1 /* 2 * Copyright (C) 2007 Google Inc. 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package com.google.common.collect; 18 19 import com.google.common.annotations.GwtCompatible; 20 import static com.google.common.base.Preconditions.checkNotNull; 21 22 import java.util.Collection; 23 import java.util.Iterator; 24 import java.util.Map; 25 import java.util.Set; 26 27 import javax.annotation.Nullable; 28 29 /** 30 * Factory and utilities pertaining to the {@code MapConstraint} interface. 31 * 32 * @author Mike Bostock 33 */ 34 @GwtCompatible 35 class ConstrainedMap<K, V> extends ForwardingMap<K, V> { 36 final Map<K, V> delegate; 37 final MapConstraint<? super K, ? super V> constraint; 38 private volatile Set<Entry<K, V>> entrySet; 39 40 ConstrainedMap( 41 Map<K, V> delegate, MapConstraint<? super K, ? super V> constraint) { 42 this.delegate = checkNotNull(delegate); 43 this.constraint = checkNotNull(constraint); 44 } 45 46 @Override protected Map<K, V> delegate() { 47 return delegate; 48 } 49 @Override public Set<Entry<K, V>> entrySet() { 50 if (entrySet == null) { 51 entrySet = constrainedEntrySet(delegate.entrySet(), constraint); 52 } 53 return entrySet; 54 } 55 @Override public V put(K key, V value) { 56 constraint.checkKeyValue(key, value); 57 return delegate.put(key, value); 58 } 59 @Override public void putAll(Map<? extends K, ? extends V> map) { 60 for (Entry<? extends K, ? extends V> entry : map.entrySet()) { 61 put(entry.getKey(), entry.getValue()); 62 } 63 } 64 65 private static <K, V> Entry<K, V> constrainedEntry( 66 final Entry<K, V> entry, 67 final MapConstraint<? super K, ? super V> constraint) { 68 checkNotNull(entry); 69 checkNotNull(constraint); 70 return new ForwardingMapEntry<K, V>() { 71 @Override protected Entry<K, V> delegate() { 72 return entry; 73 } 74 @Override public V setValue(V value) { 75 constraint.checkKeyValue(getKey(), value); 76 return entry.setValue(value); 77 } 78 }; 79 } 80 81 private static <K, V> Set<Entry<K, V>> constrainedEntrySet( 82 Set<Entry<K, V>> entries, 83 MapConstraint<? super K, ? super V> constraint) { 84 return new ConstrainedEntrySet<K, V>(entries, constraint); 85 } 86 87 private static class ConstrainedEntries<K, V> 88 extends ForwardingCollection<Entry<K, V>> { 89 final MapConstraint<? super K, ? super V> constraint; 90 final Collection<Entry<K, V>> entries; 91 92 ConstrainedEntries(Collection<Entry<K, V>> entries, 93 MapConstraint<? super K, ? super V> constraint) { 94 this.entries = entries; 95 this.constraint = constraint; 96 } 97 @Override protected Collection<Entry<K, V>> delegate() { 98 return entries; 99 } 100 101 @Override public Iterator<Entry<K, V>> iterator() { 102 final Iterator<Entry<K, V>> iterator = entries.iterator(); 103 return new ForwardingIterator<Entry<K, V>>() { 104 @Override public Entry<K, V> next() { 105 return constrainedEntry(iterator.next(), constraint); 106 } 107 @Override protected Iterator<Entry<K, V>> delegate() { 108 return iterator; 109 } 110 }; 111 } 112 113 // See Collections.CheckedMap.CheckedEntrySet for details on attacks. 114 115 @Override public Object[] toArray() { 116 return ObjectArrays.toArrayImpl(this); 117 } 118 @Override public <T> T[] toArray(T[] array) { 119 return ObjectArrays.toArrayImpl(this, array); 120 } 121 @Override public boolean contains(Object o) { 122 return Maps.containsEntryImpl(delegate(), o); 123 } 124 @Override public boolean containsAll(Collection<?> c) { 125 return Collections2.containsAll(this, c); 126 } 127 @Override public boolean remove(Object o) { 128 return Maps.removeEntryImpl(delegate(), o); 129 } 130 @Override public boolean removeAll(Collection<?> c) { 131 return Iterators.removeAll(iterator(), c); 132 } 133 @Override public boolean retainAll(Collection<?> c) { 134 return Iterators.retainAll(iterator(), c); 135 } 136 } 137 138 static class ConstrainedEntrySet<K, V> 139 extends ConstrainedEntries<K, V> implements Set<Entry<K, V>> { 140 ConstrainedEntrySet(Set<Entry<K, V>> entries, 141 MapConstraint<? super K, ? super V> constraint) { 142 super(entries, constraint); 143 } 144 145 // See Collections.CheckedMap.CheckedEntrySet for details on attacks. 146 147 @Override public boolean equals(@Nullable Object object) { 148 return Collections2.setEquals(this, object); 149 } 150 151 @Override public int hashCode() { 152 return Sets.hashCodeImpl(this); 153 } 154 } 155 } 156
