io.druid.query.aggregation.histogram.ApproximateHistogramAggregatorFactory Maven / Gradle / Ivy
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* Licensed to Metamarkets Group Inc. (Metamarkets) under one
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* 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
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* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package io.druid.query.aggregation.histogram;
import com.fasterxml.jackson.annotation.JsonCreator;
import com.fasterxml.jackson.annotation.JsonProperty;
import com.fasterxml.jackson.annotation.JsonTypeName;
import com.google.common.base.Preconditions;
import com.google.common.primitives.Floats;
import com.google.common.primitives.Ints;
import io.druid.java.util.common.StringUtils;
import io.druid.query.aggregation.AggregateCombiner;
import io.druid.query.aggregation.Aggregator;
import io.druid.query.aggregation.AggregatorFactory;
import io.druid.query.aggregation.AggregatorFactoryNotMergeableException;
import io.druid.query.aggregation.AggregatorUtil;
import io.druid.query.aggregation.BufferAggregator;
import io.druid.query.aggregation.ObjectAggregateCombiner;
import io.druid.segment.ColumnSelectorFactory;
import io.druid.segment.ColumnValueSelector;
import org.apache.commons.codec.binary.Base64;
import javax.annotation.Nullable;
import java.nio.ByteBuffer;
import java.util.Arrays;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;
@JsonTypeName("approxHistogram")
public class ApproximateHistogramAggregatorFactory extends AggregatorFactory
{
protected final String name;
protected final String fieldName;
protected final int resolution;
protected final int numBuckets;
protected final float lowerLimit;
protected final float upperLimit;
@JsonCreator
public ApproximateHistogramAggregatorFactory(
@JsonProperty("name") String name,
@JsonProperty("fieldName") String fieldName,
@JsonProperty("resolution") Integer resolution,
@JsonProperty("numBuckets") Integer numBuckets,
@JsonProperty("lowerLimit") Float lowerLimit,
@JsonProperty("upperLimit") Float upperLimit
)
{
this.name = name;
this.fieldName = fieldName;
this.resolution = resolution == null ? ApproximateHistogram.DEFAULT_HISTOGRAM_SIZE : resolution;
this.numBuckets = numBuckets == null ? ApproximateHistogram.DEFAULT_BUCKET_SIZE : numBuckets;
this.lowerLimit = lowerLimit == null ? Float.NEGATIVE_INFINITY : lowerLimit;
this.upperLimit = upperLimit == null ? Float.POSITIVE_INFINITY : upperLimit;
Preconditions.checkArgument(this.resolution > 0, "resolution must be greater than 1");
Preconditions.checkArgument(this.numBuckets > 0, "numBuckets must be greater than 1");
Preconditions.checkArgument(this.upperLimit > this.lowerLimit, "upperLimit must be greater than lowerLimit");
}
@Override
public Aggregator factorize(ColumnSelectorFactory metricFactory)
{
return new ApproximateHistogramAggregator(
metricFactory.makeColumnValueSelector(fieldName),
resolution,
lowerLimit,
upperLimit
);
}
@Override
public BufferAggregator factorizeBuffered(ColumnSelectorFactory metricFactory)
{
return new ApproximateHistogramBufferAggregator(
metricFactory.makeColumnValueSelector(fieldName),
resolution
);
}
@Override
public Comparator getComparator()
{
return ApproximateHistogramAggregator.COMPARATOR;
}
@Override
public Object combine(Object lhs, Object rhs)
{
return ApproximateHistogramAggregator.combineHistograms(lhs, rhs);
}
@Override
public AggregateCombiner makeAggregateCombiner()
{
// ApproximateHistogramAggregatorFactory.combine() delegates to ApproximateHistogramAggregator.combineHistograms()
// and it doesn't check for nulls, so this AggregateCombiner neither.
