Thu, 31 Aug 2017 15:18:52 +0800
merge
aoqi@0 | 1 | /* |
aoqi@0 | 2 | * Copyright (c) 1997, 2010, Oracle and/or its affiliates. All rights reserved. |
aoqi@0 | 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
aoqi@0 | 4 | * |
aoqi@0 | 5 | * This code is free software; you can redistribute it and/or modify it |
aoqi@0 | 6 | * under the terms of the GNU General Public License version 2 only, as |
aoqi@0 | 7 | * published by the Free Software Foundation. Oracle designates this |
aoqi@0 | 8 | * particular file as subject to the "Classpath" exception as provided |
aoqi@0 | 9 | * by Oracle in the LICENSE file that accompanied this code. |
aoqi@0 | 10 | * |
aoqi@0 | 11 | * This code is distributed in the hope that it will be useful, but WITHOUT |
aoqi@0 | 12 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
aoqi@0 | 13 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
aoqi@0 | 14 | * version 2 for more details (a copy is included in the LICENSE file that |
aoqi@0 | 15 | * accompanied this code). |
aoqi@0 | 16 | * |
aoqi@0 | 17 | * You should have received a copy of the GNU General Public License version |
aoqi@0 | 18 | * 2 along with this work; if not, write to the Free Software Foundation, |
aoqi@0 | 19 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
aoqi@0 | 20 | * |
aoqi@0 | 21 | * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
aoqi@0 | 22 | * or visit www.oracle.com if you need additional information or have any |
aoqi@0 | 23 | * questions. |
aoqi@0 | 24 | */ |
aoqi@0 | 25 | |
aoqi@0 | 26 | package com.sun.xml.internal.xsom.util; |
aoqi@0 | 27 | |
aoqi@0 | 28 | import java.util.ArrayList; |
aoqi@0 | 29 | import java.util.Collection; |
aoqi@0 | 30 | import java.util.Iterator; |
aoqi@0 | 31 | import java.util.List; |
aoqi@0 | 32 | import java.util.NoSuchElementException; |
aoqi@0 | 33 | |
aoqi@0 | 34 | /** |
aoqi@0 | 35 | * {@link Collection} that returns the view of objects which are actually fetched |
aoqi@0 | 36 | * lazily from an {@link Iterator}. |
aoqi@0 | 37 | * |
aoqi@0 | 38 | * @author Kohsuke Kawaguchi |
aoqi@0 | 39 | */ |
aoqi@0 | 40 | public class DeferedCollection<T> implements Collection<T> { |
aoqi@0 | 41 | /** |
aoqi@0 | 42 | * The iterator that lazily evaluates SCD query. |
aoqi@0 | 43 | */ |
aoqi@0 | 44 | private final Iterator<T> result; |
aoqi@0 | 45 | |
aoqi@0 | 46 | /** |
aoqi@0 | 47 | * Stores values that are already fetched from {@link #result}. |
aoqi@0 | 48 | */ |
aoqi@0 | 49 | private final List<T> archive = new ArrayList<T>(); |
aoqi@0 | 50 | |
aoqi@0 | 51 | public DeferedCollection(Iterator<T> result) { |
aoqi@0 | 52 | this.result = result; |
aoqi@0 | 53 | } |
aoqi@0 | 54 | |
aoqi@0 | 55 | public boolean isEmpty() { |
aoqi@0 | 56 | if(archive.isEmpty()) |
aoqi@0 | 57 | fetch(); |
aoqi@0 | 58 | return archive.isEmpty(); |
aoqi@0 | 59 | } |
aoqi@0 | 60 | |
aoqi@0 | 61 | public int size() { |
aoqi@0 | 62 | fetchAll(); |
aoqi@0 | 63 | return archive.size(); |
aoqi@0 | 64 | } |
aoqi@0 | 65 | |
aoqi@0 | 66 | public boolean contains(Object o) { |
