/*
* 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.LongState;
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 static com.facebook.presto.spi.type.BigintType.BIGINT;
@AggregationFunction("count_if")
public final class CountIfAggregation
{
private CountIfAggregation() {}
@InputFunction
public static void input(@AggregationState LongState state, @SqlType(StandardTypes.BOOLEAN) boolean value)
{
if (value) {
state.setLong(state.getLong() + 1);
}
}
@CombineFunction
public static void combine(@AggregationState LongState state, @AggregationState LongState otherState)
{
state.setLong(state.getLong() + otherState.getLong());
}
@OutputFunction(StandardTypes.BIGINT)
public static void output(@AggregationState LongState state, BlockBuilder out)
{
BIGINT.writeLong(out, state.getLong());
}
}