/*******************************************************************************
* Copyright (c) 2002 - 2006 IBM Corporation.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* IBM Corporation - initial API and implementation
*******************************************************************************/
package com.ibm.wala.util.intset;
/**
* an int vector implementation designed for low occupancy. Note that get() from
* this vector is a binary search.
*
* This should only be used for small sets ... insertion and deletion are linear
* in size of set.
*/
public class SparseIntVector implements IntVector {
private final static int INITIAL_SIZE = 5;
private final double EXPANSION = 1.5;
int maxIndex = -1;
/**
* if indices[i] = x, then data[i] == get(x)
*/
final private MutableSparseIntSet indices = MutableSparseIntSet.makeEmpty();
private int[] data = new int[INITIAL_SIZE];
private final int defaultValue;
public SparseIntVector(int defaultValue) {
this.defaultValue = defaultValue;
}
/*
* @see com.ibm.wala.util.intset.IntVector#get(int)
*/
@Override
public int get(int x) {
int index = indices.getIndex(x);
if (index == -1) {
return defaultValue;
} else {
return data[index];
}
}
/*
* TODO: this can be optimized
*
* @see com.ibm.wala.util.intset.IntVector#set(int, int)
*/
@Override
public void set(int x, int value) {
maxIndex = Math.max(maxIndex,x);
int index = indices.getIndex(x);
if (index == -1) {
indices.add(x);
index = indices.getIndex(x);
ensureCapacity(indices.size() + 1);
if (index < (data.length - 1)) {
System.arraycopy(data, index, data, index + 1, indices.size() - index);
}
}
data[index] = value;
}
private void ensureCapacity(int capacity) {
if (data.length < capacity + 1) {
int[] old = data;
data = new int[1 + (int) (capacity * EXPANSION)];
System.arraycopy(old, 0, data, 0, old.length);
}
}
/*
* @see com.ibm.wala.util.debug.VerboseAction#performVerboseAction()
*/
public void performVerboseAction() {
System.err.println((getClass() + " stats: "));
System.err.println(("data.length " + data.length));
System.err.println(("indices.size() " + indices.size()));
}
@Override
public int getMaxIndex() {
return maxIndex;
}
}