[Core] Clean up array-like msgspec structs (#32688)

python/sglang/srt/disaggregation/kv_events.py

@@ -61,7 +61,6 @@ def select_kv_publisher_dp_rank(
 class EventBatch(
     msgspec.Struct,
     array_like=True,  # type: ignore[call-arg]
-    omit_defaults=True,  # type: ignore[call-arg]
     gc=False,  # type: ignore[call-arg]
 ):
     ts: float
@@ -72,7 +71,6 @@ class EventBatch(
 class KVCacheEvent(
     msgspec.Struct,
     array_like=True,  # type: ignore[call-arg]
-    omit_defaults=True,  # type: ignore[call-arg]
     gc=False,  # type: ignore[call-arg]
     tag=True,
 ):

python/sglang/srt/sampling/sampling_params.py

@@ -72,7 +72,7 @@ def raise_if_tokenizer_required(
         )
 
 
-class SamplingParams(msgspec.Struct, kw_only=True, omit_defaults=True):
+class SamplingParams(msgspec.Struct, kw_only=True, array_like=True):
     """
     The sampling parameters.
 
@@ -106,10 +106,10 @@ class SamplingParams(msgspec.Struct, kw_only=True, omit_defaults=True):
     skip_special_tokens: bool = True
     spaces_between_special_tokens: bool = True
     no_stop_trim: bool = False
-    custom_params: Optional[Dict[str, CustomParamValue]] = None
     stream_interval: Optional[int] = None
     logit_bias: Optional[Dict[str, float]] = None
     sampling_seed: Optional[int] = None
+    custom_params: Optional[Dict[str, CustomParamValue]] = None
 
     # --- Internal fields (populated by __post_init__ or normalize(), not API-facing) ---
     stop_strs: Optional[Union[str, List[str]]] = None  # from stop
@@ -269,7 +269,7 @@ class SamplingParams(msgspec.Struct, kw_only=True, omit_defaults=True):
             tokenizer, self.stop_strs, self.stop_regex_strs, self.min_new_tokens
         )
 
-        # Clear API input aliases so omit_defaults=True drops them from the wire.
+        # Clear API input aliases after normalizing them into internal fields.
         self.stop = None
         self.stop_regex = None
         self.is_normalized = True