org.apache.parquet.pig.ParquetStorer Maven / Gradle / Ivy
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* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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 org.apache.parquet.pig;
import java.io.IOException;
import java.util.Properties;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.OutputFormat;
import org.apache.hadoop.mapreduce.RecordWriter;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.parquet.hadoop.ParquetOutputFormat;
import org.apache.parquet.io.ParquetEncodingException;
import org.apache.pig.ResourceSchema;
import org.apache.pig.ResourceStatistics;
import org.apache.pig.StoreFunc;
import org.apache.pig.StoreMetadata;
import org.apache.pig.data.Tuple;
import org.apache.pig.impl.logicalLayer.schema.Schema;
import org.apache.pig.impl.util.UDFContext;
import org.apache.pig.impl.util.Utils;
import org.apache.pig.parser.ParserException;
/**
* A pig storer implementation for the Parquet file format.
* see {@link ParquetOutputFormat} for available parameters.
*
* It uses a TupleWriteSupport to write Tuples into the ParquetOutputFormat
* The Pig schema is automatically converted to the Parquet schema using {@link PigSchemaConverter}
* and stored in the file
*/
public class ParquetStorer extends StoreFunc implements StoreMetadata {
private static final String SCHEMA = "schema";
private RecordWriter recordWriter;
private String signature;
private Properties getProperties() {
UDFContext udfc = UDFContext.getUDFContext();
Properties p = udfc.getUDFProperties(this.getClass(), new String[] {signature});
return p;
}
private Schema getSchema() {
try {
final String schemaString = getProperties().getProperty(SCHEMA);
if (schemaString == null) {
throw new ParquetEncodingException("Can not store relation in Parquet as the schema is unknown");
}
return Utils.getSchemaFromString(schemaString);
} catch (ParserException e) {
throw new ParquetEncodingException("can not get schema from context", e);
}
}
public ParquetStorer() {}
/**
* {@inheritDoc}
*/
@Override
public void setStoreFuncUDFContextSignature(String signature) {
super.setStoreFuncUDFContextSignature(signature);
this.signature = signature;
}
/**
* {@inheritDoc}
*/
@Override
public void checkSchema(ResourceSchema s) throws IOException {
getProperties().setProperty(SCHEMA, s.toString());
}
/**
* {@inheritDoc}
*/
@Override
public OutputFormat getOutputFormat() throws IOException {
Schema pigSchema = getSchema();
return new ParquetOutputFormat(new TupleWriteSupport(pigSchema));
}
/**
* {@inheritDoc}
*/
@SuppressWarnings({"rawtypes", "unchecked"}) // that's how the base class is defined
@Override
public void prepareToWrite(RecordWriter recordWriter) throws IOException {
this.recordWriter = recordWriter;
}
/**
* {@inheritDoc}
*/
@Override
public void putNext(Tuple tuple) throws IOException {
try {
this.recordWriter.write(null, tuple);
} catch (InterruptedException e) {
Thread.interrupted();
throw new ParquetEncodingException("Interrupted while writing", e);
}
}
/**
* {@inheritDoc}
*/
@Override
public void setStoreLocation(String location, Job job) throws IOException {
FileOutputFormat.setOutputPath(job, new Path(location));
}
/**
* {@inheritDoc}
*/
@Override
public void storeSchema(ResourceSchema schema, String location, Job job) throws IOException {}
/**
* {@inheritDoc}
*/
@Override
public void storeStatistics(ResourceStatistics resourceStatistics, String location, Job job) throws IOException {}
}