Collections/src/dorkbox/collections/Sort.java

67 lines
2.5 KiB
Java

/*
* Copyright (C) 2008 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS"
* BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language
* governing permissions and limitations under the License.
*/
package dorkbox.collections;
import java.util.Comparator;
/** Provides methods to sort arrays of objects. Sorting requires working memory and this class allows that memory to be reused to
* avoid allocation. The sorting is otherwise identical to the Arrays.sort methods (uses timsort).<br>
* <br>
* Note that sorting primitive arrays with the Arrays.sort methods does not allocate memory (unless sorting large arrays of char,
* short, or byte).
* @author Nathan Sweet */
@SuppressWarnings({"RedundantCast", "unchecked", "rawtypes"})
public class Sort {
static private Sort instance;
private TimSort timSort;
private ComparableTimSort comparableTimSort;
public <T> void sort (Array<T> a) {
if (comparableTimSort == null) comparableTimSort = new ComparableTimSort();
comparableTimSort.doSort((Object[])a.items, 0, a.size);
}
public <T> void sort (T[] a) {
if (comparableTimSort == null) comparableTimSort = new ComparableTimSort();
comparableTimSort.doSort(a, 0, a.length);
}
public <T> void sort (T[] a, int fromIndex, int toIndex) {
if (comparableTimSort == null) comparableTimSort = new ComparableTimSort();
comparableTimSort.doSort(a, fromIndex, toIndex);
}
public <T> void sort (Array<T> a, Comparator<? super T> c) {
if (timSort == null) timSort = new TimSort();
timSort.doSort((Object[])a.items, (Comparator)c, 0, a.size);
}
public <T> void sort (T[] a, Comparator<? super T> c) {
if (timSort == null) timSort = new TimSort();
timSort.doSort(a, c, 0, a.length);
}
public <T> void sort (T[] a, Comparator<? super T> c, int fromIndex, int toIndex) {
if (timSort == null) timSort = new TimSort();
timSort.doSort(a, c, fromIndex, toIndex);
}
/** Returns a Sort instance for convenience. Multiple threads must not use this instance at the same time. */
static public Sort instance () {
if (instance == null) instance = new Sort();
return instance;
}
}