/*
* 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.facebook.presto.operator.aggregation;
import com.facebook.presto.operator.aggregation.state.DigestAndPercentileArrayState;
import com.facebook.presto.spi.block.Block;
import com.facebook.presto.spi.block.BlockBuilder;
import com.facebook.presto.spi.function.AggregationFunction;
import com.facebook.presto.spi.function.AggregationState;
import com.facebook.presto.spi.function.CombineFunction;
import com.facebook.presto.spi.function.InputFunction;
import com.facebook.presto.spi.function.OutputFunction;
import com.facebook.presto.spi.function.SqlType;
import com.facebook.presto.spi.type.StandardTypes;
import com.google.common.collect.ImmutableList;
import io.airlift.stats.QuantileDigest;
import java.util.List;
import static com.facebook.presto.spi.StandardErrorCode.INVALID_FUNCTION_ARGUMENT;
import static com.facebook.presto.spi.type.BigintType.BIGINT;
import static com.facebook.presto.spi.type.DoubleType.DOUBLE;
import static com.facebook.presto.util.Failures.checkCondition;
@AggregationFunction("approx_percentile")
public final class ApproximateLongPercentileArrayAggregations
{
private ApproximateLongPercentileArrayAggregations() {}
@InputFunction
public static void input(@AggregationState DigestAndPercentileArrayState state, @SqlType(StandardTypes.BIGINT) long value, @SqlType("array(double)") Block percentilesArrayBlock)
{
initializePercentilesArray(state, percentilesArrayBlock);
initializeDigest(state);
QuantileDigest digest = state.getDigest();
state.addMemoryUsage(-digest.estimatedInMemorySizeInBytes());
digest.add(value);
state.addMemoryUsage(digest.estimatedInMemorySizeInBytes());
}
@InputFunction
public static void weightedInput(@AggregationState DigestAndPercentileArrayState state, @SqlType(StandardTypes.BIGINT) long value, @SqlType(StandardTypes.BIGINT) long weight, @SqlType("array(double)") Block percentilesArrayBlock)
{
initializePercentilesArray(state, percentilesArrayBlock);
initializeDigest(state);
QuantileDigest digest = state.getDigest();
state.addMemoryUsage(-digest.estimatedInMemorySizeInBytes());
digest.add(value, weight);
state.addMemoryUsage(digest.estimatedInMemorySizeInBytes());
}
@CombineFunction
public static void combine(@AggregationState DigestAndPercentileArrayState state, DigestAndPercentileArrayState otherState)
{
QuantileDigest otherDigest = otherState.getDigest();
QuantileDigest digest = state.getDigest();
if (digest == null) {
state.setDigest(otherDigest);
state.addMemoryUsage(otherDigest.estimatedInMemorySizeInBytes());
}
else {
state.addMemoryUsage(-digest.estimatedInMemorySizeInBytes());
digest.merge(otherDigest);
state.addMemoryUsage(digest.estimatedInMemorySizeInBytes());
}
state.setPercentiles(otherState.getPercentiles());
}
@OutputFunction("array(bigint)")
public static void output(@AggregationState DigestAndPercentileArrayState state, BlockBuilder out)
{
QuantileDigest digest = state.getDigest();
List<Double> percentiles = state.getPercentiles();
if (percentiles == null || digest == null) {
out.appendNull();
return;
}
BlockBuilder blockBuilder = out.beginBlockEntry();
for (int i = 0; i < percentiles.size(); i++) {
Double percentile = percentiles.get(i);
BIGINT.writeLong(blockBuilder, digest.getQuantile(percentile));
}
out.closeEntry();
}
private static void initializePercentilesArray(@AggregationState DigestAndPercentileArrayState state, Block percentilesArrayBlock)
{
if (state.getPercentiles() == null) {
ImmutableList.Builder<Double> percentilesListBuilder = ImmutableList.builder();
for (int i = 0; i < percentilesArrayBlock.getPositionCount(); i++) {
checkCondition(!percentilesArrayBlock.isNull(i), INVALID_FUNCTION_ARGUMENT, "Percentile cannot be null");
double percentile = DOUBLE.getDouble(percentilesArrayBlock, i);
checkCondition(0 <= percentile && percentile <= 1, INVALID_FUNCTION_ARGUMENT, "Percentile must be between 0 and 1");
percentilesListBuilder.add(percentile);
}
state.setPercentiles(percentilesListBuilder.build());
}
}
private static void initializeDigest(@AggregationState DigestAndPercentileArrayState state)
{
QuantileDigest digest = state.getDigest();
if (digest == null) {
digest = new QuantileDigest(0.01);
state.setDigest(digest);
state.addMemoryUsage(digest.estimatedInMemorySizeInBytes());
}
}
}