Module io.netty5.buffer
Package io.netty5.buffer.api.pool

Class PooledBufferAllocator

    • Constructor Detail

      • PooledBufferAllocator

        public PooledBufferAllocator​(MemoryManager manager,
                             boolean direct)

      • PooledBufferAllocator

        public PooledBufferAllocator​(MemoryManager manager,
                             boolean direct,
                             int numArenas,
                             int pageSize,
                             int maxOrder)

      • PooledBufferAllocator

        public PooledBufferAllocator​(MemoryManager manager,
                             boolean direct,
                             int numArenas,
                             int pageSize,
                             int maxOrder,
                             int smallCacheSize,
                             int normalCacheSize,
                             boolean useCacheForAllThreads)

      • PooledBufferAllocator

        public PooledBufferAllocator​(MemoryManager manager,
                             boolean direct,
                             int numArenas,
                             int pageSize,
                             int maxOrder,
                             int smallCacheSize,
                             int normalCacheSize,
                             boolean useCacheForAllThreads,
                             int directMemoryCacheAlignment)

    • Method Detail

      • isPooling

        public boolean isPooling()
        Description copied from interface: BufferAllocator
        Determine if this allocator is pooling and reusing its allocated memory.
        Specified by:
        isPooling in interface BufferAllocator
        Returns:
        true if this allocator is pooling and reusing its memory, false otherwise.

      • allocate

        public Buffer allocate​(int size)
        Description copied from interface: BufferAllocator
        Allocate a Buffer of the given size in bytes. This method may throw an OutOfMemoryError if there is not enough free memory available to allocate a Buffer of the requested size.

        The buffer will use big endian byte order.

        Specified by:
        allocate in interface BufferAllocator
        Parameters:
        size - The size of Buffer to allocate.
        Returns:
        The newly allocated Buffer.

      • constBufferSupplier

        public Supplier<Buffer> constBufferSupplier​(byte[] bytes)
        Description copied from interface: BufferAllocator
        Create a supplier of "constant" Buffers from this allocator, that all have the given byte contents. The buffer has the same capacity as the byte array length, and its write offset is placed at the end, and its read offset is at the beginning, such that the entire buffer contents are readable.

        The buffers produced by the supplier will each have their own independent life-cycle, and closing them will make them inaccessible, just like normally allocated buffers.

        The buffers produced are "constants", in the sense that they are read-only.

        It can generally be expected, but is not guaranteed, that the returned supplier is more resource efficient than allocating and copying memory with other available APIs. In such optimised implementations, the underlying memory baking the buffers will be shared among all the buffers produced by the supplier.

        The primary use case for this API, is when you need to repeatedly produce buffers with the same contents, and you perhaps wish to keep a static final field with these contents. The supplier-based API enforces that each usage get their own distinct buffer instance. Each of these instances cannot interfere with each other, so bugs like closing, or modifying the contents, of a shared buffer cannot occur.

        Specified by:
        constBufferSupplier in interface BufferAllocator
        Parameters:
        bytes - The byte contents of the buffers produced by the returned supplier.
        Returns:
        A supplier of read-only buffers with the given contents.

      • close

        public void close()
        Description copied from interface: BufferAllocator
        Close this allocator, freeing all of its internal resources.

        Existing (currently in-use) allocated buffers will not be impacted by calling this method. If this is a pooling or caching allocator, then existing buffers will be immediately freed when they are closed, instead of being pooled or cached.

        The allocator can no longer be used to allocate more buffers after calling this method. Attempting to allocate from a closed allocator will cause IllegalStateExceptions to be thrown.

        Specified by:
        close in interface AutoCloseable
        Specified by:
        close in interface BufferAllocator
        Specified by:
        close in interface SafeCloseable

      • defaultNumHeapArena

        public static int defaultNumHeapArena()
        Default number of heap arenas - System Property: io.netty5.allocator.numHeapArenas - default 2 * cores

      • defaultNumDirectArena

        public static int defaultNumDirectArena()
        Default number of direct arenas - System Property: io.netty5.allocator.numDirectArenas - default 2 * cores

      • defaultPageSize

        public static int defaultPageSize()
        Default buffer page size - System Property: io.netty5.allocator.pageSize - default 8192

      • defaultMaxOrder

        public static int defaultMaxOrder()
        Default maximum order - System Property: io.netty5.allocator.maxOrder - default 11

      • defaultUseCacheForAllThreads

        public static boolean defaultUseCacheForAllThreads()
        Default thread caching behavior - System Property: io.netty5.allocator.useCacheForAllThreads - default true

      • defaultPreferDirect

        public static boolean defaultPreferDirect()
        Default prefer direct - System Property: io.netty5.noPreferDirect - default false

      • defaultSmallCacheSize

        public static int defaultSmallCacheSize()
        Default small cache size - System Property: io.netty5.allocator.smallCacheSize - default 256

      • defaultNormalCacheSize

        public static int defaultNormalCacheSize()
        Default normal cache size - System Property: io.netty5.allocator.normalCacheSize - default 64

      • isDirectMemoryCacheAlignmentSupported

        public static boolean isDirectMemoryCacheAlignmentSupported()
        Return true if direct memory cache alignment is supported, false otherwise.

      • isDirectBufferPooled

        public boolean isDirectBufferPooled()

      • numArenas

        public int numArenas()

      • trimCurrentThreadCache

        public boolean trimCurrentThreadCache()
        Trim thread local cache for the current Thread, which will give back any cached memory that was not allocated frequently since the last trim operation. Returns true if a cache for the current Thread exists and so was trimmed, false otherwise.

      • dumpStats

        public String dumpStats()
        Returns the status of the allocator (which contains all metrics) as string. Be aware this may be expensive and so should not be called too frequently.