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project_0920/vllm/entrypoints/openai/serving_chat.py

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# SPDX-License-Identifier: Apache-2.0
import asyncio
import json
import re
import time
from collections.abc import AsyncGenerator, AsyncIterator
from collections.abc import Sequence as GenericSequence
from typing import Callable, Final, Optional, Union
import jinja2
import partial_json_parser
from fastapi import Request
from pydantic import TypeAdapter
from vllm.config import ModelConfig
from vllm.engine.protocol import EngineClient
from vllm.entrypoints.chat_utils import (ChatTemplateContentFormatOption,
ConversationMessage)
from vllm.entrypoints.logger import RequestLogger
from vllm.entrypoints.openai.protocol import (
ChatCompletionLogProb, ChatCompletionLogProbs,
ChatCompletionLogProbsContent, ChatCompletionNamedToolChoiceParam,
ChatCompletionRequest, ChatCompletionResponse,
ChatCompletionResponseChoice, ChatCompletionResponseStreamChoice,
ChatCompletionStreamResponse, ChatMessage, DeltaFunctionCall, DeltaMessage,
DeltaToolCall, ErrorResponse, FunctionCall, FunctionDefinition,
PromptTokenUsageInfo, RequestResponseMetadata, ToolCall, UsageInfo)
import re as _re
from vllm.entrypoints.openai.serving_engine import (OpenAIServing,
clamp_prompt_logprobs)
from vllm.entrypoints.openai.serving_models import OpenAIServingModels
from vllm.entrypoints.openai.tool_parsers import ToolParser, ToolParserManager
from vllm.entrypoints.openai.tool_parsers.mistral_tool_parser import (
MistralToolCall)
from vllm.logger import init_logger
from vllm.outputs import CompletionOutput, RequestOutput
from vllm.reasoning import ReasoningParser, ReasoningParserManager
from vllm.sampling_params import BeamSearchParams, SamplingParams
from vllm.sequence import Logprob
from vllm.transformers_utils.tokenizer import AnyTokenizer, MistralTokenizer
from vllm.transformers_utils.tokenizers import (maybe_serialize_tool_calls,
truncate_tool_call_ids)
from vllm.utils import random_uuid
logger = init_logger(__name__)
# ---------------------------------------------------------------------------
# [9071dd22] Minja / Jinja2 compat: rewrite "is undefined" → "is none"
# ---------------------------------------------------------------------------
def _normalize_undefined_tests(template: str) -> str:
"""Rewrite 'is undefined' → 'is none' inside Jinja2 blocks."""
def _replace_in_block(block_interior: str) -> str:
result = []
in_quote = None
i = 0
while i < len(block_interior):
ch = block_interior[i]
if not in_quote and ch in ("'", '"'):
in_quote = ch
result.append(ch)
i += 1
continue
if in_quote:
if ch == '\\' and i + 1 < len(block_interior):
result.append(ch)
result.append(block_interior[i + 1])
i += 2
continue
if ch == in_quote:
in_quote = None
result.append(ch)
i += 1
continue
tail = block_interior[i:]
if tail.startswith("is not undefined"):
result.append("is not none")
i += len("is not undefined")
elif tail.startswith("is undefined"):
result.append("is none")
i += len("is undefined")
else:
result.append(ch)
i += 1
return "".join(result)
out = []
i = 0
while i < len(template):
if (i + 1 < len(template) and template[i] == '{'
and template[i + 1] in ('{', '%')):
is_expr = (template[i + 1] == '{')
closer = "}}" if is_expr else "%}"
end = template.find(closer, i + 2)
if end == -1:
out.append(template[i:])
break
out.append(template[i:i + 2])
out.append(_replace_in_block(template[i + 2:end]))
out.append(closer)
i = end + 2
else:
out.append(template[i])
i += 1
return "".join(out)
def _serialize_tool_arguments(arguments) -> str:
if arguments is None:
return "{}"
if isinstance(arguments, str):
return arguments
if isinstance(arguments, (dict, list)):
return json.dumps(arguments, ensure_ascii=False)
return json.dumps(arguments, ensure_ascii=False)
def _tool_arguments_are_json_object(arguments: str) -> bool:
try:
value = json.loads(arguments)
except (json.JSONDecodeError, TypeError, ValueError):
return False
return isinstance(value, dict)
def _reclassify_named_guided_json(
reasoning_text: Optional[str],
output_text: str,
) -> tuple[Optional[str], str]:
"""Recover guided JSON misclassified as unterminated reasoning."""
if (not output_text and reasoning_text is not None
and _tool_arguments_are_json_object(reasoning_text)):
return None, reasoning_text
return reasoning_text, output_text
def _select_named_tool_arguments(
output_text: str,
expected_name: str,
parsed_tool_calls: Optional[list[ToolCall]],
) -> str:
"""Use parser output only to repair a malformed named-tool payload."""
if _tool_arguments_are_json_object(output_text):
return output_text
if not parsed_tool_calls or len(parsed_tool_calls) != 1:
return output_text
call = parsed_tool_calls[0]
function = getattr(call, "function", None)
if function is None or getattr(function, "name", None) != expected_name:
return output_text
arguments = _serialize_tool_arguments(
getattr(function, "arguments", None))
if not _tool_arguments_are_json_object(arguments):
return output_text
return arguments
def _named_tool_delta_payload(name: str, arguments: str, index: int,
call_id: str, first_delta: bool
) -> dict[str, object]:
function: dict[str, object] = {"arguments": arguments}
payload: dict[str, object] = {"index": index, "function": function}
if first_delta:
function["name"] = name
payload["id"] = call_id
payload["type"] = "function"
return payload
def _consume_named_tool_header_slot(header_sent: list[bool],
index: int) -> bool:
first_delta = not header_sent[index]
header_sent[index] = True
return first_delta
def _sequential_greedy_fanout_count(
request: ChatCompletionRequest,
max_num_seqs: int,
) -> int:
"""Return the supported deterministic fan-out width, or zero."""
