Github user kl0u commented on a diff in the pull request: https://github.com/apache/flink/pull/5230#discussion_r163872816 --- Diff: flink-runtime/src/main/java/org/apache/flink/runtime/state/BackendWritableBroadcastState.java --- @@ -0,0 +1,42 @@ +/* + * 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 org.apache.flink.api.common.state.BroadcastState; +import org.apache.flink.core.fs.FSDataOutputStream; + +import java.io.IOException; + +/** + * An interface with methods related to the interplay between the {@link BroadcastState} + * and the {@link OperatorStateBackend}. + * + * @param <K> The key type of the elements in the {@link BroadcastState}. + * @param <V> The value type of the elements in the {@link BroadcastState}. + */ +public interface BackendWritableBroadcastState<K, V> extends BroadcastState<K, V> { + + BackendWritableBroadcastState<K, V> deepCopy(); + + long[] write(FSDataOutputStream out) throws IOException; --- End diff -- Here I believe we could return just the offset of the first element, as we treat the whole block containing the broadcast state as a single element. It is true that even this, it is not strictly needed but I left it for compatibility with previous code. Is this what you meant?
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