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  * The Universal Permissive License (UPL), Version 1.0
   6  *
   7  * Subject to the condition set forth below, permission is hereby granted to any
   8  * person obtaining a copy of this software, associated documentation and/or
   9  * data (collectively the "Software"), free of charge and under any and all
  10  * copyright rights in the Software, and any and all patent rights owned or
  11  * freely licensable by each licensor hereunder covering either (i) the
  12  * unmodified Software as contributed to or provided by such licensor, or (ii)
  13  * the Larger Works (as defined below), to deal in both
  14  *
  15  * (a) the Software, and
  16  *
  17  * (b) any piece of software and/or hardware listed in the lrgrwrks.txt file if
  18  * one is included with the Software each a "Larger Work" to which the Software
  19  * is contributed by such licensors),
  20  *
  21  * without restriction, including without limitation the rights to copy, create
  22  * derivative works of, display, perform, and distribute the Software and make,
  23  * use, sell, offer for sale, import, export, have made, and have sold the
  24  * Software and the Larger Work(s), and to sublicense the foregoing rights on
  25  * either these or other terms.
  26  *
  27  * This license is subject to the following condition:
  28  *
  29  * The above copyright notice and either this complete permission notice or at a
  30  * minimum a reference to the UPL must be included in all copies or substantial
  31  * portions of the Software.
  32  *
  33  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  34  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  35  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  36  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  37  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  38  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  39  * SOFTWARE.
  40  */
  41 package jdk.internal.vm.compiler.collections;
  42 
  43 /**
  44  * Unmodifiable memory efficient set data structure.
  45  *
  46  * @since 1.0
  47  */
  48 public interface UnmodifiableEconomicSet<E> extends Iterable<E> {
  49 
  50     /**
  51      * Returns {@code true} if this set contains a mapping for the {@code element}.
  52      *
  53      * @since 1.0
  54      */
  55     boolean contains(E element);
  56 
  57     /**
  58      * Returns the number of elements in this set.
  59      *
  60      * @since 1.0
  61      */
  62     int size();
  63 
  64     /**
  65      * Returns {@code true} if this set contains no elements.
  66      *
  67      * @since 1.0
  68      */
  69     boolean isEmpty();
  70 
  71     /**
  72      * Stores all of the elements in this set into {@code target}. An
  73      * {@link UnsupportedOperationException} will be thrown if the length of {@code target} does not
  74      * match the size of this set.
  75      *
  76      * @return an array containing all the elements in this set.
  77      * @throws UnsupportedOperationException if the length of {@code target} does not equal the size
  78      *             of this set.
  79      * @since 1.0
  80      */
  81     default E[] toArray(E[] target) {
  82         if (target.length != size()) {
  83             throw new UnsupportedOperationException("Length of target array must equal the size of the set.");
  84         }
  85 
  86         int index = 0;
  87         for (E element : this) {
  88             target[index++] = element;
  89         }
  90 
  91         return target;
  92     }
  93 }