/**
* 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.hadoop.hbase.coprocessor;
import java.io.IOException;
import java.util.List;
import java.util.SortedSet;
import java.util.TreeSet;
import org.apache.hadoop.hbase.DoNotRetryIOException;
import org.apache.hadoop.hbase.HRegionInfo;
import org.apache.hadoop.hbase.client.Mutation;
import org.apache.hadoop.hbase.regionserver.HRegion;
import org.apache.hadoop.hbase.regionserver.WrongRegionException;
import org.apache.hadoop.hbase.util.Bytes;
/**
* This class demonstrates how to implement atomic multi row transactions using
* {@link HRegion#mutateRowsWithLocks(java.util.Collection, java.util.Collection)}
* and Coprocessor endpoints.
*/
public class MultiRowMutationEndpoint extends BaseEndpointCoprocessor implements
MultiRowMutationProtocol {
@Override
public void mutateRows(List<Mutation> mutations) throws IOException {
// get the coprocessor environment
RegionCoprocessorEnvironment env = (RegionCoprocessorEnvironment) getEnvironment();
// set of rows to lock, sorted to avoid deadlocks
SortedSet<byte[]> rowsToLock = new TreeSet<byte[]>(Bytes.BYTES_COMPARATOR);
HRegionInfo regionInfo = env.getRegion().getRegionInfo();
for (Mutation m : mutations) {
// check whether rows are in range for this region
if (!HRegion.rowIsInRange(regionInfo, m.getRow())) {
String msg = "Requested row out of range '"
+ Bytes.toStringBinary(m.getRow()) + "'";
if (rowsToLock.isEmpty()) {
// if this is the first row, region might have moved,
// allow client to retry
throw new WrongRegionException(msg);
} else {
// rows are split between regions, do not retry
throw new DoNotRetryIOException(msg);
}
}
rowsToLock.add(m.getRow());
}
// call utility method on region
env.getRegion().mutateRowsWithLocks(mutations, rowsToLock);
}
}