Class ObjectBuffer

java.lang.Object
tools.jackson.databind.util.ObjectBuffer
public final class ObjectBuffer extends Object
Helper class to use for constructing Object arrays by appending entries to create arrays of various lengths (length that is not known a priori).

  • Field Details

    • SMALL_CHUNK

      private static final int SMALL_CHUNK
      Also: let's expand by doubling up until 64k chunks (which is 16k entries for 32-bit machines)
      See Also:

    • MAX_CHUNK

      private static final int MAX_CHUNK
      Let's limit maximum size of chunks we use; helps avoid excessive allocation overhead for huge data sets. For now, let's limit to quarter million entries, 1 meg chunks for 32-bit machines.
      See Also:

    • _head

      private LinkedNode<Object[]> _head

    • _tail

      private LinkedNode<Object[]> _tail

    • _size

      private int _size
      Number of total buffered entries in this buffer, counting all instances within linked list formed by following _head.

    • _freeBuffer

      private Object[] _freeBuffer
      Reusable Object array, stored here after buffer has been released having been used previously.

  • Constructor Details

    • ObjectBuffer

      public ObjectBuffer()

  • Method Details

    • resetAndStart

      public Object[] resetAndStart()
      Method called to start buffering process. Will ensure that the buffer is empty, and then return an object array to start chunking content on

    • resetAndStart

      public Object[] resetAndStart(Object[] base, int count)
      Since:
      2.9

    • appendCompletedChunk

      public Object[] appendCompletedChunk(Object[] fullChunk)
      Method called to add a full Object array as a chunk buffered within this buffer, and to obtain a new array to fill. Caller is not to use the array it gives; but to use the returned array for continued buffering.
      Parameters:
      fullChunk - Completed chunk that the caller is requesting to append to this buffer. It is generally chunk that was returned by an earlier call to resetAndStart() or appendCompletedChunk(Object[]) (although this is not required or enforced)
      Returns:
      New chunk buffer for caller to fill

    • completeAndClearBuffer

      public Object[] completeAndClearBuffer(Object[] lastChunk, int lastChunkEntries)
      Method called to indicate that the buffering process is now complete; and to construct a combined exactly-sized result array. Additionally the buffer itself will be reset to reduce memory retention.

      Resulting array will be of generic Object[] type: if a typed array is needed, use the method with additional type argument.

    • completeAndClearBuffer

      public <T> T[] completeAndClearBuffer(Object[] lastChunk, int lastChunkEntries, Class<T> componentType)
      Type-safe alternative to completeAndClearBuffer(Object[], int), to allow for constructing explicitly typed result array.
      Parameters:
      componentType - Type of elements included in the buffer. Will be used for constructing the result array.

    • completeAndClearBuffer

      public void completeAndClearBuffer(Object[] lastChunk, int lastChunkEntries, List<Object> resultList)

    • initialCapacity

      public int initialCapacity()
      Helper method that can be used to check how much free capacity will this instance start with. Can be used to choose the best instance to reuse, based on size of reusable object chunk buffer holds reference to.

    • bufferedSize

      public int bufferedSize()
      Method that can be used to check how many Objects have been buffered within this buffer.

    • _reset

      protected void _reset()

    • _copyTo

      protected final void _copyTo(Object resultArray, int totalSize, Object[] lastChunk, int lastChunkEntries)