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A Java Optimization Framework
package soot.util;
/*-
* #%L
* Soot - a J*va Optimization Framework
* %%
* Copyright (C) 1997 - 1999 Raja Vallee-Rai
* %%
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation, either version 2.1 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Lesser Public License for more details.
*
* You should have received a copy of the GNU General Lesser Public
* License along with this program. If not, see
* .
* #L%
*/
import java.util.AbstractSet;
import java.util.Arrays;
import java.util.Collection;
import java.util.Iterator;
import java.util.NoSuchElementException;
/**
* Provides an implementation of the Set object using java.util.Array
*/
public class ArraySet extends AbstractSet {
private static final int DEFAULT_SIZE = 8;
private int numElements;
private int maxElements;
private Object[] elements;
public ArraySet(int size) {
maxElements = size;
elements = new Object[size];
numElements = 0;
}
public ArraySet() {
this(DEFAULT_SIZE);
}
/**
* Create a set which contains the given elements.
*/
public ArraySet(E[] elements) {
this();
for (E element : elements) {
add(element);
}
}
@Override
final public void clear() {
numElements = 0;
}
@Override
final public boolean contains(Object obj) {
for (int i = 0; i < numElements; i++) {
if (elements[i].equals(obj)) {
return true;
}
}
return false;
}
/**
* Add an element without checking whether it is already in the set. It is up to the caller to guarantee that it isn't.
*/
final public boolean addElement(E e) {
if (e == null) {
throw new RuntimeException("oops");
}
// Expand array if necessary
if (numElements == maxElements) {
doubleCapacity();
}
// Add element
elements[numElements++] = e;
return true;
}
@Override
final public boolean add(E e) {
if (e == null) {
throw new RuntimeException("oops");
}
if (contains(e)) {
return false;
} else {
// Expand array if necessary
if (numElements == maxElements) {
doubleCapacity();
}
// Add element
elements[numElements++] = e;
return true;
}
}
@Override
@SuppressWarnings("unchecked")
final public boolean addAll(Collection s) {
boolean ret = false;
if (!(s instanceof ArraySet)) {
return super.addAll(s);
}
ArraySet as = (ArraySet) s;
int asSize = as.size();
Object[] asElements = as.elements;
for (int i = 0; i < asSize; i++) {
ret = add((E) asElements[i]) | ret;
}
return ret;
}
@Override
final public int size() {
return numElements;
}
@Override
final public Iterator iterator() {
return new ArrayIterator();
}
private class ArrayIterator implements Iterator {
int nextIndex;
ArrayIterator() {
nextIndex = 0;
}
@Override
final public boolean hasNext() {
return nextIndex < numElements;
}
@Override
@SuppressWarnings("unchecked")
final public V next() throws NoSuchElementException {
if (!(nextIndex < numElements)) {
throw new NoSuchElementException();
}
return (V) elements[nextIndex++];
}
@Override
final public void remove() throws NoSuchElementException {
if (nextIndex == 0) {
throw new NoSuchElementException();
} else {
removeElementAt(nextIndex - 1);
nextIndex = nextIndex - 1;
}
}
}
final private void removeElementAt(int index) {
// Handle simple case
if (index == numElements - 1) {
numElements--;
return;
}
// Else, shift over elements
System.arraycopy(elements, index + 1, elements, index, numElements - (index + 1));
numElements--;
}
final private void doubleCapacity() {
// plus one to ensure that we have at least one element
int newSize = maxElements * 2 + 1;
Object[] newElements = new Object[newSize];
System.arraycopy(elements, 0, newElements, 0, numElements);
elements = newElements;
maxElements = newSize;
}
@Override
final public Object[] toArray() {
Object[] array = new Object[numElements];
System.arraycopy(elements, 0, array, 0, numElements);
return array;
}
@SuppressWarnings("unchecked")
@Override
final public T[] toArray(T[] array) {
if (array.length < numElements) {
return (T[]) Arrays.copyOf(elements, numElements, array.getClass());
} else {
System.arraycopy(elements, 0, array, 0, numElements);
if (array.length > numElements) {
array[numElements] = null;
}
return array;
}
}
final public Object[] getUnderlyingArray() {
return elements;
}
class Array {
private final int DEFAULT_SIZE = 8;
private int numElements;
private int maxElements;
private Object[] elements;
final public void clear() {
numElements = 0;
}
public Array() {
elements = new Object[DEFAULT_SIZE];
maxElements = DEFAULT_SIZE;
numElements = 0;
}
final private void doubleCapacity() {
int newSize = maxElements * 2;
Object[] newElements = new Object[newSize];
System.arraycopy(elements, 0, newElements, 0, numElements);
elements = newElements;
maxElements = newSize;
}
final public void addElement(Object e) {
// Expand array if necessary
if (numElements == maxElements) {
doubleCapacity();
}
// Add element
elements[numElements++] = e;
}
final public void insertElementAt(Object e, int index) {
// Expaxpand array if necessary
if (numElements == maxElements) {
doubleCapacity();
}
// Handle simple case
if (index == numElements) {
elements[numElements++] = e;
return;
}
// Shift things over
System.arraycopy(elements, index, elements, index + 1, numElements - index);
elements[index] = e;
numElements++;
}
final public boolean contains(Object e) {
for (int i = 0; i < numElements; i++) {
if (elements[i].equals(e)) {
return true;
}
}
return false;
}
final public int size() {
return numElements;
}
final public Object elementAt(int index) {
return elements[index];
}
final public void removeElementAt(int index) {
// Handle simple case
if (index == numElements - 1) {
numElements--;
return;
}
// Else, shift over elements
System.arraycopy(elements, index + 1, elements, index, numElements - (index + 1));
numElements--;
}
}
}