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enginex-biren-vllm/vllm/reasoning/gptoss_reasoning_parser.py
2026-03-10 13:31:25 +08:00

88 lines
3.4 KiB
Python

# SPDX-License-Identifier: Apache-2.0
# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
from collections.abc import Sequence
from typing import Optional, Union
from transformers import PreTrainedTokenizerBase
from vllm.entrypoints.harmony_utils import parse_chat_output
from vllm.entrypoints.openai.protocol import (ChatCompletionRequest,
DeltaMessage)
from vllm.logger import init_logger
from vllm.reasoning import ReasoningParser, ReasoningParserManager
logger = init_logger(__name__)
@ReasoningParserManager.register_module("openai_gptoss")
class GptOssReasoningParser(ReasoningParser):
"""
Reasoning parser for GptOss model.
The GptOss model uses harmony to extract reasoning content and this parser
is only used for detecting the end of the reasoning content.
"""
def __init__(self, tokenizer: PreTrainedTokenizerBase, *args, **kwargs):
super().__init__(tokenizer, *args, **kwargs)
self.reasoning_end_token_ids = self.model_tokenizer.encode(
"<|start|>assistant<|channel|>final<|message|>")
def is_reasoning_end(self, input_ids: list[int]) -> bool:
end_token_ids = self.reasoning_end_token_ids
assert len(end_token_ids) > 0, "reasoning_end_token_ids is empty"
# Check if the end sequence is present in the input_ids.
# We search from the end of input_ids to find the last match.
for i in range(len(input_ids) - len(end_token_ids), -1, -1):
if input_ids[i:i + len(end_token_ids)] == end_token_ids:
return True
return False
def extract_content_ids(self, input_ids: list[int]) -> list[int]:
_, content, _ = parse_chat_output(input_ids)
if content is None:
return []
return self.model_tokenizer.encode(content)
def extract_reasoning_content_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],
) -> Union[DeltaMessage, None]:
prev_reasoning, prev_content, _ = parse_chat_output(
list(previous_token_ids))
cur_reasoning, cur_content, _ = parse_chat_output(
list(current_token_ids))
reasoning_delta = None
content_delta = None
if cur_reasoning is not None:
prev_r = prev_reasoning or ""
if cur_reasoning.startswith(prev_r):
reasoning_delta = cur_reasoning[len(prev_r):] or None
else:
reasoning_delta = cur_reasoning
if cur_content is not None:
prev_c = prev_content or ""
if cur_content.startswith(prev_c):
content_delta = cur_content[len(prev_c):] or None
else:
content_delta = cur_content
if reasoning_delta is None and content_delta is None:
return None
return DeltaMessage(reasoning_content=reasoning_delta,
content=content_delta)
def extract_reasoning_content(
self,
model_output: str,
request: ChatCompletionRequest,
) -> tuple[Optional[str], Optional[str]]:
raise NotImplementedError(
"gpt-oss has a special branch for parsing reasoning in non-streaming mode. This method shouldn't be used." # noqa: E501
)