Package io.netty.util.internal

Class MathUtil

  • public final class MathUtil
extends java.lang.Object
    Math utility methods.

    • Method Summary

      All Methods Static Methods Concrete Methods Deprecated Methods 
      Modifier and Type Method Description
      static int compare​(int x, int y)
      Deprecated.
      not used anymore.
      static int compare​(long x, long y)
      Deprecated.
      not used anymore.
      static int findNextPositivePowerOfTwo​(int value)
      Fast method of finding the next power of 2 greater than or equal to the supplied value.
      static boolean isOutOfBounds​(int index, int length, int capacity)
      Determine if the requested index and length will fit within capacity.
      static int safeFindNextPositivePowerOfTwo​(int value)
      Fast method of finding the next power of 2 greater than or equal to the supplied value.

      • Methods inherited from class java.lang.Object

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

    • Method Detail

      • findNextPositivePowerOfTwo

        public static int findNextPositivePowerOfTwo​(int value)
        Fast method of finding the next power of 2 greater than or equal to the supplied value.

        If the value is <= 0 then 1 will be returned. This method is not suitable for Integer.MIN_VALUE or numbers greater than 2^30.

        Parameters:
        value - from which to search for next power of 2
        Returns:
        The next power of 2 or the value itself if it is a power of 2

      • safeFindNextPositivePowerOfTwo

        public static int safeFindNextPositivePowerOfTwo​(int value)
        Fast method of finding the next power of 2 greater than or equal to the supplied value.

        This method will do runtime bounds checking and call findNextPositivePowerOfTwo(int) if within a valid range.

        Parameters:
        value - from which to search for next power of 2
        Returns:
        The next power of 2 or the value itself if it is a power of 2.

        Special cases for return values are as follows:

        • <= 0 -> 1
        • >= 2^30 -> 2^30

      • isOutOfBounds

        public static boolean isOutOfBounds​(int index,
                                    int length,
                                    int capacity)
        Determine if the requested index and length will fit within capacity.
        Parameters:
        index - The starting index.
        length - The length which will be utilized (starting from index).
        capacity - The capacity that index + length is allowed to be within.
        Returns:
        false if the requested index and length will fit within capacity. true if this would result in an index out of bounds exception.

      • compare

        @Deprecated
public static int compare​(int x,
                          int y)
        Deprecated.
        not used anymore. User Integer.compare() instead. For removal. Compares two int values.
        Parameters:
        x - the first int to compare
        y - the second int to compare
        Returns:
        the value 0 if x == y; -1 if x < y; and 1 if x > y

      • compare

        @Deprecated
public static int compare​(long x,
                          long y)
        Deprecated.
        not used anymore. User Long.compare() instead. For removal. Compare two long values.
        Parameters:
        x - the first long to compare.
        y - the second long to compare.
        Returns:
        • 0 if x == y
        • > 0 if x > y
        • < 0 if x < y