org.apache.hadoop.hbase.client.ReversedClientScanner Maven / Gradle / Ivy
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* Licensed to the Apache Software Foundation (ASF) under one
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* distributed with this work for additional information
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* 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,
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* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.hadoop.hbase.client;
import static org.apache.hadoop.hbase.client.ConnectionUtils.noMoreResultsForReverseScan;
import java.io.IOException;
import java.util.concurrent.ExecutorService;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.ipc.RpcControllerFactory;
import org.apache.yetus.audience.InterfaceAudience;
/**
* A reversed client scanner which support backward scanning
*/
@InterfaceAudience.Private
public class ReversedClientScanner extends ClientScanner {
/**
* Create a new ReversibleClientScanner for the specified table Note that the passed
* {@link Scan}'s start row maybe changed.
*/
public ReversedClientScanner(Configuration conf, Scan scan, TableName tableName,
ClusterConnection connection, RpcRetryingCallerFactory rpcFactory,
RpcControllerFactory controllerFactory, ExecutorService pool, int scanReadRpcTimeout,
int scannerTimeout, int primaryOperationTimeout) throws IOException {
super(conf, scan, tableName, connection, rpcFactory, controllerFactory, pool,
scanReadRpcTimeout, scannerTimeout, primaryOperationTimeout);
}
@Override
protected boolean setNewStartKey() {
if (noMoreResultsForReverseScan(scan, currentRegion)) {
return false;
}
scan.withStartRow(currentRegion.getStartKey(), false);
return true;
}
@Override
protected ReversedScannerCallable createScannerCallable() {
return new ReversedScannerCallable(getConnection(), getTable(), scan, this.scanMetrics,
this.rpcControllerFactory, getScanReplicaId());
}
}