Alan Viverette | ffb46bf | 2014-10-24 12:06:11 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2014 The Android Open Source Project |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | package android.util; |
| 18 | |
| 19 | import com.android.internal.util.ArrayUtils; |
Hugo Benichi | 112962a | 2017-03-27 13:45:23 +0900 | [diff] [blame] | 20 | import com.android.internal.util.Preconditions; |
Zoltan Szatmary-Ban | 9c5dfa5 | 2015-02-23 17:20:20 +0000 | [diff] [blame] | 21 | import java.util.Arrays; |
Alan Viverette | ffb46bf | 2014-10-24 12:06:11 -0700 | [diff] [blame] | 22 | import libcore.util.EmptyArray; |
| 23 | |
| 24 | /** |
| 25 | * Implements a growing array of int primitives. |
| 26 | * |
| 27 | * @hide |
| 28 | */ |
| 29 | public class IntArray implements Cloneable { |
| 30 | private static final int MIN_CAPACITY_INCREMENT = 12; |
| 31 | |
| 32 | private int[] mValues; |
| 33 | private int mSize; |
| 34 | |
Hugo Benichi | 112962a | 2017-03-27 13:45:23 +0900 | [diff] [blame] | 35 | private IntArray(int[] array, int size) { |
| 36 | mValues = array; |
| 37 | mSize = Preconditions.checkArgumentInRange(size, 0, array.length, "size"); |
| 38 | } |
| 39 | |
Alan Viverette | ffb46bf | 2014-10-24 12:06:11 -0700 | [diff] [blame] | 40 | /** |
| 41 | * Creates an empty IntArray with the default initial capacity. |
| 42 | */ |
| 43 | public IntArray() { |
| 44 | this(10); |
| 45 | } |
| 46 | |
| 47 | /** |
| 48 | * Creates an empty IntArray with the specified initial capacity. |
| 49 | */ |
| 50 | public IntArray(int initialCapacity) { |
| 51 | if (initialCapacity == 0) { |
| 52 | mValues = EmptyArray.INT; |
| 53 | } else { |
| 54 | mValues = ArrayUtils.newUnpaddedIntArray(initialCapacity); |
| 55 | } |
| 56 | mSize = 0; |
| 57 | } |
| 58 | |
| 59 | /** |
Hugo Benichi | 112962a | 2017-03-27 13:45:23 +0900 | [diff] [blame] | 60 | * Creates an IntArray wrapping the given primitive int array. |
| 61 | */ |
| 62 | public static IntArray wrap(int[] array) { |
| 63 | return new IntArray(array, array.length); |
| 64 | } |
| 65 | |
| 66 | /** |
| 67 | * Creates an IntArray from the given primitive int array, copying it. |
| 68 | */ |
| 69 | public static IntArray fromArray(int[] array, int size) { |
| 70 | return wrap(Arrays.copyOf(array, size)); |
| 71 | } |
| 72 | |
| 73 | /** |
| 74 | * Changes the size of this IntArray. If this IntArray is shrinked, the backing array capacity |
| 75 | * is unchanged. If the new size is larger than backing array capacity, a new backing array is |
| 76 | * created from the current content of this IntArray padded with 0s. |
| 77 | */ |
| 78 | public void resize(int newSize) { |
| 79 | Preconditions.checkArgumentNonnegative(newSize); |
| 80 | if (newSize <= mValues.length) { |
| 81 | Arrays.fill(mValues, newSize, mValues.length, 0); |
| 82 | } else { |
| 83 | ensureCapacity(newSize - mSize); |
| 84 | } |
| 85 | mSize = newSize; |
| 86 | } |
| 87 | |
| 88 | /** |
Alan Viverette | ffb46bf | 2014-10-24 12:06:11 -0700 | [diff] [blame] | 89 | * Appends the specified value to the end of this array. |
| 90 | */ |
| 91 | public void add(int value) { |
| 92 | add(mSize, value); |
| 93 | } |
| 94 | |
