -> DeltaMessage | None:
|
|
if self._tool_parser is None:
|
|
return None
|
|
result = None
|
|
is_tool_called: bool | Exception = False
|
|
try:
|
|
result = self._tool_parser.extract_tool_calls_streaming(
|
|
previous_text,
|
|
current_text,
|
|
delta_text,
|
|
previous_token_ids,
|
|
current_token_ids,
|
|
delta_token_ids,
|
|
request, # type: ignore[arg-type]
|
|
)
|
|
is_tool_called = bool(result and result.tool_calls)
|
|
except Exception as e:
|
|
is_tool_called = e
|
|
raise
|
|
finally:
|
|
record_tool_parser_invocation(
|
|
is_tool_called=is_tool_called,
|
|
is_streaming=True,
|
|
request=request,
|
|
)
|
|
return result
|
|
|
|
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 | ResponsesRequest,
|
|
# The following parameters are used for "required" tool choice parsing and are
|
|
# tracked in StreamState for streaming parsing.
|
|
tool_call_idx: int | None = None,
|
|
tool_call_id_type: str = "random",
|
|
function_name_returned: bool = False,
|
|
) -> tuple[DeltaMessage | None, bool]:
|
|
assert self._tool_parser is not None
|
|
supports_required_and_named = self._tool_parser.supports_required_and_named
|
|
|
|
if request.tool_choice == "none":
|
|
if self._engine_based:
|
|
# Engine-backed parsers route content extraction through
|
|
# extract_tool_calls_streaming, so run the full pipeline
|
|
# and strip tool_calls after.
|
|
delta_message = self.extract_tool_calls_streaming(
|
|
previous_text,
|
|
current_text,
|
|
delta_text,
|
|
previous_token_ids,
|
|
current_token_ids,
|
|
delta_token_ids,
|
|
request, # type: ignore[arg-type]
|
|
)
|
|
if delta_message:
|
|
delta_message.tool_calls = []
|
|
return delta_message, False
|
|
return (DeltaMessage(content=delta_text) if delta_text else None), False
|
|
|
|
if (
|
|
supports_required_and_named
|
|
and request.tool_choice
|
|
and isinstance(
|
|
request.tool_choice,
|
|
(ToolChoiceFunction, ChatCompletionNamedToolChoiceParam),
|
|
)
|
|
):
|
|
delta_message, function_name_returned = extract_named_tool_call_streaming(
|
|
delta_text=delta_text,
|
|
function_name=self._get_function_name(request),
|
|
function_name_returned=function_name_returned,
|
|
tool_call_idx=tool_call_idx,
|
|
tool_call_id_type=tool_call_id_type,
|
|
tokenizer=self.model_tokenizer,
|
|
)
|
|
return delta_message, function_name_returned
|
|
|
|
if supports_required_and_named and request.tool_choice == "required":
|
|
delta_message, function_name_returned = (
|
|
extract_required_tool_call_streaming(
|
|
previous_text=previous_text,
|
|
current_text=current_text,
|
|
delta_text=delta_text,
|
|
function_name_returned=function_name_returned,
|
|
tool_call_idx=tool_call_idx,
|
|
tool_call_id_type=tool_call_id_type,
|
|
)
|
|
)
|
|
return delta_message, function_name_returned
|
|
return self.extract_tool_calls_streaming(
|
|
previous_text,
|
|
current_text,
|
|
delta_text,
|
|
previous_token_ids,
|
|
current_token_ids,
|
|
delta_token_ids,
|
|
request,
|
|
), False
|
|
|
|
def is_reasoning_end(self, input_ids: list[int]) -> bool:
|
|
if self._reasoning_parser is None:
|
|
return False
|
|
return self._reasoning_parser.is_reasoning_end(input_ids)
|
|
|
|
def is_reasoning_end_streaming(
|
|
self, input_ids: list[int], delta_ids: list[int]
|
|
) -> bool:
|
|
if self._reasoning_parser is None:
|
|
return False
|
|
return self._reasoning_parser.is_reasoning_end_streaming(input_ids, delta_ids)
|
|
|
|
def extract_content_ids(self, input_ids: list[int]) -> list[int]:
|
|
if self._reasoning_parser is None:
|
|
return input_ids
|
|
return self._reasoning_parser.extract_content_ids(input_ids)
|
|
|
|
def _in_reasoning_phase(self, state: StreamState) -> bool:
|
|
if self._reasoning_parser is None:
|
|
return False
|
|
return not state.reasoning_ended
|
|
|
|
def _in_tool_call_phase(self, state: StreamState) -> bool:
|
|
if self._tool_parser is None:
|
|
return False
|
|
return state.reasoning_ended
|
|
|
|
def _append_unstreamed_tool_args(
|
|
self,
|
|
delta_message: DeltaMessage | None,
|
|
) -> None:
|
|
"""Append parsed-but-unstreamed tool-call arguments to *delta_message*."""
