[Speculative Decoding] Add draft_logprobs Support for Speculative Decode MTP (#4467)

* feat: add draft_logprobs for Speculative Decode MTP

* feat: add draft_logprobs for Speculative Decode MTP

* feat: add draft_logprobs for Speculative Decode MTP

* fix: postprocess for speculative decode

* test: test_speculative_decoding_use_logprobs

* fix: test_completion_echo

* fix test_max_streaming_tokens

---------

Co-authored-by: Jiang-Jia-Jun <163579578+Jiang-Jia-Jun@users.noreply.github.com>
This commit is contained in:
SunLei
2025-10-21 14:57:50 +08:00
committed by GitHub
parent 775edcc09a
commit ee915220bd
7 changed files with 422 additions and 48 deletions
@@ -205,6 +205,7 @@ class ChatCompletionResponseChoice(BaseModel):
index: int
message: ChatMessage
logprobs: Optional[LogProbs] = None
draft_logprobs: Optional[LogProbs] = None
finish_reason: Optional[Literal["stop", "length", "tool_calls", "recover_stop"]]
@@ -265,6 +266,7 @@ class ChatCompletionResponseStreamChoice(BaseModel):
index: int
delta: DeltaMessage
logprobs: Optional[LogProbs] = None
draft_logprobs: Optional[LogProbs] = None
finish_reason: Optional[Literal["stop", "length", "tool_calls"]] = None
arrival_time: Optional[float] = None
@@ -295,6 +297,7 @@ class CompletionResponseChoice(BaseModel):
completion_tokens: Optional[str] = None
arrival_time: Optional[float] = None
logprobs: Optional[CompletionLogprobs] = None
draft_logprobs: Optional[CompletionLogprobs] = None
reasoning_content: Optional[str] = None
finish_reason: Optional[Literal["stop", "length", "tool_calls"]]
tool_calls: Optional[List[DeltaToolCall | ToolCall]] = None
@@ -333,6 +336,7 @@ class CompletionResponseStreamChoice(BaseModel):
text: str
arrival_time: float = None
logprobs: Optional[CompletionLogprobs] = None
draft_logprobs: Optional[CompletionLogprobs] = None
prompt_token_ids: Optional[List[int]] = None
completion_token_ids: Optional[List[int]] = None
prompt_tokens: Optional[str] = None
@@ -420,6 +424,7 @@ class CompletionRequest(BaseModel):
echo: Optional[bool] = False
frequency_penalty: Optional[float] = Field(default=None, ge=-2, le=2)
logprobs: Optional[int] = None
include_draft_logprobs: Optional[bool] = False
# For logits and logprobs post processing
temp_scaled_logprobs: bool = False
top_p_normalized_logprobs: bool = False
@@ -555,6 +560,7 @@ class ChatCompletionRequest(BaseModel):
frequency_penalty: Optional[float] = Field(None, le=2, ge=-2)
logprobs: Optional[bool] = False
top_logprobs: Optional[int] = 0
include_draft_logprobs: Optional[bool] = False
# For logits and logprobs post processing
temp_scaled_logprobs: bool = False
@@ -316,12 +316,18 @@ class OpenAIServingChat:
output = res["outputs"]
output_top_logprobs = output["top_logprobs"]
output_draft_top_logprobs = output["draft_top_logprobs"]
previous_num_tokens[idx] += len(output["token_ids"])
logprobs_res: Optional[LogProbs] = None
draft_logprobs_res: Optional[LogProbs] = None
if request.logprobs and output_top_logprobs is not None:
logprobs_res = self._create_chat_logprobs(
output_top_logprobs, request.logprobs, request.top_logprobs
)
if request.include_draft_logprobs and output_draft_top_logprobs is not None:
draft_logprobs_res = self._create_chat_logprobs(
output_draft_top_logprobs, request.logprobs, request.top_logprobs
)
delta_message = DeltaMessage(
reasoning_content="",
@@ -348,6 +354,7 @@ class OpenAIServingChat:
index=idx,
delta=delta_message,
logprobs=logprobs_res,
draft_logprobs=draft_logprobs_res,
arrival_time=arrival_time,
)
if res["finished"]:
@@ -444,7 +451,9 @@ class OpenAIServingChat:
dealer.write([b"", rid.encode("utf-8")])
previous_num_tokens = [0] * num_choices
current_waiting_time = 0
logprob_contents = [[] for _ in range(num_choices)]
draft_logprob_contents = [[] for _ in range(num_choices)]
completion_token_ids = [[] for _ in range(num_choices)]
num_cached_tokens = [0] * num_choices
response_processor = ChatResponseProcessor(
@@ -492,12 +501,23 @@ class OpenAIServingChat:
# The logprob for handling the response
output = data["outputs"]
output_top_logprobs = output["top_logprobs"]
output_draft_top_logprobs = output["draft_top_logprobs"]
if output_top_logprobs is not None:
# logprobs
logprobs_res = self._create_chat_logprobs(
output_top_logprobs, request.logprobs, request.top_logprobs
)
if logprobs_res and logprobs_res.content is not None:
logprob_contents[idx].extend(logprobs_res.content)
# draft_logprobs
if request.include_draft_logprobs and output_draft_top_logprobs is not None:
