Package org.apache.lucene.util

Class ByteBlockPool

  • public final class ByteBlockPool
extends Object
    Class that Posting and PostingVector use to write byte streams into shared fixed-size byte[] arrays. The idea is to allocate slices of increasing lengths For example, the first slice is 5 bytes, the next slice is 14, etc. We start by writing our bytes into the first 5 bytes. When we hit the end of the slice, we allocate the next slice and then write the address of the new slice into the last 4 bytes of the previous slice (the "forwarding address"). Each slice is filled with 0's initially, and we mark the end with a non-zero byte. This way the methods that are writing into the slice don't need to record its length and instead allocate a new slice once they hit a non-zero byte.
    NOTE: This API is for internal purposes only and might change in incompatible ways in the next release.

    • Field Detail

      • buffers

        public byte[][] buffers

      • byteUpto

        public int byteUpto

      • buffer

        public byte[] buffer

      • byteOffset

        public int byteOffset

      • nextLevelArray

        public static final int[] nextLevelArray

      • levelSizeArray

        public static final int[] levelSizeArray

      • FIRST_LEVEL_SIZE

        public static final int FIRST_LEVEL_SIZE

    • Method Detail

      • dropBuffersAndReset

        public void dropBuffersAndReset()

      • reset

        public void reset()

      • nextBuffer

        public void nextBuffer()

      • newSlice

        public int newSlice​(int size)

      • allocSlice

        public int allocSlice​(byte[] slice,
                      int upto)

      • setBytesRef

        public final BytesRef setBytesRef​(BytesRef term,
                                  int textStart)

      • copy

        public final void copy​(BytesRef bytes)
        Copies the given BytesRef at the current positions ( byteUpto across buffer boundaries