rkhachatryan commented on a change in pull request #15200: URL: https://github.com/apache/flink/pull/15200#discussion_r647561889
########## File path: flink-state-backends/flink-statebackend-changelog/src/main/java/org/apache/flink/state/changelog/AbstractStateChangeLogger.java ########## @@ -0,0 +1,150 @@ +/* + * 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.state.changelog; + +import org.apache.flink.core.memory.DataOutputViewStreamWrapper; +import org.apache.flink.runtime.state.changelog.StateChangelogWriter; +import org.apache.flink.runtime.state.heap.InternalKeyContext; +import org.apache.flink.util.function.ThrowingConsumer; + +import java.io.ByteArrayOutputStream; +import java.io.IOException; +import java.util.Arrays; +import java.util.Map; +import java.util.function.Function; +import java.util.stream.Collectors; + +import static org.apache.flink.state.changelog.AbstractStateChangeLogger.StateChangeOperation.ADD; +import static org.apache.flink.state.changelog.AbstractStateChangeLogger.StateChangeOperation.CHANGE_ELEMENT; +import static org.apache.flink.state.changelog.AbstractStateChangeLogger.StateChangeOperation.CLEAR; +import static org.apache.flink.state.changelog.AbstractStateChangeLogger.StateChangeOperation.REMOVE_ELEMENT; +import static org.apache.flink.state.changelog.AbstractStateChangeLogger.StateChangeOperation.SET; +import static org.apache.flink.util.Preconditions.checkNotNull; + +abstract class AbstractStateChangeLogger<Key, State, Ns> implements StateChangeLogger<State, Ns> { + protected final StateChangelogWriter<?> stateChangelogWriter; + protected final InternalKeyContext<Key> keyContext; + + public AbstractStateChangeLogger( + StateChangelogWriter<?> stateChangelogWriter, InternalKeyContext<Key> keyContext) { + this.stateChangelogWriter = checkNotNull(stateChangelogWriter); + this.keyContext = checkNotNull(keyContext); + } + + @Override + public void stateUpdated(State newState, Ns ns) throws IOException { + if (newState == null) { + stateCleared(ns); + } else { + log(SET, out -> serializeState(newState, out), ns); + } + } + + protected abstract void serializeState(State state, DataOutputViewStreamWrapper out) + throws IOException; + + @Override + public void stateAdded(State addedState, Ns ns) throws IOException { + log(ADD, out -> serializeState(addedState, out), ns); + } + + @Override + public void stateCleared(Ns ns) throws IOException { + log(CLEAR, out -> {}, ns); + } + + @Override + public void stateElementChanged( + ThrowingConsumer<DataOutputViewStreamWrapper, IOException> dataSerializer, Ns ns) + throws IOException { + log(CHANGE_ELEMENT, dataSerializer, ns); + } + + @Override + public void stateElementRemoved( + ThrowingConsumer<DataOutputViewStreamWrapper, IOException> dataSerializer, Ns ns) + throws IOException { + log(REMOVE_ELEMENT, dataSerializer, ns); + } + + protected void log( + StateChangeOperation op, + ThrowingConsumer<DataOutputViewStreamWrapper, IOException> dataWriter, + Ns ns) + throws IOException { + // todo: log metadata (FLINK-22808) + stateChangelogWriter.append( + keyContext.getCurrentKeyGroupIndex(), serialize(op, ns, dataWriter)); + } + + private byte[] serialize( + StateChangeOperation op, + Ns ns, + ThrowingConsumer<DataOutputViewStreamWrapper, IOException> dataWriter) + throws IOException { + return serializeRaw( + wrapper -> { + wrapper.writeByte(op.code); + serializeScope(ns, wrapper); + dataWriter.accept(wrapper); + }); + } + + protected abstract void serializeScope(Ns ns, DataOutputViewStreamWrapper out) + throws IOException; + + private byte[] serializeRaw( + ThrowingConsumer<DataOutputViewStreamWrapper, IOException> dataWriter) + throws IOException { + try (ByteArrayOutputStream out = new ByteArrayOutputStream(); + DataOutputViewStreamWrapper wrapper = new DataOutputViewStreamWrapper(out)) { + dataWriter.accept(wrapper); + return out.toByteArray(); + } + } + + enum StateChangeOperation { + /** Scope: key + namespace. */ + CLEAR((byte) 0), + /** Scope: key + namespace. */ + SET((byte) 1), + /** Scope: key + namespace. */ + ADD((byte) 2), + /** Scope: key + namespace, also affecting other (source) namespaces. */ + MERGE_NS((byte) 3), + /** Scope: key + namespace + element (e.g. user map key put or list append). */ + CHANGE_ELEMENT((byte) 4), + /** Scope: key + namespace + element (e.g. user map remove or iterator remove). */ + REMOVE_ELEMENT((byte) 5), Review comment: I agree. Replaced element-related operations with: - `ADD_ELEMENT` - `ADD_OR_UPDATE_ELEMENT` - `REMOVE_ELEMENT` - `REMOVE_FIRST_ELEMENT` -- 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: [email protected]
