BaseWindowedBolt.java

/**
 * 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.storm.topology.base;

import java.io.Serializable;
import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.TimeUnit;
import org.apache.storm.Config;
import org.apache.storm.task.OutputCollector;
import org.apache.storm.task.TopologyContext;
import org.apache.storm.topology.IWindowedBolt;
import org.apache.storm.topology.OutputFieldsDeclarer;
import org.apache.storm.topology.TupleFieldTimestampExtractor;
import org.apache.storm.windowing.TimestampExtractor;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public abstract class BaseWindowedBolt implements IWindowedBolt {
    private static final Logger LOG = LoggerFactory.getLogger(BaseWindowedBolt.class);

    protected final transient Map<String, Object> windowConfiguration;
    protected TimestampExtractor timestampExtractor;

    protected BaseWindowedBolt() {
        windowConfiguration = new HashMap<>();
    }

    private BaseWindowedBolt withWindowLength(Count count) {
        if (count == null) {
            throw new IllegalArgumentException("Window length count cannot be set null");
        }
        if (count.value <= 0) {
            throw new IllegalArgumentException("Window length must be positive [" + count + "]");
        }
        windowConfiguration.put(Config.TOPOLOGY_BOLTS_WINDOW_LENGTH_COUNT, count.value);
        return this;
    }

    private BaseWindowedBolt withWindowLength(Duration duration) {
        if (duration == null) {
            throw new IllegalArgumentException("Window length duration cannot be set null");
        }
        if (duration.value <= 0) {
            throw new IllegalArgumentException("Window length must be positive [" + duration + "]");
        }

        windowConfiguration.put(Config.TOPOLOGY_BOLTS_WINDOW_LENGTH_DURATION_MS, duration.value);
        return this;
    }

    private BaseWindowedBolt withSlidingInterval(Count count) {
        if (count == null) {
            throw new IllegalArgumentException("Sliding interval count cannot be set null");
        }
        if (count.value <= 0) {
            throw new IllegalArgumentException("Sliding interval must be positive [" + count + "]");
        }
        windowConfiguration.put(Config.TOPOLOGY_BOLTS_SLIDING_INTERVAL_COUNT, count.value);
        return this;
    }

    private BaseWindowedBolt withSlidingInterval(Duration duration) {
        if (duration == null) {
            throw new IllegalArgumentException("Sliding interval duration cannot be set null");
        }
        if (duration.value <= 0) {
            throw new IllegalArgumentException("Sliding interval must be positive [" + duration + "]");
        }
        windowConfiguration.put(Config.TOPOLOGY_BOLTS_SLIDING_INTERVAL_DURATION_MS, duration.value);
        return this;
    }

    /**
     * Tuple count based sliding window configuration.
     *
     * @param windowLength    the number of tuples in the window
     * @param slidingInterval the number of tuples after which the window slides
     */
    public BaseWindowedBolt withWindow(Count windowLength, Count slidingInterval) {
        return withWindowLength(windowLength).withSlidingInterval(slidingInterval);
    }

    /**
     * Tuple count and time duration based sliding window configuration.
     *
     * @param windowLength    the number of tuples in the window
     * @param slidingInterval the time duration after which the window slides
     */
    public BaseWindowedBolt withWindow(Count windowLength, Duration slidingInterval) {
        return withWindowLength(windowLength).withSlidingInterval(slidingInterval);
    }

    /**
     * Time duration and count based sliding window configuration.
     *
     * @param windowLength    the time duration of the window
     * @param slidingInterval the number of tuples after which the window slides
     */
    public BaseWindowedBolt withWindow(Duration windowLength, Count slidingInterval) {
        return withWindowLength(windowLength).withSlidingInterval(slidingInterval);
    }

    /**
     * Time duration based sliding window configuration.
     *
     * @param windowLength    the time duration of the window
     * @param slidingInterval the time duration after which the window slides
     */
    public BaseWindowedBolt withWindow(Duration windowLength, Duration slidingInterval) {
        return withWindowLength(windowLength).withSlidingInterval(slidingInterval);
    }

    /**
     * A tuple count based window that slides with every incoming tuple.
     *
     * @param windowLength the number of tuples in the window
     */
    public BaseWindowedBolt withWindow(Count windowLength) {
        return withWindowLength(windowLength).withSlidingInterval(new Count(1));
    }

    /**
     * A time duration based window that slides with every incoming tuple.
     *
     * @param windowLength the time duration of the window
     */
    public BaseWindowedBolt withWindow(Duration windowLength) {
        return withWindowLength(windowLength).withSlidingInterval(new Count(1));
    }

    /**
     * A count based tumbling window.
     *
     * @param count the number of tuples after which the window tumbles
     */
    public BaseWindowedBolt withTumblingWindow(Count count) {
        return withWindowLength(count).withSlidingInterval(count);
    }

    /**
     * A time duration based tumbling window.
     *
     * @param duration the time duration after which the window tumbles
     */
    public BaseWindowedBolt withTumblingWindow(Duration duration) {
        return withWindowLength(duration).withSlidingInterval(duration);
    }

    /**
     * Specify a field in the tuple that represents the timestamp as a long value. If this field is not present in the incoming tuple, an
     * {@link IllegalArgumentException} will be thrown. The field MUST contain a timestamp in milliseconds
     *
     * @param fieldName the name of the field that contains the timestamp
     */
    public BaseWindowedBolt withTimestampField(String fieldName) {
        return withTimestampExtractor(TupleFieldTimestampExtractor.of(fieldName));
    }

