1 /* 2 * Copyright (c) 2017, 2017, 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 package jdk.internal.vm.compiler.collections; 26 27 /** 28 * Unmodifiable memory efficient map data structure. 29 * 30 * @since 1.0 31 */ 32 public interface UnmodifiableEconomicMap<K, V> { 33 34 /** 35 * Returns the value to which {@code key} is mapped, or {@code null} if this map contains no 36 * mapping for {@code key}. 37 * 38 * @since 1.0 39 */ 40 V get(K key); 41 42 /** 43 * Returns the value to which {@code key} is mapped, or {@code defaultValue} if this map 44 * contains no mapping for {@code key}. 45 * 46 * @since 1.0 47 */ 48 default V get(K key, V defaultValue) { 49 V v = get(key); 50 if (v == null) { 51 return defaultValue; 52 } 53 return v; 54 } 55 56 /** 57 * Returns {@code true} if this map contains a mapping for {@code key}. 58 * 59 * @since 1.0 60 */ 61 boolean containsKey(K key); 62 63 /** 64 * Returns the number of key-value mappings in this map. 65 * 66 * @since 1.0 67 */ 68 int size(); 69 70 /** 71 * Returns {@code true} if this map contains no key-value mappings. 72 * 73 * @since 1.0 74 */ 75 boolean isEmpty(); 76 77 /** 78 * Returns a {@link Iterable} view of the values contained in this map. 79 * 80 * @since 1.0 81 */ 82 Iterable<V> getValues(); 83 84 /** 85 * Returns a {@link Iterable} view of the keys contained in this map. 86 * 87 * @since 1.0 88 */ 89 Iterable<K> getKeys(); 90 91 /** 92 * Returns a {@link UnmodifiableMapCursor} view of the mappings contained in this map. 93 * 94 * @since 1.0 95 */ 96 UnmodifiableMapCursor<K, V> getEntries(); 97 }