Small refactor DeepEPMode to clean up code a bit (#4992)

python/sglang/srt/utils.py

@@ -37,6 +37,7 @@ import time
 import traceback
 import warnings
 from contextlib import contextmanager
+from enum import Enum
 from functools import lru_cache
 from importlib.metadata import PackageNotFoundError, version
 from importlib.util import find_spec
@@ -1838,3 +1839,24 @@ def flatten_nested_list(nested_list):
         ]
     else:
         return [nested_list]
+
+
+class DeepEPMode(Enum):
+    normal = "normal"
+    low_latency = "low_latency"
+    auto = "auto"
+
+    def enable_normal(self):
+        return self in [DeepEPMode.normal, DeepEPMode.auto]
+
+    def enable_low_latency(self):
+        return self in [DeepEPMode.low_latency, DeepEPMode.auto]
+
+    def resolve(self, forward_mode):
+        if self != DeepEPMode.auto:
+            return self
+
+        if forward_mode.is_decode():
+            return DeepEPMode.low_latency
+        else:
+            return DeepEPMode.normal