/* Soot - a J*va Optimization Framework
* Copyright (C) 1997-1999 Raja Vallee-Rai
*
* This library 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 library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
/*
* Modified by the Sable Research Group and others 1997-1999.
* See the 'credits' file distributed with Soot for the complete list of
* contributors. (Soot is distributed at http://www.sable.mcgill.ca/soot)
*/
package soot.util;
import java.util.*;
/**
* Provides an implementation of the Set object using java.util.Array
*/
public class ArraySet<E> extends AbstractSet<E>
{
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);
}
final public void clear()
{
numElements = 0;
}
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;
}
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;
}
}
@SuppressWarnings("unchecked")
final public boolean addAll(Collection<? extends E> 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;
}
final public int size()
{
return numElements;
}
final public Iterator<E> iterator()
{
return new ArrayIterator<E>();
}
private class ArrayIterator<V> implements Iterator<V>
{
int nextIndex;
ArrayIterator()
{
nextIndex = 0;
}
final public boolean hasNext()
{
return nextIndex < numElements;
}
@SuppressWarnings("unchecked")
final public V next() throws NoSuchElementException
{
if(!(nextIndex < numElements))
throw new NoSuchElementException();
return (V) elements[nextIndex++];
}
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()
{
int newSize = maxElements * 2;
Object[] newElements = new Object[newSize];
System.arraycopy(elements, 0, newElements, 0, numElements);
elements = newElements;
maxElements = newSize;
}
final public Object[] toArray()
{
Object[] array = new Object[numElements];
System.arraycopy(elements, 0, array, 0, numElements);
return array;
}
final public <T> T[] toArray( T[] array )
{
System.arraycopy(elements, 0, array, 0, numElements);
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--;
}
}
}