net.openhft.chronicle.bytes.pool.BytesPool Maven / Gradle / Ivy
/*
* Copyright (c) 2016-2022 chronicle.software
*
* https://chronicle.software
*
* 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 net.openhft.chronicle.bytes.pool;
import net.openhft.chronicle.bytes.Bytes;
import net.openhft.chronicle.core.Jvm;
import net.openhft.chronicle.core.io.IOTools;
import net.openhft.chronicle.core.scoped.ScopedResourcePool;
import net.openhft.chronicle.core.scoped.ScopedThreadLocal;
import org.jetbrains.annotations.NotNull;
/**
* A thread-local pool of reusable {@link Bytes} instances.
*
* This class uses a {@link ThreadLocal} to store a single {@link Bytes} instance per thread,
* which can be reused to avoid the overhead of creating a new instance every time bytes are
* needed for operations.
*
* This class is primarily meant to be used in high-performance environments where reducing
* object creation is crucial.
*/
public final class BytesPool {
private static final int DEFAULT_BYTES_POOL_SIZE_PER_THREAD = Jvm.getInteger("chronicle.bytesPool.instancesPerThread", 4);
/**
* Create a scoped-thread-local pool of bytes resources
*
* @return The pool
*/
public static ScopedResourcePool> createThreadLocal() {
return createThreadLocal(DEFAULT_BYTES_POOL_SIZE_PER_THREAD);
}
/**
* Create a scoped-thread-local pool of bytes resources
*
* @param instancesPerThread The maximum number of instances to retain per thread
* @return The pool
*/
public static ScopedResourcePool> createThreadLocal(int instancesPerThread) {
return new ScopedThreadLocal<>(
BytesPool::createBytes,
Bytes::clear,
instancesPerThread);
}
/**
* Thread-local variable that holds the {@link Bytes} instance for each thread.
*/
final ThreadLocal> bytesTL = new ThreadLocal<>();
/**
* Creates a new {@link Bytes} instance.
*
* This method is called internally when there is no {@link Bytes} instance available
* in the thread-local pool for the current thread.
*
* @return A newly created {@link Bytes} instance.
*/
@NotNull
private static Bytes createBytes() {
Bytes bbb = Bytes.allocateElasticDirect(256);
IOTools.unmonitor(bbb);
return bbb;
}
}