| /* |
| * Copyright (C) 2006 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.android.internal.util; |
| |
| import android.annotation.NonNull; |
| import android.annotation.Nullable; |
| import android.util.ArraySet; |
| |
| import dalvik.system.VMRuntime; |
| |
| import libcore.util.EmptyArray; |
| |
| import java.lang.reflect.Array; |
| import java.util.ArrayList; |
| import java.util.Arrays; |
| import java.util.Objects; |
| |
| /** |
| * ArrayUtils contains some methods that you can call to find out |
| * the most efficient increments by which to grow arrays. |
| */ |
| public class ArrayUtils { |
| private static final int CACHE_SIZE = 73; |
| private static Object[] sCache = new Object[CACHE_SIZE]; |
| |
| private ArrayUtils() { /* cannot be instantiated */ } |
| |
| public static byte[] newUnpaddedByteArray(int minLen) { |
| return (byte[])VMRuntime.getRuntime().newUnpaddedArray(byte.class, minLen); |
| } |
| |
| public static char[] newUnpaddedCharArray(int minLen) { |
| return (char[])VMRuntime.getRuntime().newUnpaddedArray(char.class, minLen); |
| } |
| |
| public static int[] newUnpaddedIntArray(int minLen) { |
| return (int[])VMRuntime.getRuntime().newUnpaddedArray(int.class, minLen); |
| } |
| |
| public static boolean[] newUnpaddedBooleanArray(int minLen) { |
| return (boolean[])VMRuntime.getRuntime().newUnpaddedArray(boolean.class, minLen); |
| } |
| |
| public static long[] newUnpaddedLongArray(int minLen) { |
| return (long[])VMRuntime.getRuntime().newUnpaddedArray(long.class, minLen); |
| } |
| |
| public static float[] newUnpaddedFloatArray(int minLen) { |
| return (float[])VMRuntime.getRuntime().newUnpaddedArray(float.class, minLen); |
| } |
| |
| public static Object[] newUnpaddedObjectArray(int minLen) { |
| return (Object[])VMRuntime.getRuntime().newUnpaddedArray(Object.class, minLen); |
| } |
| |
| @SuppressWarnings("unchecked") |
| public static <T> T[] newUnpaddedArray(Class<T> clazz, int minLen) { |
| return (T[])VMRuntime.getRuntime().newUnpaddedArray(clazz, minLen); |
| } |
| |
| /** |
| * Checks if the beginnings of two byte arrays are equal. |
| * |
| * @param array1 the first byte array |
| * @param array2 the second byte array |
| * @param length the number of bytes to check |
| * @return true if they're equal, false otherwise |
| */ |
| public static boolean equals(byte[] array1, byte[] array2, int length) { |
| if (length < 0) { |
| throw new IllegalArgumentException(); |
| } |
| |
| if (array1 == array2) { |
| return true; |
| } |
| if (array1 == null || array2 == null || array1.length < length || array2.length < length) { |
| return false; |
| } |
| for (int i = 0; i < length; i++) { |
| if (array1[i] != array2[i]) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| /** |
| * Returns an empty array of the specified type. The intent is that |
| * it will return the same empty array every time to avoid reallocation, |
| * although this is not guaranteed. |
| */ |
| @SuppressWarnings("unchecked") |
| public static <T> T[] emptyArray(Class<T> kind) { |
| if (kind == Object.class) { |
| return (T[]) EmptyArray.OBJECT; |
| } |
| |
| int bucket = (kind.hashCode() & 0x7FFFFFFF) % CACHE_SIZE; |
| Object cache = sCache[bucket]; |
| |
| if (cache == null || cache.getClass().getComponentType() != kind) { |
| cache = Array.newInstance(kind, 0); |
| sCache[bucket] = cache; |
| |
| // Log.e("cache", "new empty " + kind.getName() + " at " + bucket); |
| } |
| |
| return (T[]) cache; |
| } |
| |
| /** |
| * Checks if given array is null or has zero elements. |
| */ |
| public static <T> boolean isEmpty(@Nullable T[] array) { |
| return array == null || array.length == 0; |
| } |
| |
| /** |
| * Checks if given array is null or has zero elements. |
| */ |
| public static boolean isEmpty(@Nullable int[] array) { |
| return array == null || array.length == 0; |
| } |
| |
| /** |
| * Checks if given array is null or has zero elements. |
| */ |
| public static boolean isEmpty(@Nullable long[] array) { |
| return array == null || array.length == 0; |