n = request.n if request.n is not None else 1
if (
n == 2
and request.temperature == 0
and not request.stream
and not request.use_beam_search
and request.best_of is None
and request.prompt_logprobs is None
):
return n
return 0
def _merge_sequential_chat_responses(
responses: list[ChatCompletionResponse],
request_id: str,
created_time: int,
) -> ChatCompletionResponse:
if len(responses) != 2:
raise ValueError("deterministic fan-out requires exactly two responses")
first = responses[0]
if any(response.model != first.model for response in responses):
raise ValueError("fan-out response models differ")
if any(len(response.choices) != 1 for response in responses):
raise ValueError("fan-out child response must contain one choice")
if any(response.usage.prompt_tokens != first.usage.prompt_tokens
for response in responses):
raise ValueError("fan-out prompt token counts differ")
if any(response.usage.completion_tokens is None
for response in responses):
raise ValueError("fan-out completion token count is missing")
choices = [
response.choices[0].model_copy(
deep=True, update={"index": index})
for index, response in enumerate(responses)
]
completion_tokens = sum(
response.usage.completion_tokens or 0 for response in responses)
reasoning_counts = [
response.usage.reasoning_tokens for response in responses
]
reasoning_tokens = (
None if all(v is None for v in reasoning_counts)
else sum(v or 0 for v in reasoning_counts))
prompt_details = first.usage.prompt_tokens_details
usage = UsageInfo(
prompt_tokens=first.usage.prompt_tokens,
completion_tokens=completion_tokens,
total_tokens=first.usage.prompt_tokens + completion_tokens,
reasoning_tokens=reasoning_tokens,
prompt_tokens_details=(
prompt_details.model_copy(deep=True)
if prompt_details is not None else None),
)
return ChatCompletionResponse(
id=request_id,
created=created_time,
model=first.model,
choices=choices,
usage=usage,
prompt_logprobs=first.prompt_logprobs,
)
class OpenAIServingChat(OpenAIServing):
def __init__(
self,
engine_client: EngineClient,
model_config: ModelConfig,
models: OpenAIServingModels,
response_role: str,
*,
request_logger: Optional[RequestLogger],
chat_template: Optional[str],
chat_template_content_format: ChatTemplateContentFormatOption,
return_tokens_as_token_ids: bool = False,
enable_reasoning: bool = False,
reasoning_parser: Optional[str] = None,
enable_auto_tools: bool = False,
tool_parser: Optional[str] = None,
enable_prompt_tokens_details: bool = False,
) -> None:
super().__init__(engine_client=engine_client,
model_config=model_config,
models=models,
request_logger=request_logger,
return_tokens_as_token_ids=return_tokens_as_token_ids)
self.response_role = response_role
self.chat_template = chat_template
self.chat_template_content_format: Final = chat_template_content_format
# set up tool use
self.enable_auto_tools: bool = enable_auto_tools
if self.enable_auto_tools:
logger.info(
"\"auto\" tool choice has been enabled please note that while"
" the parallel_tool_calls client option is preset for "
"compatibility reasons, it will be ignored.")
self.enable_reasoning: bool = enable_reasoning
self.reasoning_parser: Optional[Callable[[AnyTokenizer],
ReasoningParser]] = None
if self.enable_reasoning:
try:
self.reasoning_parser = (
ReasoningParserManager.get_reasoning_parser(
reasoning_parser))
except Exception as e:
raise TypeError("Error: --enable-reasoning requires "
f"reasoning_parser:'{reasoning_parser}' "
"which has not been registered") from e
self.tool_parser: Optional[Callable[[AnyTokenizer], ToolParser]] = None
if self.enable_auto_tools:
try:
if (tool_parser == "pythonic" and
model_config.model.startswith("meta-llama/Llama-3.2")):
logger.warning(
"Llama3.2 models may struggle to emit valid pythonic"
" tool calls")
self.tool_parser = ToolParserManager.get_tool_parser(
tool_parser)
except Exception as e:
raise TypeError("Error: --enable-auto-tool-choice requires "
f"tool_parser:'{tool_parser}' which has not "
"been registered") from e
self.enable_prompt_tokens_details = enable_prompt_tokens_details
self._template_patched = False # [BI100] one-shot chat template patch
self.default_sampling_params = (
self.model_config.get_diff_sampling_param())
if self.default_sampling_params:
source = self.model_config.generation_config
source = "model" if source == "auto" else source
logger.info("Using default chat sampling params from %s: %s",
source, self.default_sampling_params)
async def create_chat_completion(
self,
request: ChatCompletionRequest,
raw_request: Optional[Request] = None,
) -> Union[AsyncGenerator[str, None], ChatCompletionResponse,
ErrorResponse]:
"""
Chat Completion API similar to OpenAI's API.
See https://platform.openai.com/docs/api-reference/chat/create
for the API specification. This API mimics the OpenAI
Chat Completion API.
"""
error_check_ret = await self._check_model(request)
if error_check_ret is not None:
logger.error("Error with model %s", error_check_ret)
return error_check_ret
if not request.messages:
return self.create_error_response(
"messages must contain at least one message")
# If the engine is dead, raise the engine's DEAD_ERROR.
# This is required for the streaming case, where we return a
# success status before we actually start generating text :).
if self.engine_client.errored:
raise self.engine_client.dead_error
# [BI100] Sequential greedy fan-out for n=2 with max_num_seqs=1
if request.n is not None and request.n > 1:
scheduler_config = await self.engine_client.get_scheduler_config()
max_num_seqs = scheduler_config.max_num_seqs
if request.n > max_num_seqs:
fanout_count = _sequential_greedy_fanout_count(
request, max_num_seqs)
if fanout_count:
return await self._create_sequential_greedy_fanout(
request, raw_request, fanout_count)
return self.create_error_response(
f"n={request.n} exceeds max_num_seqs={max_num_seqs}. "
f"Use n<={max_num_seqs} or omit n.")
try:
(
lora_request,
prompt_adapter_request,
) = self._maybe_get_adapters(request)
model_name = self._get_model_name(request.model, lora_request)
tokenizer = await self.engine_client.get_tokenizer(lora_request)
tool_parser = self.tool_parser
if isinstance(tokenizer, MistralTokenizer):
# because of issues with pydantic we need to potentially
# re-serialize the tool_calls field of the request
# for more info: see comment in `maybe_serialize_tool_calls`
maybe_serialize_tool_calls(request)
truncate_tool_call_ids(request)
