TerraForged/TerraForgedCore/src/main/java/com/terraforged/core/util/concurrent/ObjectPool.java

104 lines
2.9 KiB
Java

/*
*
* MIT License
*
* Copyright (c) 2020 TerraForged
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
package com.terraforged.core.util.concurrent;
import java.util.ArrayList;
import java.util.List;
import java.util.function.Supplier;
public class ObjectPool<T> {
private final int capacity;
private final List<Item<T>> pool;
private final Supplier<? extends T> supplier;
public ObjectPool(int size, Supplier<? extends T> supplier) {
this.capacity = size;
this.pool = new ArrayList<>(size);
this.supplier = supplier;
}
public Item<T> get() {
synchronized (pool) {
if (pool.size() > 0) {
return pool.remove(pool.size() - 1).retain();
}
}
return new Item<>(supplier.get(), this);
}
public int size() {
synchronized (pool) {
return pool.size();
}
}
private boolean restore(Item<T> item) {
synchronized (pool) {
int size = pool.size();
if (size < capacity) {
pool.add(item);
return true;
}
}
return false;
}
public static class Item<T> implements AutoCloseable {
private final T value;
private final ObjectPool<T> pool;
private boolean released = false;
private Item(T value, ObjectPool<T> pool) {
this.value = value;
this.pool = pool;
}
public T getValue() {
return value;
}
public void release() {
if (!released) {
released = true;
released = pool.restore(this);
}
}
private Item<T> retain() {
released = false;
return this;
}
@Override
public void close() {
release();
}
}
}