io.trino.operator.aggregation.StringApproximateMostFrequentStateSerializer Maven / Gradle / Ivy
/*
* 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 io.trino.operator.aggregation;
import io.airlift.slice.DynamicSliceOutput;
import io.airlift.slice.Slice;
import io.airlift.slice.SliceInput;
import io.trino.spi.block.Block;
import io.trino.spi.block.BlockBuilder;
import io.trino.spi.function.AccumulatorStateSerializer;
import io.trino.spi.type.Type;
import static io.trino.spi.type.VarbinaryType.VARBINARY;
public class StringApproximateMostFrequentStateSerializer
implements AccumulatorStateSerializer
{
public static void serializeBucket(Slice key, Long count, DynamicSliceOutput output)
{
output.appendInt(key.length());
output.appendBytes(key);
output.appendLong(count);
}
public static void deserializeBucket(SliceInput input, ApproximateMostFrequentHistogram histogram)
{
int keySize = input.readInt();
Slice key = input.readSlice(keySize);
long count = input.readLong();
histogram.add(key, count);
}
@Override
public Type getSerializedType()
{
return VARBINARY;
}
@Override
public void serialize(VarcharApproximateMostFrequent.State state, BlockBuilder out)
{
if (state.get() == null) {
out.appendNull();
}
else {
VARBINARY.writeSlice(out, state.get().serialize());
}
}
@Override
public void deserialize(Block block, int index, VarcharApproximateMostFrequent.State state)
{
state.set(new ApproximateMostFrequentHistogram(
VARBINARY.getSlice(block, index),
StringApproximateMostFrequentStateSerializer::serializeBucket,
StringApproximateMostFrequentStateSerializer::deserializeBucket));
}
}