1 /*

     2  * Copyright (c) 2016, 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.  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 

    26 package jdk.jfr.consumer;

    27 

    28 import java.util.HashMap;

    29 import java.util.Iterator;

    30 

    31 /**

    32  * Commonly used data structure for looking up objects given an id (long value)

    33  *

    34  * TODO: Implement without using Map and Long objects, to minimize allocation

    35  *

    36  * @param <T>

    37  */

    38 final class LongMap<T> implements Iterable<T> {

    39     private final HashMap<Long, T> map;

    40 

    41     LongMap() {

    42         map = new HashMap<>(101);

    43     }

    44 

    45     void put(long id, T object) {

    46         map.put(id, object);

    47     }

    48 

    49     T get(long id) {

    50         return map.get(id);

    51     }

    52 

    53     @Override

    54     public Iterator<T> iterator() {

    55         return map.values().iterator();

    56     }

    57 

    58     Iterator<Long> keys() {

    59         return map.keySet().iterator();

    60     }

    61 }