com.facebook.presto.decoder.raw.RawRowDecoder 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 com.facebook.presto.decoder.raw;
import com.facebook.presto.decoder.DecoderColumnHandle;
import com.facebook.presto.decoder.FieldValueProvider;
import com.facebook.presto.decoder.RowDecoder;
import java.util.Map;
import java.util.Optional;
import java.util.Set;
import static com.google.common.collect.ImmutableMap.toImmutableMap;
import static java.util.Objects.requireNonNull;
import static java.util.function.Function.identity;
/**
* Decoder for raw (direct byte) rows. All field decoders map bytes directly to Presto columns.
*/
public class RawRowDecoder
implements RowDecoder
{
public static final String NAME = "raw";
private final Map columnDecoders;
public RawRowDecoder(Set columnHandles)
{
requireNonNull(columnHandles, "columnHandles is null");
columnDecoders = columnHandles.stream()
.collect(toImmutableMap(identity(), this::createColumnDecoder));
}
private RawColumnDecoder createColumnDecoder(DecoderColumnHandle columnHandle)
{
return new RawColumnDecoder(columnHandle);
}
@Override
public Optional> decodeRow(byte[] data, Map dataMap)
{
return Optional.of(columnDecoders.entrySet().stream()
.collect(toImmutableMap(
Map.Entry::getKey,
entry -> entry.getValue().decodeField(data))));
}
}