package net.sf.saxon.sort;
import net.sf.saxon.om.FastStringBuffer;
import java.io.Serializable;
import java.util.Arrays;
/**
* Set of int values. This implementation of IntSet uses a sorted array
* of integer ranges.
*
* @author Michael Kay
*/
public class IntRangeSet implements Serializable, IntSet {
// The array of start points, which will always be sorted
private int[] startPoints;
// The array of end points, which will always be sorted
private int[] endPoints;
// The number of elements of the above two arrays that are actually in use
private int used = 0;
// Hashcode, evaluated lazily
private int hashCode = -1;
// The number of items in the set
private int size = 0;
/**
* Create an empty set
*/
public IntRangeSet() {
startPoints = new int[4];
endPoints = new int[4];
used = 0;
size = 0;
hashCode = -1;
}
/**
* Create one IntRangeSet as a copy of another
* @param input the IntRangeSet to be copied
*/
public IntRangeSet(IntRangeSet input) {
startPoints = new int[input.used];
endPoints = new int[input.used];
used = input.used;
System.arraycopy(input.startPoints, 0, startPoints, 0, used);
System.arraycopy(input.endPoints, 0, endPoints, 0, used);
hashCode = input.hashCode;
}
/**
* Create an IntRangeSet given the start points and end points of the integer ranges.
* The two arrays must be the same length; each must be in ascending order; and the n'th end point
* must be greater than the n'th start point, and less than the n+1'th start point, for all n.
* @param startPoints the start points of the integer ranges
* @param endPoints the end points of the integer ranges
* @throws IllegalArgumentException if the two arrays are different lengths. Other error conditions
* in the input are not currently detected.
*/
public IntRangeSet(int[] startPoints, int[] endPoints) {
if (startPoints.length != endPoints.length) {
throw new IllegalArgumentException("Array lengths differ");
}
this.startPoints = startPoints;
this.endPoints = endPoints;
used = startPoints.length;
for (int i=0; i<used; i++) {
size += (endPoints[i] - startPoints[i] + 1);
}
}
public void clear() {
startPoints = new int[4];
endPoints = new int[4];
used = 0;
hashCode = -1;
}
public int size() {
return size;
}
public boolean isEmpty() {
return size == 0;
}
public boolean contains(int value) {
if (value > endPoints[used-1]) {
return false;
}
if (value < startPoints[0]) {
return false;
}
int i = 0;
int j = used;
do {
int mid = i + (j-i)/2;
if (endPoints[mid] < value) {
i = Math.max(mid, i+1);
} else if (startPoints[mid] > value) {
j = Math.min(mid, j-1);
} else {
return true;
}
} while (i != j);
return false;
}
public boolean remove(int value) {
throw new UnsupportedOperationException("remove");
}
/**
* Add an integer to the set
* @param value the integer to be added
* @return true if the integer was added, false if it was already present
*/
public boolean add(int value) {
hashCode = -1;
if (used == 0) {
ensureCapacity(1);
startPoints[used-1] = value;
endPoints[used-1] = value;
size++;
return true;
}
if (value > endPoints[used-1]) {
if (value == endPoints[used-1] + 1) {
endPoints[used-1]++;
} else {
ensureCapacity(used+1);
startPoints[used-1] = value;
endPoints[used-1] = value;
}
size++;
return true;
}
if (value < startPoints[0]) {
if (value == startPoints[0] - 1) {
startPoints[0]--;
} else {
ensureCapacity(used+1);
System.arraycopy(startPoints, 0, startPoints, 1, used-1);
System.arraycopy(endPoints, 0, endPoints, 1, used-1);
startPoints[0] = value;
endPoints[0] = value;
}
size++;
return true;
}
int i = 0;
int j = used;
do {
int mid = i + (j-i)/2;
if (endPoints[mid] < value) {
i = Math.max(mid, i+1);
} else if (startPoints[mid] > value) {
j = Math.min(mid, j-1);
} else {
return false; // value is already present
}
} while (i != j);
if (i > 0 && endPoints[i-1]+1 == value) {
i--;
} else if (i < used-1 && startPoints[i+1]-1 == value) {
i++;
}
if (endPoints[i]+1 == value) {
if (value == startPoints[i+1]-1) {
// merge the two ranges
endPoints[i] = endPoints[i+1];
System.arraycopy(startPoints, i+2, startPoints, i+1, used-i-2);
System.arraycopy(endPoints, i+2, endPoints, i+1, used-i-2);
used--;
} else {
endPoints[i]++;
}
size++;
return true;
} else if (startPoints[i]-1 == value) {
if (value == endPoints[i-1]+1) {