|
|
if (
|
|
self._tool_parser is not None
|
|
and delta_message
|
|
and delta_message.tool_calls
|
|
and (last_tc := delta_message.tool_calls[-1]).function
|
|
):
|
|
last_tc.function.arguments = (
|
|
last_tc.function.arguments or ""
|
|
) + self._tool_parser.get_remaining_unstreamed_args()
|
|
|
|
def finalize_generation(
|
|
self,
|
|
delta_message: DeltaMessage | None,
|
|
request: ChatCompletionRequest | ResponsesRequest,
|
|
state: StreamState,
|
|
) -> DeltaMessage | None:
|
|
"""Finalize generation for cases where generation was incomplete.
|
|
For example, if streaming terminated before reasoning ended
|
|
"""
|
|
fallback_fn = getattr(
|
|
self._reasoning_parser, "get_streaming_fallback_content", None
|
|
)
|
|
if fallback_fn is not None and not state.reasoning_ended:
|
|
promoted = fallback_fn(state.previous_text, request)
|
|
if promoted:
|
|
if delta_message is None:
|
|
delta_message = DeltaMessage()
|
|
delta_message.content = (delta_message.content or "") + promoted
|
|
|
|
self._append_unstreamed_tool_args(delta_message)
|
|
return delta_message
|
|
|
|
def parse(
|
|
self,
|
|
model_output: str,
|
|
request: ChatCompletionRequest | ResponsesRequest,
|
|
enable_auto_tools: bool = False,
|
|
model_output_token_ids: Sequence[int] = (),
|
|
) -> tuple[str | None, str | None, list[FunctionCall] | None]:
|
|
self._initialize_history_tool_call_cnt(request)
|
|
reasoning, content = self.extract_reasoning(model_output, request)
|
|
tool_calls, content = self._extract_tool_calls(
|
|
content=content,
|
|
request=request,
|
|
enable_auto_tools=enable_auto_tools,
|
|
)
|
|
return reasoning, content, tool_calls
|
|
|
|
def parse_delta(
|
|
self,
|
|
delta_text: str,
|
|
delta_token_ids: list[int],
|
|
request: ChatCompletionRequest | ResponsesRequest,
|
|
prompt_token_ids: list[int] | None = None,
|
|
*,
|
|
finished: bool,
|
|
) -> DeltaMessage | None:
|
|
self._initialize_history_tool_call_cnt(request)
|
|
state = self._stream_state
|
|
|
|
if not state.prompt_reasoning_checked and prompt_token_ids is not None:
|
|
state.prompt_reasoning_checked = True
|
|
if self._reasoning_parser is None or self.is_reasoning_end(
|
|
prompt_token_ids
|
|
):
|
|
state.reasoning_ended = True
|
|
else:
|
|
# Reasoning is still open at the end of the prompt; let the
|
|
# reasoning parser adjust its initial parsing state so the
|
|
# first generated tokens are classified correctly.
|
|
self._reasoning_parser.adjust_initial_state_from_prompt(
|
|
prompt_token_ids
|
|
)
|
|
|
|
current_text, current_token_ids = state.advance(delta_text, delta_token_ids)
|
|
delta_message: DeltaMessage | None = None
|
|
reasoning_transitioned = False
|
|
|
|
# Reasoning extraction
|
|
if self._in_reasoning_phase(state):
|
|
delta_message = self.extract_reasoning_streaming(
|
|
previous_text=state.previous_text,
|
|
current_text=current_text,
|
|
delta_text=delta_text,
|
|
previous_token_ids=state.previous_token_ids,
|
|
current_token_ids=current_token_ids,
|
|
delta_token_ids=delta_token_ids,
|
|
)
|
|
reasoning_parser = self._reasoning_parser
|
|
if reasoning_parser is not None and reasoning_parser.engine_based_streaming:
|
|
should_transition = (
|
|
reasoning_parser.has_engine_confirmed_reasoning_end()
|
|
)
|
|
else:
|
|
should_transition = self.is_reasoning_end_streaming(
|
|
current_token_ids, delta_token_ids
|
|
)
|
|
if should_transition:
|
|
state.reasoning_ended = True
|
|
reasoning_transitioned = True
|
|
current_token_ids = self.extract_content_ids(delta_token_ids)
|
|
if self._engine_based:
|
|
flush_delta = reasoning_parser.finish_streaming() # type: ignore[union-attr, attr-defined]
|
|
current_text = (
|
|
(delta_message.content if delta_message else None) or ""
|
|
) + ((flush_delta.content if flush_delta else None) or "")
|
|
if delta_message and self._tool_parser is not None:
|
|
delta_message.content = None
