| /** |
| * 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.client; |
| |
| import java.io.IOException; |
| import java.util.ArrayList; |
| import java.util.List; |
| import org.apache.hadoop.conf.Configuration; |
| import org.apache.hadoop.fs.FileSystem; |
| import org.apache.hadoop.fs.Path; |
| import org.apache.hadoop.hbase.Cell; |
| import org.apache.hadoop.hbase.PrivateCellUtil; |
| import org.apache.hadoop.hbase.client.metrics.ScanMetrics; |
| import org.apache.hadoop.hbase.mob.MobFileCache; |
| import org.apache.hadoop.hbase.regionserver.HRegion; |
| import org.apache.hadoop.hbase.regionserver.RegionScanner; |
| import org.apache.hadoop.hbase.util.CommonFSUtils; |
| import org.apache.yetus.audience.InterfaceAudience; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| /** |
| * A client scanner for a region opened for read-only on the client side. Assumes region data |
| * is not changing. |
| */ |
| @InterfaceAudience.Private |
| public class ClientSideRegionScanner extends AbstractClientScanner { |
| |
| private static final Logger LOG = LoggerFactory.getLogger(ClientSideRegionScanner.class); |
| |
| private HRegion region; |
| RegionScanner scanner; |
| List<Cell> values; |
| |
| public ClientSideRegionScanner(Configuration conf, FileSystem fs, |
| Path rootDir, TableDescriptor htd, RegionInfo hri, Scan scan, ScanMetrics scanMetrics) |
| throws IOException { |
| // region is immutable, set isolation level |
| scan.setIsolationLevel(IsolationLevel.READ_UNCOMMITTED); |
| |
| htd = TableDescriptorBuilder.newBuilder(htd).setReadOnly(true).build(); |
| |
| // open region from the snapshot directory |
| region = HRegion.newHRegion(CommonFSUtils.getTableDir(rootDir, htd.getTableName()), null, fs, |
| conf, hri, htd, null); |
| region.setRestoredRegion(true); |
| // we won't initialize the MobFileCache when not running in RS process. so provided an |
| // initialized cache. Consider the case: an CF was set from an mob to non-mob. if we only |
| // initialize cache for MOB region, NPE from HMobStore will still happen. So Initialize the |
| // cache for every region although it may hasn't any mob CF, BTW the cache is very light-weight. |
| region.setMobFileCache(new MobFileCache(conf)); |
| region.initialize(); |
| |
| // create an internal region scanner |
| this.scanner = region.getScanner(scan); |
| values = new ArrayList<>(); |
| |
| if (scanMetrics == null) { |
| initScanMetrics(scan); |
| } else { |
| this.scanMetrics = scanMetrics; |
| } |
| region.startRegionOperation(); |
| } |
| |
| @Override |
| public Result next() throws IOException { |
| values.clear(); |
| scanner.nextRaw(values); |
| if (values.isEmpty()) { |
| //we are done |
| return null; |
| } |
| |
| Result result = Result.create(values); |
| if (this.scanMetrics != null) { |
| long resultSize = 0; |
| for (Cell cell : values) { |
| resultSize += PrivateCellUtil.estimatedSerializedSizeOf(cell); |
| } |
| this.scanMetrics.countOfBytesInResults.addAndGet(resultSize); |
| this.scanMetrics.countOfRowsScanned.incrementAndGet(); |
| } |
| |
| return result; |
| } |
| |
| @Override |
| public void close() { |
| if (this.scanner != null) { |
| try { |
| this.scanner.close(); |
| this.scanner = null; |
| } catch (IOException ex) { |
| LOG.warn("Exception while closing scanner", ex); |
| } |
| } |
| if (this.region != null) { |
| try { |
| this.region.closeRegionOperation(); |
| this.region.close(true); |
| this.region = null; |
| } catch (IOException ex) { |
| LOG.warn("Exception while closing region", ex); |
| } |
| } |
| } |
| |
| @Override |
| public boolean renewLease() { |
| throw new UnsupportedOperationException(); |
| } |
| } |