| /* |
| * 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 org.apache.hadoop.hbase.Cell; |
| import org.apache.hadoop.hbase.DoNotRetryIOException; |
| import org.apache.hadoop.hbase.HConstants; |
| import org.apache.hadoop.hbase.PrivateCellUtil; |
| import org.apache.hadoop.hbase.client.Scan; |
| import org.apache.hadoop.hbase.util.Bytes; |
| import org.apache.yetus.audience.InterfaceAudience; |
| |
| /** |
| * ReversibleRegionScannerImpl extends from RegionScannerImpl, and is used to support reversed |
| * scanning. |
| */ |
| @InterfaceAudience.Private |
| class ReversedRegionScannerImpl extends RegionScannerImpl { |
| |
| ReversedRegionScannerImpl(Scan scan, List<KeyValueScanner> additionalScanners, HRegion region, |
| long nonceGroup, long nonce) throws IOException { |
| super(scan, additionalScanners, region, nonceGroup, nonce); |
| } |
| |
| @Override |
| protected void initializeKVHeap(List<KeyValueScanner> scanners, |
| List<KeyValueScanner> joinedScanners, HRegion region) throws IOException { |
| this.storeHeap = new ReversedKeyValueHeap(scanners, comparator); |
| if (!joinedScanners.isEmpty()) { |
| throw new DoNotRetryIOException("Reverse scan with loading CFs on demand is not supported"); |
| } |
| } |
| |
| @Override |
| protected boolean shouldStop(Cell currentRowCell) { |
| if (currentRowCell == null) { |
| return true; |
| } |
| if (stopRow == null || Bytes.equals(stopRow, HConstants.EMPTY_START_ROW)) { |
| return false; |
| } |
| int c = comparator.compareRows(currentRowCell, stopRow, 0, stopRow.length); |
| return c < 0 || (c == 0 && !includeStopRow); |
| } |
| |
| @Override |
| protected boolean nextRow(ScannerContext scannerContext, Cell curRowCell) throws IOException { |
| assert super.joinedContinuationRow == null : "Trying to go to next row during joinedHeap read."; |
| this.storeHeap.seekToPreviousRow(PrivateCellUtil.createFirstOnRow(curRowCell)); |
| resetFilters(); |
| // Calling the hook in CP which allows it to do a fast forward |
| if (this.region.getCoprocessorHost() != null) { |
| return this.region.getCoprocessorHost().postScannerFilterRow(this, curRowCell); |
| } |
| return true; |
| } |
| |
| } |