[Perf] Optimize detokenizer python logic (#32975)

Signed-off-by: yewentao256 <zhyanwentao@126.com>
Signed-off-by: Wentao Ye <44945378+yewentao256@users.noreply.github.com>
Co-authored-by: Nick Hill <nhill@redhat.com>
This commit is contained in:
Wentao Ye
2026-02-10 02:54:41 -05:00
committed by GitHub
parent 97fa8f6590
commit e1060a71a1
2 changed files with 10 additions and 6 deletions

View File

@@ -35,6 +35,9 @@ class IncrementalDetokenizer:
def output_token_ids(self) -> list[int]: def output_token_ids(self) -> list[int]:
return self.token_ids return self.token_ids
def num_output_tokens(self) -> int:
return len(self.token_ids)
def update(self, new_token_ids: list[int], stop_terminated: bool) -> str | None: def update(self, new_token_ids: list[int], stop_terminated: bool) -> str | None:
self.token_ids.extend(new_token_ids) self.token_ids.extend(new_token_ids)
return None return None
@@ -112,14 +115,12 @@ class BaseIncrementalDetokenizer(IncrementalDetokenizer, ABC):
skipped_stop_token_id = None skipped_stop_token_id = None
# 1) Detokenize the new token ids incrementally. # 1) Detokenize the new token ids incrementally.
# TODO(woosuk): This method becomes very inefficient when the number of
# new_token_ids is more than 1. We need to optimize this.
stop_check_offset = len(self.output_text) stop_check_offset = len(self.output_text)
for new_token_id in new_token_ids: for new_token_id in new_token_ids:
self.token_ids.append(new_token_id) self.token_ids.append(new_token_id)
self.output_text += self.decode_next(new_token_id) self.output_text += self.decode_next(new_token_id)
# Support min_tokens, see https://github.com/vllm-project/vllm/pull/22014 # Support min_tokens, see https://github.com/vllm-project/vllm/pull/22014
if self.min_tokens and len(self.output_token_ids) <= self.min_tokens: if self.min_tokens and self.num_output_tokens() <= self.min_tokens:
stop_check_offset = len(self.output_text) stop_check_offset = len(self.output_text)
if skipped_stop_token_id is not None: if skipped_stop_token_id is not None:
@@ -128,7 +129,7 @@ class BaseIncrementalDetokenizer(IncrementalDetokenizer, ABC):
# 2) Evaluate stop strings. # 2) Evaluate stop strings.
stop_string = None stop_string = None
if self.stop and len(self.output_token_ids) > self.min_tokens: if self.stop and self.num_output_tokens() > self.min_tokens:
stop = check_stop_strings( stop = check_stop_strings(
output_text=self.output_text, output_text=self.output_text,
new_char_count=len(self.output_text) - stop_check_offset, new_char_count=len(self.output_text) - stop_check_offset,
@@ -295,6 +296,9 @@ class SlowIncrementalDetokenizer(BaseIncrementalDetokenizer):
else (self.token_ids[self.prompt_len :]) else (self.token_ids[self.prompt_len :])
) )
def num_output_tokens(self) -> int:
return len(self.token_ids) - self.prompt_len
def decode_next(self, next_token_id: int) -> str: def decode_next(self, next_token_id: int) -> str:
new_tokens, decoded_text, prefix_offset, read_offset = detokenize_incrementally( new_tokens, decoded_text, prefix_offset, read_offset = detokenize_incrementally(
tokenizer=self.tokenizer, tokenizer=self.tokenizer,

View File

@@ -292,7 +292,7 @@ class RequestState:
if not ( if not (
finished finished
or self.sent_tokens_offset == 0 or self.sent_tokens_offset == 0
or len(self.detokenizer.output_token_ids) - self.sent_tokens_offset or self.detokenizer.num_output_tokens() - self.sent_tokens_offset
>= self.stream_interval >= self.stream_interval
): ):
return None return None
@@ -303,7 +303,7 @@ class RequestState:
new_token_ids = self.detokenizer.output_token_ids[ new_token_ids = self.detokenizer.output_token_ids[
self.sent_tokens_offset : self.sent_tokens_offset :
] ]
self.sent_tokens_offset = len(self.detokenizer.output_token_ids) self.sent_tokens_offset = self.detokenizer.num_output_tokens()
external_req_id = self.external_req_id external_req_id = self.external_req_id