BitUtil (rsocket-core 1.0.0-RC1 API)

java.lang.Object
- io.rsocket.internal.BitUtil

```
public class BitUtil
extends Object
```
Miscellaneous useful functions for dealing with low level bits and bytes.

Field Summary

Fields
Modifier and Type	Field and Description
`static int`	`CACHE_LINE_LENGTH` Length of the data blocks used by the CPU cache sub-system in bytes.
`static int`	`SIZE_OF_BOOLEAN` Size of a boolean in bytes
`static int`	`SIZE_OF_BYTE` Size of a byte in bytes
`static int`	`SIZE_OF_CHAR` Size of a char in bytes
`static int`	`SIZE_OF_DOUBLE` Size of a double in bytes
`static int`	`SIZE_OF_FLOAT` Size of a float in bytes
`static int`	`SIZE_OF_INT` Size of an int in bytes
`static int`	`SIZE_OF_LONG` Size of a long in bytes
`static int`	`SIZE_OF_SHORT` Size of a short in bytes

Constructor Summary

Constructors
Constructor and Description

BitUtil()

Constructors
Constructor and Description
`BitUtil()`

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method and Description
`static int`	`align(int value, int alignment)` Align a value to the next multiple up of alignment.
`static int`	`calculateShiftForScale(int scale)` Calculate the shift value to scale a number based on how refs are compressed or not.
`static int`	`findNextPositivePowerOfTwo(int value)` Fast method of finding the next power of 2 greater than or equal to the supplied value.
`static byte[]`	`fromHex(String string)` Generate a byte array from a string that is the hex representation of the given byte array.
`static byte[]`	`fromHexByteArray(byte[] buffer)` Generate a byte array from the hex representation of the given byte array.
`static int`	`generateRandomisedId()` Generate a randomised integer over [`Integer.MIN_VALUE`, `Integer.MAX_VALUE`].
`static boolean`	`isAligned(long address, int alignment)` Is an address aligned on a boundary.
`static boolean`	`isEven(int value)` Is a number even.
`static boolean`	`isPowerOfTwo(int value)` Is a value a positive power of 2.
`static int`	`next(int current, int max)` Cycles indices of an array one at a time in a forward fashion
`static int`	`previous(int current, int max)` Cycles indices of an array one at a time in a backwards fashion
`static String`	`toHex(byte[] buffer)` Generate a string that is the hex representation of a given byte array.
`static String`	`toHex(byte[] buffer, int offset, int length)` Generate a string that is the hex representation of a given byte array.
`static byte[]`	`toHexByteArray(byte[] buffer)` Generate a byte array that is a hex representation of a given byte array.
`static byte[]`	`toHexByteArray(byte[] buffer, int offset, int length)` Generate a byte array that is a hex representation of a given byte array.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - SIZE_OF_BYTE
```
public static final int SIZE_OF_BYTE
```
    Size of a byte in bytes
    
    See Also:
    
    Constant Field Values
  - SIZE_OF_BOOLEAN
```
public static final int SIZE_OF_BOOLEAN
```
    Size of a boolean in bytes
    
    See Also:
    
    Constant Field Values
  - SIZE_OF_CHAR
```
public static final int SIZE_OF_CHAR
```
    Size of a char in bytes
    
    See Also:
    
    Constant Field Values
  - SIZE_OF_SHORT
```
public static final int SIZE_OF_SHORT
```
    Size of a short in bytes
    
    See Also:
    
    Constant Field Values
  - SIZE_OF_INT
```
public static final int SIZE_OF_INT
```
    Size of an int in bytes
    
    See Also:
    
    Constant Field Values
  - SIZE_OF_FLOAT
```
public static final int SIZE_OF_FLOAT
```
    Size of a float in bytes
    
    See Also:
    
    Constant Field Values
  - SIZE_OF_LONG
```
public static final int SIZE_OF_LONG
```
    Size of a long in bytes
    
    See Also:
    
    Constant Field Values
  - SIZE_OF_DOUBLE
```
public static final int SIZE_OF_DOUBLE
```
    Size of a double in bytes
    
    See Also:
    
    Constant Field Values
  - CACHE_LINE_LENGTH
```
public static final int CACHE_LINE_LENGTH
```
    Length of the data blocks used by the CPU cache sub-system in bytes.
    
    See Also:
    
    Constant Field Values
- Constructor Detail
  - BitUtil
```
public BitUtil()
```
- 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
  - align
```
public static int align(int value,
                        int alignment)
```
    Align a value to the next multiple up of alignment. If the value equals an alignment multiple then it is returned unchanged.
    This method executes without branching. This code is designed to be use in the fast path and should not be used with negative numbers. Negative numbers will result in undefined behaviour.
    
