AHeise commented on a change in pull request #11354: [FLINK-14551][task] Unaligned checkpoints: API for persistence URL: https://github.com/apache/flink/pull/11354#discussion_r390266828
########## File path: flink-runtime/src/main/java/org/apache/flink/runtime/checkpoint/channel/ChannelStateWriter.java ########## @@ -0,0 +1,101 @@ +/* + * 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.checkpoint.channel; + +import org.apache.flink.annotation.Internal; +import org.apache.flink.runtime.io.network.buffer.Buffer; +import org.apache.flink.runtime.state.StateObject; + +import java.util.Collection; +import java.util.Collections; +import java.util.concurrent.CompletableFuture; +import java.util.concurrent.Future; + +/** + * Writes channel state during checkpoint/savepoint. + */ +@Internal +public interface ChannelStateWriter extends AutoCloseable { + + /** + * Initiate write of channel state for the given checkpoint id. + */ + void start(long checkpointId); + + /** + * Add in-flight buffers from the {@link org.apache.flink.runtime.io.network.partition.consumer.InputChannel InputChannel}. + * <p>Must be called after {@link #start} and before {@link #finish(long)}.</p> + * @param startSeqNum is the sequence number of the 1st passed buffer + * It’s intended use is incremental snapshots + * For the restored buffers it should be -1 + * For MVP it can always be -2 + * If no data is passed it is ignored + */ + void addInputData(long checkpointId, InputChannelInfo info, int startSeqNum, Buffer... data); + + /** + * Add in-flight buffers from the {@link org.apache.flink.runtime.io.network.partition.ResultSubpartition ResultSubpartition}. + * <p>Must be called after {@link #start} and before {@link #finish(long)}.</p> + * @param startSeqNum is the sequence number of the 1st passed buffer + * It’s intended use is incremental snapshots + * For the restored buffers it should be -1 + * For MVP it can always be -2 + * If no data is passed it is ignored + */ + void addOutputData(long checkpointId, ResultSubpartitionInfo info, int startSeqNum, Buffer... data); + + /** + * Finalize write of channel state for the given checkpoint id. + * <p>Must be called after {@link #start}.</p> + */ + void finish(long checkpointId); + + /** + * <p>Must be called after {@link #finish}.</p> + */ + Future<Collection<StateObject>> getWriteCompletionFuture(long checkpointId); Review comment: Ah yes, if it does not need to be called after finish, it will be much more usable and I agree it should be separate. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org With regards, Apache Git Services
