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'rapiddweller Common' is an open source Java library
forked from Databene Commons by Volker Bergmann.
It provides extensions to the Java core library by utility classes, abstract concepts
and concrete implementations.
/*
* Copyright (C) 2004-2015 Volker Bergmann ([email protected]).
* All rights reserved.
*
* Licensed under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.rapiddweller.common.collection;
import com.rapiddweller.common.math.IntRange;
import java.util.Iterator;
import java.util.Map.Entry;
import java.util.TreeMap;
/**
* Collects int values in a compressed way.
* Created: 05.10.2010 19:17:30
*
* @author Volker Bergmann
* @since 0.5.4
*/
public class CompressedIntSet {
/**
* The Numbers.
*/
protected TreeMap numbers;
/**
* The Size.
*/
protected long size;
/**
* Instantiates a new Compressed int set.
*/
public CompressedIntSet() {
this.numbers = new TreeMap<>();
this.size = 0;
}
/**
* Clear.
*/
public void clear() {
numbers.clear();
this.size = 0;
}
/**
* Add all.
*
* @param numbers the numbers
*/
public void addAll(int... numbers) {
for (int number : numbers) {
add(number);
}
}
/**
* Add.
*
* @param i the
*/
public void add(int i) {
if (numbers.isEmpty()) {
// if the set is empty, insert the number
insertNumber(i);
size = 1;
} else {
// search the highest entry which is less or equals to i
Entry floorEntry = numbers.floorEntry(i);
IntRange rangeBelow;
if (floorEntry == null) {
extendRangeAboveOrInsertNumber(i); // no range below found, check above
} else {
// check found range
rangeBelow = floorEntry.getValue();
if (rangeBelow.contains(i)) {
return;
}
if (rangeBelow.getMax() + 1 == i) {
// extend found range if applicable
rangeBelow.setMax(i);
size++;
// check if two adjacent ranges can be merged
IntRange upperNeighbor = numbers.get(i + 1);
if (upperNeighbor != null) {
numbers.remove(i + 1);
rangeBelow.setMax(upperNeighbor.getMax());
}
} else {
extendRangeAboveOrInsertNumber(i);
}
}
}
}
private void extendRangeAboveOrInsertNumber(int i) {
IntRange rangeAbove = numbers.get(i + 1);
if (rangeAbove != null) {
numbers.remove(i + 1);
rangeAbove.setMin(i);
numbers.put(i, rangeAbove);
} else {
insertNumber(i);
}
size++;
}
private void insertNumber(int i) {
numbers.put(i, new IntRange(i, i));
}
/**
* Contains boolean.
*
* @param i the
* @return the boolean
*/
public boolean contains(int i) {
Entry floorEntry = numbers.floorEntry(i);
return (floorEntry != null && floorEntry.getValue().contains(i));
}
/**
* Remove boolean.
*
* @param i the
* @return the boolean
*/
public boolean remove(int i) {
Entry floorEntry = numbers.floorEntry(i);
if (floorEntry == null || !floorEntry.getValue().contains(i)) {
return false;
}
IntRange range = floorEntry.getValue();
if (i == range.getMax() && range.getMax() > range.getMin()) {
range.setMax(i - 1);
} else if (i == range.getMin()) {
numbers.remove(i);
if (range.getMax() > i) {
range.setMin(i + 1);
numbers.put(i + 1, range);
}
} else {
int max = range.getMax();
range.setMax(i - 1);
IntRange range2 = new IntRange(i + 1, max);
numbers.put(i + 1, range2);
}
return true;
}
/**
* Is empty boolean.
*
* @return the boolean
*/
public boolean isEmpty() {
return numbers.isEmpty();
}
/**
* Size long.
*
* @return the long
*/
public long size() {
return size;
}
/**
* Iterator iterator.
*
* @return the iterator
*/
public Iterator iterator() {
return new CompressedSetIterator();
}
// java.lang.Object overrides --------------------------------------------------------------------------------------
@Override
public boolean equals(Object obj) {
if (this == obj) {
return true;
}
if (obj == null || getClass() != obj.getClass()) {
return false;
}
CompressedIntSet that = (CompressedIntSet) obj;
return this.equals(that.numbers);
}
@Override
public int hashCode() {
return numbers.hashCode();
}
@Override
public String toString() {
return numbers.values().toString();
}
// Iterator class --------------------------------------------------------------------------------------------------
/**
* The type Compressed set iterator.
*/
public class CompressedSetIterator implements Iterator {
/**
* The Int range iterator.
*/
protected Iterator intRangeIterator;
/**
* The Current int range.
*/
protected IntRange currentIntRange;
/**
* The Last int.
*/
protected Integer lastInt;
/**
* Instantiates a new Compressed set iterator.
*/
protected CompressedSetIterator() {
intRangeIterator = numbers.values().iterator();
currentIntRange = null;
lastInt = null;
}
@Override
public boolean hasNext() {
if (currentIntRange == null) {
if (intRangeIterator != null && intRangeIterator.hasNext()) {
currentIntRange = intRangeIterator.next();
lastInt = null;
return true;
} else {
intRangeIterator = null;
return false;
}
}
return (lastInt == null || lastInt < currentIntRange.getMax());
}
@Override
public Integer next() {
if (intRangeIterator != null && currentIntRange == null) {
if (intRangeIterator.hasNext()) {
currentIntRange = intRangeIterator.next();
} else {
intRangeIterator = null;
currentIntRange = null;
}
}
if (intRangeIterator == null || currentIntRange == null) {
throw new IllegalStateException("No 'next' value available. Check hasNext() before calling next().");
}
lastInt = (lastInt != null ? ++lastInt : currentIntRange.getMin());
if (lastInt == currentIntRange.getMax()) {
currentIntRange = null;
}
return lastInt;
}
@Override
public void remove() {
CompressedIntSet.this.remove(lastInt);
}
}
}