io.netty.util.internal.ObjectPool Maven / Gradle / Ivy
/*
* Copyright 2019 The Netty Project
*
* The Netty Project licenses this file to you 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:
*
* https://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.netty.util.internal;
import io.netty.util.Recycler;
/**
* Light-weight object pool.
*
* @param the type of the pooled object
*/
public abstract class ObjectPool {
ObjectPool() { }
/**
* Get a {@link Object} from the {@link ObjectPool}. The returned {@link Object} may be created via
* {@link ObjectCreator#newObject(Handle)} if no pooled {@link Object} is ready to be reused.
*/
public abstract T get();
/**
* Handle for an pooled {@link Object} that will be used to notify the {@link ObjectPool} once it can
* reuse the pooled {@link Object} again.
* @param
*/
public interface Handle {
/**
* Recycle the {@link Object} if possible and so make it ready to be reused.
*/
void recycle(T self);
}
/**
* Creates a new Object which references the given {@link Handle} and calls {@link Handle#recycle(Object)} once
* it can be re-used.
*
* @param the type of the pooled object
*/
public interface ObjectCreator {
/**
* Creates an returns a new {@link Object} that can be used and later recycled via
* {@link Handle#recycle(Object)}.
*
* @param handle can NOT be null.
*/
T newObject(Handle handle);
}
/**
* Creates a new {@link ObjectPool} which will use the given {@link ObjectCreator} to create the {@link Object}
* that should be pooled.
*/
public static ObjectPool newPool(final ObjectCreator creator) {
return new RecyclerObjectPool(ObjectUtil.checkNotNull(creator, "creator"));
}
private static final class RecyclerObjectPool extends ObjectPool {
private final Recycler recycler;
RecyclerObjectPool(final ObjectCreator creator) {
recycler = new Recycler() {
@Override
protected T newObject(Handle handle) {
return creator.newObject(handle);
}
};
}
@Override
public T get() {
return recycler.get();
}
}
}