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.  Oracle designates this

     8  * particular file as subject to the "Classpath" exception as provided

     9  * by Oracle in the LICENSE file that accompanied this code.

    10  *

    11  * This code is distributed in the hope that it will be useful, but WITHOUT

    12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    14  * version 2 for more details (a copy is included in the LICENSE file that

    15  * accompanied this code).

    16  *

    17  * You should have received a copy of the GNU General Public License version

    18  * 2 along with this work; if not, write to the Free Software Foundation,

    19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    20  *

    21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    22  * or visit www.oracle.com if you need additional information or have any

    23  * questions.

    24  */

    25 package org.graalvm.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 }