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There is a newer version: 1.29

package host.anzo.commons.unsafe;

import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.nio.ByteBuffer;

/**
 * @author ANZO
 * @since 6/30/2023
 */
public class ByteBufferCleaner {
	private static final Cleaner INSTANCE = getCleaner();

	/**
	 * Releases memory held by the given {@link ByteBuffer}.
	 * @param buffer to release.
	 * @throws IllegalStateException on internal failure.
	 */
	public static void clean(final ByteBuffer buffer) {
		try {
			INSTANCE.clean(buffer);
		}
		catch (final Exception e) {
			throw new IllegalStateException("Failed to clean direct buffer.", e);
		}
	}

	private static Cleaner getCleaner() {
		try {
			return new Java8Cleaner();
		}
		catch (final Exception e) {
			try {
				return new Java9Cleaner();
			}
			catch (final Exception e1) {
				throw new IllegalStateException("Failed to initialize a Cleaner.", e);
			}
		}
	}

	private interface Cleaner {
		void clean(ByteBuffer buffer) throws ReflectiveOperationException;
	}

	private static class Java8Cleaner implements Cleaner {
		private final Method cleanerMethod;
		private final Method cleanMethod;

		private Java8Cleaner() throws ReflectiveOperationException, SecurityException {
			cleanMethod = Class.forName("sun.misc.Cleaner").getMethod("clean");
			cleanerMethod = Class.forName("sun.nio.ch.DirectBuffer").getMethod("cleaner");
		}

		@Override
		public void clean(final ByteBuffer buffer) throws ReflectiveOperationException {
			final Object cleaner = cleanerMethod.invoke(buffer);
			if (cleaner != null) {
				cleanMethod.invoke(cleaner);
			}
		}
	}

	private static class Java9Cleaner implements Cleaner {
		private final Object theUnsafe;
		private final Method invokeCleaner;

		private Java9Cleaner() throws ReflectiveOperationException, SecurityException {
			final Class unsafeClass = Class.forName("sun.misc.Unsafe");
			final Field field = unsafeClass.getDeclaredField("theUnsafe");
			field.setAccessible(true);
			theUnsafe = field.get(null);
			invokeCleaner = unsafeClass.getMethod("invokeCleaner", ByteBuffer.class);
		}

		@Override
		public void clean(final ByteBuffer buffer) throws ReflectiveOperationException {
			invokeCleaner.invoke(theUnsafe, buffer);
		}
	}
}