11d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert/* 21d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Copyright (C) 2007 The Guava Authors 31d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 41d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Licensed under the Apache License, Version 2.0 (the "License"); 51d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * you may not use this file except in compliance with the License. 61d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * You may obtain a copy of the License at 71d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 81d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * http://www.apache.org/licenses/LICENSE-2.0 91d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 101d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Unless required by applicable law or agreed to in writing, software 111d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * distributed under the License is distributed on an "AS IS" BASIS, 121d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 131d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * See the License for the specific language governing permissions and 141d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * limitations under the License. 151d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 161d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 171d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertpackage com.google.common.collect; 181d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 191d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport com.google.common.annotations.Beta; 201d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport com.google.common.annotations.GwtCompatible; 211d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 221d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport java.util.Comparator; 231d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport java.util.Iterator; 241d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport java.util.NoSuchElementException; 251d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport java.util.SortedMap; 261d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 271d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport javax.annotation.Nullable; 281d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 291d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert/** 301d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * A sorted map which forwards all its method calls to another sorted map. 311d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Subclasses should override one or more methods to modify the behavior of 321d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * the backing sorted map as desired per the <a 331d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>. 341d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 351d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * <p><i>Warning:</i> The methods of {@code ForwardingSortedMap} forward 361d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * <i>indiscriminately</i> to the methods of the delegate. For example, 371d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * overriding {@link #put} alone <i>will not</i> change the behavior of {@link 381d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * #putAll}, which can lead to unexpected behavior. In this case, you should 391d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * override {@code putAll} as well, either providing your own implementation, or 401d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * delegating to the provided {@code standardPutAll} method. 411d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 421d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * <p>Each of the {@code standard} methods, where appropriate, use the 431d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * comparator of the map to test equality for both keys and values, unlike 441d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * {@code ForwardingMap}. 451d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 461d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * <p>The {@code standard} methods and the collection views they return are not 471d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * guaranteed to be thread-safe, even when all of the methods that they depend 481d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * on are thread-safe. 491d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 501d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * @author Mike Bostock 511d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * @author Louis Wasserman 521d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * @since 2.0 (imported from Google Collections Library) 531d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 541d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert@GwtCompatible 551d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertpublic abstract class ForwardingSortedMap<K, V> extends ForwardingMap<K, V> 561d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert implements SortedMap<K, V> { 571d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert // TODO(user): identify places where thread safety is actually lost 581d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 591d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert /** Constructor for use by subclasses. */ 601d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert protected ForwardingSortedMap() {} 611d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 621d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @Override protected abstract SortedMap<K, V> delegate(); 631d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 641d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @Override 651d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public Comparator<? super K> comparator() { 661d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return delegate().comparator(); 671d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 681d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 691d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @Override 701d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public K firstKey() { 711d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return delegate().firstKey(); 721d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 731d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 741d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @Override 751d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public SortedMap<K, V> headMap(K toKey) { 761d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return delegate().headMap(toKey); 771d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 781d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 791d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @Override 801d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public K lastKey() { 811d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return delegate().lastKey(); 821d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 831d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 841d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @Override 851d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public SortedMap<K, V> subMap(K fromKey, K toKey) { 861d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return delegate().subMap(fromKey, toKey); 871d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 881d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 891d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @Override 901d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public SortedMap<K, V> tailMap(K fromKey) { 911d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return delegate().tailMap(fromKey); 921d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 931d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 941d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert // unsafe, but worst case is a CCE is thrown, which callers will be expecting 951d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @SuppressWarnings("unchecked") 961d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert private int unsafeCompare(Object k1, Object k2) { 971d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert Comparator<? super K> comparator = comparator(); 981d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert if (comparator == null) { 991d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return ((Comparable<Object>) k1).compareTo(k2); 1001d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } else { 1011d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return ((Comparator<Object>) comparator).compare(k1, k2); 1021d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 1031d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 1041d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 1051d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert /** 1061d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * A sensible definition of {@link #containsKey} in terms of the {@code 1071d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * firstKey()} method of {@link #tailMap}. If you override {@link #tailMap}, 1081d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * you may wish to override {@link #containsKey} to forward to this 1091d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * implementation. 1101d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 1111d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * @since 7.0 1121d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 1131d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @Override @Beta protected boolean standardContainsKey(@Nullable Object key) { 1141d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert try { 1151d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert // any CCE will be caught 1161d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @SuppressWarnings("unchecked") 1171d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert SortedMap<Object, V> self = (SortedMap<Object, V>) this; 1181d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert Object ceilingKey = self.tailMap(key).firstKey(); 1191d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return unsafeCompare(ceilingKey, key) == 0; 1201d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } catch (ClassCastException e) { 1211d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return false; 1221d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } catch (NoSuchElementException e) { 1231d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return false; 1241d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } catch (NullPointerException e) { 1251d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return false; 1261d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 1271d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 1281d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 1291d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert /** 1301d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * A sensible definition of {@link #remove} in terms of the {@code 1311d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * iterator()} of the {@code entrySet()} of {@link #tailMap}. If you override 1321d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * {@link #tailMap}, you may wish to override {@link #remove} to forward 1331d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * to this implementation. 1341d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 1351d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * @since 7.0 1361d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 1371d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @Override @Beta protected V standardRemove(@Nullable Object key) { 1381d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert try { 1391d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert // any CCE will be caught 1401d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @SuppressWarnings("unchecked") 1411d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert SortedMap<Object, V> self = (SortedMap<Object, V>) this; 1421d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert Iterator<Entry<Object, V>> entryIterator = 1431d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert self.tailMap(key).entrySet().iterator(); 1441d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert if (entryIterator.hasNext()) { 1451d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert Entry<Object, V> ceilingEntry = entryIterator.next(); 1461d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert if (unsafeCompare(ceilingEntry.getKey(), key) == 0) { 1471d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert V value = ceilingEntry.getValue(); 1481d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert entryIterator.remove(); 1491d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return value; 1501d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 1511d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 1521d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } catch (ClassCastException e) { 1531d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return null; 1541d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } catch (NullPointerException e) { 1551d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return null; 1561d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 1571d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return null; 1581d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 1591d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 1601d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert /** 1611d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * A sensible default implementation of {@link #subMap(Object, Object)} in 1621d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * terms of {@link #headMap(Object)} and {@link #tailMap(Object)}. In some 1631d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * situations, you may wish to override {@link #subMap(Object, Object)} to 1641d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * forward to this implementation. 1651d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 1661d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * @since 7.0 1671d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 1681d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @Beta protected SortedMap<K, V> standardSubMap(K fromKey, K toKey) { 1691d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return tailMap(fromKey).headMap(toKey); 1701d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 1711d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert} 172