/*
* Copyright (C) 2014 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 com.glview.internal.util;
/**
* A helper class that aims to provide comparable growth performance to ArrayList, but on primitive
* arrays. Common array operations are implemented for efficient use in dynamic containers.
*
* All methods in this class assume that the length of an array is equivalent to its capacity and
* NOT the number of elements in the array. The current size of the array is always passed in as a
* parameter.
*
* @hide
*/
public final class GrowingArrayUtils {
/**
* Primitive int version of {@link #append(Object[], int, Object)}.
*/
public static int[] append(int[] array, int currentSize, int element) {
assert currentSize <= array.length;
if (currentSize + 1 > array.length) {
int[] newArray = new int[growSize(currentSize)];
System.arraycopy(array, 0, newArray, 0, currentSize);
array = newArray;
}
array[currentSize] = element;
return array;
}
/**
* Primitive long version of {@link #append(Object[], int, Object)}.
*/
public static long[] append(long[] array, int currentSize, long element) {
assert currentSize <= array.length;
if (currentSize + 1 > array.length) {
long[] newArray = new long[growSize(currentSize)];
System.arraycopy(array, 0, newArray, 0, currentSize);
array = newArray;
}
array[currentSize] = element;
return array;
}
/**
* Primitive boolean version of {@link #append(Object[], int, Object)}.
*/
public static boolean[] append(boolean[] array, int currentSize, boolean element) {
assert currentSize <= array.length;
if (currentSize + 1 > array.length) {
boolean[] newArray = new boolean[growSize(currentSize)];
System.arraycopy(array, 0, newArray, 0, currentSize);
array = newArray;
}
array[currentSize] = element;
return array;
}
/**
* Primitive int version of {@link #insert(Object[], int, int, Object)}.
*/
public static int[] insert(int[] array, int currentSize, int index, int element) {
assert currentSize <= array.length;
if (currentSize + 1 <= array.length) {
System.arraycopy(array, index, array, index + 1, currentSize - index);
array[index] = element;
return array;
}
int[] newArray = new int[growSize(currentSize)];
System.arraycopy(array, 0, newArray, 0, index);
newArray[index] = element;
System.arraycopy(array, index, newArray, index + 1, array.length - index);
return newArray;
}
/**
* Primitive long version of {@link #insert(Object[], int, int, Object)}.
*/
public static long[] insert(long[] array, int currentSize, int index, long element) {
assert currentSize <= array.length;
if (currentSize + 1 <= array.length) {
System.arraycopy(array, index, array, index + 1, currentSize - index);
array[index] = element;
return array;
}
long[] newArray = new long[growSize(currentSize)];
System.arraycopy(array, 0, newArray, 0, index);
newArray[index] = element;
System.arraycopy(array, index, newArray, index + 1, array.length - index);
return newArray;
}
/**
* Primitive boolean version of {@link #insert(Object[], int, int, Object)}.
*/
public static boolean[] insert(boolean[] array, int currentSize, int index, boolean element) {
assert currentSize <= array.length;
if (currentSize + 1 <= array.length) {
System.arraycopy(array, index, array, index + 1, currentSize - index);
array[index] = element;
return array;
}
boolean[] newArray = new boolean[growSize(currentSize)];
System.arraycopy(array, 0, newArray, 0, index);
newArray[index] = element;
System.arraycopy(array, index, newArray, index + 1, array.length - index);
return newArray;
}
/**
* Given the current size of an array, returns an ideal size to which the array should grow.
* This is typically double the given size, but should not be relied upon to do so in the
* future.
*/
public static int growSize(int currentSize) {
return currentSize <= 4 ? 8 : currentSize * 2;
}
// Uninstantiable
private GrowingArrayUtils() {}
}