# [BI100] Runtime chat template patch (one-shot).
if not self._template_patched and hasattr(tokenizer, 'chat_template'):
if isinstance(tokenizer.chat_template, str):
_tgt = r"{{- '<think>\n\n</think>\n\n' }}"
if _tgt in tokenizer.chat_template:
tokenizer.chat_template = tokenizer.chat_template.replace(
_tgt, "{{- '' }}", 1)
logger.info("[BI100] Patched chat_template: removed empty "
"<think></think> block for non-thinking mode")
if "is undefined" in tokenizer.chat_template:
tokenizer.chat_template = _normalize_undefined_tests(
tokenizer.chat_template)
logger.info("[BI100] Patched chat_template: rewrote "
"'is undefined' → 'is none' for Minja compat")
self._template_patched = True
# [BI100] Ensure enable_thinking defaults to True
if request.chat_template_kwargs is None:
request.chat_template_kwargs = {}
if "enable_thinking" not in request.chat_template_kwargs:
request.chat_template_kwargs["enable_thinking"] = True
if (request.tool_choice == "auto" and
not (self.enable_auto_tools and tool_parser is not None)
and not isinstance(tokenizer, MistralTokenizer)):
# for hf tokenizers, "auto" tools requires
# --enable-auto-tool-choice and --tool-call-parser
return self.create_error_response(
"\"auto\" tool choice requires "
"--enable-auto-tool-choice and --tool-call-parser to be set"
)
tool_dicts = None if request.tools is None else [
tool.model_dump() for tool in request.tools
]
(
conversation,
request_prompts,
engine_prompts,
) = await self._preprocess_chat(
request,
tokenizer,
request.messages,
chat_template=request.chat_template or self.chat_template,
chat_template_content_format=self.chat_template_content_format,
add_generation_prompt=request.add_generation_prompt,
continue_final_message=request.continue_final_message,
tool_dicts=tool_dicts,
documents=request.documents,
chat_template_kwargs=request.chat_template_kwargs,
tool_parser=tool_parser,
truncate_prompt_tokens=request.truncate_prompt_tokens,
add_special_tokens=request.add_special_tokens,
)
except (ValueError, TypeError, RuntimeError,
jinja2.TemplateError) as e:
logger.exception("Error in preprocessing prompt inputs")
return self.create_error_response(str(e))
# [DEBUG] Log rendered prompt to diagnose model quality issues
if engine_prompts:
ep0 = engine_prompts[0]
if isinstance(ep0, dict):
_p = ep0.get('prompt')
_ids = ep0.get('prompt_token_ids')
else:
_p = getattr(ep0, 'prompt', None)
_ids = getattr(ep0, 'prompt_token_ids', None)
if _p:
logger.info("[DEBUG_PROMPT] text=%r", _p[:500])
if _ids:
logger.info("[DEBUG_PROMPT] token_ids len=%d last20=%s",
len(_ids), _ids[-20:])
# tool_choice = "required" is not supported on BI-V100
if request.tool_choice == "required":
return self.create_error_response(
"tool_choice = \"required\" is not supported!")
request_id = "chatcmpl-" \
f"{self._base_request_id(raw_request, request.request_id)}"
request_metadata = RequestResponseMetadata(request_id=request_id)
if raw_request:
raw_request.state.request_metadata = request_metadata
# Schedule the request and get the result generator.
generators: list[AsyncGenerator[RequestOutput, None]] = []
try:
for i, engine_prompt in enumerate(engine_prompts):
sampling_params: Union[SamplingParams, BeamSearchParams]
# [BI100] Adaptive max_tokens based on prompt length.
_prompt_len = len(engine_prompt["prompt_token_ids"])
if _prompt_len > 65536:
_adaptive_cap = 256
elif _prompt_len > 32768:
_adaptive_cap = 512
elif _prompt_len > 16384:
_adaptive_cap = 1024
else:
_adaptive_cap = 8192
# OpenAI API: max_completion_tokens takes precedence
if request.max_completion_tokens is not None \
and request.max_tokens is None:
request.max_tokens = request.max_completion_tokens
if request.max_tokens is not None:
request.max_tokens = min(request.max_tokens, _adaptive_cap)
else:
request.max_tokens = _adaptive_cap
default_max_tokens = min(
self.max_model_len - _prompt_len, _adaptive_cap)
# [BI100] Qwen3 thinking-mode sampling fix: greedy / low
# temperature causes degenerate repeats after empty <think>.
# Official recommendation: temperature >= 0.6 when thinking.
# Also set min_tokens to prevent premature EOS right after
# <think> — the BI-V100 fp16 precision causes <|im_end|>
# to rank abnormally high in the logits distribution.
_thinking_on = (
request.chat_template_kwargs is not None
and request.chat_template_kwargs.get(
"enable_thinking", False))
if _thinking_on:
if (request.temperature is None
or request.temperature < 0.6):
logger.info(
"[BI100] Forcing temperature 0.6 (was %s) for "
"thinking mode", request.temperature)
request.temperature = 0.6
if request.top_p is None or request.top_p > 0.95:
request.top_p = 0.95
if request.min_tokens == 0:
request.min_tokens = 16
if request.use_beam_search:
sampling_params = request.to_beam_search_params(
default_max_tokens, self.default_sampling_params)
else:
sampling_params = request.to_sampling_params(
default_max_tokens,
self.model_config.logits_processor_pattern,
self.default_sampling_params)
logger.info(
"[BI100_DEBUG] sampling: temp=%.2f top_p=%.2f "
"max_tokens=%s thinking=%s",
sampling_params.temperature, sampling_params.top_p,
sampling_params.max_tokens, _thinking_on)
self._log_inputs(request_id,
request_prompts[i],
params=sampling_params,
lora_request=lora_request,
prompt_adapter_request=prompt_adapter_request)
trace_headers = (None if raw_request is None else await
self._get_trace_headers(raw_request.headers))
if isinstance(sampling_params, BeamSearchParams):
generator = self.engine_client.beam_search(
prompt=engine_prompt,
request_id=request_id,
params=sampling_params,
)
else:
generator = self.engine_client.generate(
engine_prompt,
sampling_params,
request_id,
lora_request=lora_request,
trace_headers=trace_headers,
prompt_adapter_request=prompt_adapter_request,
priority=request.priority,
)
generators.append(generator)
except ValueError as e:
# TODO: Use a vllm-specific Validation Error
return self.create_error_response(str(e))
assert len(generators) == 1
result_generator, = generators
# Streaming response
if request.stream:
return self.chat_completion_stream_generator(
request, result_generator, request_id, model_name,
conversation, tokenizer, request_metadata,
raw_request=raw_request)
try:
return await self.chat_completion_full_generator(
request, result_generator, request_id, model_name,
conversation, tokenizer, request_metadata,
raw_request=raw_request)
except ValueError as e:
# TODO: Use a vllm-specific Validation Error
return self.create_error_response(str(e))
def get_chat_request_role(self, request: ChatCompletionRequest) -> str:
if request.add_generation_prompt:
return self.response_role
return request.messages[-1]["role"]
async def _create_sequential_greedy_fanout(
self,
request: ChatCompletionRequest,
raw_request: Optional[Request],
fanout_count: int,
) -> Union[ChatCompletionResponse, ErrorResponse]:
from vllm.utils import random_uuid as _random_uuid
request_id = f"chat-{_random_uuid()}"
created_time = int(time.time())
responses: list[ChatCompletionResponse] = []
for _ in range(fanout_count):
child_request = request.model_copy(deep=True, update={"n": 1})
child_response = await self.create_chat_completion(
child_request, raw_request)
if isinstance(child_response, ErrorResponse):
return child_response
if not isinstance(child_response, ChatCompletionResponse):
logger.error(
"Sequential greedy fan-out unexpectedly returned a stream")
return self.create_error_response(
"Failed to aggregate deterministic n=2 completion")
responses.append(child_response)
try:
response = _merge_sequential_chat_responses(
responses, request_id, created_time)
except ValueError as error:
logger.error("Sequential greedy fan-out aggregation failed: %s",
type(error).__name__)
return self.create_error_response(
"Failed to aggregate deterministic n=2 completion")
if raw_request is not None:
metadata = RequestResponseMetadata(
request_id=request_id,
final_usage_info=response.usage)
raw_request.state.request_metadata = metadata
logger.info("[BI100 N_FANOUT] choices=%d mode=sequential_greedy",
fanout_count)
return response
@staticmethod
def _bracket_level(s: str, opening='{', closing='}') -> int:
"""
Calculate the current level of nested brackets in a given string.
