| /** |
| * |
| * 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 org.apache.hadoop.hbase.Cell; |
| import org.apache.hadoop.hbase.CellComparator; |
| import org.apache.yetus.audience.InterfaceAudience; |
| |
| import java.io.IOException; |
| import java.util.ArrayList; |
| import java.util.List; |
| |
| /** |
| * The MemStoreMergerSegmentsIterator extends MemStoreSegmentsIterator |
| * and performs the scan for simple merge operation meaning it is NOT based on SQM |
| */ |
| @InterfaceAudience.Private |
| public class MemStoreMergerSegmentsIterator extends MemStoreSegmentsIterator { |
| |
| // heap of scanners, lazily initialized |
| private KeyValueHeap heap = null; |
| // remember the initial version of the scanners list |
| List<KeyValueScanner> scanners = new ArrayList<KeyValueScanner>(); |
| |
| private boolean closed = false; |
| |
| // C-tor |
| public MemStoreMergerSegmentsIterator(List<ImmutableSegment> segments, CellComparator comparator, |
| int compactionKVMax) throws IOException { |
| super(compactionKVMax); |
| // create the list of scanners to traverse over all the data |
| // no dirty reads here as these are immutable segments |
| AbstractMemStore.addToScanners(segments, Long.MAX_VALUE, scanners); |
| heap = new KeyValueHeap(scanners, comparator); |
| } |
| |
| @Override |
| public boolean hasNext() { |
| if (closed) { |
| return false; |
| } |
| if (this.heap != null) { |
| return (this.heap.peek() != null); |
| } |
| // Doing this way in case some test cases tries to peek directly |
| return false; |
| } |
| |
| @Override |
| public Cell next() { |
| try { // try to get next |
| if (!closed && heap != null) { |
| return heap.next(); |
| } |
| } catch (IOException ie) { |
| throw new IllegalStateException(ie); |
| } |
| return null; |
| } |
| |
| @Override |
| public void close() { |
| if (closed) { |
| return; |
| } |
| // Ensuring that all the segment scanners are closed |
| if (heap != null) { |
| heap.close(); |
| // It is safe to do close as no new calls will be made to this scanner. |
| heap = null; |
| } else { |
| for (KeyValueScanner scanner : scanners) { |
| scanner.close(); |
| } |
| } |
| closed = true; |
| } |
| |
| @Override |
| public void remove() { |
| throw new UnsupportedOperationException(); |
| } |
| } |