SimpleStringWriterBuilder.java
/*
* 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.wikimedia.gobblin.writer;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import org.apache.gobblin.codec.StreamCodec;
import org.apache.gobblin.compression.CompressionConfigParser;
import org.apache.gobblin.configuration.State;
import org.apache.gobblin.crypto.EncryptionConfigParser;
import org.apache.gobblin.crypto.EncryptionFactory;
import org.apache.gobblin.instrumented.writer.InstrumentedDataWriterDecorator;
import org.apache.gobblin.writer.DataWriter;
import org.apache.gobblin.writer.DataWriterBuilder;
import org.apache.gobblin.writer.FsDataWriterBuilder;
import org.apache.gobblin.writer.MetadataWriterWrapper;
import org.wikimedia.gobblin.compression.CompressionFactory;
import com.google.common.base.Preconditions;
/**
* A {@link DataWriterBuilder} for building {@link DataWriter} that writes String.
*
* @author akshay@nerdwallet.com
*/
public class SimpleStringWriterBuilder extends FsDataWriterBuilder<String, Object> {
/**
* Build a {@link org.apache.gobblin.writer.DataWriter}.
*
* @return the built {@link org.apache.gobblin.writer.DataWriter}
* @throws java.io.IOException if there is anything wrong building the writer
*/
@Override
public DataWriter<Object> build() throws IOException {
State state = this.destination.getProperties();
return new InstrumentedDataWriterDecorator<>(new MetadataWriterWrapper<>(
new SimpleStringWriter(this, state),
String.class,
this.branches,
this.branch,
state
), state);
}
@Override
protected List<StreamCodec> buildEncoders() {
Preconditions.checkNotNull(this.destination, "Destination must be set before building encoders");
List<StreamCodec> encoders = new ArrayList<>();
// TODO: refactor this when capability support comes back in
// Compress first since compressing encrypted data will give no benefit
Map<String, Object> compressionConfig =
CompressionConfigParser.getConfigForBranch(this.destination.getProperties(), this.branches, this.branch);
if (compressionConfig != null) {
// WARNING: Using wmf CompressionFactory for '.gz' instead of '.gzip' extension problem
encoders.add(CompressionFactory.buildStreamCompressor(compressionConfig));
}
Map<String, Object> encryptionConfig = EncryptionConfigParser
.getConfigForBranch(EncryptionConfigParser.EntityType.WRITER, this.destination.getProperties(), this.branches,
this.branch);
if (encryptionConfig != null) {
encoders.add(EncryptionFactory.buildStreamCryptoProvider(encryptionConfig));
}
return encoders;
}
}