zhijiangW 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_r390392642
########## File path: flink-runtime/src/main/java/org/apache/flink/runtime/checkpoint/channel/ChannelStateWriter.java ########## @@ -0,0 +1,116 @@ +/* + * 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 { + + /** + * Sequence number for restored buffers (rather than received from the upstream or from the operator). + */ + int SEQUENCE_NUMBER_RESTORED = -1; + + /** + * Signifies that buffer sequence number is unknown. Review comment: TBH I am not very clear of the scenarios of unknown, can you explain a bit if possible in the javadoc? ---------------------------------------------------------------- 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