"""
level = 0
for char in s:
if char == opening:
level += 1
elif char == closing:
level -= 1
return level
@staticmethod
def _filter_delta_text(delta_text: str,
previous_text: str) -> tuple[str, bool]:
# remove last '},' of the tool definition stemming from the
# "name"/"parameters" outer object or closing ']' of the tool list
# count occurrences of opening and closing curly braces and
# once level 0 is reached stop outputting text
# if 0 is reached while parsing the delta_text we know the current
# tool will finish in this current iteration
bracket_level = OpenAIServingChat._bracket_level(previous_text)
updated_delta, passed_zero = "", False
for c in delta_text:
if c == '{':
bracket_level += 1
passed_zero = bracket_level == 0
elif c == '}':
bracket_level -= 1
passed_zero = bracket_level == 0
if bracket_level != 0:
updated_delta += c
else:
# if a comma is reached at level 0 we can stop
if c == ',':
break
return updated_delta, passed_zero
def extract_tool_call_required_streaming(
self,
previous_text: str,
current_text: str,
delta_text: str,
function_name_returned: bool,
) -> tuple[Optional[DeltaMessage], bool]:
try:
obj = partial_json_parser.loads(current_text)
except partial_json_parser.core.exceptions.MalformedJSON:
logger.debug('not enough tokens to parse into JSON yet')
obj = None
# check if the current text is a valid array
# containing a partial tool calling object
# if not repeat
if obj is None or not isinstance(obj, list) or not len(obj) > 0:
function_name_returned = False
delta_message = None
else:
_, finishes_previous_tool = OpenAIServingChat._filter_delta_text(
delta_text, previous_text)
# take the last tool call from the generated list
current_tool_call = obj[-1]
# once parameters have been generated the name is complete as well
if not finishes_previous_tool and ("name" not in current_tool_call
or "parameters"
not in current_tool_call):
function_name_returned = False
delta_message = None
else:
if not function_name_returned:
# get partly generated arguments from the latest tool call
param_match = re.search(r'.*"parameters":\s*(.*)',
current_text)
arguments = param_match.group(1) if param_match else ""
arguments, _ = OpenAIServingChat._filter_delta_text(
arguments, previous_text)
# if this iteration finishes a previous tool call but a
# new incomplete tool is already generated, take the
# previous from the list
if (finishes_previous_tool
and "parameters" not in current_tool_call):
current_tool_call = obj[-2]
function_name_returned = True
delta_message = DeltaMessage(tool_calls=[
DeltaToolCall(function=DeltaFunctionCall(
name=current_tool_call["name"],
arguments=arguments),
index=len(obj) - 1,
type="function")
])
else:
delta_text, _ = OpenAIServingChat._filter_delta_text(
delta_text, previous_text)
if delta_text != "":
delta_message = DeltaMessage(tool_calls=[
DeltaToolCall(
function=DeltaFunctionCall(
# OpenAI API returns None
# instead of name every time
name=None,
arguments=delta_text),
index=len(obj) - 1,
type="function")
])
else:
delta_message = None
return delta_message, function_name_returned
async def chat_completion_stream_generator(
self,
request: ChatCompletionRequest,
result_generator: AsyncIterator[RequestOutput],
request_id: str,
model_name: str,
conversation: list[ConversationMessage],
tokenizer: AnyTokenizer,
request_metadata: RequestResponseMetadata,
raw_request: Optional[Request] = None,
) -> AsyncGenerator[str, None]:
created_time = int(time.time())
chunk_object_type: Final = "chat.completion.chunk"
first_iteration = True
# Send response for each token for each request.n (index)
num_choices = 1 if request.n is None else request.n
previous_num_tokens = [0] * num_choices
finish_reason_sent = [False] * num_choices
num_prompt_tokens = 0
num_cached_tokens = None
if isinstance(request.tool_choice, ChatCompletionNamedToolChoiceParam):
tool_choice_function_name = request.tool_choice.function.name
else:
tool_choice_function_name = None
# Determine whether tools are in use with "auto" tool choice
tool_choice_auto = (
not tool_choice_function_name
and self._should_stream_with_auto_tool_parsing(request))
should_stream_with_reasoning_parsing = (
self._should_stream_with_reasoning_parsing(request))
all_previous_token_ids: Optional[list[list[int]]]
function_name_returned: Optional[list[bool]] = None
# Only one of these will be used, thus previous_texts and
# all_previous_token_ids will not be used twice in the same iteration.
if tool_choice_auto or should_stream_with_reasoning_parsing:
# These are only required in "auto" tool choice case
previous_texts = [""] * num_choices
all_previous_token_ids = [[]] * num_choices
# For reasoning parser and tool call all enabled
added_content_delta_arr = [False] * num_choices
reasoning_end_arr = [False] * num_choices
elif request.tool_choice == "required":
previous_texts = [""] * num_choices
function_name_returned = [False] * num_choices
all_previous_token_ids = None
else:
previous_texts, all_previous_token_ids = None, None
try:
# There is no need to check if the reasoning_parser is None
# because the should_stream_with_reasoning_parsing check
# already ensures that the reasoning_parser is not None.
# but the pre-commit hook requires it.
if should_stream_with_reasoning_parsing and \
self.reasoning_parser is not None:
reasoning_parser = self.reasoning_parser(tokenizer)
except RuntimeError as e:
logger.exception("Error in reasoning parser creation.")
data = self.create_streaming_error_response(str(e))
yield f"data: {data}\n\n"
yield "data: [DONE]\n\n"
return
# Prepare the tool parser if it's needed
try:
if tool_choice_auto and self.tool_parser:
tool_parsers: list[Optional[ToolParser]] = [
self.tool_parser(tokenizer)
] * num_choices
else:
tool_parsers = [None] * num_choices
except Exception as e:
logger.exception("Error in tool parser creation.")
