| /** |
| * |
| * 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.AbstractCollection; |
| import java.util.ArrayList; |
| import java.util.List; |
| import java.util.NoSuchElementException; |
| |
| import org.apache.yetus.audience.InterfaceAudience; |
| |
| /** |
| * A collection class that contains multiple sub-lists, which allows us to not copy lists. |
| * This class does not support modification. The derived classes that add modifications are |
| * not thread-safe. |
| * NOTE: Doesn't implement list as it is not necessary for current usage, feel free to add. |
| */ |
| @InterfaceAudience.Private |
| public class ConcatenatedLists<T> extends AbstractCollection<T> { |
| protected final ArrayList<List<T>> components = new ArrayList<>(); |
| protected int size = 0; |
| |
| public void addAllSublists(List<? extends List<T>> items) { |
| for (List<T> list : items) { |
| addSublist(list); |
| } |
| } |
| |
| public void addSublist(List<T> items) { |
| if (!items.isEmpty()) { |
| this.components.add(items); |
| this.size += items.size(); |
| } |
| } |
| |
| @Override |
| public int size() { |
| return this.size; |
| } |
| |
| @Override |
| public java.util.Iterator<T> iterator() { |
| return new Iterator(); |
| } |
| |
| @edu.umd.cs.findbugs.annotations.SuppressWarnings( |
| value="URF_UNREAD_PUBLIC_OR_PROTECTED_FIELD", |
| justification="nextWasCalled is using by StripeStoreFileManager") |
| public class Iterator implements java.util.Iterator<T> { |
| protected int currentComponent = 0; |
| protected int indexWithinComponent = -1; |
| protected boolean nextWasCalled = false; |
| |
| @Override |
| public boolean hasNext() { |
| return (currentComponent + 1) < components.size() |
| || ((currentComponent + 1) == components.size() |
| && ((indexWithinComponent + 1) < components.get(currentComponent).size())); |
| } |
| |
| @Override |
| public T next() { |
| if (!components.isEmpty()) { |
| this.nextWasCalled = true; |
| List<T> src = components.get(currentComponent); |
| if (++indexWithinComponent < src.size()) { |
| return src.get(indexWithinComponent); |
| } |
| |
| if (++currentComponent < components.size()) { |
| indexWithinComponent = 0; |
| src = components.get(currentComponent); |
| assert src.size() > 0; |
| return src.get(indexWithinComponent); |
| } |
| } |
| this.nextWasCalled = false; |
| throw new NoSuchElementException(); |
| } |
| |
| @Override |
| public void remove() { |
| throw new UnsupportedOperationException(); |
| } |
| } |
| } |