| } |
| |
| /** |
| * Checks if given array is null or has zero elements. |
| */ |
| public static boolean isEmpty(@Nullable byte[] array) { |
| return array == null || array.length == 0; |
| } |
| |
| /** |
| * Checks that value is present as at least one of the elements of the array. |
| * @param array the array to check in |
| * @param value the value to check for |
| * @return true if the value is present in the array |
| */ |
| public static <T> boolean contains(@Nullable T[] array, T value) { |
| return indexOf(array, value) != -1; |
| } |
| |
| /** |
| * Return first index of {@code value} in {@code array}, or {@code -1} if |
| * not found. |
| */ |
| public static <T> int indexOf(@Nullable T[] array, T value) { |
| if (array == null) return -1; |
| for (int i = 0; i < array.length; i++) { |
| if (Objects.equals(array[i], value)) return i; |
| } |
| return -1; |
| } |
| |
| /** |
| * Test if all {@code check} items are contained in {@code array}. |
| */ |
| public static <T> boolean containsAll(@Nullable T[] array, T[] check) { |
| if (check == null) return true; |
| for (T checkItem : check) { |
| if (!contains(array, checkItem)) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| public static boolean contains(@Nullable int[] array, int value) { |
| if (array == null) return false; |
| for (int element : array) { |
| if (element == value) { |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| public static boolean contains(@Nullable long[] array, long value) { |
| if (array == null) return false; |
| for (long element : array) { |
| if (element == value) { |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| public static long total(@Nullable long[] array) { |
| long total = 0; |
| if (array != null) { |
| for (long value : array) { |
| total += value; |
| } |
| } |
| return total; |
| } |
| |
| /** |
| * Adds value to given array if not already present, providing set-like |
| * behavior. |
| */ |
| @SuppressWarnings("unchecked") |
| public static @NonNull <T> T[] appendElement(Class<T> kind, @Nullable T[] array, T element) { |
| final T[] result; |
| final int end; |
| if (array != null) { |
| if (contains(array, element)) return array; |
| end = array.length; |
| result = (T[])Array.newInstance(kind, end + 1); |
| System.arraycopy(array, 0, result, 0, end); |
| } else { |
| end = 0; |
| result = (T[])Array.newInstance(kind, 1); |
| } |
| result[end] = element; |
| return result; |
| } |
| |
| /** |
| * Removes value from given array if present, providing set-like behavior. |
| */ |
| @SuppressWarnings("unchecked") |
| public static @Nullable <T> T[] removeElement(Class<T> kind, @Nullable T[] array, T element) { |
| if (array != null) { |
| if (!contains(array, element)) return array; |
| final int length = array.length; |
| for (int i = 0; i < length; i++) { |
| if (Objects.equals(array[i], element)) { |
| if (length == 1) { |
| return null; |
| } |
| T[] result = (T[])Array.newInstance(kind, length - 1); |
| System.arraycopy(array, 0, result, 0, i); |
| System.arraycopy(array, i + 1, result, i, length - i - 1); |
| return result; |
| } |
| } |
| } |
| return array; |
| } |
| |
| /** |
| * Adds value to given array if not already present, providing set-like |
| * behavior. |
| */ |
| public static @NonNull int[] appendInt(@Nullable int[] cur, int val) { |
| if (cur == null) { |
| return new int[] { val }; |
| } |
| final int N = cur.length; |
| for (int i = 0; i < N; i++) { |
| if (cur[i] == val) { |
| return cur; |
| } |
| } |
| int[] ret = new int[N + 1]; |
| System.arraycopy(cur, 0, ret, 0, N); |
| ret[N] = val; |
| return ret; |
| } |
| |
| /** |
| * Removes value from given array if present, providing set-like behavior. |
| */ |
| public static @Nullable int[] removeInt(@Nullable int[] cur, int val) { |
| if (cur == null) { |
| return null; |
| } |
| final int N = cur.length; |
| for (int i = 0; i < N; i++) { |
| if (cur[i] == val) { |
| int[] ret = new int[N - 1]; |
| if (i > 0) { |
| System.arraycopy(cur, 0, ret, 0, i); |