aoqi@0 | 67 | if(archive.contains(o)) |
aoqi@0 | 68 | return true; |
aoqi@0 | 69 | while(result.hasNext()) { |
aoqi@0 | 70 | T value = result.next(); |
aoqi@0 | 71 | archive.add(value); |
aoqi@0 | 72 | if(value.equals(o)) |
aoqi@0 | 73 | return true; |
aoqi@0 | 74 | } |
aoqi@0 | 75 | return false; |
aoqi@0 | 76 | } |
aoqi@0 | 77 | |
aoqi@0 | 78 | public boolean containsAll(Collection<?> c) { |
aoqi@0 | 79 | for (Object o : c) { |
aoqi@0 | 80 | if(!contains(o)) |
aoqi@0 | 81 | return false; |
aoqi@0 | 82 | } |
aoqi@0 | 83 | return true; |
aoqi@0 | 84 | } |
aoqi@0 | 85 | |
aoqi@0 | 86 | public Iterator<T> iterator() { |
aoqi@0 | 87 | return new Iterator<T>() { |
aoqi@0 | 88 | int idx=0; |
aoqi@0 | 89 | public boolean hasNext() { |
aoqi@0 | 90 | if(idx<archive.size()) |
aoqi@0 | 91 | return true; |
aoqi@0 | 92 | return result.hasNext(); |
aoqi@0 | 93 | } |
aoqi@0 | 94 | |
aoqi@0 | 95 | public T next() { |
aoqi@0 | 96 | if(idx==archive.size()) |
aoqi@0 | 97 | fetch(); |
aoqi@0 | 98 | if(idx==archive.size()) |
aoqi@0 | 99 | throw new NoSuchElementException(); |
aoqi@0 | 100 | return archive.get(idx++); |
aoqi@0 | 101 | } |
aoqi@0 | 102 | |
aoqi@0 | 103 | public void remove() { |
aoqi@0 | 104 | // TODO |
aoqi@0 | 105 | } |
aoqi@0 | 106 | }; |
aoqi@0 | 107 | } |
aoqi@0 | 108 | |
aoqi@0 | 109 | public Object[] toArray() { |
aoqi@0 | 110 | fetchAll(); |
aoqi@0 | 111 | return archive.toArray(); |
aoqi@0 | 112 | } |
aoqi@0 | 113 | |
aoqi@0 | 114 | public <T>T[] toArray(T[] a) { |
aoqi@0 | 115 | fetchAll(); |
aoqi@0 | 116 | return archive.toArray(a); |
aoqi@0 | 117 | } |
aoqi@0 | 118 | |
aoqi@0 | 119 | |
aoqi@0 | 120 | |
aoqi@0 | 121 | private void fetchAll() { |
aoqi@0 | 122 | while(result.hasNext()) |
aoqi@0 | 123 | archive.add(result.next()); |
aoqi@0 | 124 | } |
aoqi@0 | 125 | |
aoqi@0 | 126 | /** |
aoqi@0 | 127 | * Fetches another item from {@link |
aoqi@0 | 128 | */ |
aoqi@0 | 129 | private void fetch() { |
aoqi@0 | 130 | if(result.hasNext()) |
aoqi@0 | 131 | archive.add(result.next()); |
aoqi@0 | 132 | } |
aoqi@0 | 133 | |
aoqi@0 | 134 | // mutation methods are unsupported |
aoqi@0 | 135 | public boolean add(T o) { |
aoqi@0 | 136 | throw new UnsupportedOperationException(); |
aoqi@0 | 137 | } |
aoqi@0 | 138 | |
aoqi@0 | 139 | public boolean remove(Object o) { |
aoqi@0 | 140 | throw new UnsupportedOperationException(); |
aoqi@0 | 141 | } |
aoqi@0 | 142 | |
aoqi@0 | 143 | public boolean addAll(Collection<? extends T> c) { |
aoqi@0 | 144 | throw new UnsupportedOperationException(); |
aoqi@0 | 145 | } |
aoqi@0 | 146 | |
aoqi@0 | 147 | public boolean removeAll(Collection<?> c) { |
aoqi@0 | 148 | throw new UnsupportedOperationException(); |
aoqi@0 | 149 | } |
aoqi@0 | 150 | |
aoqi@0 | 151 | public boolean retainAll(Collection<?> c) { |
aoqi@0 | 152 | throw new UnsupportedOperationException(); |
aoqi@0 | 153 | } |
aoqi@0 | 154 | |
aoqi@0 | 155 | public void clear() { |
aoqi@0 | 156 | throw new UnsupportedOperationException(); |
aoqi@0 | 157 | } |
aoqi@0 | 158 | } |