| /* |
| * |
| * 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.util; |
| |
| import java.util.ArrayList; |
| import java.util.Collections; |
| import java.util.Iterator; |
| import java.util.List; |
| import java.util.SortedSet; |
| |
| import org.apache.hadoop.hbase.classification.InterfaceAudience; |
| import org.apache.hadoop.hbase.Cell; |
| import org.apache.hadoop.hbase.CellComparator; |
| import org.apache.hadoop.hbase.regionserver.NonReversedNonLazyKeyValueScanner; |
| |
| /** |
| * Utility scanner that wraps a sortable collection and serves as a KeyValueScanner. |
| */ |
| @InterfaceAudience.Private |
| public class CollectionBackedScanner extends NonReversedNonLazyKeyValueScanner { |
| final private Iterable<Cell> data; |
| final CellComparator comparator; |
| private Iterator<Cell> iter; |
| private Cell current; |
| |
| public CollectionBackedScanner(SortedSet<Cell> set) { |
| this(set, CellComparator.COMPARATOR); |
| } |
| |
| public CollectionBackedScanner(SortedSet<Cell> set, |
| CellComparator comparator) { |
| this.comparator = comparator; |
| data = set; |
| init(); |
| } |
| |
| public CollectionBackedScanner(List<Cell> list) { |
| this(list, CellComparator.COMPARATOR); |
| } |
| |
| public CollectionBackedScanner(List<Cell> list, |
| CellComparator comparator) { |
| Collections.sort(list, comparator); |
| this.comparator = comparator; |
| data = list; |
| init(); |
| } |
| |
| public CollectionBackedScanner(CellComparator comparator, |
| Cell... array) { |
| this.comparator = comparator; |
| |
| List<Cell> tmp = new ArrayList<Cell>(array.length); |
| Collections.addAll(tmp, array); |
| Collections.sort(tmp, comparator); |
| data = tmp; |
| init(); |
| } |
| |
| private void init() { |
| iter = data.iterator(); |
| if(iter.hasNext()){ |
| current = iter.next(); |
| } |
| } |
| |
| @Override |
| public Cell peek() { |
| return current; |
| } |
| |
| @Override |
| public Cell next() { |
| Cell oldCurrent = current; |
| if(iter.hasNext()){ |
| current = iter.next(); |
| } else { |
| current = null; |
| } |
| return oldCurrent; |
| } |
| |
| @Override |
| public boolean seek(Cell seekCell) { |
| // restart iterator |
| iter = data.iterator(); |
| return reseek(seekCell); |
| } |
| |
| @Override |
| public boolean reseek(Cell seekCell) { |
| while(iter.hasNext()){ |
| Cell next = iter.next(); |
| int ret = comparator.compare(next, seekCell); |
| if(ret >= 0){ |
| current = next; |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| /** |
| * @see org.apache.hadoop.hbase.regionserver.KeyValueScanner#getScannerOrder() |
| */ |
| @Override |
| public long getScannerOrder() { |
| return 0; |
| } |
| |
| @Override |
| public void close() { |
| // do nothing |
| } |
| } |