|
|
else:
|
|
current_text = (
|
|
delta_message.content
|
|
if delta_message and delta_message.content
|
|
else ""
|
|
)
|
|
delta_text = current_text
|
|
|
|
# Tool call extraction
|
|
if self._in_tool_call_phase(state):
|
|
if not state.tool_call_text_started:
|
|
state.tool_call_text_started = True
|
|
state.previous_text = ""
|
|
state.previous_token_ids = []
|
|
delta_text = current_text
|
|
delta_token_ids = current_token_ids
|
|
|
|
reasoning_from_this_batch = (
|
|
delta_message.reasoning if delta_message else None
|
|
)
|
|
|
|
delta_message, state.function_name_returned = (
|
|
self._extract_tool_calls_streaming(
|
|
previous_text=state.previous_text,
|
|
current_text=current_text,
|
|
delta_text=delta_text,
|
|
previous_token_ids=state.previous_token_ids,
|
|
current_token_ids=current_token_ids,
|
|
delta_token_ids=delta_token_ids,
|
|
request=request, # type: ignore[arg-type]
|
|
tool_call_idx=state.history_tool_call_cnt,
|
|
tool_call_id_type=state.tool_call_id_type,
|
|
function_name_returned=state.function_name_returned,
|
|
)
|
|
)
|
|
|
|
if reasoning_from_this_batch:
|
|
if delta_message is None:
|
|
delta_message = DeltaMessage(reasoning=reasoning_from_this_batch)
|
|
elif not delta_message.reasoning:
|
|
delta_message.reasoning = reasoning_from_this_batch
|
|
|
|
if (
|
|
delta_message
|
|
and delta_message.tool_calls
|
|
and delta_message.tool_calls[0].id is not None
|
|
):
|
|
state.history_tool_call_cnt += 1
|
|
|
|
# No phase active: pass through as content.
|
|
# Skip when reasoning just ended in this delta — the engine already
|
|
# consumed the end-of-reasoning marker (e.g. </think>) and
|
|
# delta_text still contains the raw marker text.
|
|
if (
|
|
delta_message is None
|
|
and not reasoning_transitioned
|
|
and not self._in_reasoning_phase(state)
|
|
and not self._in_tool_call_phase(state)
|
|
):
|
|
delta_message = DeltaMessage(content=delta_text)
|
|
|
|
state.commit(current_text, current_token_ids)
|
|
|
|
if finished:
|
|
delta_message = self.finalize_generation(delta_message, request, state)
|
|
delta_message = self._flush_engine_parsers(delta_message)
|
|
|
|
# Suppress reasoning deltas if not requested
|
|
if delta_message and not request.include_reasoning:
|
|
delta_message.reasoning = None
|
|
|
|
# If only reasoning was in the message (no content, no tool_calls)
|
|
# skip emitting entirely
|
|
if not delta_message.content and not delta_message.tool_calls:
|
|
delta_message = None
|
|
|
|
return delta_message
|
|
|
|
def _flush_engine_parsers(
|
|
self, delta_message: DeltaMessage | None
|
|
) -> DeltaMessage | None:
|
|
"""Flush buffered state from engine-based parsers at stream end."""
|
|
reasoning_ended = self._stream_state.reasoning_ended
|
|
for parser in (self._reasoning_parser, self._tool_parser):
|
|
if not getattr(parser, "engine_based_streaming", False):
|
|
continue
|
|
# When reasoning has ended and we transitioned to the tool
|
|
# phase, the reasoning parser's engine may still have buffered
|
|
# characters from tool-call markup it saw with
|
|
# skip_tool_parsing=True. Flushing that would leak spurious
|
|
# content (e.g. a stray '"'), so skip it.
|
|
if parser is self._reasoning_parser and reasoning_ended:
|
|
continue
|
|
finish = getattr(parser, "finish_streaming", None)
|
|
if finish is None:
|
|
continue
|
|
flush_delta = finish()
|
|
if flush_delta is None:
|
|
continue
|
|
if delta_message is None:
|
|
delta_message = flush_delta
|
|
else:
|
|
if flush_delta.content:
|
|
delta_message.content = (
|
|
delta_message.content or ""
|
|
) + flush_delta.content
|
|
if flush_delta.reasoning:
|
|
delta_message.reasoning = (
|
|
delta_message.reasoning or ""
|
|
) + flush_delta.reasoning
|
|
if flush_delta.tool_calls:
|
|
delta_message.tool_calls = (
|
|
delta_message.tool_calls or []
|
|
) + flush_delta.tool_calls
|
|
return delta_message
|