io.datakernel.common.Recyclable Maven / Gradle / Ivy
/*
* Copyright (C) 2015-2018 SoftIndex LLC.
*
* 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 io.datakernel.common;
import org.jetbrains.annotations.Nullable;
import java.util.Arrays;
import java.util.Collection;
import java.util.Iterator;
import java.util.Map;
/**
* Since some objects (mainly {@link io.datakernel.bytebuf.ByteBuf ByteBufs}) have
* the notion of ownership and recyclability, a way to recognize them is needed.
* This interface marks objects that need to be recycled at the end of their lifetime,
* so that some generic abstraction (such as CSP) could try to recycle some object that it consumes.
*/
@SuppressWarnings("JavadocReference")
public interface Recyclable {
/**
* Free some resource that this object posesses, e.g. return itself to the pool etc.
*/
void recycle();
/**
* A method that should be called by generic consuming abstractions as described in class doc.
*/
static void tryRecycle(@Nullable Object object) {
if (object instanceof Recyclable) {
((Recyclable) object).recycle();
}
}
/**
* "Recursive implementation of Recyclable for some standard collections".
*
* This method is called to make sure that some kind of object structure is fully recycled.
*/
static void deepRecycle(@Nullable Object object) {
if (object == null) return;
if (object instanceof Recyclable) {
Recyclable recyclable = (Recyclable) object;
recyclable.recycle();
} else if (object instanceof Iterator) {
Iterator it = (Iterator) object;
while (it.hasNext()) {
deepRecycle(it.next());
}
} else if (object instanceof Collection) {
deepRecycle(((Collection) object).iterator());
((Collection) object).clear();
} else if (object instanceof Iterable) {
deepRecycle(((Iterable) object).iterator());
} else if (object instanceof Map) {
deepRecycle(((Map) object).values());
((Map) object).clear();
} else if (object instanceof Object[]) {
Object[] objects = (Object[]) object;
for (Object element : objects) {
deepRecycle(element);
}
Arrays.fill(objects, null);
}
}
}