/*
* 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 android.util;
import com.android.internal.util.ArrayUtils;
import com.android.internal.util.Preconditions;
import libcore.util.EmptyArray;
import java.util.Arrays;
/**
* Implements a growing array of int primitives.
*
* @hide
*/
public class IntArray implements Cloneable {
private static final int MIN_CAPACITY_INCREMENT = 12;
private int[] mValues;
private int mSize;
private IntArray(int[] array, int size) {
mValues = array;
mSize = Preconditions.checkArgumentInRange(size, 0, array.length, "size");
}
/**
* Creates an empty IntArray with the default initial capacity.
*/
public IntArray() {
this(10);
}
/**
* Creates an empty IntArray with the specified initial capacity.
*/
public IntArray(int initialCapacity) {
if (initialCapacity == 0) {
mValues = EmptyArray.INT;
} else {
mValues = ArrayUtils.newUnpaddedIntArray(initialCapacity);
}
mSize = 0;
}
/**
* Creates an IntArray wrapping the given primitive int array.
*/
public static IntArray wrap(int[] array) {
return new IntArray(array, array.length);
}
/**
* Creates an IntArray from the given primitive int array, copying it.
*/
public static IntArray fromArray(int[] array, int size) {
return wrap(Arrays.copyOf(array, size));
}
/**
* Changes the size of this IntArray. If this IntArray is shrinked, the backing array capacity
* is unchanged. If the new size is larger than backing array capacity, a new backing array is
* created from the current content of this IntArray padded with 0s.
*/
public void resize(int newSize) {
Preconditions.checkArgumentNonnegative(newSize);
if (newSize <= mValues.length) {
Arrays.fill(mValues, newSize, mValues.length, 0);
} else {
ensureCapacity(newSize - mSize);
}
mSize = newSize;
}
/**
* Appends the specified value to the end of this array.
*/
public void add(int value) {
add(mSize, value);
}
/**
* Inserts a value at the specified position in this array. If the specified index is equal to
* the length of the array, the value is added at the end.
*
* @throws IndexOutOfBoundsException when index < 0 || index > size()
*/
public void add(int index, int value) {
ensureCapacity(1);
int rightSegment = mSize - index;
mSize++;
ArrayUtils.checkBounds(mSize, index);
if (rightSegment != 0) {
// Move by 1 all values from the right of 'index'
System.arraycopy(mValues, index, mValues, index + 1, rightSegment);
}
mValues[index] = value;
}
/**
* Searches the array for the specified value using the binary search algorithm. The array must
* be sorted (as by the {@link Arrays#sort(int[], int, int)} method) prior to making this call.
* If it is not sorted, the results are undefined. If the range contains multiple elements with
* the specified value, there is no guarantee which one will be found.
*
* @param value The value to search for.
* @return index of the search key, if it is contained in the array; otherwise, <i>(-(insertion
* point) - 1)</i>. The insertion point is defined as the point at which the key would
* be inserted into the array: the index of the first element greater than the key, or
* {@link #size()} if all elements in the array are less than the specified key.
* Note that this guarantees that the return value will be >= 0 if and only if the key
* is found.
*/
public int binarySearch(int value) {
return ContainerHelpers.binarySearch(mValues, mSize, value);
}
/**
* Adds the values in the specified array to this array.
*/
public void addAll(IntArray values) {
final int count = values.mSize;
ensureCapacity(count);
System.arraycopy(values.mValues, 0, mValues, mSize, count);
mSize += count;
}
/**
* Ensures capacity to append at least <code>count</code> values.
*/
private void ensureCapacity(int count) {
final int currentSize = mSize;
final int minCapacity = currentSize + count;
if (minCapacity >= mValues.length) {
final int targetCap = currentSize + (currentSize < (MIN_CAPACITY_INCREMENT / 2) ?
MIN_CAPACITY_INCREMENT : currentSize >> 1);
final int newCapacity = targetCap > minCapacity ? targetCap : minCapacity;
final int[] newValues = ArrayUtils.newUnpaddedIntArray(newCapacity);
System.arraycopy(mValues, 0, newValues, 0, currentSize);
mValues = newValues;
}
}
/**
* Removes all values from this array.
*/
public void clear() {
mSize = 0;
}
@Override
public IntArray clone() throws CloneNotSupportedException {
final IntArray clone = (IntArray) super.clone();
clone.mValues = mValues.clone();
return clone;
}
/**
* Returns the value at the specified position in this array.
*/
public int get(int index) {
ArrayUtils.checkBounds(mSize, index);
return mValues[index];
}
/**
* Sets the value at the specified position in this array.
*/
public void set(int index, int value) {
ArrayUtils.checkBounds(mSize, index);
mValues[index] = value;
}
/**
* Returns the index of the first occurrence of the specified value in this
* array, or -1 if this array does not contain the value.
*/
public int indexOf(int value) {
final int n = mSize;
for (int i = 0; i < n; i++) {
if (mValues[i] == value) {
return i;
}
}
return -1;
}
/**
* Removes the value at the specified index from this array.
*/
public void remove(int index) {
ArrayUtils.checkBounds(mSize, index);
System.arraycopy(mValues, index + 1, mValues, index, mSize - index - 1);
mSize--;
}
/**
* Returns the number of values in this array.
*/
public int size() {
return mSize;
}
/**
* Returns a new array with the contents of this IntArray.
*/
public int[] toArray() {
return Arrays.copyOf(mValues, mSize);
}
}