io.prestosql.parquet.reader.LongDecimalColumnReader Maven / Gradle / Ivy

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/*
 * 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.prestosql.parquet.reader;

import io.airlift.slice.Slice;
import io.prestosql.parquet.RichColumnDescriptor;
import io.prestosql.spi.block.BlockBuilder;
import io.prestosql.spi.type.DecimalType;
import io.prestosql.spi.type.Decimals;
import io.prestosql.spi.type.Type;
import org.apache.parquet.io.ParquetDecodingException;
import org.apache.parquet.io.api.Binary;

import java.math.BigInteger;

import static io.prestosql.spi.type.DecimalConversions.longToLongCast;
import static io.prestosql.spi.type.DecimalConversions.longToShortCast;
import static java.lang.String.format;
import static java.util.Objects.requireNonNull;

public class LongDecimalColumnReader
        extends PrimitiveColumnReader
{
    private final DecimalType parquetDecimalType;

    LongDecimalColumnReader(RichColumnDescriptor descriptor, DecimalType parquetDecimalType)
    {
        super(descriptor);
        this.parquetDecimalType = requireNonNull(parquetDecimalType, "parquetDecimalType is null");
    }

    @Override
    protected void readValue(BlockBuilder blockBuilder, Type prestoType)
    {
        if (!(prestoType instanceof DecimalType)) {
            throw new ParquetDecodingException(format("Unsupported Presto column type (%s) for Parquet column (%s)", prestoType, columnDescriptor));
        }

        DecimalType prestoDecimalType = (DecimalType) prestoType;

        if (definitionLevel == columnDescriptor.getMaxDefinitionLevel()) {
            Binary binary = valuesReader.readBytes();
            Slice value = Decimals.encodeUnscaledValue(new BigInteger(binary.getBytes()));

            if (prestoDecimalType.isShort()) {
                prestoType.writeLong(blockBuilder, longToShortCast(
                        value,
                        parquetDecimalType.getPrecision(),
                        parquetDecimalType.getScale(),
                        prestoDecimalType.getPrecision(),
                        prestoDecimalType.getScale()));
            }
            else {
                prestoType.writeSlice(blockBuilder, longToLongCast(
                        value,
                        parquetDecimalType.getPrecision(),
                        parquetDecimalType.getScale(),
                        prestoDecimalType.getPrecision(),
                        prestoDecimalType.getScale()));
            }
        }
        else if (isValueNull()) {
            blockBuilder.appendNull();
        }
    }

    @Override
    protected void skipValue()
    {
        if (definitionLevel == columnDescriptor.getMaxDefinitionLevel()) {
            valuesReader.readBytes();
        }
    }
}