hf_text-generation-inference/server/text_generation_server/utils/segments.py

67 lines
2.6 KiB
Python

# Origin: https://github.com/predibase/lorax
# Path: lorax/server/lorax_server/utils/segments.py
# License: Apache License Version 2.0, January 2004
from typing import List, Tuple, Union
import torch
def find_segments(
adapter_indices: Union[torch.Tensor, List[int]]
) -> Tuple[List[int], List[int]]:
segments = [0]
segment_indices = []
if isinstance(adapter_indices, torch.Tensor):
# Calling .item() repeatedly on CUDA tensor is very slow, so we move it to CPU first
adapter_indices = adapter_indices.cpu().tolist()
start_index = 0
for i in range(1, len(adapter_indices)):
if adapter_indices[i] != adapter_indices[i - 1]:
segments.append(i)
segment_indices.append(adapter_indices[i - 1])
start_index = i
# Handle the last segment
if start_index < len(adapter_indices):
segments.append(len(adapter_indices))
segment_indices.append(adapter_indices[-1])
return segments, segment_indices
class SegmentConcatBuilder:
def __init__(self):
self.adapter_segment_indices = []
self.adapter_segment_tensors = []
def concat(self, adapter_segments: torch.Tensor, segment_indices: List[int]):
# Update adapter segments
if self.adapter_segment_tensors:
# Because we have already processed at least one batch, remove the 0 start index
# from this batch denoting the beginning of the segment, then offset all segment
# positions by the value of the last segment in the previous batch to account for
# the concatenation.
adapter_segments = (
adapter_segments[1:] + self.adapter_segment_tensors[-1][-1]
)
if (
self.adapter_segment_indices
and self.adapter_segment_indices[-1] == segment_indices[0]
):
# If the last segment in the previous batch is the same as the first segment in this batch,
# then we merge them together into a single segment. In effect, this means removing it from
# the segment indices of this batch, and extending the segment span by removing the segment
# end index from the previous batch.
segment_indices = segment_indices[1:]
self.adapter_segment_tensors[-1] = self.adapter_segment_tensors[-1][:-1]
self.adapter_segment_indices.extend(segment_indices)
self.adapter_segment_tensors.append(adapter_segments)
def build(self) -> Tuple[torch.Tensor, List[int]]:
return torch.concat(self.adapter_segment_tensors), self.adapter_segment_indices