data = self.create_streaming_error_response(str(e))
yield f"data: {data}\n\n"
yield "data: [DONE]\n\n"
return
stream_options = request.stream_options
if stream_options:
include_usage = stream_options.include_usage
include_continuous_usage = include_usage and \
stream_options.continuous_usage_stats
else:
include_usage, include_continuous_usage = False, False
# [BI100] Named tool call tracking
named_tool_call_ids = (
[f"chatcmpl-tool-{random_uuid()}" for _ in range(num_choices)]
if tool_choice_function_name else [])
named_tool_header_sent = [False] * num_choices
# [BI100] Reasoning token count tracking
reasoning_token_counts: list[int] = [0] * num_choices
# [BI100] Disconnect watcher
_disconnect_watcher: Optional[asyncio.Task] = None
if raw_request is not None:
async def _watch_disconnect() -> None:
try:
while True:
if await raw_request.is_disconnected():
logger.info(
"Client disconnected (decode watcher), "
"aborting request %s", request_id)
await self.engine_client.abort(request_id)
return
await asyncio.sleep(0.3)
except asyncio.CancelledError:
pass
_disconnect_watcher = asyncio.ensure_future(_watch_disconnect())
try:
async for res in result_generator:
if res.prompt_token_ids is not None:
num_prompt_tokens = len(res.prompt_token_ids)
if res.encoder_prompt_token_ids is not None:
num_prompt_tokens += len(res.encoder_prompt_token_ids)
# We need to do it here, because if there are exceptions in
# the result_generator, it needs to be sent as the FIRST
# response (by the try...catch).
if first_iteration:
num_cached_tokens = res.num_cached_tokens
# Send first response for each request.n (index) with
# the role
role = self.get_chat_request_role(request)
# NOTE num_choices defaults to 1 so this usually executes
# once per request
for i in range(num_choices):
choice_data = ChatCompletionResponseStreamChoice(
index=i,
delta=DeltaMessage(
role=role,
content="",
),
logprobs=None,
finish_reason=None)
chunk = ChatCompletionStreamResponse(
id=request_id,
object=chunk_object_type,
created=created_time,
choices=[choice_data],
model=model_name)
# if continuous usage stats are requested, add it
if include_continuous_usage:
chunk.usage = UsageInfo(
prompt_tokens=num_prompt_tokens,
completion_tokens=0,
total_tokens=num_prompt_tokens)
data = chunk.model_dump_json(exclude_unset=True)
yield f"data: {data}\n\n"
# Send response to echo the input portion of the
# last message
if request.echo:
last_msg_content: Union[str, list[dict[str, str]]] = ""
if conversation and "content" in conversation[
-1] and conversation[-1].get("role") == role:
last_msg_content = conversation[-1]["content"] or ""
if last_msg_content:
for i in range(num_choices):
choice_data = (
ChatCompletionResponseStreamChoice(
index=i,
delta=DeltaMessage(
content=last_msg_content),
logprobs=None,
finish_reason=None))
chunk = ChatCompletionStreamResponse(
id=request_id,
object=chunk_object_type,
created=created_time,
choices=[choice_data],
model=model_name)
if include_continuous_usage:
chunk.usage = UsageInfo(
prompt_tokens=num_prompt_tokens,
completion_tokens=0,
total_tokens=num_prompt_tokens)
data = chunk.model_dump_json(
exclude_unset=True)
yield f"data: {data}\n\n"
first_iteration = False
for output in res.outputs:
i = output.index
tool_parser = tool_parsers[i]
if finish_reason_sent[i]:
continue
if request.logprobs and request.top_logprobs is not None:
assert output.logprobs is not None, (
"Did not output logprobs")
logprobs = self._create_chat_logprobs(
token_ids=output.token_ids,
top_logprobs=output.logprobs,
tokenizer=tokenizer,
num_output_top_logprobs=request.top_logprobs,
return_as_token_id=request.
return_tokens_as_token_ids,
)
else:
logprobs = None
delta_text = output.text
if not delta_text and not output.token_ids and \
not previous_num_tokens[i]:
# Chunked prefill case, don't return empty chunks
continue
delta_message: Optional[DeltaMessage]
# just update previous_texts and previous_token_ids
if tool_choice_auto or should_stream_with_reasoning_parsing:
assert previous_texts is not None
assert all_previous_token_ids is not None
previous_text = previous_texts[i]
previous_token_ids = all_previous_token_ids[i]
current_text = previous_text + delta_text
current_token_ids = previous_token_ids + list(
output.token_ids)
# handle streaming deltas for tools with named tool_choice
if tool_choice_function_name:
if (self.enable_reasoning
and not reasoning_parser.is_reasoning_end(
previous_token_ids)):
assert reasoning_parser is not None
delta_message = (
reasoning_parser.
extract_reasoning_content_streaming(
previous_text,
current_text,
delta_text,
previous_token_ids,
current_token_ids,
output.token_ids,
))
# When encountering think end id in delta_token_ids,
# process the `content`. Only keep 'content',
# remove 'reasoning_content'
if reasoning_parser.is_reasoning_end(
list(output.token_ids)):
if delta_message and delta_message.content:
# This need to be added to next `delta_text`
current_text = delta_message.content
delta_message.content = None
else:
current_text = ""
else:
# Just to add remaining `content`
if self.enable_reasoning:
delta_text = previous_text + delta_text
current_text = ""
first_named_delta = _consume_named_tool_header_slot(
named_tool_header_sent, i)
delta_message = DeltaMessage(tool_calls=[
DeltaToolCall(**_named_tool_delta_payload(
tool_choice_function_name,
delta_text,
i,
named_tool_call_ids[i],
first_named_delta,
))
])
elif request.tool_choice == "required":
assert previous_texts is not None
assert function_name_returned is not None
previous_text = previous_texts[i]
current_text = previous_text + delta_text
fn_name_returned = function_name_returned[i]
delta_message, function_name_returned[i] = (
self.extract_tool_call_required_streaming(
previous_text=previous_text,
current_text=current_text,
delta_text=delta_text,
function_name_returned=fn_name_returned))
# update the previous values for the next iteration
previous_texts[i] = current_text
# handle streaming deltas for tools with "auto" tool choice
# and reasoning parser
elif tool_choice_auto and self.enable_reasoning:
assert tool_parser is not None
assert reasoning_parser is not None
assert added_content_delta_arr is not None
assert reasoning_end_arr is not None
if not reasoning_end_arr[i]:
delta_message = (
reasoning_parser.
