Package org.roaringbitmap.longlong

Class LongUtils

  • public class LongUtils
extends java.lang.Object

    • Constructor Summary

      Constructors 
      Constructor Description
      LongUtils()  

    • Method Summary

      All Methods Static Methods Concrete Methods 
      Modifier and Type Method Description
      static int compareHigh​(byte[] a, byte[] b)
      compare according to the dictionary order
      static long fromBDBytes​(byte[] work)
      get the long from the big endian representation bytes
      static byte[] highPart​(long num)
      get the high 48 bit parts of the input data
      static byte[] highPartInPlace​(long num, byte[] high48)
      set the high 48 bit parts of the input number into the given byte array
      static long initWithFirst4Byte​(int v)
      initialize a long value with the given fist 32 bit
      static boolean isMaxHigh​(byte[] high48)
      checks if given high48 is the maximum possible one (e.g. it is the case for -1L, which is the maximum unsigned long)
      static long leftShiftHighPart​(long num)
      shift the long by left the container size amount so we use the value after have done our steps
      static char lowPart​(long num)
      get the low 16 bit parts of the input data
      static int maxLowBitAsInteger()  
      static long rightShiftHighPart​(long num)
      shift the long right by the container size amount so we can loop across containers by +1 steps
      static byte[] toBDBytes​(long v)
      to big endian bytes representation
      static long toLong​(byte[] high, char low)
      reconstruct the long data

      • Methods inherited from class java.lang.Object

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

    • Constructor Detail

      • LongUtils

        public LongUtils()

    • Method Detail

      • highPart

        public static byte[] highPart​(long num)
        get the high 48 bit parts of the input data
        Parameters:
        num - the long number
        Returns:
        the high 48 bit

      • lowPart

        public static char lowPart​(long num)
        get the low 16 bit parts of the input data
        Parameters:
        num - the long number
        Returns:
        the low 16 bit

      • toLong

        public static long toLong​(byte[] high,
                          char low)
        reconstruct the long data
        Parameters:
        high - the high 48 bit
        low - the low 16 bit
        Returns:
        the long data

      • toBDBytes

        public static byte[] toBDBytes​(long v)
        to big endian bytes representation
        Parameters:
        v - a long value
        Returns:
        the input long value's big endian byte array representation

      • fromBDBytes

        public static long fromBDBytes​(byte[] work)
        get the long from the big endian representation bytes
        Parameters:
        work - the byte array
        Returns:
        the long data

      • compareHigh

        public static int compareHigh​(byte[] a,
                              byte[] b)
        compare according to the dictionary order
        Parameters:
        a - a byte array
        b - another byte array
        Returns:
        1 indicates a greater than b,0 indicates equal,-1 indicates a smaller than b

      • initWithFirst4Byte

        public static long initWithFirst4Byte​(int v)
        initialize a long value with the given fist 32 bit
        Parameters:
        v - first 32 bit value
        Returns:
        a long value

      • rightShiftHighPart

        public static long rightShiftHighPart​(long num)
        shift the long right by the container size amount so we can loop across containers by +1 steps
        Parameters:
        num - long being treated as unsigned long
        Returns:
        value shifted out of value space into container high part

      • leftShiftHighPart

        public static long leftShiftHighPart​(long num)
        shift the long by left the container size amount so we use the value after have done our steps
        Parameters:
        num - uint48 to be shift back into uint64
        Returns:
        value shifted out of container high part back into value space

      • maxLowBitAsInteger

        public static int maxLowBitAsInteger()

      • highPartInPlace

        public static byte[] highPartInPlace​(long num,
                                     byte[] high48)
        set the high 48 bit parts of the input number into the given byte array
        Parameters:
        num - the long number
        high48 - the byte array
        Returns:
        the high 48 bit

      • isMaxHigh

        public static boolean isMaxHigh​(byte[] high48)
        checks if given high48 is the maximum possible one (e.g. it is the case for -1L, which is the maximum unsigned long)
        Parameters:
        high48 - the byte array
        Returns:
        true if this the maximum high part