[minor] simplify the TokenToKVPoolAllocator (#7414)

python/sglang/srt/mem_cache/radix_cache.py

@@ -23,7 +23,7 @@ import heapq
 import time
 from collections import defaultdict
 from functools import partial
-from typing import TYPE_CHECKING, List, Optional, Tuple
+from typing import TYPE_CHECKING, List, Optional
 
 import torch
 
@@ -31,10 +31,10 @@ from sglang.srt.disaggregation.kv_events import (
     AllBlocksCleared,
     BlockRemoved,
     BlockStored,
-    KVCacheEvent,
 )
+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, TokenToKVPoolAllocator
+from sglang.srt.mem_cache.memory_pool import ReqToTokenPool
 
 if TYPE_CHECKING:
     from sglang.srt.managers.schedule_batch import Req
@@ -98,7 +98,7 @@ class RadixCache(BasePrefixCache):
     def __init__(
         self,
         req_to_token_pool: ReqToTokenPool,
-        token_to_kv_pool_allocator: TokenToKVPoolAllocator,
+        token_to_kv_pool_allocator: BaseTokenToKVPoolAllocator,
         page_size: int,
         disable: bool = False,
         enable_kv_cache_events: bool = False,