org.apache.flink.runtime.state.DefaultOperatorStateBackendSnapshotStrategy Maven / Gradle / Ivy

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 * 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.core.memory.DataOutputView;
import org.apache.flink.core.memory.DataOutputViewStreamWrapper;
import org.apache.flink.runtime.checkpoint.CheckpointOptions;
import org.apache.flink.runtime.state.metainfo.StateMetaInfoSnapshot;

import javax.annotation.Nonnull;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/** Snapshot strategy for this backend. */
class DefaultOperatorStateBackendSnapshotStrategy
        implements SnapshotStrategy<
                OperatorStateHandle,
                DefaultOperatorStateBackendSnapshotStrategy
                        .DefaultOperatorStateBackendSnapshotResources> {
    private final ClassLoader userClassLoader;
    private final Map> registeredOperatorStates;
    private final Map> registeredBroadcastStates;

    protected DefaultOperatorStateBackendSnapshotStrategy(
            ClassLoader userClassLoader,
            Map> registeredOperatorStates,
            Map> registeredBroadcastStates) {
        this.userClassLoader = userClassLoader;
        this.registeredOperatorStates = registeredOperatorStates;
        this.registeredBroadcastStates = registeredBroadcastStates;
    }

    @Override
    public DefaultOperatorStateBackendSnapshotResources syncPrepareResources(long checkpointId) {
        if (registeredOperatorStates.isEmpty() && registeredBroadcastStates.isEmpty()) {
            return new DefaultOperatorStateBackendSnapshotResources(
                    Collections.emptyMap(), Collections.emptyMap());
        }

        final Map> registeredOperatorStatesDeepCopies =
                new HashMap<>(registeredOperatorStates.size());
        final Map> registeredBroadcastStatesDeepCopies =
                new HashMap<>(registeredBroadcastStates.size());

        ClassLoader snapshotClassLoader = Thread.currentThread().getContextClassLoader();
        Thread.currentThread().setContextClassLoader(userClassLoader);
        try {
            // eagerly create deep copies of the list and the broadcast states (if any)
            // in the synchronous phase, so that we can use them in the async writing.

            if (!registeredOperatorStates.isEmpty()) {
                for (Map.Entry> entry :
                        registeredOperatorStates.entrySet()) {
                    PartitionableListState listState = entry.getValue();
                    if (null != listState) {
                        listState = listState.deepCopy();
                    }
                    registeredOperatorStatesDeepCopies.put(entry.getKey(), listState);
                }
            }

            if (!registeredBroadcastStates.isEmpty()) {
                for (Map.Entry> entry :
                        registeredBroadcastStates.entrySet()) {
                    BackendWritableBroadcastState broadcastState = entry.getValue();
                    if (null != broadcastState) {
                        broadcastState = broadcastState.deepCopy();
                    }
                    registeredBroadcastStatesDeepCopies.put(entry.getKey(), broadcastState);
                }
            }
        } finally {
            Thread.currentThread().setContextClassLoader(snapshotClassLoader);
        }

        return new DefaultOperatorStateBackendSnapshotResources(
                registeredOperatorStatesDeepCopies, registeredBroadcastStatesDeepCopies);
    }

    @Override
    public SnapshotResultSupplier asyncSnapshot(
            DefaultOperatorStateBackendSnapshotResources syncPartResource,
            long checkpointId,
            long timestamp,
            @Nonnull CheckpointStreamFactory streamFactory,
            @Nonnull CheckpointOptions checkpointOptions) {

        Map> registeredOperatorStatesDeepCopies =
                syncPartResource.getRegisteredOperatorStatesDeepCopies();
        Map> registeredBroadcastStatesDeepCopies =
                syncPartResource.getRegisteredBroadcastStatesDeepCopies();

        if (registeredBroadcastStatesDeepCopies.isEmpty()
                && registeredOperatorStatesDeepCopies.isEmpty()) {
            return snapshotCloseableRegistry -> SnapshotResult.empty();
        }

        return (snapshotCloseableRegistry) -> {
            CheckpointStateOutputStream localOut =
                    streamFactory.createCheckpointStateOutputStream(
                            CheckpointedStateScope.EXCLUSIVE);
            snapshotCloseableRegistry.registerCloseable(localOut);

