ObjectPool.java

package com.hypixel.hytale.server.worldgen.util;

import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.BlockingQueue;
import java.util.function.Function;
import java.util.function.Supplier;
import javax.annotation.Nonnull;

public class ObjectPool<T extends Function<T, T>> implements Function<T, T> {
   @Nonnull
   private final BlockingQueue<T> items;
   private final Supplier<T> supplier;

   public ObjectPool(int size, Supplier<T> supplier) {
      this.items = new ArrayBlockingQueue(size);
      this.supplier = supplier;
   }

   public T acquire() {
      T v = (T)(this.items.poll());
      return (T)(v == null ? (Function)this.supplier.get() : v);
   }

   public <K extends T> void recycle(@Nonnull K v) {
      this.items.offer(v);
   }

   public int size() {
      return this.items.size();
   }

   public T apply(T cachedKey) {
      return (T)(this.acquire().apply(cachedKey));
   }
}