extract_reasoning_content_streaming(
previous_text,
current_text,
delta_text,
previous_token_ids,
current_token_ids,
output.token_ids,
))
# When encountering think end id in delta_token_ids,
# set reasoning status to end.
# Remove the text and token ids related
# to 'reasoning_content'.
if reasoning_parser.is_reasoning_end(
list(output.token_ids)):
reasoning_end_arr[i] = True
current_token_ids = \
reasoning_parser.extract_content_ids(
list(output.token_ids))
if delta_message and delta_message.content:
current_text = delta_message.content
delta_message.content = None
else:
current_text = ""
# handle tool calls only after reasoning is done,
else:
delta_token_ids = list(output.token_ids)
# First time to tool call,
# add the remaining text and token ids
# to delta from previous
if not added_content_delta_arr[i]:
added_content_delta_arr[i] = True
previous_text = ""
previous_token_ids = []
delta_text = current_text
delta_token_ids = current_token_ids
delta_message = (
tool_parser.extract_tool_calls_streaming(
previous_text=previous_text,
current_text=current_text,
delta_text=delta_text,
previous_token_ids=previous_token_ids,
current_token_ids=current_token_ids,
delta_token_ids=delta_token_ids,
request=request))
# when only tool calls
elif tool_choice_auto:
assert tool_parser is not None
delta_message = (
tool_parser.extract_tool_calls_streaming(
previous_text=previous_text,
current_text=current_text,
delta_text=delta_text,
previous_token_ids=previous_token_ids,
current_token_ids=current_token_ids,
delta_token_ids=output.token_ids,
request=request))
# when only reasoning
elif self.enable_reasoning:
assert reasoning_parser is not None
delta_message = (reasoning_parser.
extract_reasoning_content_streaming(
previous_text,
current_text,
delta_text,
previous_token_ids,
current_token_ids,
output.token_ids,
))
# handle streaming just a content delta
else:
delta_message = DeltaMessage(content=delta_text)
# update the previous values for the next iteration
if tool_choice_auto or should_stream_with_reasoning_parsing:
assert previous_texts is not None
assert all_previous_token_ids is not None
previous_texts[i] = current_text
all_previous_token_ids[i] = current_token_ids
# set the previous values for the next iteration
previous_num_tokens[i] += len(output.token_ids)
# if the message delta is None (e.g. because it was a
# "control token" for tool calls or the parser otherwise
# wasn't ready to send a token, then
# get the next token without streaming a chunk
if delta_message is None:
continue
if output.finish_reason is None:
# Send token-by-token response for each request.n
choice_data = ChatCompletionResponseStreamChoice(
index=i,
delta=delta_message,
logprobs=logprobs,
finish_reason=None)
# if the model is finished generating
else:
# check to make sure we haven't "forgotten" to stream
# any tokens that were generated but previously
# matched by partial json parsing
# only happens if we are NOT using guided decoding
auto_tools_called = False
if tool_parser:
auto_tools_called = len(
tool_parser.prev_tool_call_arr) > 0
index = len(tool_parser.prev_tool_call_arr
) - 1 if auto_tools_called else 0
else:
index = 0
if self._should_check_for_unstreamed_tool_arg_tokens(
delta_message, output) and tool_parser:
latest_delta_len = 0
if ((isinstance(
delta_message.tool_calls[0].function,
DeltaFunctionCall)) and isinstance(
delta_message.tool_calls[0].function.
arguments, str)):
latest_delta_len = len(
delta_message.tool_calls[0].function.
arguments)
# get the expected call based on partial JSON
# parsing which "autocompletes" the JSON
expected_call = json.dumps(
tool_parser.prev_tool_call_arr[index].get(
"arguments", {}),
ensure_ascii=False)
# get what we've streamed so far for arguments
# for the current tool
actual_call = tool_parser.streamed_args_for_tool[
index]
if (latest_delta_len > 0):
actual_call = actual_call[:-latest_delta_len]
# check to see if there's anything left to stream
remaining_call = expected_call.replace(
actual_call, "", 1)
# set that as a delta message
delta_message = DeltaMessage(tool_calls=[
DeltaToolCall(index=index,
function=DeltaFunctionCall(
arguments=remaining_call).
model_dump(exclude_none=True))
])
# [BI100] Count reasoning tokens at finish time.
if should_stream_with_reasoning_parsing \
and all_previous_token_ids is not None \
and self.reasoning_parser is not None:
r_parser = self.reasoning_parser(tokenizer)
reasoning_token_counts[i] = \
r_parser.count_reasoning_tokens(
all_previous_token_ids[i])
# Send the finish response for each request.n only once
choice_data = ChatCompletionResponseStreamChoice(
index=i,
delta=delta_message,
logprobs=logprobs,
finish_reason=("tool_calls" if (
auto_tools_called or tool_choice_function_name)
else output.finish_reason),
stop_reason=output.stop_reason)
finish_reason_sent[i] = True
chunk = ChatCompletionStreamResponse(
id=request_id,
object=chunk_object_type,
created=created_time,
choices=[choice_data],
model=model_name)
# handle usage stats if requested & if continuous
if include_continuous_usage:
completion_tokens = previous_num_tokens[i]
chunk.usage = UsageInfo(
prompt_tokens=num_prompt_tokens,
completion_tokens=completion_tokens,
total_tokens=num_prompt_tokens + completion_tokens,
)
data = chunk.model_dump_json(exclude_unset=True)
yield f"data: {data}\n\n"
# once the final token is handled, if stream_options.include_usage
# is sent, send the usage
if include_usage:
completion_tokens = sum(previous_num_tokens)
total_reasoning = sum(reasoning_token_counts) \
if should_stream_with_reasoning_parsing else None
final_usage = UsageInfo(
prompt_tokens=num_prompt_tokens,
completion_tokens=completion_tokens,
total_tokens=num_prompt_tokens + completion_tokens,
reasoning_tokens=total_reasoning,
prompt_tokens_details=(
PromptTokenUsageInfo(cached_tokens=num_cached_tokens)
if num_cached_tokens is not None else None),
)
final_usage_chunk = ChatCompletionStreamResponse(
id=request_id,
object=chunk_object_type,
created=created_time,
choices=[],
model=model_name,
usage=final_usage)
final_usage_data = (final_usage_chunk.model_dump_json(
exclude_unset=True, exclude_none=True))
yield f"data: {final_usage_data}\n\n"
# report to FastAPI middleware aggregate usage across all choices
num_completion_tokens = sum(previous_num_tokens)
total_reasoning = sum(reasoning_token_counts) \
if should_stream_with_reasoning_parsing else None
request_metadata.final_usage_info = UsageInfo(
prompt_tokens=num_prompt_tokens,
completion_tokens=num_completion_tokens,
total_tokens=num_prompt_tokens + num_completion_tokens,
reasoning_tokens=total_reasoning)
except asyncio.CancelledError:
await self.engine_client.abort(request_id)
return
except Exception as e:
# TODO: Use a vllm-specific Validation Error
logger.exception("Error in chat completion stream generator.")