            // get the registered operator state infos ...
            List operatorMetaInfoSnapshots =
                    new ArrayList<>(registeredOperatorStatesDeepCopies.size());

            for (Map.Entry> entry :
                    registeredOperatorStatesDeepCopies.entrySet()) {
                operatorMetaInfoSnapshots.add(entry.getValue().getStateMetaInfo().snapshot());
            }

            // ... get the registered broadcast operator state infos ...
            List broadcastMetaInfoSnapshots =
                    new ArrayList<>(registeredBroadcastStatesDeepCopies.size());

            for (Map.Entry> entry :
                    registeredBroadcastStatesDeepCopies.entrySet()) {
                broadcastMetaInfoSnapshots.add(entry.getValue().getStateMetaInfo().snapshot());
            }

            // ... write them all in the checkpoint stream ...
            DataOutputView dov = new DataOutputViewStreamWrapper(localOut);

            OperatorBackendSerializationProxy backendSerializationProxy =
                    new OperatorBackendSerializationProxy(
                            operatorMetaInfoSnapshots, broadcastMetaInfoSnapshots);

            backendSerializationProxy.write(dov);

            // ... and then go for the states ...

            // we put BOTH normal and broadcast state metadata here
            int initialMapCapacity =
                    registeredOperatorStatesDeepCopies.size()
                            + registeredBroadcastStatesDeepCopies.size();
            final Map writtenStatesMetaData =
                    new HashMap<>(initialMapCapacity);

            for (Map.Entry> entry :
                    registeredOperatorStatesDeepCopies.entrySet()) {

                PartitionableListState value = entry.getValue();
                long[] partitionOffsets = value.write(localOut);
                OperatorStateHandle.Mode mode = value.getStateMetaInfo().getAssignmentMode();
                writtenStatesMetaData.put(
                        entry.getKey(),
                        new OperatorStateHandle.StateMetaInfo(partitionOffsets, mode));
            }

            // ... and the broadcast states themselves ...
            for (Map.Entry> entry :
                    registeredBroadcastStatesDeepCopies.entrySet()) {

                BackendWritableBroadcastState value = entry.getValue();
                long[] partitionOffsets = {value.write(localOut)};
                OperatorStateHandle.Mode mode = value.getStateMetaInfo().getAssignmentMode();
                writtenStatesMetaData.put(
                        entry.getKey(),
                        new OperatorStateHandle.StateMetaInfo(partitionOffsets, mode));
            }

            // ... and, finally, create the state handle.
            OperatorStateHandle retValue = null;

            if (snapshotCloseableRegistry.unregisterCloseable(localOut)) {

                StreamStateHandle stateHandle = localOut.closeAndGetHandle();

                if (stateHandle != null) {
                    retValue = new OperatorStreamStateHandle(writtenStatesMetaData, stateHandle);
                }

                return SnapshotResult.of(retValue);
            } else {
                throw new IOException("Stream was already unregistered.");
            }
        };
    }

    static class DefaultOperatorStateBackendSnapshotResources implements SnapshotResources {

        private final Map> registeredOperatorStatesDeepCopies;
        private final Map>
                registeredBroadcastStatesDeepCopies;

        DefaultOperatorStateBackendSnapshotResources(
                Map> registeredOperatorStatesDeepCopies,
                Map>
                        registeredBroadcastStatesDeepCopies) {
            this.registeredOperatorStatesDeepCopies = registeredOperatorStatesDeepCopies;
            this.registeredBroadcastStatesDeepCopies = registeredBroadcastStatesDeepCopies;
        }

        public Map> getRegisteredOperatorStatesDeepCopies() {
            return registeredOperatorStatesDeepCopies;
        }

        public Map>
                getRegisteredBroadcastStatesDeepCopies() {
            return registeredBroadcastStatesDeepCopies;
        }

        @Override
        public void release() {}
    }
}