Package org.apache.datasketches.memory

Class DefaultMemoryRequestServer

  • All Implemented Interfaces:
    MemoryRequestServer
    public final class DefaultMemoryRequestServer
extends Object
implements MemoryRequestServer
    This example MemoryRequestServer is simple but demonstrates one of many ways to manage continuous requests for larger memory. This capability is only available for writable, non-file-memory-mapping resources.
    Author:
    Lee Rhodes

    • Constructor Detail

      • DefaultMemoryRequestServer

        public DefaultMemoryRequestServer()
        Default constructor. Create new memory on-heap and do not copy old contents to new memory.

      • DefaultMemoryRequestServer

        public DefaultMemoryRequestServer​(boolean offHeap,
                                  boolean copyOldToNew)
        Constructor with parameters
        Parameters:
        offHeap - if true, the returned new memory will be off heap
        copyOldToNew - if true, the data from the current memory will be copied to the new memory, starting at address 0, and through the currentMemory capacity.

    • Method Detail

      • request

        public WritableMemory request​(WritableMemory currentWmem,
                              long newCapacityBytes)
        Description copied from interface: MemoryRequestServer
        Request new WritableMemory with the given newCapacityBytes. The current Writable Memory will be used to determine the byte order of the returned WritableMemory and other properties.
        Specified by:
        request in interface MemoryRequestServer
        Parameters:
        currentWmem - the current writableMemory of the client. It must be non-null.
        newCapacityBytes - The capacity being requested. It must be > the capacity of the currentWritableMemory.
        Returns:
        new WritableMemory with the requested capacity.

      • requestClose

        public void requestClose​(WritableMemory memToClose,
                         WritableMemory newMemory)
        Description copied from interface: MemoryRequestServer
        Request to close the resource, if applicable.
        Specified by:
        requestClose in interface MemoryRequestServer
        Parameters:
        memToClose - the relevant WritbleMemory to be considered for closing. It must be non-null.
        newMemory - the newly allocated WritableMemory. The newMemory reference is returned from the client for the convenience of the system that owns the responsibility of memory allocation. It may be null.