data = self.create_streaming_error_response(str(e))
yield f"data: {data}\n\n"
finally:
if _disconnect_watcher is not None and not _disconnect_watcher.done():
_disconnect_watcher.cancel()
try:
await _disconnect_watcher
except asyncio.CancelledError:
pass
await self.engine_client.abort(request_id)
# Send the final done message after all response.n are finished
yield "data: [DONE]\n\n"
async def chat_completion_full_generator(
self,
request: ChatCompletionRequest,
result_generator: AsyncIterator[RequestOutput],
request_id: str,
model_name: str,
conversation: list[ConversationMessage],
tokenizer: AnyTokenizer,
request_metadata: RequestResponseMetadata,
raw_request: Optional[Request] = None,
) -> Union[ErrorResponse, ChatCompletionResponse]:
created_time = int(time.time())
final_res: Optional[RequestOutput] = None
should_stream_with_reasoning_parsing = (
self._should_stream_with_reasoning_parsing(request))
# [BI100] Disconnect watcher for non-streaming
_disconnect_watcher: Optional[asyncio.Task] = None
if raw_request is not None:
async def _watch_disconnect() -> None:
try:
while True:
if await raw_request.is_disconnected():
logger.info(
"Client disconnected (non-stream watcher), "
"aborting request %s", request_id)
await self.engine_client.abort(request_id)
return
await asyncio.sleep(0.3)
except asyncio.CancelledError:
pass
_disconnect_watcher = asyncio.ensure_future(_watch_disconnect())
try:
async for res in result_generator:
final_res = res
except asyncio.CancelledError:
await self.engine_client.abort(request_id)
return self.create_error_response("Client disconnected")
except ValueError as e:
# TODO: Use a vllm-specific Validation Error
return self.create_error_response(str(e))
finally:
if _disconnect_watcher is not None and not _disconnect_watcher.done():
_disconnect_watcher.cancel()
try:
await _disconnect_watcher
except asyncio.CancelledError:
pass
await self.engine_client.abort(request_id)
assert final_res is not None
choices: list[ChatCompletionResponseChoice] = []
role = self.get_chat_request_role(request)
for output in final_res.outputs:
token_ids = output.token_ids
out_logprobs = output.logprobs
if request.logprobs and request.top_logprobs is not None:
assert out_logprobs is not None, "Did not output logprobs"
logprobs = self._create_chat_logprobs(
token_ids=token_ids,
top_logprobs=out_logprobs,
num_output_top_logprobs=request.top_logprobs,
tokenizer=tokenizer,
return_as_token_id=request.return_tokens_as_token_ids,
)
else:
logprobs = None
# Extract reasoning content if parser is configured.
reasoning_content: Optional[str] = None
output_text: str = output.text
if should_stream_with_reasoning_parsing and \
self.reasoning_parser is not None:
try:
reasoning_parser = self.reasoning_parser(tokenizer)
except RuntimeError as e:
logger.exception("Error in reasoning parser creation.")
return self.create_error_response(str(e))
logger.info(
"[DEBUG_REASONING] raw output.text=%r token_ids=%s",
output.text[:200] if output.text else output.text,
list(output.token_ids[:20]) if output.token_ids else [])
reasoning_content, extracted = (
reasoning_parser.extract_reasoning_content(
output.text, request=request))
logger.info(
"[DEBUG_REASONING] after parse: reasoning=%r content=%r",
reasoning_content[:200] if reasoning_content else reasoning_content,
extracted[:200] if extracted else extracted)
output_text = extracted or ""
if isinstance(request.tool_choice,
ChatCompletionNamedToolChoiceParam):
reasoning_content, output_text = \
_reclassify_named_guided_json(
reasoning_content, output_text)
else:
reasoning_content = None
output_text = output.text
named_tool_called = False
auto_tools_called = False
# if auto tools are not enabled, and a named tool choice using
# outlines is not being used
if (not self.enable_auto_tools or not self.tool_parser) and \
(not isinstance(request.tool_choice,
ChatCompletionNamedToolChoiceParam
) and request.tool_choice != "required"):
message = ChatMessage(role=role,
reasoning_content=reasoning_content,
content=output_text)
# if the request uses tools and specified a tool choice
elif request.tool_choice and type(
request.tool_choice) is ChatCompletionNamedToolChoiceParam:
named_tool_called = True
parsed_named_tool_calls: Optional[list[ToolCall]] = None
if (not _tool_arguments_are_json_object(output_text)
and self.tool_parser is not None):
try:
named_tool_info = self.tool_parser(
tokenizer).extract_tool_calls(
output_text, request=request)
if named_tool_info.tools_called:
parsed_named_tool_calls = named_tool_info.tool_calls
except RuntimeError as e:
logger.warning(
"Named tool parser unavailable; preserving raw "
"arguments: %s", type(e).__name__)
named_arguments = _select_named_tool_arguments(
output_text,
request.tool_choice.function.name,
parsed_named_tool_calls,
)
tool_call_class = MistralToolCall if isinstance(
tokenizer, MistralTokenizer) else ToolCall
message = ChatMessage(
role=role,
reasoning_content=reasoning_content,
content="",
tool_calls=[
tool_call_class(function=FunctionCall(
name=request.tool_choice.function.name,
arguments=named_arguments))
])
# if the request doesn't use tool choice
# OR specifies to not use a tool
elif not request.tool_choice or request.tool_choice == "none":
message = ChatMessage(role=role,
reasoning_content=reasoning_content,
content=output_text)
# handle when there are tools and tool choice is auto
elif request.tools and (
request.tool_choice == "auto"
or request.tool_choice is None) and self.enable_auto_tools \
and self.tool_parser:
try:
tool_parser = self.tool_parser(tokenizer)
except RuntimeError as e:
logger.exception("Error in tool parser creation.")
return self.create_error_response(str(e))
tool_call_info = tool_parser.extract_tool_calls(
output_text if output_text is not None else "",
request=request)
auto_tools_called = tool_call_info.tools_called
if tool_call_info.tools_called:
message = ChatMessage(role=role,
reasoning_content=reasoning_content,
content=tool_call_info.content,
tool_calls=tool_call_info.tool_calls)
else:
message = ChatMessage(role=role,
reasoning_content=reasoning_content,
content=output_text)
# undetermined case that is still important to handle
else:
logger.error(
"Error in chat_completion_full_generator - cannot determine"
" if tools should be extracted. Returning a standard chat "
"completion.")