| 95 | /** |
Hugo Benichi | 112962a | 2017-03-27 13:45:23 +0900 | [diff] [blame] | 96 | * Inserts a value at the specified position in this array. If the specified index is equal to |
| 97 | * the length of the array, the value is added at the end. |
Alan Viverette | ffb46bf | 2014-10-24 12:06:11 -0700 | [diff] [blame] | 98 | * |
| 99 | * @throws IndexOutOfBoundsException when index < 0 || index > size() |
| 100 | */ |
| 101 | public void add(int index, int value) { |
Alan Viverette | ffb46bf | 2014-10-24 12:06:11 -0700 | [diff] [blame] | 102 | ensureCapacity(1); |
Hugo Benichi | 112962a | 2017-03-27 13:45:23 +0900 | [diff] [blame] | 103 | int rightSegment = mSize - index; |
| 104 | mSize++; |
| 105 | checkBounds(index); |
Alan Viverette | ffb46bf | 2014-10-24 12:06:11 -0700 | [diff] [blame] | 106 | |
Hugo Benichi | 112962a | 2017-03-27 13:45:23 +0900 | [diff] [blame] | 107 | if (rightSegment != 0) { |
| 108 | // Move by 1 all values from the right of 'index' |
| 109 | System.arraycopy(mValues, index, mValues, index + 1, rightSegment); |
Alan Viverette | ffb46bf | 2014-10-24 12:06:11 -0700 | [diff] [blame] | 110 | } |
| 111 | |
| 112 | mValues[index] = value; |
Alan Viverette | ffb46bf | 2014-10-24 12:06:11 -0700 | [diff] [blame] | 113 | } |
| 114 | |
| 115 | /** |
Zoltan Szatmary-Ban | 9c5dfa5 | 2015-02-23 17:20:20 +0000 | [diff] [blame] | 116 | * Searches the array for the specified value using the binary search algorithm. The array must |
| 117 | * be sorted (as by the {@link Arrays#sort(int[], int, int)} method) prior to making this call. |
| 118 | * If it is not sorted, the results are undefined. If the range contains multiple elements with |
| 119 | * the specified value, there is no guarantee which one will be found. |
| 120 | * |
| 121 | * @param value The value to search for. |
| 122 | * @return index of the search key, if it is contained in the array; otherwise, <i>(-(insertion |
| 123 | * point) - 1)</i>. The insertion point is defined as the point at which the key would |
| 124 | * be inserted into the array: the index of the first element greater than the key, or |
| 125 | * {@link #size()} if all elements in the array are less than the specified key. |
| 126 | * Note that this guarantees that the return value will be >= 0 if and only if the key |
| 127 | * is found. |
| 128 | */ |
| 129 | public int binarySearch(int value) { |
| 130 | return ContainerHelpers.binarySearch(mValues, mSize, value); |
| 131 | } |
| 132 | |
| 133 | /** |
Alan Viverette | ffb46bf | 2014-10-24 12:06:11 -0700 | [diff] [blame] | 134 | * Adds the values in the specified array to this array. |
| 135 | */ |
| 136 | public void addAll(IntArray values) { |
| 137 | final int count = values.mSize; |
| 138 | ensureCapacity(count); |
| 139 | |
| 140 | System.arraycopy(values.mValues, 0, mValues, mSize, count); |
| 141 | mSize += count; |
| 142 | } |
| 143 | |
| 144 | /** |
| 145 | * Ensures capacity to append at least <code>count</code> values. |
| 146 | */ |
| 147 | private void ensureCapacity(int count) { |
| 148 | final int currentSize = mSize; |
| 149 | final int minCapacity = currentSize + count; |
| 150 | if (minCapacity >= mValues.length) { |
