SCViewer/com.minres.scviewer.databas.../src/org/apache/jdbm/BTreeSet.java

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/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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 org.apache.jdbm;
import java.util.*;
/**
* Wrapper class for <code>>SortedMap</code> to implement <code>>NavigableSet</code>
* <p/>
* This code originally comes from Apache Harmony, was adapted by Jan Kotek for JDBM
*/
class BTreeSet<E> extends AbstractSet<E> implements NavigableSet<E> {
/**
* use keyset from this map
*/
final BTreeMap<E, Object> map;
BTreeSet(BTreeMap<E, Object> map) {
this.map = map;
}
public boolean add(E object) {
return map.put(object, Utils.EMPTY_STRING) == null;
}
public boolean addAll(Collection<? extends E> collection) {
return super.addAll(collection);
}
public void clear() {
map.clear();
}
public Comparator<? super E> comparator() {
return map.comparator();
}
public boolean contains(Object object) {
return map.containsKey(object);
}
public boolean isEmpty() {
return map.isEmpty();
}
public E lower(E e) {
return map.lowerKey(e);
}
public E floor(E e) {
return map.floorKey(e);
}
public E ceiling(E e) {
return map.ceilingKey(e);
}
public E higher(E e) {
return map.higherKey(e);
}
public E pollFirst() {
Map.Entry<E,Object> e = map.pollFirstEntry();
return e!=null? e.getKey():null;
}
public E pollLast() {
Map.Entry<E,Object> e = map.pollLastEntry();
return e!=null? e.getKey():null;
}
public Iterator<E> iterator() {
final Iterator<Map.Entry<E,Object>> iter = map.entrySet().iterator();
return new Iterator<E>() {
public boolean hasNext() {
return iter.hasNext();
}
public E next() {
Map.Entry<E,Object> e = iter.next();
return e!=null?e.getKey():null;
}
public void remove() {
iter.remove();
}
};
}
public NavigableSet<E> descendingSet() {
return map.descendingKeySet();
}
public Iterator<E> descendingIterator() {
return map.descendingKeySet().iterator();
}
public NavigableSet<E> subSet(E fromElement, boolean fromInclusive, E toElement, boolean toInclusive) {
return map.subMap(fromElement,fromInclusive,toElement,toInclusive).navigableKeySet();
}
public NavigableSet<E> headSet(E toElement, boolean inclusive) {
return map.headMap(toElement,inclusive).navigableKeySet();
}
public NavigableSet<E> tailSet(E fromElement, boolean inclusive) {
return map.tailMap(fromElement,inclusive).navigableKeySet();
}
public boolean remove(Object object) {
return map.remove(object) != null;
}
public int size() {
return map.size();
}
public E first() {
return map.firstKey();
}
public E last() {
return map.lastKey();
}
public SortedSet<E> subSet(E start, E end) {
Comparator<? super E> c = map.comparator();
int compare = (c == null) ? ((Comparable<E>) start).compareTo(end) : c
.compare(start, end);
if (compare <= 0) {
return new BTreeSet<E>((BTreeMap<E,Object>) map.subMap(start, true,end,false));
}
throw new IllegalArgumentException();
}
public SortedSet<E> headSet(E end) {
// Check for errors
Comparator<? super E> c = map.comparator();
if (c == null) {
((Comparable<E>) end).compareTo(end);
} else {
c.compare(end, end);
}
return new BTreeSet<E>((BTreeMap<E,Object>) map.headMap(end,false));
}
public SortedSet<E> tailSet(E start) {
// Check for errors
Comparator<? super E> c = map.comparator();
if (c == null) {
((Comparable<E>) start).compareTo(start);
} else {
c.compare(start, start);
}
return new BTreeSet<E>((BTreeMap<E,Object>) map.tailMap(start,true));
}
}