draft_logprobs_res = self._create_chat_logprobs(
output_draft_top_logprobs, request.logprobs, request.top_logprobs
)
if draft_logprobs_res and draft_logprobs_res.content is not None:
draft_logprob_contents[idx].extend(draft_logprobs_res.content)
if data["finished"]:
num_choices -= 1
choice = await self._create_chat_completion_choice(
@@ -234,6 +234,7 @@ class OpenAIServingCompletion:
valid_results = [dict()] * num_choices
output_tokens = [0] * num_choices
aggregated_top_logprobs = [[[], [], []] for _ in range(num_choices)]
aggregated_draft_top_logprobs = [[[], [], []] for _ in range(num_choices)]
aggregated_token_ids = [[] for _ in range(num_choices)]
completion_batched_token_ids = [[] for _ in range(num_choices)]
current_waiting_time = 0
@@ -266,12 +267,19 @@ class OpenAIServingCompletion:
raise ValueError("{}".format(data["error_msg"]))
output = data["outputs"]
output_top_logprobs = output["top_logprobs"]
output_top_logprobs = output.get("top_logprobs") or None
output_draft_top_logprobs = output.get("draft_top_logprobs") or None
if output_top_logprobs is not None:
aggregated_top_logprobs[rid][0].extend(output_top_logprobs[0])
aggregated_top_logprobs[rid][1].extend(output_top_logprobs[1])
aggregated_top_logprobs[rid][2].extend(output_top_logprobs[2])
# draft logprobs
if request.include_draft_logprobs and output_draft_top_logprobs is not None:
aggregated_draft_top_logprobs[rid][0].extend(output_draft_top_logprobs[0])
aggregated_draft_top_logprobs[rid][1].extend(output_draft_top_logprobs[1])
aggregated_draft_top_logprobs[rid][2].extend(output_draft_top_logprobs[2])
aggregated_token_ids[rid].extend(data["outputs"]["token_ids"])
self.engine_client.data_processor.process_response_dict(
@@ -282,6 +290,7 @@ class OpenAIServingCompletion:
if data.get("finished", False):
data["output_token_ids"] = output_tokens[rid]
data["outputs"]["top_logprobs"] = aggregated_top_logprobs[rid]
data["outputs"]["draft_top_logprobs"] = aggregated_draft_top_logprobs[rid]
data["outputs"]["token_ids"] = aggregated_token_ids[rid]
valid_results[rid] = data
num_choices -= 1
@@ -437,10 +446,17 @@ class OpenAIServingCompletion:
await self._process_echo_logic(request, idx, res["outputs"])
output = res["outputs"]
output_top_logprobs = output["top_logprobs"]
output_draft_top_logprobs = output["draft_top_logprobs"]
logprobs_res: Optional[CompletionLogprobs] = None
draft_logprobs_res: Optional[CompletionLogprobs] = None
if request.logprobs and output_top_logprobs is not None:
logprobs_res = self._create_completion_logprobs(output_top_logprobs, request.logprobs, 0)
# draft logprobs
if request.include_draft_logprobs and output_draft_top_logprobs is not None:
draft_logprobs_res = self._create_completion_logprobs(
output_draft_top_logprobs, request.logprobs, 0
)
output_tokens[idx] += 1
delta_message = CompletionResponseStreamChoice(
index=idx,
@@ -452,6 +468,7 @@ class OpenAIServingCompletion:
reasoning_content="",
arrival_time=arrival_time,
logprobs=logprobs_res,
draft_logprobs=draft_logprobs_res,
)
if not res["finished"] and "delta_message" in output:
delta_message_output = output["delta_message"]
@@ -541,15 +558,23 @@ class OpenAIServingCompletion:
final_res = final_res_batch[idx]
prompt_token_ids = prompt_batched_token_ids[idx // (1 if request.n is None else request.n)]
assert prompt_token_ids is not None
prompt_text = request.prompt
completion_token_ids = completion_batched_token_ids[idx]
output = final_res["outputs"]
output_top_logprobs = output["top_logprobs"]
output_top_logprobs = output.get("top_logprobs") or None
output_draft_top_logprobs = output.get("draft_top_logprobs") or None
aggregated_logprobs: Optional[CompletionLogprobs] = None
if output_top_logprobs is not None:
aggregated_logprobs = self._create_completion_logprobs(output_top_logprobs, request.logprobs, 0)
aggregated_draft_logprobs: Optional[CompletionLogprobs] = None
if output_draft_top_logprobs is not None:
aggregated_draft_logprobs = self._create_completion_logprobs(
output_draft_top_logprobs, request.logprobs, 0
)
if request.echo:
prompt_text = self._echo_back_prompt(request, idx // (1 if request.n is None else request.n))
token_ids = [*prompt_token_ids, *output["token_ids"]]
@@ -574,6 +599,7 @@ class OpenAIServingCompletion:
reasoning_content=output.get("reasoning_content"),
tool_calls=output.get("tool_call"),
logprobs=aggregated_logprobs,
draft_logprobs=aggregated_draft_logprobs,
finish_reason=finish_reason,
)
choices.append(choice_data)