// merge the two ranges
endPoints[i-1] = endPoints[i];
System.arraycopy(startPoints, i+1, startPoints, i, used-i-1);
System.arraycopy(endPoints, i+1, endPoints, i, used-i-1);
used--;
} else {
startPoints[i]--;
}
size++;
return true;
} else {
if (value > endPoints[i]) {
i++;
}
ensureCapacity(used+1);
try {
System.arraycopy(startPoints, i, startPoints, i+1, used-i-1);
System.arraycopy(endPoints, i, endPoints, i+1, used-i-1);
} catch (Exception err) {
err.printStackTrace();
}
startPoints[i] = value;
endPoints[i] = value;
size++;
return true;
}
}
private void ensureCapacity(int n) {
if (startPoints.length < n) {
int[] s = new int[startPoints.length * 2];
int[] e = new int[startPoints.length * 2];
System.arraycopy(startPoints, 0, s, 0, used);
System.arraycopy(endPoints, 0, e, 0, used);
startPoints = s;
endPoints = e;
}
used = n;
}
/**
* Get an iterator over the values
*/
public IntIterator iterator() {
return new IntRangeSetIterator();
}
public String toString() {
FastStringBuffer sb = new FastStringBuffer(used*8);
for (int i=0; i<used; i++) {
sb.append(startPoints[i] + "-" + endPoints[i] + ",");
}
return sb.toString();
}
/**
* Test whether this set has exactly the same members as another set. Note that
* IntRangeSet values are <b>NOT</b> comparable with other implementations of IntSet
*/
public boolean equals(Object other) {
if (other instanceof IntRangeSet) {
return used == ((IntRangeSet)other).used &&
Arrays.equals(startPoints, ((IntRangeSet)other).startPoints) &&
Arrays.equals(endPoints, ((IntRangeSet)other).endPoints) ;
}
return containsAll((IntSet)other);
}
/**
* Construct a hash key that supports the equals() test
*/
public int hashCode() {
// Note, hashcodes are NOT the same as those used by IntHashSet and IntArraySet
if (hashCode == -1) {
int h = 0x836a89f1;
for (int i=0; i<used; i++) {
h ^= startPoints[i] + (endPoints[i]<<3);
}
hashCode = h;
}
return hashCode;
}
/**
* Test if this set is a superset of another set
*/
public boolean containsAll(IntSet other) {
IntIterator it = other.iterator();
while (it.hasNext()) {
if (!contains(it.next())) {
return false;
}
}
return true;
}
/**
* Add a range of integers to the set.
* This is optimized for the case where these are all greater than any existing integer
* in the set.
* @param low the low end of the new range
* @param high the high end of the new range
*/
public void addRange(int low, int high) {
hashCode = -1;
if (used == 0) {
ensureCapacity(1);
startPoints[used-1] = low;
endPoints[used-1] = high;
size += (high - low + 1);
} else if (low > endPoints[used-1]) {
if (low == endPoints[used-1] + 1) {
endPoints[used-1] = high;
} else {
ensureCapacity(used+1);
startPoints[used-1] = low;
endPoints[used-1] = high;
}
size += (high - low + 1);
} else {
for (int i=low; i<=high; i++) {
add(i);
}
}
}
/**
* Get the start points of the ranges
*/
public int[] getStartPoints() {
return startPoints;
}
/**
* Get the end points of the ranges
*/
public int[] getEndPoints() {
return endPoints;
}
/**
* Get the number of ranges actually in use
*/
public int getNumberOfRanges() {
return used;
}
/**
* Iterator class
*/
private class IntRangeSetIterator implements IntIterator, Serializable {
private int i = 0;
private int current = 0;
public IntRangeSetIterator() {
i = -1;
current = Integer.MIN_VALUE;
}
public boolean hasNext() {
if (i<0) {
return size > 0;
} else {
return current < endPoints[used-1];
}
}
public int next() {
if (i < 0) {
i = 0;
current = startPoints[0];
return current;
}
if (current == endPoints[i]) {
current = startPoints[++i];
return current;
} else {
return ++current;
}
}
}
}
//
// The contents of this file are subject to the Mozilla Public License Version 1.0 (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.mozilla.org/MPL/
//
// Software distributed under the License is distributed on an "AS IS" basis,
// WITHOUT WARRANTY OF ANY KIND, either express or implied.
// See the License for the specific language governing rights and limitations under the License.
//
// The Original Code is: all this file.
//
// The Initial Developer of the Original Code is Michael Kay.
//
// Portions created by (your name) are Copyright (C) (your legal entity). All Rights Reserved.
//
// Contributor(s): none.