| } |
| if (i < (N - 1)) { |
| System.arraycopy(cur, i + 1, ret, i, N - i - 1); |
| } |
| return ret; |
| } |
| } |
| return cur; |
| } |
| |
| /** |
| * Removes value from given array if present, providing set-like behavior. |
| */ |
| public static @Nullable String[] removeString(@Nullable String[] cur, String val) { |
| if (cur == null) { |
| return null; |
| } |
| final int N = cur.length; |
| for (int i = 0; i < N; i++) { |
| if (Objects.equals(cur[i], val)) { |
| String[] ret = new String[N - 1]; |
| if (i > 0) { |
| System.arraycopy(cur, 0, ret, 0, i); |
| } |
| if (i < (N - 1)) { |
| System.arraycopy(cur, i + 1, ret, i, N - i - 1); |
| } |
| return ret; |
| } |
| } |
| return cur; |
| } |
| |
| /** |
| * Adds value to given array if not already present, providing set-like |
| * behavior. |
| */ |
| public static @NonNull long[] appendLong(@Nullable long[] cur, long val) { |
| if (cur == null) { |
| return new long[] { val }; |
| } |
| final int N = cur.length; |
| for (int i = 0; i < N; i++) { |
| if (cur[i] == val) { |
| return cur; |
| } |
| } |
| long[] ret = new long[N + 1]; |
| System.arraycopy(cur, 0, ret, 0, N); |
| ret[N] = val; |
| return ret; |
| } |
| |
| /** |
| * Removes value from given array if present, providing set-like behavior. |
| */ |
| public static @Nullable long[] removeLong(@Nullable long[] cur, long val) { |
| if (cur == null) { |
| return null; |
| } |
| final int N = cur.length; |
| for (int i = 0; i < N; i++) { |
| if (cur[i] == val) { |
| long[] ret = new long[N - 1]; |
| if (i > 0) { |
| System.arraycopy(cur, 0, ret, 0, i); |
| } |
| if (i < (N - 1)) { |
| System.arraycopy(cur, i + 1, ret, i, N - i - 1); |
| } |
| return ret; |
| } |
| } |
| return cur; |
| } |
| |
| public static @Nullable long[] cloneOrNull(@Nullable long[] array) { |
| return (array != null) ? array.clone() : null; |
| } |
| |
| public static @Nullable <T> ArraySet<T> cloneOrNull(@Nullable ArraySet<T> array) { |
| return (array != null) ? new ArraySet<T>(array) : null; |
| } |
| |
| public static @NonNull <T> ArraySet<T> add(@Nullable ArraySet<T> cur, T val) { |
| if (cur == null) { |
| cur = new ArraySet<>(); |
| } |
| cur.add(val); |
| return cur; |
| } |
| |
| public static @Nullable <T> ArraySet<T> remove(@Nullable ArraySet<T> cur, T val) { |
| if (cur == null) { |
| return null; |
| } |
| cur.remove(val); |
| if (cur.isEmpty()) { |
| return null; |
| } else { |
| return cur; |
| } |
| } |
| |
| public static <T> boolean contains(@Nullable ArraySet<T> cur, T val) { |
| return (cur != null) ? cur.contains(val) : false; |
| } |
| |
| public static @NonNull <T> ArrayList<T> add(@Nullable ArrayList<T> cur, T val) { |
| if (cur == null) { |
| cur = new ArrayList<>(); |
| } |
| cur.add(val); |
| return cur; |
| } |
| |
| public static @Nullable <T> ArrayList<T> remove(@Nullable ArrayList<T> cur, T val) { |
| if (cur == null) { |
| return null; |
| } |
| cur.remove(val); |
| if (cur.isEmpty()) { |
| return null; |
| } else { |
| return cur; |
| } |
| } |
| |
| public static <T> boolean contains(@Nullable ArrayList<T> cur, T val) { |
| return (cur != null) ? cur.contains(val) : false; |
| } |
| |
| public static @Nullable <T> T[] trimToSize(@Nullable T[] array, int size) { |
| if (array == null || size == 0) { |
| return null; |
| } else if (array.length == size) { |
| return array; |
| } else { |
| return Arrays.copyOf(array, size); |
| } |
| } |
| |
| /** |
| * Returns true if the two ArrayLists are equal with respect to the objects they contain. |
| * The objects must be in the same order and be reference equal (== not .equals()). |
| */ |
| public static <T> boolean referenceEquals(ArrayList<T> a, ArrayList<T> b) { |
| if (a == b) { |
| return true; |
| } |
| |
| final int sizeA = a.size(); |
| final int sizeB = b.size(); |
| if (a == null || b == null || sizeA != sizeB) { |
| return false; |
| } |
| |
| boolean diff = false; |
| for (int i = 0; i < sizeA && !diff; i++) { |
| diff |= a.get(i) != b.get(i); |
| } |
| return !diff; |
| } |
| } |