YT-21306: Add EnumHasDefaultValue

d9b67f1778da2d15dd94f7285afe4e3490a233ab

7 files changed, 45 insertions, 4 deletions

diff --git a/library/cpp/yt/misc/cast-inl.h b/library/cpp/yt/misc/cast-inl.h
index a694394f88..795682864f 100644
--- a/library/cpp/yt/misc/cast-inl.h
+++ b/library/cpp/yt/misc/cast-inl.h
@@ -124,6 +124,10 @@ T CheckedEnumCast(S value)
 {
     T result;
     if (!TryEnumCast<T>(value, &result)) {
+        if constexpr (TEnumHasDefaultValue<T>::value) {
+            return GetDefaultValue(T{});
+        }
+
         throw TSimpleException(Sprintf("Error casting %s value \"%d\" to enum %s",
             TypeName<S>().c_str(),
             static_cast<int>(value),
diff --git a/library/cpp/yt/misc/enum.h b/library/cpp/yt/misc/enum.h
index 954b63cbc0..11e168948f 100644
--- a/library/cpp/yt/misc/enum.h
+++ b/library/cpp/yt/misc/enum.h
@@ -197,6 +197,20 @@ constexpr bool None(E value) noexcept;
 
 ////////////////////////////////////////////////////////////////////////////////
 
+template <typename E, typename = void>
+    requires TEnumTraits<E>::IsEnum
+struct TEnumHasDefaultValue
+    : std::false_type
+{ };
+
+template <typename E>
+    requires TEnumTraits<E>::IsEnum
+struct TEnumHasDefaultValue<E, std::void_t<decltype(GetDefaultValue(std::declval<E>()))>>
+    : std::is_same<decltype(GetDefaultValue(std::declval<E>())), E>
+{ };
+
+////////////////////////////////////////////////////////////////////////////////
+
 } // namespace NYT
 
 #define ENUM_INL_H_
diff --git a/library/cpp/yt/string/enum-inl.h b/library/cpp/yt/string/enum-inl.h
index 41f7197d15..19ba1f7fe5 100644
--- a/library/cpp/yt/string/enum-inl.h
+++ b/library/cpp/yt/string/enum-inl.h
@@ -87,6 +87,11 @@ T ParseEnum(TStringBuf value)
     if (auto optionalResult = TryParseEnum<T>(value)) {
         return *optionalResult;
     }
+
+    if constexpr (TEnumHasDefaultValue<T>::value) {
+        return GetDefaultValue(T{});
+    }
+
     NYT::NDetail::ThrowMalformedEnumValueException(TEnumTraits<T>::GetTypeName(), value);
 }
 
diff --git a/yt/yt/core/bus/public.cpp b/yt/yt/core/bus/public.cpp
index 6cff5f25eb..0487d79fd6 100644
--- a/yt/yt/core/bus/public.cpp
+++ b/yt/yt/core/bus/public.cpp
@@ -9,5 +9,11 @@ const TString LocalNetworkName("local");
 
 ////////////////////////////////////////////////////////////////////////////////
 
-} // namespace NYT::NBus
+EMultiplexingBand GetDefaultValue(EMultiplexingBand)
+{
+    return EMultiplexingBand::Default;
+}
+
+////////////////////////////////////////////////////////////////////////////////
 
+} // namespace NYT::NBus
diff --git a/yt/yt/core/bus/public.h b/yt/yt/core/bus/public.h
index f5359d51b7..5a07031874 100644
--- a/yt/yt/core/bus/public.h
+++ b/yt/yt/core/bus/public.h
@@ -34,8 +34,11 @@ DEFINE_ENUM(EMultiplexingBand,
     ((Heavy)                 (2))
     ((Interactive)           (3))
     ((RealTime)              (4))
+    ((Journal)               (5))
 );
 
+EMultiplexingBand GetDefaultValue(EMultiplexingBand);
+
 YT_DEFINE_ERROR_ENUM(
     ((TransportError)       (100))
     ((SslError)             (119))
@@ -59,4 +62,3 @@ extern const TString LocalNetworkName;
 ////////////////////////////////////////////////////////////////////////////////
 
 } // namespace NYT::NBus
-
diff --git a/yt/yt/core/misc/protobuf_helpers-inl.h b/yt/yt/core/misc/protobuf_helpers-inl.h
index adf5a30851..00ae1906ff 100644
--- a/yt/yt/core/misc/protobuf_helpers-inl.h
+++ b/yt/yt/core/misc/protobuf_helpers-inl.h
@@ -181,7 +181,11 @@ template <class T>
     requires TEnumTraits<T>::IsEnum && (!TEnumTraits<T>::IsBitEnum)
 void FromProto(T* original, int serialized)
 {
-    *original = static_cast<T>(serialized);
+    if constexpr (TEnumHasDefaultValue<T>::value) {
+        *original = CheckedEnumCast<T>(serialized);
+    } else {
+        *original = static_cast<T>(serialized);
+    }
 }
 
 template <class T>
@@ -195,7 +199,11 @@ template <class T>
     requires TEnumTraits<T>::IsBitEnum
 void FromProto(T* original, ui64 serialized)
 {
-    *original = static_cast<T>(serialized);
+    if constexpr (TEnumHasDefaultValue<T>::value) {
+        *original = CheckedEnumCast<T>(serialized);
+    } else {
+        *original = static_cast<T>(serialized);
+    }
 }
 
 ////////////////////////////////////////////////////////////////////////////////
diff --git a/yt/yt_proto/yt/client/api/rpc_proxy/proto/api_service.proto b/yt/yt_proto/yt/client/api/rpc_proxy/proto/api_service.proto
index 39ef2f681b..0333b8d4f0 100644
--- a/yt/yt_proto/yt/client/api/rpc_proxy/proto/api_service.proto
+++ b/yt/yt_proto/yt/client/api/rpc_proxy/proto/api_service.proto
@@ -224,6 +224,8 @@ enum EMultiplexingBand
     MB_CONTROL = 1;
     MB_HEAVY = 2;
     MB_INTERACTIVE = 3;
+    MB_REAL_TIME = 4;
+    MB_JOURNAL = 5;
 }
 
 enum ETableSchemaModification