/*
* 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.state;
import com.facebook.presto.spi.block.Block;
import com.facebook.presto.spi.block.BlockBuilder;
import com.facebook.presto.spi.type.Type;
import io.airlift.slice.DynamicSliceOutput;
import io.airlift.slice.Slice;
import io.airlift.slice.SliceInput;
import io.airlift.stats.QuantileDigest;
import static com.facebook.presto.spi.type.VarcharType.VARCHAR;
import static io.airlift.slice.SizeOf.SIZE_OF_DOUBLE;
public class DigestAndPercentileStateSerializer
implements AccumulatorStateSerializer<DigestAndPercentileState>
{
@Override
public Type getSerializedType()
{
return VARCHAR;
}
@Override
public void serialize(DigestAndPercentileState state, BlockBuilder out)
{
if (state.getDigest() == null) {
out.appendNull();
}
else {
DynamicSliceOutput sliceOutput = new DynamicSliceOutput(state.getDigest().estimatedSerializedSizeInBytes() + SIZE_OF_DOUBLE);
// write digest
state.getDigest().serialize(sliceOutput);
// write percentile
sliceOutput.appendDouble(state.getPercentile());
Slice slice = sliceOutput.slice();
VARCHAR.writeSlice(out, slice);
}
}
@Override
public void deserialize(Block block, int index, DigestAndPercentileState state)
{
if (!block.isNull(index)) {
SliceInput input = VARCHAR.getSlice(block, index).getInput();
// read digest
state.setDigest(QuantileDigest.deserialize(input));
state.addMemoryUsage(state.getDigest().estimatedInMemorySizeInBytes());
// read percentile
state.setPercentile(input.readDouble());
}
}
}