| 151 | final int targetCap = currentSize + (currentSize < (MIN_CAPACITY_INCREMENT / 2) ? |
| 152 | MIN_CAPACITY_INCREMENT : currentSize >> 1); |
| 153 | final int newCapacity = targetCap > minCapacity ? targetCap : minCapacity; |
| 154 | final int[] newValues = ArrayUtils.newUnpaddedIntArray(newCapacity); |
| 155 | System.arraycopy(mValues, 0, newValues, 0, currentSize); |
| 156 | mValues = newValues; |
| 157 | } |
| 158 | } |
| 159 | |
| 160 | /** |
| 161 | * Removes all values from this array. |
| 162 | */ |
| 163 | public void clear() { |
| 164 | mSize = 0; |
| 165 | } |
| 166 | |
| 167 | @Override |
| 168 | public IntArray clone() throws CloneNotSupportedException { |
| 169 | final IntArray clone = (IntArray) super.clone(); |
| 170 | clone.mValues = mValues.clone(); |
| 171 | return clone; |
| 172 | } |
| 173 | |
| 174 | /** |
| 175 | * Returns the value at the specified position in this array. |
| 176 | */ |
| 177 | public int get(int index) { |
Hugo Benichi | 112962a | 2017-03-27 13:45:23 +0900 | [diff] [blame] | 178 | checkBounds(index); |
Alan Viverette | ffb46bf | 2014-10-24 12:06:11 -0700 | [diff] [blame] | 179 | return mValues[index]; |
| 180 | } |
| 181 | |
| 182 | /** |
Hugo Benichi | 112962a | 2017-03-27 13:45:23 +0900 | [diff] [blame] | 183 | * Sets the value at the specified position in this array. |
| 184 | */ |
| 185 | public void set(int index, int value) { |
| 186 | checkBounds(index); |
| 187 | mValues[index] = value; |
| 188 | } |
| 189 | |
| 190 | /** |
Alan Viverette | ffb46bf | 2014-10-24 12:06:11 -0700 | [diff] [blame] | 191 | * Returns the index of the first occurrence of the specified value in this |
| 192 | * array, or -1 if this array does not contain the value. |
| 193 | */ |
| 194 | public int indexOf(int value) { |
| 195 | final int n = mSize; |
| 196 | for (int i = 0; i < n; i++) { |
| 197 | if (mValues[i] == value) { |
| 198 | return i; |
| 199 | } |
| 200 | } |
| 201 | return -1; |
| 202 | } |
| 203 | |
| 204 | /** |
| 205 | * Removes the value at the specified index from this array. |
| 206 | */ |
| 207 | public void remove(int index) { |
Hugo Benichi | 112962a | 2017-03-27 13:45:23 +0900 | [diff] [blame] | 208 | checkBounds(index); |
Alan Viverette | ffb46bf | 2014-10-24 12:06:11 -0700 | [diff] [blame] | 209 | System.arraycopy(mValues, index + 1, mValues, index, mSize - index - 1); |
| 210 | mSize--; |
| 211 | } |
| 212 | |
| 213 | /** |
| 214 | * Returns the number of values in this array. |
| 215 | */ |
| 216 | public int size() { |
| 217 | return mSize; |
| 218 | } |
Zoltan Szatmary-Ban | 9c5dfa5 | 2015-02-23 17:20:20 +0000 | [diff] [blame] | 219 | |
| 220 | /** |
| 221 | * Returns a new array with the contents of this IntArray. |
| 222 | */ |
| 223 | public int[] toArray() { |
| 224 | return Arrays.copyOf(mValues, mSize); |
| 225 | } |
Hugo Benichi | 112962a | 2017-03-27 13:45:23 +0900 | [diff] [blame] | 226 | |
| 227 | private void checkBounds(int index) { |
| 228 | if (index < 0 || mSize <= index) { |
| 229 | throw new ArrayIndexOutOfBoundsException(mSize, index); |
| 230 | } |
| 231 | } |
Alan Viverette | ffb46bf | 2014-10-24 12:06:11 -0700 | [diff] [blame] | 232 | } |