return new ObjectAggregateCombiner()
{
private final ApproximateHistogram combined = new ApproximateHistogram();
@Override
public void reset(ColumnValueSelector selector)
{
ApproximateHistogram first = (ApproximateHistogram) selector.getObject();
combined.copy(first);
}
@Override
public void fold(ColumnValueSelector selector)
{
ApproximateHistogram other = (ApproximateHistogram) selector.getObject();
combined.foldFast(other);
}
@Override
public Class classOfObject()
{
return ApproximateHistogram.class;
}
@Nullable
@Override
public ApproximateHistogram getObject()
{
return combined;
}
};
}
@Override
public AggregatorFactory getCombiningFactory()
{
return new ApproximateHistogramFoldingAggregatorFactory(name, name, resolution, numBuckets, lowerLimit, upperLimit);
}
@Override
public AggregatorFactory getMergingFactory(AggregatorFactory other) throws AggregatorFactoryNotMergeableException
{
if (other.getName().equals(this.getName()) && other instanceof ApproximateHistogramAggregatorFactory) {
ApproximateHistogramAggregatorFactory castedOther = (ApproximateHistogramAggregatorFactory) other;
return new ApproximateHistogramFoldingAggregatorFactory(
name,
name,
Math.max(resolution, castedOther.resolution),
numBuckets,
Math.min(lowerLimit, castedOther.lowerLimit),
Math.max(upperLimit, castedOther.upperLimit)
);
} else {
throw new AggregatorFactoryNotMergeableException(this, other);
}
}
@Override
public List getRequiredColumns()
{
return Arrays.asList(
new ApproximateHistogramAggregatorFactory(
fieldName,
fieldName,
resolution,
numBuckets,
lowerLimit,
upperLimit
)
);
}
@Override
public Object deserialize(Object object)
{
if (object instanceof byte[]) {
final ApproximateHistogram ah = ApproximateHistogram.fromBytes((byte[]) object);
ah.setLowerLimit(lowerLimit);
ah.setUpperLimit(upperLimit);
return ah;
} else if (object instanceof ByteBuffer) {
final ApproximateHistogram ah = ApproximateHistogram.fromBytes((ByteBuffer) object);
ah.setLowerLimit(lowerLimit);
ah.setUpperLimit(upperLimit);
return ah;
} else if (object instanceof String) {
byte[] bytes = Base64.decodeBase64(StringUtils.toUtf8((String) object));
final ApproximateHistogram ah = ApproximateHistogram.fromBytes(bytes);
ah.setLowerLimit(lowerLimit);
ah.setUpperLimit(upperLimit);
return ah;
} else {
return object;
}
}
@Override
public Object finalizeComputation(Object object)
{
return ((ApproximateHistogram) object).toHistogram(numBuckets);
}
@JsonProperty
@Override
public String getName()
{
return name;
}
@JsonProperty
public String getFieldName()
{
return fieldName;
}
@JsonProperty
public int getResolution()
{
return resolution;
}
@JsonProperty
public float getLowerLimit()
{
return lowerLimit;
}
@JsonProperty
public float getUpperLimit()
{
return upperLimit;
}
@JsonProperty
public int getNumBuckets()
{
return numBuckets;
}
@Override
public List requiredFields()
{
return Collections.singletonList(fieldName);
}
@Override
public byte[] getCacheKey()
{
byte[] fieldNameBytes = StringUtils.toUtf8(fieldName);
return ByteBuffer.allocate(1 + fieldNameBytes.length + Ints.BYTES * 2 + Floats.BYTES * 2)
.put(AggregatorUtil.APPROX_HIST_CACHE_TYPE_ID)
.put(fieldNameBytes)
.putInt(resolution)
.putInt(numBuckets)
.putFloat(lowerLimit)
.putFloat(upperLimit).array();
}
@Override
public String getTypeName()
{
return "approximateHistogram";
}
@Override
public int getMaxIntermediateSize()
{
return new ApproximateHistogram(resolution).getMaxStorageSize();
}
@Override
public boolean equals(Object o)
{
if (this == o) {
return true;
}
if (o == null || getClass() != o.getClass()) {
return false;
}
ApproximateHistogramAggregatorFactory that = (ApproximateHistogramAggregatorFactory) o;
if (Float.compare(that.lowerLimit, lowerLimit) != 0) {
return false;
}
if (numBuckets != that.numBuckets) {
return false;
}
if (resolution != that.resolution) {
return false;
}
if (Float.compare(that.upperLimit, upperLimit) != 0) {
return false;
}
if (fieldName != null ? !fieldName.equals(that.fieldName) : that.fieldName != null) {
return false;
}
if (name != null ? !name.equals(that.name) : that.name != null) {
return false;
}
return true;
}
@Override
public int hashCode()
{
int result = name != null ? name.hashCode() : 0;
result = 31 * result + (fieldName != null ? fieldName.hashCode() : 0);
result = 31 * result + resolution;
result = 31 * result + numBuckets;
result = 31 * result + (lowerLimit != +0.0f ? Float.floatToIntBits(lowerLimit) : 0);
result = 31 * result + (upperLimit != +0.0f ? Float.floatToIntBits(upperLimit) : 0);
return result;
}
@Override
public String toString()
{
return "ApproximateHistogramAggregatorFactory{" +
"name='" + name + '\'' +
", fieldName='" + fieldName + '\'' +
", resolution=" + resolution +
", numBuckets=" + numBuckets +
", lowerLimit=" + lowerLimit +
", upperLimit=" + upperLimit +
'}';
}
}
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