Package org.apache.druid.segment.data

Class VByte

  • public class VByte
extends Object

    • Constructor Detail

      • VByte

        public VByte()

    • Method Detail

      • readInt

        public static int readInt​(ByteBuffer buffer)
        Read a variable byte (vbyte) encoded integer from a ByteBuffer at the current position. Moves the buffer ahead by 1 to 5 bytes depending on how many bytes was required to encode the integer value. vbyte encoding stores values in the last 7 bits of a byte and reserves the high bit for the 'contination'. If 0, one or more aditional bytes must be read to complete the value, and a 1 indicates the terminal byte. Because of this, it can only store positive values, and larger integers can take up to 5 bytes. implementation based on: https://github.com/lemire/JavaFastPFOR/blob/master/src/main/java/me/lemire/integercompression/VariableByte.java

      • writeInt

        public static int writeInt​(ByteBuffer buffer,
                           int val)
        Write a variable byte (vbyte) encoded integer to a ByteBuffer at the current position, advancing the buffer position by the number of bytes required to represent the integer, between 1 and 5 bytes. vbyte encoding stores values in the last 7 bits of a byte and reserves the high bit for the 'contination'. If 0, one or more aditional bytes must be read to complete the value, and a 1 indicates the terminal byte. Because of this, it can only store positive values, and larger integers can take up to 5 bytes. implementation based on: https://github.com/lemire/JavaFastPFOR/blob/master/src/main/java/me/lemire/integercompression/VariableByte.java

      • computeIntSize

        public static int computeIntSize​(int val)
        Compute number of bytes required to represent variable byte encoded integer. vbyte encoding stores values in the last 7 bits of a byte and reserves the high bit for the 'contination'. If 0, one or more aditional bytes must be read to complete the value, and a 1 indicates the terminal byte. Because of this, it can only store positive values, and larger integers can take up to 5 bytes.