netty-incubator-buffer-api/buffer-api/src/main/java/io/netty/buffer/api/MemoryManagers.java

76 lines
2.7 KiB
Java

/*
* Copyright 2021 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.buffer.api;
import java.util.ServiceLoader;
import java.util.function.Supplier;
import java.util.stream.Stream;
/**
* The MemoryManagers interface is the handle through which {@link BufferAllocator buffer allocators} access the low
* level memory management APIs.
* <p>
* This is hidden behind this interface in order to make allocation and pool agnostic and reusable across buffer and
* memory implementations.
*/
public interface MemoryManagers {
/**
* Get the default, or currently configured, memory managers instance.
* @return A MemoryManagers instance.
*/
static MemoryManagers getManagers() {
return MemoryManagersOverride.getManagers();
}
/**
* Temporarily override the default configured memory managers instance.
* <p>
* Calls to {@link #getManagers()} from within the given supplier will get the given managers instance.
*
* @param managers Override the default configured managers instance with this instance.
* @param supplier The supplier function to be called while the override is in place.
* @param <T> The result type from the supplier.
* @return The result from the supplier.
*/
static <T> T using(MemoryManagers managers, Supplier<T> supplier) {
return MemoryManagersOverride.using(managers, supplier);
}
/**
* Get a lazy-loading stream of all available memory managers.
*
* @return A stream of providers of memory managers instances.
*/
static Stream<ServiceLoader.Provider<MemoryManagers>> getAllManagers() {
var loader = ServiceLoader.load(MemoryManagers.class);
return loader.stream();
}
/**
* Get a {@link MemoryManager} instance that is suitable for allocating on-heap {@link Buffer} instances.
*
* @return An on-heap {@link MemoryManager}.
*/
MemoryManager getHeapMemoryManager();
/**
* Get a {@link MemoryManager} instance that is suitable for allocating off-heap {@link Buffer} instances.
*
* @return An off-heap {@link MemoryManager}.
*/
MemoryManager getNativeMemoryManager();
}