infinispan.com.google.common.collect.SortedMultisets Maven / Gradle / Ivy
/*
* Copyright (C) 2011 The Guava Authors
*
* 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.google.common.collect;
import com.google.common.annotations.GwtCompatible;
import com.google.common.collect.Multiset.Entry;
import java.util.Comparator;
import java.util.Iterator;
import java.util.NoSuchElementException;
import java.util.Set;
import java.util.SortedSet;
/**
* Provides static utility methods for creating and working with
* {@link SortedMultiset} instances.
*
* @author Louis Wasserman
*/
@GwtCompatible
final class SortedMultisets {
private SortedMultisets() {
}
/**
* A skeleton implementation for {@link SortedMultiset#elementSet}.
*/
static abstract class ElementSet extends Multisets.ElementSet implements
SortedSet {
@Override abstract SortedMultiset multiset();
@Override public Comparator comparator() {
return multiset().comparator();
}
@Override public SortedSet subSet(E fromElement, E toElement) {
return multiset().subMultiset(fromElement, BoundType.CLOSED, toElement,
BoundType.OPEN).elementSet();
}
@Override public SortedSet headSet(E toElement) {
return multiset().headMultiset(toElement, BoundType.OPEN).elementSet();
}
@Override public SortedSet tailSet(E fromElement) {
return multiset().tailMultiset(fromElement, BoundType.CLOSED)
.elementSet();
}
@Override public E first() {
return getElementOrThrow(multiset().firstEntry());
}
@Override public E last() {
return getElementOrThrow(multiset().lastEntry());
}
}
private static E getElementOrThrow(Entry entry) {
if (entry == null) {
throw new NoSuchElementException();
}
return entry.getElement();
}
/**
* A skeleton implementation of a descending multiset. Only needs
* {@code forwardMultiset()} and {@code entryIterator()}.
*/
static abstract class DescendingMultiset extends ForwardingMultiset
implements SortedMultiset {
abstract SortedMultiset forwardMultiset();
private transient Comparator comparator;
@Override public Comparator comparator() {
Comparator result = comparator;
if (result == null) {
return comparator =
Ordering.from(forwardMultiset().comparator()).reverse();
}
return result;
}
private transient SortedSet elementSet;
@Override public SortedSet elementSet() {
SortedSet result = elementSet;
if (result == null) {
return elementSet = new SortedMultisets.ElementSet() {
@Override SortedMultiset multiset() {
return DescendingMultiset.this;
}
};
}
return result;
}
@Override public Entry pollFirstEntry() {
return forwardMultiset().pollLastEntry();
}
@Override public Entry pollLastEntry() {
return forwardMultiset().pollFirstEntry();
}
@Override public SortedMultiset headMultiset(E toElement,
BoundType boundType) {
return forwardMultiset().tailMultiset(toElement, boundType)
.descendingMultiset();
}
@Override public SortedMultiset subMultiset(E fromElement,
BoundType fromBoundType, E toElement, BoundType toBoundType) {
return forwardMultiset().subMultiset(toElement, toBoundType, fromElement,
fromBoundType).descendingMultiset();
}
@Override public SortedMultiset tailMultiset(E fromElement,
BoundType boundType) {
return forwardMultiset().headMultiset(fromElement, boundType)
.descendingMultiset();
}
@Override protected Multiset delegate() {
return forwardMultiset();
}
@Override public SortedMultiset descendingMultiset() {
return forwardMultiset();
}
@Override public Entry firstEntry() {
return forwardMultiset().lastEntry();
}
@Override public Entry lastEntry() {
return forwardMultiset().firstEntry();
}
abstract Iterator> entryIterator();
private transient Set> entrySet;
@Override public Set> entrySet() {
Set> result = entrySet;
return (result == null) ? entrySet = createEntrySet() : result;
}
Set> createEntrySet() {
return new Multisets.EntrySet() {
@Override Multiset multiset() {
return DescendingMultiset.this;
}
@Override public Iterator> iterator() {
return entryIterator();
}
@Override public int size() {
return forwardMultiset().entrySet().size();
}
};
}
@Override public Iterator iterator() {
return Multisets.iteratorImpl(this);
}
@Override public Object[] toArray() {
return standardToArray();
}
@Override public T[] toArray(T[] array) {
return standardToArray(array);
}
@Override public String toString() {
return entrySet().toString();
}
}
}