AdaptiveByteBufAllocator Class — netty Architecture

Source Code

buffer/src/main/java/io/netty/buffer/AdaptiveByteBufAllocator.java lines 31–119

public final class AdaptiveByteBufAllocator extends AbstractByteBufAllocator
        implements ByteBufAllocatorMetricProvider, ByteBufAllocatorMetric {
    private static final InternalLogger logger = InternalLoggerFactory.getInstance(AdaptiveByteBufAllocator.class);
    private static final boolean DEFAULT_USE_CACHED_MAGAZINES_FOR_NON_EVENT_LOOP_THREADS;

    static {
        DEFAULT_USE_CACHED_MAGAZINES_FOR_NON_EVENT_LOOP_THREADS = SystemPropertyUtil.getBoolean(
                "io.netty.allocator.useCachedMagazinesForNonEventLoopThreads", false);
        logger.debug("-Dio.netty.allocator.useCachedMagazinesForNonEventLoopThreads: {}",
                     DEFAULT_USE_CACHED_MAGAZINES_FOR_NON_EVENT_LOOP_THREADS);
    }

    private final AdaptivePoolingAllocator direct;
    private final AdaptivePoolingAllocator heap;

    public AdaptiveByteBufAllocator() {
        this(!PlatformDependent.isExplicitNoPreferDirect());
    }

    public AdaptiveByteBufAllocator(boolean preferDirect) {
        this(preferDirect, DEFAULT_USE_CACHED_MAGAZINES_FOR_NON_EVENT_LOOP_THREADS);
    }

    public AdaptiveByteBufAllocator(boolean preferDirect, boolean useCacheForNonEventLoopThreads) {
        super(preferDirect);
        direct = new AdaptivePoolingAllocator(new DirectChunkAllocator(this), useCacheForNonEventLoopThreads);
        heap = new AdaptivePoolingAllocator(new HeapChunkAllocator(this), useCacheForNonEventLoopThreads);
    }

    @Override
    protected ByteBuf newHeapBuffer(int initialCapacity, int maxCapacity) {
        return toLeakAwareBuffer(heap.allocate(initialCapacity, maxCapacity));
    }

    @Override
    protected ByteBuf newDirectBuffer(int initialCapacity, int maxCapacity) {
        return toLeakAwareBuffer(direct.allocate(initialCapacity, maxCapacity));
    }

    @Override
    public boolean isDirectBufferPooled() {
        return true;
    }

    @Override
    public long usedHeapMemory() {
        return heap.usedMemory();
    }

    @Override
    public long usedDirectMemory() {
        return direct.usedMemory();
    }

    @Override
    public ByteBufAllocatorMetric metric() {
        return this;
    }

    private static final class HeapChunkAllocator implements AdaptivePoolingAllocator.ChunkAllocator {
        private final ByteBufAllocator allocator;

        private HeapChunkAllocator(ByteBufAllocator allocator) {
            this.allocator = allocator;
        }

        @Override
        public AbstractByteBuf allocate(int initialCapacity, int maxCapacity) {
            return PlatformDependent.hasUnsafe() ?
                    new UnpooledUnsafeHeapByteBuf(allocator, initialCapacity, maxCapacity) :
                    new UnpooledHeapByteBuf(allocator, initialCapacity, maxCapacity);
        }
    }

    private static final class DirectChunkAllocator implements AdaptivePoolingAllocator.ChunkAllocator {
        private final ByteBufAllocator allocator;

        private DirectChunkAllocator(ByteBufAllocator allocator) {
            this.allocator = allocator;
        }