Files
sglang/python/sglang/srt/mem_cache/chunk_cache.py
2025-06-22 12:37:18 +08:00

66 lines
2.0 KiB
Python

from __future__ import annotations
"""Cache for chunked prefill, used when RadixCache is disabled."""
from typing import TYPE_CHECKING, Any
import torch
from sglang.srt.mem_cache.allocator import BaseTokenToKVPoolAllocator
from sglang.srt.mem_cache.base_prefix_cache import BasePrefixCache, MatchResult
from sglang.srt.mem_cache.memory_pool import ReqToTokenPool
if TYPE_CHECKING:
from sglang.srt.managers.schedule_batch import Req
class ChunkCache(BasePrefixCache):
def __init__(
self,
req_to_token_pool: ReqToTokenPool,
token_to_kv_pool_allocator: BaseTokenToKVPoolAllocator,
page_size: int,
):
self.req_to_token_pool = req_to_token_pool
self.token_to_kv_pool_allocator = token_to_kv_pool_allocator
self.page_size = page_size
def reset(self):
pass
def match_prefix(self, **unused_kwargs) -> MatchResult:
return MatchResult(
device_indices=torch.empty((0,), dtype=torch.int64),
last_device_node=None,
last_host_node=None,
)
def cache_finished_req(self, req: Req):
kv_indices = self.req_to_token_pool.req_to_token[
req.req_pool_idx,
# For decode server: if req.output_ids is empty, we want to free all req.origin_input_ids
: len(req.origin_input_ids) + max(len(req.output_ids) - 1, 0),
]
self.req_to_token_pool.free(req.req_pool_idx)
self.token_to_kv_pool_allocator.free(kv_indices)
def cache_unfinished_req(self, req: Req):
kv_indices = self.req_to_token_pool.req_to_token[
req.req_pool_idx, : len(req.fill_ids)
]
# `req.prefix_indices` will be used in `PrefillAdder::add_chunked_req` later
req.prefix_indices = kv_indices
def evict(self, num_tokens: int):
pass
def inc_lock_ref(self, node: Any):
return 0
def dec_lock_ref(self, node: Any):
return 0
def pretty_print(self):
return ""