    Parameters:
    
    value - to be aligned up.
    
    alignment - to be used.
    
    Returns:
    
    the value aligned to the next boundary.
  - fromHexByteArray
```
public static byte[] fromHexByteArray(byte[] buffer)
```
    Generate a byte array from the hex representation of the given byte array.
    
    Parameters:
    
    buffer - to convert from a hex representation (in Big Endian).
    
    Returns:
    
    new byte array that is decimal representation of the passed array.
  - toHexByteArray
```
public static byte[] toHexByteArray(byte[] buffer)
```
    Generate a byte array that is a hex representation of a given byte array.
    
    Parameters:
    
    buffer - to convert to a hex representation.
    
    Returns:
    
    new byte array that is hex representation (in Big Endian) of the passed array.
  - toHexByteArray
```
public static byte[] toHexByteArray(byte[] buffer,
                                    int offset,
                                    int length)
```
    Generate a byte array that is a hex representation of a given byte array.
    
    Parameters:
    
    buffer - to convert to a hex representation.
    
    offset - the offset into the buffer.
    
    length - the number of bytes to convert.
    
    Returns:
    
    new byte array that is hex representation (in Big Endian) of the passed array.
  - fromHex
```
public static byte[] fromHex(String string)
```
    Generate a byte array from a string that is the hex representation of the given byte array.
    
    Parameters:
    
    string - to convert from a hex representation (in Big Endian).
    
    Returns:
    
    new byte array holding the decimal representation of the passed array.
  - toHex
```
public static String toHex(byte[] buffer,
                           int offset,
                           int length)
```
    Generate a string that is the hex representation of a given byte array.
    
    Parameters:
    
    buffer - to convert to a hex representation.
    
    offset - the offset into the buffer.
    
    length - the number of bytes to convert.
    
    Returns:
    
    new String holding the hex representation (in Big Endian) of the passed array.
  - toHex
```
public static String toHex(byte[] buffer)
```
    Generate a string that is the hex representation of a given byte array.
    
    Parameters:
    
    buffer - to convert to a hex representation.
    
    Returns:
    
    new String holding the hex representation (in Big Endian) of the passed array.
  - isEven
```
public static boolean isEven(int value)
```
    Is a number even.
    
    Parameters:
    
    value - to check.
    
    Returns:
    
    true if the number is even otherwise false.
  - isPowerOfTwo
```
public static boolean isPowerOfTwo(int value)
```
    Is a value a positive power of 2.
    
    Parameters:
    
    value - to be checked.
    
    Returns:
    
    true if the number is a positive power of 2, otherwise false.
  - next
```
public static int next(int current,
                       int max)
```
    Cycles indices of an array one at a time in a forward fashion
    
    Parameters:
    
    current - value to be incremented.
    
    max - value for the cycle.
    
    Returns:
    
    the next value, or zero if max is reached.
  - previous
```
public static int previous(int current,
                           int max)
```
    Cycles indices of an array one at a time in a backwards fashion
    
    Parameters:
    
    current - value to be decremented.
    
    max - value of the cycle.
    
    Returns:
    
    the next value, or max - 1 if current is zero.
  - calculateShiftForScale
```
public static int calculateShiftForScale(int scale)
```
    Calculate the shift value to scale a number based on how refs are compressed or not.
    
    Parameters:
    
    scale - of the number reported by Unsafe.
    
    Returns:
    
    how many times the number needs to be shifted to the left.
  - generateRandomisedId
```
public static int generateRandomisedId()
```
    Generate a randomised integer over [Integer.MIN_VALUE, Integer.MAX_VALUE].
    
    Returns:
    
    randomised integer suitable as an Id.
  - isAligned
```
public static boolean isAligned(long address,
                                int alignment)
```
    Is an address aligned on a boundary.
    
    Parameters:
    
    address - to be tested.
    
    alignment - boundary the address is tested against.
    
    Returns:
    
    true if the address is on the aligned boundary otherwise false.
    
    Throws:
    
    IllegalArgumentException - if the alignment is not a power of 2.

Class BitUtil

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

SIZE_OF_BYTE

SIZE_OF_BOOLEAN

SIZE_OF_CHAR

SIZE_OF_SHORT

SIZE_OF_INT

SIZE_OF_FLOAT

SIZE_OF_LONG

SIZE_OF_DOUBLE

CACHE_LINE_LENGTH

Constructor Detail

BitUtil

Method Detail

findNextPositivePowerOfTwo

align

fromHexByteArray

toHexByteArray

toHexByteArray

fromHex

toHex

toHex

isEven

isPowerOfTwo

next

previous

calculateShiftForScale

generateRandomisedId

isAligned