[Env] centralize hicache vars in environ.py (#17204)

python/sglang/srt/environ.py

@@ -268,6 +268,8 @@ class Envs:
 
     # Hi-Cache
     SGLANG_HICACHE_HF3FS_CONFIG_PATH = EnvStr(None)
+    SGLANG_HICACHE_FILE_BACKEND_STORAGE_DIR = EnvStr(None)
+    SGLANG_HICACHE_NIXL_BACKEND_STORAGE_DIR = EnvStr(None)
 
     # Mooncake KV Transfer
     SGLANG_MOONCAKE_CUSTOM_MEM_POOL = EnvStr(None)

python/sglang/srt/mem_cache/hicache_storage.py

@@ -7,6 +7,7 @@ from typing import Any, List, Optional
 
 import torch
 
+from sglang.srt.environ import envs
 from sglang.srt.mem_cache.memory_pool_host import HostKVCache
 
 logger = logging.getLogger(__name__)
@@ -186,7 +187,7 @@ class HiCacheFile(HiCacheStorage):
     def __init__(
         self, storage_config: HiCacheStorageConfig, file_path: str = "/tmp/hicache"
     ):
-        self.file_path = os.getenv("SGLANG_HICACHE_FILE_BACKEND_STORAGE_DIR", file_path)
+        self.file_path = envs.SGLANG_HICACHE_FILE_BACKEND_STORAGE_DIR.get() or file_path
 
         tp_rank, tp_size, model_name, is_mla_model = (
             storage_config.tp_rank,

python/sglang/srt/mem_cache/storage/nixl/hicache_nixl.py

@@ -1,11 +1,11 @@
 import logging
-import os
 import time
 import uuid
 from typing import Any, List, Optional, Union
 
 import torch
 
+from sglang.srt.environ import envs
 from sglang.srt.mem_cache.hicache_storage import HiCacheStorage, HiCacheStorageConfig
 
 from .nixl_utils import (
@@ -44,7 +44,7 @@ class HiCacheNixl(HiCacheStorage):
         plugin = nixlconfig.get_specified_plugin()
 
         # Might be better to be unified across HiCache backends and moved to HiCacheController
-        file_path = os.getenv("SGLANG_HICACHE_NIXL_BACKEND_STORAGE_DIR", file_path)
+        file_path = envs.SGLANG_HICACHE_NIXL_BACKEND_STORAGE_DIR.get() or file_path
         self.file_manager = (
             NixlFileManager(file_path)
             if plugin not in NixlBackendSelection.OBJ_PLUGINS