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Lite version of Protocol Buffers library. This version is optimized for code size, but does
not guarantee API/ABI stability.
// Protocol Buffers - Google's data interchange format
// Copyright 2008 Google Inc. All rights reserved.
//
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file or at
// https://developers.google.com/open-source/licenses/bsd
package com.google.protobuf;
import static com.google.protobuf.Internal.checkNotNull;
import static java.lang.Math.max;
import com.google.protobuf.Internal.IntList;
import java.util.Arrays;
import java.util.Collection;
import java.util.RandomAccess;
/**
* An implementation of {@link IntList} on top of a primitive array.
*
* @author [email protected] (Daniel Weis)
*/
final class IntArrayList extends AbstractProtobufList
implements IntList, RandomAccess, PrimitiveNonBoxingCollection {
private static final int[] EMPTY_ARRAY = new int[0];
private static final IntArrayList EMPTY_LIST = new IntArrayList(EMPTY_ARRAY, 0, false);
public static IntArrayList emptyList() {
return EMPTY_LIST;
}
/** The backing store for the list. */
private int[] array;
/**
* The size of the list distinct from the length of the array. That is, it is the number of
* elements set in the list.
*/
private int size;
/** Constructs a new mutable {@code IntArrayList} with default capacity. */
IntArrayList() {
this(EMPTY_ARRAY, 0, true);
}
/**
* Constructs a new mutable {@code IntArrayList} containing the same elements as {@code other}.
*/
private IntArrayList(int[] other, int size, boolean isMutable) {
super(isMutable);
this.array = other;
this.size = size;
}
@Override
protected void removeRange(int fromIndex, int toIndex) {
ensureIsMutable();
if (toIndex < fromIndex) {
throw new IndexOutOfBoundsException("toIndex < fromIndex");
}
System.arraycopy(array, toIndex, array, fromIndex, size - toIndex);
size -= (toIndex - fromIndex);
modCount++;
}
@Override
public boolean equals(Object o) {
if (this == o) {
return true;
}
if (!(o instanceof IntArrayList)) {
return super.equals(o);
}
IntArrayList other = (IntArrayList) o;
if (size != other.size) {
return false;
}
final int[] arr = other.array;
for (int i = 0; i < size; i++) {
if (array[i] != arr[i]) {
return false;
}
}
return true;
}
@Override
public int hashCode() {
int result = 1;
for (int i = 0; i < size; i++) {
result = (31 * result) + array[i];
}
return result;
}
@Override
public IntList mutableCopyWithCapacity(int capacity) {
if (capacity < size) {
throw new IllegalArgumentException();
}
int[] newArray = capacity == 0 ? EMPTY_ARRAY : Arrays.copyOf(array, capacity);
return new IntArrayList(newArray, size, true);
}
@Override
public Integer get(int index) {
return getInt(index);
}
@Override
public int getInt(int index) {
ensureIndexInRange(index);
return array[index];
}
@Override
public int indexOf(Object element) {
if (!(element instanceof Integer)) {
return -1;
}
int unboxedElement = (Integer) element;
int numElems = size();
for (int i = 0; i < numElems; i++) {
if (array[i] == unboxedElement) {
return i;
}
}
return -1;
}
@Override
public boolean contains(Object element) {
return indexOf(element) != -1;
}
@Override
public int size() {
return size;
}
@Override
public Integer set(int index, Integer element) {
return setInt(index, element);
}
@Override
public int setInt(int index, int element) {
ensureIsMutable();
ensureIndexInRange(index);
int previousValue = array[index];
array[index] = element;
return previousValue;
}
@Override
public boolean add(Integer element) {
addInt(element);
return true;
}
@Override
public void add(int index, Integer element) {
addInt(index, element);
}
/** Like {@link #add(Integer)} but more efficient in that it doesn't box the element. */
@Override
public void addInt(int element) {
ensureIsMutable();
if (size == array.length) {
int length = growSize(array.length);
int[] newArray = new int[length];
System.arraycopy(array, 0, newArray, 0, size);
array = newArray;
}
array[size++] = element;
}
/** Like {@link #add(int, Integer)} but more efficient in that it doesn't box the element. */
private void addInt(int index, int element) {
ensureIsMutable();
if (index < 0 || index > size) {
throw new IndexOutOfBoundsException(makeOutOfBoundsExceptionMessage(index));
}
if (size < array.length) {
// Shift everything over to make room
System.arraycopy(array, index, array, index + 1, size - index);
} else {
int length = growSize(array.length);
int[] newArray = new int[length];
// Copy the first part directly
System.arraycopy(array, 0, newArray, 0, index);
// Copy the rest shifted over by one to make room
System.arraycopy(array, index, newArray, index + 1, size - index);
array = newArray;
}
array[index] = element;
size++;
modCount++;
}
@Override
public boolean addAll(Collection collection) {
ensureIsMutable();
checkNotNull(collection);
// We specialize when adding another IntArrayList to avoid boxing elements.
if (!(collection instanceof IntArrayList)) {
return super.addAll(collection);
}
IntArrayList list = (IntArrayList) collection;
if (list.size == 0) {
return false;
}
int overflow = Integer.MAX_VALUE - size;
if (overflow < list.size) {
// We can't actually represent a list this large.
throw new OutOfMemoryError();
}
int newSize = size + list.size;
if (newSize > array.length) {
array = Arrays.copyOf(array, newSize);
}
System.arraycopy(list.array, 0, array, size, list.size);
size = newSize;
modCount++;
return true;
}
@Override
public Integer remove(int index) {
ensureIsMutable();
ensureIndexInRange(index);
int value = array[index];
if (index < size - 1) {
System.arraycopy(array, index + 1, array, index, size - index - 1);
}
size--;
modCount++;
return value;
}
/** Ensures the backing array can fit at least minCapacity elements. */
void ensureCapacity(int minCapacity) {
if (minCapacity <= array.length) {
return;
}
if (array.length == 0) {
array = new int[max(minCapacity, DEFAULT_CAPACITY)];
return;
}
// To avoid quadratic copying when calling .addAllFoo(List) in a loop, we must not size to
// exactly the requested capacity, but must exponentially grow instead. This is similar
// behaviour to ArrayList.
int n = array.length;
while (n < minCapacity) {
n = growSize(n);
}
array = Arrays.copyOf(array, n);
}
private static int growSize(int previousSize) {
// Resize to 1.5x the size, rounding up to DEFAULT_CAPACITY.
return max(((previousSize * 3) / 2) + 1, DEFAULT_CAPACITY);
}
/**
* Ensures that the provided {@code index} is within the range of {@code [0, size]}. Throws an
* {@link IndexOutOfBoundsException} if it is not.
*
* @param index the index to verify is in range
*/
private void ensureIndexInRange(int index) {
if (index < 0 || index >= size) {
throw new IndexOutOfBoundsException(makeOutOfBoundsExceptionMessage(index));
}
}
private String makeOutOfBoundsExceptionMessage(int index) {
return "Index:" + index + ", Size:" + size;
}
}