[RadixTree][3/N Refactor]：Support unified insert/evict params (#17401)

python/sglang/srt/mem_cache/chunk_cache.py

@@ -9,6 +9,10 @@ import torch
 
 from sglang.srt.mem_cache.base_prefix_cache import (
     BasePrefixCache,
+    EvictParams,
+    EvictResult,
+    InsertParams,
+    InsertResult,
     MatchPrefixParams,
     MatchResult,
 )
@@ -54,6 +58,10 @@ class ChunkCache(BasePrefixCache):
             last_host_node=None,
         )
 
+    def insert(self, params: InsertParams) -> InsertResult:
+        # ChunkCache does not support prefix caching, so insert is a no-op
+        return InsertResult(prefix_len=0)
+
     def cache_finished_req(self, req: Req, is_insert: bool = True):
         kv_committed_len = req.pop_committed_kv_cache()
         # For decode server: if req.output_ids is empty, we want to free all req.origin_input_ids
@@ -70,8 +78,8 @@ class ChunkCache(BasePrefixCache):
         # `req.prefix_indices` will be used in `PrefillAdder::add_chunked_req` later
         req.prefix_indices = kv_indices.to(dtype=torch.int64, copy=True)
 
-    def evict(self, num_tokens: int):
-        pass
+    def evict(self, params: EvictParams) -> EvictResult:
+        return EvictResult()
 
     def inc_lock_ref(self, node: Any):
         return 0
@@ -103,5 +111,5 @@ class SWAChunkCache(ChunkCache):
         ), "sliding_window_size must be set for SWAChunkCache"
         return True
 
-    def evict(self, num_tokens: int):
-        pass
+    def evict(self, params: EvictParams) -> EvictResult:
+        return EvictResult()