/*
* 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.DigestAndPercentileState;
import com.facebook.presto.spi.block.BlockBuilder;
import com.facebook.presto.spi.type.StandardTypes;
import com.facebook.presto.spi.type.Type;
import com.facebook.presto.type.SqlType;
import com.google.common.collect.ImmutableList;
import io.airlift.stats.QuantileDigest;
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;
import static com.google.common.base.Preconditions.checkState;
@AggregationFunction("approx_percentile")
public final class ApproximateDoublePercentileAggregations
{
public static final InternalAggregationFunction DOUBLE_APPROXIMATE_PERCENTILE_AGGREGATION = new AggregationCompiler().generateAggregationFunction(ApproximateDoublePercentileAggregations.class, DOUBLE, ImmutableList.<Type>of(DOUBLE, DOUBLE));
public static final InternalAggregationFunction DOUBLE_APPROXIMATE_PERCENTILE_WEIGHTED_AGGREGATION = new AggregationCompiler().generateAggregationFunction(ApproximateDoublePercentileAggregations.class, DOUBLE, ImmutableList.<Type>of(DOUBLE, BIGINT, DOUBLE));
private ApproximateDoublePercentileAggregations() {}
@InputFunction
public static void input(DigestAndPercentileState state, @SqlType(StandardTypes.DOUBLE) double value, @SqlType(StandardTypes.DOUBLE) double percentile)
{
ApproximateLongPercentileAggregations.input(state, doubleToSortableLong(value), percentile);
}
@InputFunction
public static void weightedInput(DigestAndPercentileState state, @SqlType(StandardTypes.DOUBLE) double value, @SqlType(StandardTypes.BIGINT) long weight, @SqlType(StandardTypes.DOUBLE) double percentile)
{
ApproximateLongPercentileAggregations.weightedInput(state, doubleToSortableLong(value), weight, percentile);
}
@CombineFunction
public static void combine(DigestAndPercentileState state, DigestAndPercentileState otherState)
{
ApproximateLongPercentileAggregations.combine(state, otherState);
}
@OutputFunction(StandardTypes.DOUBLE)
public static void output(DigestAndPercentileState state, BlockBuilder out)
{
QuantileDigest digest = state.getDigest();
double percentile = state.getPercentile();
if (digest == null || digest.getCount() == 0.0) {
out.appendNull();
}
else {
checkState(percentile != -1.0, "Percentile is missing");
checkCondition(0 <= percentile && percentile <= 1, INVALID_FUNCTION_ARGUMENT, "Percentile must be between 0 and 1");
DOUBLE.writeDouble(out, longToDouble(digest.getQuantile(percentile)));
}
}
private static double longToDouble(long value)
{
if (value < 0) {
value ^= 0x7fffffffffffffffL;
}
return Double.longBitsToDouble(value);
}
private static long doubleToSortableLong(double value)
{
long result = Double.doubleToRawLongBits(value);
if (result < 0) {
result ^= 0x7fffffffffffffffL;
}
return result;
}
}