All Downloads are FREE. Search and download functionalities are using the official Maven repository.

com.hazelcast.jet.impl.processor.InsertWatermarksP Maven / Gradle / Ivy

Go to download

There is a newer version: 4.5.4
Show newest version
/*
 * Copyright (c) 2008-2018, Hazelcast, Inc. All Rights Reserved.
 *
 * Licensed 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 com.hazelcast.jet.impl.processor;

import com.hazelcast.jet.Traverser;
import com.hazelcast.jet.core.AbstractProcessor;
import com.hazelcast.jet.core.BroadcastKey;
import com.hazelcast.jet.core.WatermarkGenerationParams;
import com.hazelcast.jet.core.WatermarkSourceUtil;

import javax.annotation.Nonnull;
import javax.annotation.Nullable;

import static com.hazelcast.jet.core.BroadcastKey.broadcastKey;
import static com.hazelcast.jet.impl.util.LoggingUtil.logFine;

/**
 * See {@link com.hazelcast.jet.core.processor.Processors#insertWatermarksP}.
 *
 * @param  type of the stream item
 */
public class InsertWatermarksP extends AbstractProcessor {

    private final WatermarkSourceUtil wsu;
    private Traverser traverser;

    // value to be used temporarily during snapshot restore
    private long minRestoredWm = Long.MAX_VALUE;

    public InsertWatermarksP(WatermarkGenerationParams wmGenParams) {
        wsu = new WatermarkSourceUtil<>(wmGenParams);
        wsu.increasePartitionCount(1);
    }

    @Override
    public boolean tryProcess() {
        return tryProcessInternal(null);
    }

    @Override
    protected boolean tryProcess(int ordinal, @Nonnull Object item) {
        return tryProcessInternal(item);
    }

    private boolean tryProcessInternal(@Nullable Object item) {
        if (traverser == null) {
            traverser = wsu.handleEvent((T) item, 0);
        }
        if (emitFromTraverser(traverser)) {
            traverser = null;
            return true;
        }
        return false;
    }

    @Override
    public boolean saveToSnapshot() {
        return tryEmitToSnapshot(broadcastKey(Keys.LAST_EMITTED_WM), wsu.getWatermark(0));
    }

    @Override
    public void restoreFromSnapshot(@Nonnull Object key, @Nonnull Object value) {
        assert ((BroadcastKey) key).key().equals(Keys.LAST_EMITTED_WM) : "Unexpected key: " + key;
        // we restart at the oldest WM any instance was at at the time of snapshot
        minRestoredWm = Math.min(minRestoredWm, (long) value);
    }

    @Override
    public boolean finishSnapshotRestore() {
        wsu.restoreWatermark(0, minRestoredWm);
        logFine(getLogger(), "restored lastEmittedWm=%s", minRestoredWm);
        return true;
    }

    private enum Keys {
        LAST_EMITTED_WM
    }
}
    

    

    
            
    
            







    
© 2015 - 2024 Weber Informatics LLC | Privacy Policy