/*
* Copyright © 2014 Cask Data, 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 co.cask.tigon.internal.app.runtime.flow;
import co.cask.tigon.api.flow.flowlet.OutputEmitter;
import co.cask.tigon.data.queue.QueueEntry;
import co.cask.tigon.data.queue.QueueProducer;
import co.cask.tigon.internal.io.DatumWriter;
import co.cask.tigon.internal.io.Schema;
import co.cask.tigon.io.BinaryEncoder;
import com.google.common.base.Function;
import com.google.common.base.Throwables;
import com.google.common.collect.ImmutableMap;
import com.google.common.collect.Maps;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.Map;
import javax.annotation.Nullable;
/**
* @param <T>
*/
public final class DatumOutputEmitter<T> implements OutputEmitter<T> {
public static final Function<Object, Integer> PARTITION_MAP_TRANSFORMER = new PartitionMapTransformer();
private final QueueProducer queueProducer;
private final byte[] schemaHash;
private final DatumWriter<T> writer;
public DatumOutputEmitter(QueueProducer queueProducer, Schema schema, DatumWriter<T> writer) {
this.queueProducer = queueProducer;
this.schemaHash = schema.getSchemaHash().toByteArray();
this.writer = writer;
}
@Override
public void emit(T data) {
emit(data, ImmutableMap.<String, Object>of());
}
@Override
public void emit(T data, String partitionKey, Object partitionValue) {
emit(data, ImmutableMap.of(partitionKey, partitionValue));
}
@Override
public void emit(T data, Map<String, Object> partitions) {
try {
ByteArrayOutputStream output = new ByteArrayOutputStream();
output.write(schemaHash);
writer.encode(data, new BinaryEncoder(output));
queueProducer.enqueue(new QueueEntry(Maps.transformValues(partitions, PARTITION_MAP_TRANSFORMER),
output.toByteArray()));
} catch (IOException e) {
throw Throwables.propagate(e);
}
}
private static final class PartitionMapTransformer implements Function<Object, Integer> {
@Override
public Integer apply(@Nullable Object input) {
return input == null ? 0 : input.hashCode();
}
}
}