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/*
* Copyright (C) 2024 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 android.utils;
import android.annotation.NonNull;
import android.annotation.Nullable;
import java.io.File;
import java.util.List;
import java.util.Objects;
/**
* Copied over from frameworks/base/core/java/com/android/internal/util/ArrayUtils.java
*
* @hide
*/
public class ArrayUtils {
private ArrayUtils() { /* cannot be instantiated */ }
public static final File[] EMPTY_FILE = new File[0];
/**
* 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;
}
/** @hide */
public static @NonNull File[] defeatNullable(@Nullable File[] val) {
return (val != null) ? val : EMPTY_FILE;
}
/**
* Checks if given array is null or has zero elements.
*/
public static boolean isEmpty(@Nullable int[] array) {
return array == null || array.length == 0;
}
/**
* True if the byte array is null or has length 0.
*/
public static boolean isEmpty(@Nullable byte[] array) {
return array == null || array.length == 0;
}
/**
* Converts from List of bytes to byte array
* @param list
* @return byte[]
*/
public static byte[] toPrimitive(List<byte[]> list) {
if (list.size() == 0) {
return new byte[0];
}
int byteLen = list.get(0).length;
byte[] array = new byte[list.size() * byteLen];
for (int i = 0; i < list.size(); i++) {
for (int j = 0; j < list.get(i).length; j++) {
array[i * byteLen + j] = list.get(i)[j];
}
}
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) {
return appendInt(cur, val, false);
}
/**
* Adds value to given array.
*/
public static @NonNull int[] appendInt(@Nullable int[] cur, int val,
boolean allowDuplicates) {
if (cur == null) {
return new int[] { val };
}
final int n = cur.length;
if (!allowDuplicates) {
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;
}
}
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