parquet.hadoop.example.GroupReadSupport Maven / Gradle / Ivy
/**
* Copyright 2012 Twitter, Inc.
*
* 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 parquet.hadoop.example;
import java.util.Map;
import org.apache.hadoop.conf.Configuration;
import parquet.example.data.Group;
import parquet.example.data.simple.convert.GroupRecordConverter;
import parquet.hadoop.api.ReadSupport;
import parquet.io.api.RecordMaterializer;
import parquet.schema.MessageType;
public class GroupReadSupport extends ReadSupport {
@Override
public parquet.hadoop.api.ReadSupport.ReadContext init(
Configuration configuration, Map keyValueMetaData,
MessageType fileSchema) {
String partialSchemaString = configuration.get(ReadSupport.PARQUET_READ_SCHEMA);
MessageType requestedProjection = getSchemaForRead(fileSchema, partialSchemaString);
return new ReadContext(requestedProjection);
}
@Override
public RecordMaterializer prepareForRead(Configuration configuration,
Map keyValueMetaData, MessageType fileSchema,
parquet.hadoop.api.ReadSupport.ReadContext readContext) {
return new GroupRecordConverter(readContext.getRequestedSchema());
}
}