1 /* 2 * Copyright (c) 2017, 2018, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 */ 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 package jdk.internal.vm.compiler.collections; 42 43 /** 44 * Unmodifiable memory efficient map data structure. 45 * 46 * @since 1.0 47 */ 48 public interface UnmodifiableEconomicMap<K, V> { 49 50 /** 51 * Returns the value to which {@code key} is mapped, or {@code null} if this map contains no 52 * mapping for {@code key}. 53 * 54 * @since 1.0 55 */ 56 V get(K key); 57 58 /** 59 * Returns the value to which {@code key} is mapped, or {@code defaultValue} if this map 60 * contains no mapping for {@code key}. 61 * 62 * @since 1.0 63 */ 64 default V get(K key, V defaultValue) { 65 V v = get(key); 66 if (v == null) { 67 return defaultValue; 68 } 69 return v; 70 } 71 72 /** 73 * Returns {@code true} if this map contains a mapping for {@code key}. 74 * 75 * @since 1.0 76 */ 77 boolean containsKey(K key); 78 79 /** 80 * Returns the number of key-value mappings in this map. 81 * 82 * @since 1.0 83 */ 84 int size(); 85 86 /** 87 * Returns {@code true} if this map contains no key-value mappings. 88 * 89 * @since 1.0 90 */ 91 boolean isEmpty(); 92 93 /** 94 * Returns a {@link Iterable} view of the values contained in this map. 95 * 96 * @since 1.0 97 */ 98 Iterable<V> getValues(); 99 100 /** 101 * Returns a {@link Iterable} view of the keys contained in this map. 102 * 103 * @since 1.0 104 */ 105 Iterable<K> getKeys(); 106 107 /** 108 * Returns a {@link UnmodifiableMapCursor} view of the mappings contained in this map. 109 * 110 * @since 1.0 111 */ 112 UnmodifiableMapCursor<K, V> getEntries(); 113 }