cn.zenliu.classes.DelegateSet Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of units-classes Show documentation
Show all versions of units-classes Show documentation
Units of tool for class and class loading. Also with some tool type.
The newest version!
/*
* Source of units
* Copyright (C) 2023. Zen.Liu
*
* SPDX-License-Identifier: GPL-2.0-only WITH Classpath-exception-2.0"
*
* This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; version 2.
* This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
* You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* Class Path Exception
* Linking this library statically or dynamically with other modules is making a combined work based on this library. Thus, the terms and conditions of the GNU General Public License cover the whole combination.
* As a special exception, the copyright holders of this library give you permission to link this library with independent modules to produce an executable, regardless of the license terms of these independent modules, and to copy and distribute the resulting executable under terms of your choice, provided that you also meet, for each linked independent module, the terms and conditions of the license of that module. An independent module is a module which is not derived from or based on this library. If you modify this library, you may extend this exception to your version of the library, but you are not obligated to do so. If you do not wish to do so, delete this exception statement from your version.
*/
package cn.zenliu.classes;
import lombok.NonNull;
import org.jetbrains.annotations.NotNull;
import java.util.*;
import java.util.concurrent.ConcurrentHashMap;
import java.util.function.Predicate;
/**
* A HashSet delegate a collection actions as a set.
* 1. it may change the source to remove already exists duplicated elements.
* 2. all final result will affect on underlying collection.
*
* @author Zen.Liu
* @since 2023-04-30
*/
public interface DelegateSet> extends Set {
C unwrap();
@Override
default int size() {
return unwrap().size();
}
@Override
default boolean isEmpty() {
return unwrap().isEmpty();
}
@Override
default boolean contains(Object o) {
return unwrap().contains(o);
}
@NotNull
@Override
default Iterator iterator() {
return unwrap().iterator();
}
@NotNull
@Override
default Object[] toArray() {
return unwrap().toArray();
}
@NotNull
@Override
default T[] toArray(@NotNull T[] a) {
return unwrap().toArray(a);
}
@Override
default boolean add(E e) {
return !contains(e) && unwrap().add(e);
}
@Override
default boolean remove(Object o) {
return unwrap().remove(o);
}
@Override
default boolean containsAll(@NotNull Collection c) {
return unwrap().containsAll(c);
}
@Override
default boolean addAll(@NotNull Collection c) {
for (E e : c) {
if (unwrap().contains(e)) return false;
}
return unwrap().addAll(c);
}
@Override
default boolean retainAll(@NotNull Collection c) {
return unwrap().retainAll(c);
}
@Override
default boolean removeAll(@NotNull Collection c) {
return unwrap().removeAll(c);
}
@Override
default void clear() {
unwrap().clear();
}
/**
* a implement with extra hash set check.
*
* @param element type
* @param collection type
*/
final class Impl> implements DelegateSet {
final Set hash;
final C unwrap;
final boolean eager;
public Impl(@NonNull C o, boolean eager) {
this.unwrap = o;
this.hash = ConcurrentHashMap.newKeySet(o.size() == 0 ? 16 : o.size());
this.eager = eager;
if (eager) {
unwrap.removeIf(e -> !hash.add(e.hashCode()));
}
}
private void initHash() {
if (!eager && hash.isEmpty()) {
synchronized (hash) {
if (hash.isEmpty()) {
unwrap.removeIf(e -> !hash.add(e.hashCode()));
}
}
}
}
@Override
public C unwrap() {
return unwrap;
}
@Override
public boolean add(E e) {
initHash();
if (hash.add(e.hashCode()))
unwrap.add(e);
return false;
}
@Override
public boolean addAll(@NotNull Collection c) {
initHash();
if (c.isEmpty()) return false;
List temp = new ArrayList();
for (var v : c) {
if (hash.add(v.hashCode())) {
temp.add(v);
}
}
if (temp.isEmpty()) return false;
return unwrap.addAll(temp);
}
@Override
public boolean contains(Object o) {
if (o == null) return false;
initHash();
return hash.contains(o.hashCode());
}
@Override
public boolean remove(Object o) {
if (o == null) return false;
initHash();
if (!hash.contains(o.hashCode())) return false;
return unwrap.remove(o);
}
@Override
public boolean containsAll(@NotNull Collection c) {
initHash();
for (var o : c) {
if (o == null || !hash.contains(o.hashCode())) return false;
}
return true;
}
@Override
public boolean retainAll(@NotNull Collection c) {
initHash();
var modified = false;
var it = unwrap.iterator();
while (it.hasNext()) {
var e = it.next();
if (!c.contains(e)) {
hash.remove(e.hashCode());
it.remove();
modified = true;
}
}
return modified;
}
@Override
public boolean removeAll(@NotNull Collection c) {
initHash();
var modified = false;
var it = unwrap.iterator();
while (it.hasNext()) {
var e = it.next();
if (c.contains(e)) {
hash.remove(e.hashCode());
it.remove();
modified = true;
}
}
return modified;
}
@Override
public boolean removeIf(Predicate filter) {
Objects.requireNonNull(filter);
var removed = false;
var each = iterator();
while (each.hasNext()) {
var e = each.next();
if (filter.test(e)) {
hash.remove(e.hashCode());
each.remove();
removed = true;
}
}
return removed;
}
@Override
public boolean equals(Object o) {
if (o instanceof DelegateSet) {
return Objects.equals(((DelegateSet) o).unwrap(), unwrap());
}
return unwrap().equals(o);
}
@Override
public int hashCode() {
return unwrap().hashCode();
}
}
static > DelegateSet of(C collection, boolean eager) {
return new Impl<>(collection, eager);
}
}