message = ChatMessage(role=role,
reasoning_content=reasoning_content,
content=output_text)
choice_data = ChatCompletionResponseChoice(
index=output.index,
message=message,
logprobs=logprobs,
finish_reason="tool_calls" if (
auto_tools_called or named_tool_called) else
output.finish_reason if output.finish_reason else "stop",
stop_reason=output.stop_reason)
choices.append(choice_data)
if request.echo:
last_msg_content: Union[str, list[dict[str, str]]] = ""
if conversation and "content" in conversation[-1] and conversation[
-1].get("role") == role:
last_msg_content = conversation[-1]["content"] or ""
if isinstance(last_msg_content, list):
last_msg_content = "\n".join(msg['text']
for msg in last_msg_content)
for choice in choices:
full_message = last_msg_content + (choice.message.content
or "")
choice.message.content = full_message
assert final_res.prompt_token_ids is not None
num_prompt_tokens = len(final_res.prompt_token_ids)
if final_res.encoder_prompt_token_ids is not None:
num_prompt_tokens += len(final_res.encoder_prompt_token_ids)
num_generated_tokens = sum(
len(output.token_ids) for output in final_res.outputs)
# [BI100] Reasoning token counting
total_reasoning_tokens: Optional[int] = None
if self.reasoning_parser is not None:
rp = self.reasoning_parser(tokenizer)
total_reasoning_tokens = sum(
rp.count_reasoning_tokens(list(output.token_ids))
for output in final_res.outputs)
num_cached_tokens = (final_res.num_cached_tokens
if hasattr(final_res, 'num_cached_tokens')
else None)
usage = UsageInfo(
prompt_tokens=num_prompt_tokens,
completion_tokens=num_generated_tokens,
total_tokens=num_prompt_tokens + num_generated_tokens,
reasoning_tokens=total_reasoning_tokens,
prompt_tokens_details=(
PromptTokenUsageInfo(cached_tokens=num_cached_tokens)
if num_cached_tokens is not None else None),
)
request_metadata.final_usage_info = usage
# [BI100] Sampled prompt logprobs
prompt_logprobs = final_res.prompt_logprobs
sample_positions = request.bi100_prompt_logprobs_sample_positions
if sample_positions is not None:
if num_cached_tokens not in (None, 0):
return self.create_error_response(
"BI100 sampled prompt logprobs require a cold request.")
if prompt_logprobs is None or (
sample_positions
and sample_positions[-1] >= len(prompt_logprobs)):
return self.create_error_response(
"BI100 prompt-logprob sample positions exceed the prompt.")
selected = set(sample_positions)
prompt_logprobs = [
row if position in selected else None
for position, row in enumerate(prompt_logprobs)
]
response = ChatCompletionResponse(
id=request_id,
created=created_time,
model=model_name,
choices=choices,
usage=usage,
prompt_logprobs=clamp_prompt_logprobs(prompt_logprobs),
)
return response
def _get_top_logprobs(
self, logprobs: dict[int, Logprob], top_logprobs: Optional[int],
tokenizer: AnyTokenizer,
should_return_as_token_id: bool) -> list[ChatCompletionLogProb]:
return [
ChatCompletionLogProb(token=(token := self._get_decoded_token(
p[1],
p[0],
tokenizer,
return_as_token_id=should_return_as_token_id)),
logprob=max(p[1].logprob, -9999.0),
bytes=list(
token.encode("utf-8", errors="replace")))
for i, p in enumerate(logprobs.items())
if top_logprobs and i < top_logprobs
]
def _create_chat_logprobs(
self,
token_ids: GenericSequence[int],
top_logprobs: GenericSequence[Optional[dict[int, Logprob]]],
tokenizer: AnyTokenizer,
num_output_top_logprobs: Optional[int] = None,
return_as_token_id: Optional[bool] = None,
) -> ChatCompletionLogProbs:
"""Create OpenAI-style logprobs."""
logprobs_content: list[ChatCompletionLogProbsContent] = []
should_return_as_token_id = return_as_token_id if \
return_as_token_id is not None else self.return_tokens_as_token_ids
for i, token_id in enumerate(token_ids):
step_top_logprobs = top_logprobs[i]
if step_top_logprobs is None:
token = tokenizer.decode(token_id)
if should_return_as_token_id:
token = f"token_id:{token_id}"
logprobs_content.append(
ChatCompletionLogProbsContent(
token=token,
bytes=list(token.encode("utf-8", errors="replace")),
))
else:
step_token = step_top_logprobs[token_id]
step_decoded = step_token.decoded_token
logprobs_content.append(
ChatCompletionLogProbsContent(
token=self._get_decoded_token(
step_token,
token_id,
tokenizer,
should_return_as_token_id,
),
logprob=max(step_token.logprob, -9999.0),
bytes=None if step_decoded is None else list(
step_decoded.encode("utf-8", errors="replace")),
top_logprobs=self._get_top_logprobs(
step_top_logprobs, num_output_top_logprobs,
tokenizer, should_return_as_token_id),
))
return ChatCompletionLogProbs(content=logprobs_content)
def _should_stream_with_auto_tool_parsing(self,
request: ChatCompletionRequest):
"""
Utility function to check if streamed tokens should go through the tool
call parser that was configured.
We only want to do this IF user-provided tools are set, a tool parser
is configured, "auto" tool choice is enabled, and the request's tool
choice field indicates that "auto" tool choice should be used.
"""
return (request.tools and self.tool_parser and self.enable_auto_tools
and request.tool_choice in ['auto', None])
def _should_stream_with_reasoning_parsing(self,
request: ChatCompletionRequest):
"""
Utility function to check if streamed tokens should go through the
reasoning parser that was configured.
We only want to do this IF reasoning is enabled and a reasoning
parser is configured.
"""
return self.enable_reasoning and self.reasoning_parser is not None
def _should_check_for_unstreamed_tool_arg_tokens(
self,
delta_message: Optional[DeltaMessage],
output: CompletionOutput,
) -> bool:
"""
Check to see if we should check for unstreamed tool arguments tokens.
This is only applicable when auto tool parsing is enabled, the delta
is a tool call with arguments.
"""
# yapf: disable
return bool(
# if there is a delta message that includes tool calls which
# include a function that has arguments
output.finish_reason is not None
and self.enable_auto_tools and self.tool_parser and delta_message
and delta_message.tool_calls and delta_message.tool_calls[0]
and delta_message.tool_calls[0].function
and delta_message.tool_calls[0].function.arguments is not None
)