    /**
     * Specify the timestamp extractor implementation.
     *
     * @param timestampExtractor the {@link TimestampExtractor} implementation
     */
    public BaseWindowedBolt withTimestampExtractor(TimestampExtractor timestampExtractor) {
        if (timestampExtractor == null) {
            throw new IllegalArgumentException("Timestamp extractor cannot be set to null");
        }
        if (this.timestampExtractor != null) {
            throw new IllegalArgumentException("Window is already configured with a timestamp extractor: " + timestampExtractor);
        }
        this.timestampExtractor = timestampExtractor;
        return this;
    }

    @Override
    public TimestampExtractor getTimestampExtractor() {
        return timestampExtractor;
    }

    /**
     * Specify a stream id on which late tuples are going to be emitted. They are going to be accessible via the {@link
     * org.apache.storm.topology.WindowedBoltExecutor#LATE_TUPLE_FIELD} field. It must be defined on a per-component basis, and in
     * conjunction with the {@link BaseWindowedBolt#withTimestampField}, otherwise {@link IllegalArgumentException} will be thrown.
     *
     * @param streamId the name of the stream used to emit late tuples on
     */
    public BaseWindowedBolt withLateTupleStream(String streamId) {
        if (streamId == null) {
            throw new IllegalArgumentException("Cannot set late tuple stream id to null");
        }
        windowConfiguration.put(Config.TOPOLOGY_BOLTS_LATE_TUPLE_STREAM, streamId);
        return this;
    }

    /**
     * Specify the maximum time lag of the tuple timestamp in milliseconds. It means that the tuple timestamps cannot be out of order by
     * more than this amount.
     *
     * @param duration the max lag duration
     */
    public BaseWindowedBolt withLag(Duration duration) {
        windowConfiguration.put(Config.TOPOLOGY_BOLTS_TUPLE_TIMESTAMP_MAX_LAG_MS, duration.value);
        return this;
    }

    /**
     * Specify the watermark event generation interval. For tuple based timestamps, watermark events are used to track the progress of time
     *
     * @param interval the interval at which watermark events are generated
     */
    public BaseWindowedBolt withWatermarkInterval(Duration interval) {
        if (interval == null) {
            throw new IllegalArgumentException("Watermark interval cannot be set null");
        }
        windowConfiguration.put(Config.TOPOLOGY_BOLTS_WATERMARK_EVENT_INTERVAL_MS, interval.value);
        return this;
    }

    @Override
    public void prepare(Map<String, Object> topoConf, TopologyContext context, OutputCollector collector) {
        // NOOP
    }

    @Override
    public void cleanup() {
        // NOOP
    }

    @Override
    public void declareOutputFields(OutputFieldsDeclarer declarer) {
        // NOOP
    }

    @Override
    public Map<String, Object> getComponentConfiguration() {
        return windowConfiguration;
    }

    /**
     * Holds a count value for count based windows and sliding intervals.
     */
    public static class Count implements Serializable {
        public final int value;

        public Count(int value) {
            this.value = value;
        }

        /**
         * Returns a {@link Count} of given value.
         *
         * @param value the count value
         * @return the Count
         */
        public static Count of(int value) {
            return new Count(value);
        }

        @Override
        public boolean equals(Object o) {
            if (this == o) {
                return true;
            }
            if (o == null || getClass() != o.getClass()) {
                return false;
            }

            Count count = (Count) o;

            return value == count.value;

        }

        @Override
        public int hashCode() {
            return value;
        }

        @Override
        public String toString() {
            return "Count{" +
                   "value=" + value +
                   '}';
        }
    }

    /**
     * Holds a Time duration for time based windows and sliding intervals.
     */
    public static class Duration implements Serializable {
        public final int value;

        public Duration(int value, TimeUnit timeUnit) {
            if (value < 0) {
                throw new IllegalArgumentException("Duration cannot be negative");
            }
            long longVal = timeUnit.toMillis(value);
            if (longVal > (long) Integer.MAX_VALUE) {
                throw new IllegalArgumentException("Duration is too long");
            }
            this.value = (int) longVal;
        }

        /**
         * Returns a {@link Duration} corresponding to the the given value in milli seconds.
         *
         * @param milliseconds the duration in milliseconds
         * @return the Duration
         */
        public static Duration of(int milliseconds) {
            return new Duration(milliseconds, TimeUnit.MILLISECONDS);
        }

        /**
         * Returns a {@link Duration} corresponding to the the given value in days.
         *
         * @param days the number of days
         * @return the Duration
         */
        public static Duration days(int days) {
            return new Duration(days, TimeUnit.DAYS);
        }

        /**
         * Returns a {@link Duration} corresponding to the the given value in hours.
         *
         * @param hours the number of hours
         * @return the Duration
         */
        public static Duration hours(int hours) {
            return new Duration(hours, TimeUnit.HOURS);
        }

        /**
         * Returns a {@link Duration} corresponding to the the given value in minutes.
         *
         * @param minutes the number of minutes
         * @return the Duration
         */
        public static Duration minutes(int minutes) {
            return new Duration(minutes, TimeUnit.MINUTES);
        }

        /**
         * Returns a {@link Duration} corresponding to the the given value in seconds.
         *
         * @param seconds the number of seconds
         * @return the Duration
         */
        public static Duration seconds(int seconds) {
            return new Duration(seconds, TimeUnit.SECONDS);
        }

        @Override
        public boolean equals(Object o) {
            if (this == o) {
                return true;
            }
            if (o == null || getClass() != o.getClass()) {
                return false;
            }

            Duration duration = (Duration) o;

            return value == duration.value;

        }

        @Override
        public int hashCode() {
            return value;
        }

        @Override
        public String toString() {
            return "Duration{" +
                   "value=" + value +
                   '}';
        }
    }
}