sglang0.4.5.post1/python/sglang/srt/sampling/penaltylib/frequency_penalty.py

66 lines
2.1 KiB
Python

import torch
from sglang.srt.sampling.penaltylib.orchestrator import (
BatchedPenalizerOrchestrator,
_BatchedPenalizer,
)
class BatchedFrequencyPenalizer(_BatchedPenalizer):
"""
Frequency penalizer penalizes tokens based on their frequency in the output.
"""
def __init__(self, orchestrator: BatchedPenalizerOrchestrator):
self.orchestrator = orchestrator
self._is_prepared = False
def _is_required(self) -> bool:
return any(
req.sampling_params.frequency_penalty != 0.0
for req in self.orchestrator.reqs()
)
def _prepare(self):
self.cumulated_frequency_penalties = torch.zeros(
(len(self.orchestrator.reqs()), self.orchestrator.vocab_size),
dtype=torch.float32,
device=self.orchestrator.device,
)
self.frequency_penalties = (
torch.tensor(
data=[
req.sampling_params.frequency_penalty
for req in self.orchestrator.reqs()
],
dtype=torch.float32,
device=self.orchestrator.device,
)
).unsqueeze_(1)
def _cumulate_output_tokens(self, output_ids: torch.Tensor):
self.cumulated_frequency_penalties.scatter_add_(
dim=1,
index=output_ids.unsqueeze(1),
src=self.frequency_penalties,
)
def _apply(self, logits: torch.Tensor) -> torch.Tensor:
logits.sub_(self.cumulated_frequency_penalties)
def _filter(self, keep_indices: torch.Tensor):
self.frequency_penalties = self.frequency_penalties[keep_indices]
self.cumulated_frequency_penalties = self.cumulated_frequency_penalties[
keep_indices
]
def _merge(self, their: "BatchedFrequencyPenalizer"):
self.frequency_penalties = torch.cat(
[self.frequency_penalties, their.frequency_penalties], dim=0
)
self.cumulated_frequency_penalties = torch.cat(
[self.cumulated_frequency_penalties, their.cumulated_frequency_penalties],
dim=0,
)