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sglang/python/sglang/srt/sampling/penaltylib/penalizers/min_new_tokens.py

106 lines
3.5 KiB
Python

import typing
import torch
from ..orchestrator import _BatchedPenalizer, _TokenIDs
class BatchedMinNewTokensPenalizer(_BatchedPenalizer):
"""
Min new tokens penalizer penalizes tokens based on the length of the output.
"""
min_new_tokens: torch.Tensor = None
stop_token_penalties: torch.Tensor = None
len_output_tokens: torch.Tensor = None
def _is_required(self) -> bool:
return any(
req.sampling_params.min_new_tokens > 0 for req in self.orchestrator.reqs()
)
def _prepare(self):
self.min_new_tokens = torch.tensor(
data=[
req.sampling_params.min_new_tokens for req in self.orchestrator.reqs()
],
dtype=torch.int32,
device=self.orchestrator.device,
).unsqueeze_(1)
padded_stop_token_ids = torch.nn.utils.rnn.pad_sequence(
sequences=[
torch.tensor(
data=list(
req.sampling_params.stop_token_ids
| {req.tokenizer.eos_token_id}
),
dtype=torch.int64,
device=self.orchestrator.device,
)
for req in self.orchestrator.reqs()
],
batch_first=True,
padding_value=self.orchestrator.vocab_size,
)
self.stop_token_penalties = torch.zeros(
size=(self.orchestrator.batch_size(), self.orchestrator.vocab_size + 1),
dtype=torch.float32,
device=self.orchestrator.device,
).scatter_add_(
dim=1,
index=padded_stop_token_ids,
src=torch.full_like(
input=padded_stop_token_ids,
dtype=torch.float32,
fill_value=float("-inf"),
device=self.orchestrator.device,
),
)[
:, : self.orchestrator.vocab_size
]
self.len_output_tokens = torch.zeros(
size=(self.orchestrator.batch_size(), 1),
dtype=torch.int32,
device=self.orchestrator.device,
)
def _teardown(self):
del self.min_new_tokens
del self.stop_token_penalties
del self.len_output_tokens
self.min_new_tokens = None
self.stop_token_penalties = None
self.len_output_tokens = None
def _cumulate_input_tokens(self, input_ids: _TokenIDs):
pass
def _cumulate_output_tokens(self, output_ids: _TokenIDs):
self.len_output_tokens += 1
def _apply(self, logits: torch.Tensor) -> torch.Tensor:
mask = (self.len_output_tokens < self.min_new_tokens).expand_as(logits)
logits[mask] += self.stop_token_penalties[mask]
return logits
def _filter(
self, indices_to_keep: typing.List[int], indices_tensor_to_keep: torch.Tensor
):
self.min_new_tokens = self.min_new_tokens[indices_tensor_to_keep]
self.stop_token_penalties = self.stop_token_penalties[indices_tensor_to_keep]
self.len_output_tokens = self.len_output_tokens[indices_tensor_to_keep]
def _merge(self, their: "BatchedMinNewTokensPenalizer"):
self.min_new_tokens = torch.cat(
[self.min_new_tokens, their.min_new_tokens], dim=0
)
self.stop_token_penalties = torch.cat(
[self.stop_token_penalties, their.stop_token_penalties], dim=0
)
self.len_output_tokens = torch.cat(
[self.len_output_tokens, their.len_output_tokens], dim=0
)