/*
* 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.redis.decoder.hash;
import com.facebook.presto.decoder.DecoderColumnHandle;
import com.facebook.presto.decoder.FieldDecoder;
import com.facebook.presto.decoder.FieldValueProvider;
import com.facebook.presto.decoder.RowDecoder;
import java.util.List;
import java.util.Map;
import java.util.Set;
import static com.google.common.base.Preconditions.checkState;
/**
* The row decoder for the Redis values that are stored in Hash format.
*/
public class HashRedisRowDecoder
implements RowDecoder
{
public static final String NAME = "hash";
@Override
public String getName()
{
return NAME;
}
@Override
public boolean decodeRow(byte[] data,
Map<String, String> dataMap,
Set<FieldValueProvider> fieldValueProviders,
List<DecoderColumnHandle> columnHandles,
Map<DecoderColumnHandle, FieldDecoder<?>> fieldDecoders)
{
if (dataMap == null) {
return false;
}
for (DecoderColumnHandle columnHandle : columnHandles) {
if (columnHandle.isInternal()) {
continue;
}
String mapping = columnHandle.getMapping();
checkState(mapping != null, "No mapping for column handle %s!", columnHandle);
String valueField = dataMap.get(mapping);
@SuppressWarnings("unchecked")
FieldDecoder<String> decoder = (FieldDecoder<String>) fieldDecoders.get(columnHandle);
if (decoder != null) {
fieldValueProviders.add(decoder.decode(valueField, columnHandle));
}
}
return false;
}
}