Files
sglang/python/sglang/srt/mem_cache/allocator/token.py
T

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2.7 KiB
Python

"""
Copyright 2025 SGLang Team
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
"""
from __future__ import annotations
from typing import TYPE_CHECKING
import torch
from sglang.srt.mem_cache.allocator.base import BaseTokenToKVPoolAllocator
if TYPE_CHECKING:
from sglang.srt.mem_cache.memory_pool import KVCache
class TokenToKVPoolAllocator(BaseTokenToKVPoolAllocator):
"""An allocator managing the indices to kv cache data."""
def __init__(
self,
size: int,
dtype: torch.dtype,
device: str,
kvcache: KVCache,
need_sort: bool,
):
super().__init__(size, 1, dtype, device, kvcache, need_sort)
self.clear()
def clear(self):
# The padded slot 0 is used for writing dummy outputs from padded tokens.
self.free_pages = torch.arange(
1, self.size + 1, dtype=torch.int64, device=self.device
)
self.is_not_in_free_group = True
self.free_group = []
self.release_pages = torch.empty((0,), dtype=torch.int64, device=self.device)
def available_size(self):
# To avoid minor "len(free_pages) * 1" overhead
return len(self.free_pages) + len(self.release_pages)
def alloc(self, need_size: int):
if self.need_sort and need_size > len(self.free_pages):
self.merge_and_sort_free()
if need_size > len(self.free_pages):
return None
select_index = self.free_pages[:need_size]
self.free_pages = self.free_pages[need_size:]
return select_index
def free(self, free_index: torch.Tensor):
if free_index.numel() == 0:
return
if self.is_not_in_free_group:
if self.need_sort:
self.release_pages = torch.cat((self.release_pages, free_index))
else:
self.free_pages = torch.cat((self.free_pages, free_index))
else:
self.free_group.append(self._copy_for_free_group(free_index))
def get_cpu_copy(self, indices, mamba_indices=None):
return self._kvcache.get_cpu_copy(indices, mamba_indices=mamba_indices)
def load_cpu_copy(self, kv_cache_cpu, indices, mamba_indices=None):
return self._kvcache.load_cpu_copy(
kv_cache_cpu, indices, mamba_indices=mamba_indices
)