| /** |
| * |
| * 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.regionserver; |
| |
| import java.io.IOException; |
| import java.util.List; |
| import java.util.NavigableSet; |
| |
| import org.apache.hadoop.hbase.Cell; |
| import org.apache.hadoop.hbase.classification.InterfaceAudience; |
| import org.apache.hadoop.hbase.client.Scan; |
| import org.apache.hadoop.hbase.mob.MobUtils; |
| |
| /** |
| * Scanner scans both the memstore and the MOB Store. Coalesce KeyValue stream into |
| * {@code List<KeyValue>} for a single row. |
| */ |
| @InterfaceAudience.Private |
| public class MobStoreScanner extends StoreScanner { |
| |
| private boolean cacheMobBlocks = false; |
| private boolean rawMobScan = false; |
| private boolean readEmptyValueOnMobCellMiss = false; |
| private final HMobStore mobStore; |
| |
| public MobStoreScanner(Store store, ScanInfo scanInfo, Scan scan, |
| final NavigableSet<byte[]> columns, long readPt) throws IOException { |
| super(store, scanInfo, scan, columns, readPt); |
| cacheMobBlocks = MobUtils.isCacheMobBlocks(scan); |
| rawMobScan = MobUtils.isRawMobScan(scan); |
| readEmptyValueOnMobCellMiss = MobUtils.isReadEmptyValueOnMobCellMiss(scan); |
| if (!(store instanceof HMobStore)) { |
| throw new IllegalArgumentException("The store " + store + " is not a HMobStore"); |
| } |
| mobStore = (HMobStore) store; |
| } |
| |
| /** |
| * Firstly reads the cells from the HBase. If the cell are a reference cell (which has the |
| * reference tag), the scanner need seek this cell from the mob file, and use the cell found |
| * from the mob file as the result. |
| */ |
| @Override |
| public boolean next(List<Cell> outResult, ScannerContext ctx) throws IOException { |
| boolean result = super.next(outResult, ctx); |
| if (!rawMobScan) { |
| // retrieve the mob data |
| if (outResult.isEmpty()) { |
| return result; |
| } |
| long mobKVCount = 0; |
| long mobKVSize = 0; |
| for (int i = 0; i < outResult.size(); i++) { |
| Cell cell = outResult.get(i); |
| if (MobUtils.isMobReferenceCell(cell)) { |
| Cell mobCell = mobStore |
| .resolve(cell, cacheMobBlocks, readPt, readEmptyValueOnMobCellMiss); |
| mobKVCount++; |
| mobKVSize += mobCell.getValueLength(); |
| outResult.set(i, mobCell); |
| } |
| } |
| mobStore.updateMobScanCellsCount(mobKVCount); |
| mobStore.updateMobScanCellsSize(mobKVSize); |
| } |
| return result; |
| } |
| } |