/*
* 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.data.transaction.queue.coprocessor.hbase94;
import co.cask.tephra.Transaction;
import co.cask.tigon.data.queue.ConsumerConfig;
import co.cask.tigon.data.transaction.queue.hbase.DequeueScanAttributes;
import org.apache.hadoop.hbase.client.Scan;
import org.apache.hadoop.hbase.coprocessor.BaseRegionObserver;
import org.apache.hadoop.hbase.coprocessor.ObserverContext;
import org.apache.hadoop.hbase.coprocessor.RegionCoprocessorEnvironment;
import org.apache.hadoop.hbase.filter.Filter;
import org.apache.hadoop.hbase.filter.FilterList;
import org.apache.hadoop.hbase.regionserver.RegionScanner;
import java.io.IOException;
/**
*
*/
public class DequeueScanObserver extends BaseRegionObserver {
@Override
public RegionScanner preScannerOpen(ObserverContext<RegionCoprocessorEnvironment> e, Scan scan, RegionScanner s)
throws IOException {
ConsumerConfig consumerConfig = DequeueScanAttributes.getConsumerConfig(scan);
Transaction tx = DequeueScanAttributes.getTx(scan);
byte[] queueRowPrefix = DequeueScanAttributes.getQueueRowPrefix(scan);
if (consumerConfig == null || tx == null || queueRowPrefix == null) {
return super.preScannerOpen(e, scan, s);
}
Filter dequeueFilter = new DequeueFilter(queueRowPrefix, consumerConfig, tx);
Filter existing = scan.getFilter();
if (existing != null) {
Filter combined = new FilterList(FilterList.Operator.MUST_PASS_ALL, existing, dequeueFilter);
scan.setFilter(combined);
} else {
scan.setFilter(dequeueFilter);
}
return super.preScannerOpen(e, scan, s);
}
}