[FLINK-33341][state] Refactoring: introduce common superclass for all…

… IncrementalKeyedStateHandle.

flink-runtime/src/main/java/org/apache/flink/runtime/checkpoint/metadata/MetadataV2V3SerializerBase.java

@@ -341,7 +341,7 @@ static void serializeKeyedStateHandle(KeyedStateHandle stateHandle, DataOutputSt
             dos.writeInt(incrementalKeyedStateHandle.getKeyGroupRange().getNumberOfKeyGroups());
             dos.writeLong(incrementalKeyedStateHandle.getCheckpointedSize());
 
-            serializeStreamStateHandle(incrementalKeyedStateHandle.getMetaStateHandle(), dos);
+            serializeStreamStateHandle(incrementalKeyedStateHandle.getMetaDataStateHandle(), dos);
 
             serializeHandleAndLocalPathList(incrementalKeyedStateHandle.getSharedState(), dos);
             serializeHandleAndLocalPathList(incrementalKeyedStateHandle.getPrivateState(), dos);

flink-runtime/src/main/java/org/apache/flink/runtime/state/AbstractIncrementalStateHandle.java

@@ -0,0 +1,106 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.flink.runtime.state;
+
+import javax.annotation.Nonnull;
+
+import java.util.List;
+import java.util.UUID;
+
+/** Abstract superclass for all {@link IncrementalKeyedStateHandle}. */
+public abstract class AbstractIncrementalStateHandle implements IncrementalKeyedStateHandle {
+    private static final long serialVersionUID = 1L;
+
+    /** The checkpoint Id. */
+    protected final long checkpointId;
+
+    /**
+     * UUID to identify the backend which created this state handle. This is in creating the key for
+     * the {@link SharedStateRegistry}.
+     */
+    protected final UUID backendIdentifier;
+
+    /** The key-group range covered by this state handle. */
+    protected final KeyGroupRange keyGroupRange;
+
+    /** Shared state in the incremental checkpoint. */
+    protected final List<HandleAndLocalPath> sharedState;
+
+    /** Primary meta data state of the incremental checkpoint. */
+    protected final StreamStateHandle metaStateHandle;
+
+    /** Unique id for this state handle. */
+    protected final StateHandleID stateHandleId;
+
+    public AbstractIncrementalStateHandle(
+            UUID backendIdentifier,
+            KeyGroupRange keyGroupRange,
+            long checkpointId,
+            List<HandleAndLocalPath> sharedState,
+            StreamStateHandle metaStateHandle,
+            StateHandleID stateHandleId) {
+        this.checkpointId = checkpointId;
+        this.keyGroupRange = keyGroupRange;
+        this.backendIdentifier = backendIdentifier;
+        this.sharedState = sharedState;
+        this.metaStateHandle = metaStateHandle;
+        this.stateHandleId = stateHandleId;
+    }
+
+    @Override
+    public long getCheckpointId() {
+        return checkpointId;
+    }
+
+    @Nonnull
+    @Override
+    public UUID getBackendIdentifier() {
+        return backendIdentifier;
+    }
+
+    @Override
+    public KeyGroupRange getKeyGroupRange() {
+        return keyGroupRange;
+    }
+
+    @Nonnull
+    @Override
+    public List<HandleAndLocalPath> getSharedStateHandles() {
+        return sharedState;
+    }
+
+    @Nonnull
+    @Override
+    public StreamStateHandle getMetaDataStateHandle() {
+        return metaStateHandle;
+    }
+
+    @Override
+    public StateHandleID getStateHandleId() {
+        return stateHandleId;
+    }
+
+    @Override
+    public KeyedStateHandle getIntersection(KeyGroupRange keyGroupRange) {
+        return KeyGroupRange.EMPTY_KEY_GROUP_RANGE.equals(
+                        getKeyGroupRange().getIntersection(keyGroupRange))
+                ? null
+                : this;
+    }
+}

flink-runtime/src/main/java/org/apache/flink/runtime/state/IncrementalKeyedStateHandle.java

@@ -42,6 +42,9 @@ public interface IncrementalKeyedStateHandle
     @Nonnull
     List<HandleAndLocalPath> getSharedStateHandles();
 
+    @Nonnull
+    StreamStateHandle getMetaDataStateHandle();
+
     /** A Holder of StreamStateHandle and the corresponding localPath. */
     final class HandleAndLocalPath implements Serializable {