Package org.apache.druid.segment.data

Class VByte

java.lang.Object
org.apache.druid.segment.data.VByte
public class VByte extends Object

  • Constructor Summary

    Constructors
    Constructor
    Description
    VByte()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    static int
    computeIntSize(int val)
    Compute number of bytes required to represent variable byte encoded integer.
    static int
    readInt(ByteBuffer buffer)
    Read a variable byte (vbyte) encoded integer from a ByteBuffer at the current position.
    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.

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Constructor Details

    • VByte

      public VByte()

  • Method Details

    • 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.