io.druid.query.aggregation.last.DoubleLastBufferAggregator.java Source code

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Here is the source code for io.druid.query.aggregation.last.DoubleLastBufferAggregator.java

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/*
 * Licensed to Metamarkets Group Inc. (Metamarkets) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. Metamarkets 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 io.druid.query.aggregation.last;

import com.google.common.primitives.Longs;
import io.druid.collections.SerializablePair;
import io.druid.query.aggregation.BufferAggregator;
import io.druid.segment.FloatColumnSelector;
import io.druid.segment.LongColumnSelector;

import java.nio.ByteBuffer;

public class DoubleLastBufferAggregator implements BufferAggregator {
    private final LongColumnSelector timeSelector;
    private final FloatColumnSelector valueSelector;

    public DoubleLastBufferAggregator(LongColumnSelector timeSelector, FloatColumnSelector valueSelector) {
        this.timeSelector = timeSelector;
        this.valueSelector = valueSelector;
    }

    @Override
    public void init(ByteBuffer buf, int position) {
        buf.putLong(position, Long.MIN_VALUE);
        buf.putDouble(position + Longs.BYTES, 0);
    }

    @Override
    public void aggregate(ByteBuffer buf, int position) {
        long time = timeSelector.get();
        long lastTime = buf.getLong(position);
        if (time >= lastTime) {
            buf.putLong(position, time);
            buf.putDouble(position + Longs.BYTES, valueSelector.get());
        }
    }

    @Override
    public Object get(ByteBuffer buf, int position) {
        return new SerializablePair<>(buf.getLong(position), buf.getDouble(position + Longs.BYTES));
    }

    @Override
    public float getFloat(ByteBuffer buf, int position) {
        return (float) buf.getDouble(position + Longs.BYTES);
    }

    @Override
    public long getLong(ByteBuffer buf, int position) {
        return (long) buf.getDouble(position + Longs.BYTES);
    }

    @Override
    public void close() {
        // no resources to cleanup
    }
}