Files
sglang/python/sglang/srt/mem_cache/chunk_cache.py
2025-03-05 08:06:07 -08:00

98 lines
2.6 KiB
Python

from __future__ import annotations
"""Cache for chunked prefill, used when RadixCache is disabled."""
from typing import TYPE_CHECKING, Callable, Dict, List, Optional, Tuple
import torch
from sglang.srt.mem_cache.base_prefix_cache import BasePrefixCache
from sglang.srt.mem_cache.memory_pool import ReqToTokenPool, TokenToKVPoolAllocator
if TYPE_CHECKING:
from sglang.srt.managers.schedule_batch import Req
class ChunkCacheEntry:
def __init__(self, rid: str, value: torch.Tensor):
self.rid = rid
self.value = value
class ChunkCache(BasePrefixCache):
def __init__(
self,
req_to_token_pool: ReqToTokenPool,
token_to_kv_pool_allocator: TokenToKVPoolAllocator,
):
self.disable = True
self.req_to_token_pool = req_to_token_pool
self.token_to_kv_pool_allocator = token_to_kv_pool_allocator
self.entries: Dict[str, ChunkCacheEntry] = {}
self.reset()
def reset(self):
self.entries = {}
def match_prefix(self, rid: int, key: List[int]) -> Tuple[List[int], int]:
if rid not in self.entries:
return [], None
entry = self.entries[rid]
max_prefix_len = len(key)
return entry.value[:max_prefix_len], entry
def cache_finished_req(self, req: Req, token_ids: Optional[List[int]] = None):
if token_ids is None:
token_id_len = len(req.origin_input_ids) + len(req.output_ids) - 1
else:
token_id_len = len(token_ids)
kv_indices = self.req_to_token_pool.req_to_token[
req.req_pool_idx, :token_id_len
]
self.req_to_token_pool.free(req.req_pool_idx)
self.token_to_kv_pool_allocator.free(kv_indices)
if req.rid in self.entries:
del self.entries[req.rid]
def cache_unfinished_req(self, req: Req):
token_id_len = len(req.fill_ids)
kv_indices = self.req_to_token_pool.req_to_token[
req.req_pool_idx, :token_id_len
]
if req.rid not in self.entries:
self.entries[req.rid] = ChunkCacheEntry(req.rid, kv_indices)
entry = self.entries[req.rid]
entry.value = kv_indices
req.prefix_indices = kv_indices
req.last_node = entry
def insert(self):
raise NotImplementedError()
def evict(self, num_tokens: int, evict_callback: Callable):
pass
def inc_lock_ref(self, node):
return 0
def dec_lock_ref(self, node):
return 0
def evictable_size(self):
return 0
def pretty_print(self):
return ""
def protected_size(self):
return 0
def pretty_print(self):
return ""