com.alexkasko.unsafe.bytearray

Class ByteArrayTool

java.lang.Object

com.alexkasko.unsafe.bytearray.ByteArrayTool

Direct Known Subclasses:

BitShiftLittleEndianByteArrayTool, UnsafeByteArrayTool

public abstract class ByteArrayTool
extends Object

Front-end class for operations over byte arrays. Default implementation uses sun.misc.Unsafe with assert boundary checks. To enable boundary check use -ea java switch, without boundary checks invalid input will crash (segfault) JVM. Fallback implementation uses standard byte array access and bit shifting. Unsafe implementation uses native endianness (LE on most platforms). Fallback implementation uses Little Endian byte order.

Author:

alexkasko Date: 12/11/12

Constructor Summary

Constructors

Constructor and Description
ByteArrayTool()

Method Summary

Methods

Modifier and Type	Method and Description
static ByteArrayTool	bitshift() Instantiates bitshift tool
abstract void	copy(byte[] src, int srcPos, byte[] dest, int destPos, int length) Copies part of one array into another.
static ByteArrayTool	get() Instantiates unsafe tool, if proper sun.misc.Unsafe implementation is available.
abstract byte	getByte(byte[] data, int offset) Gets byte
abstract int	getInt(byte[] data, int offset) Gets four bytes as int
abstract long	getLong(byte[] data, int offset) Gets long
abstract short	getShort(byte[] data, int offset) Gets two bytes as short
abstract short	getUnsignedByte(byte[] data, int offset) Gets one byte (stored as one signed byte), converts it to unsigned and returns it as short
abstract long	getUnsignedInt(byte[] data, int offset) Gets unsigned int (stored as 4 bytes) and returns it as long
abstract int	getUnsignedShort(byte[] data, int offset) Gets unsigned short (stored as two bytes) and returns it as int
abstract boolean	isUnsafe() Whether current tool instance uses sun.misc.Unsafe
abstract void	putByte(byte[] data, int offset, byte value) Puts byte
abstract void	putInt(byte[] data, int offset, int value) Puts int as four bytes
abstract void	putLong(byte[] data, int offset, long value) Puts long as eight bytes
abstract void	putShort(byte[] data, int offset, short value) Puts short as two bytes
abstract void	putUnsignedByte(byte[] data, int offset, short value) Puts short with value from 0 to 255 inclusive into byte array as one signed byte
abstract void	putUnsignedInt(byte[] data, int offset, long value) Puts long value from 0 to 4294967295 inclusive as four bytes
abstract void	putUnsignedShort(byte[] data, int offset, int value) Puts int with value from 0 to 65535 inclusive as two bytes
static ByteArrayTool	unsafe() Instantiates unsafe tool

Methods inherited from class java.lang.Object

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

Constructor Detail

ByteArrayTool

public ByteArrayTool()

Method Detail

get

public static ByteArrayTool get()

Instantiates unsafe tool, if proper sun.misc.Unsafe implementation is available. Otherwise instantiates fallback (bitshift) implementation.

Returns:

tool instance

unsafe

public static ByteArrayTool unsafe()
                            throws Exception

Instantiates unsafe tool

Returns:

unsafe tool instance

Throws:

Exception - if proper sun.misc.Unsafe implementation is not available

bitshift

public static ByteArrayTool bitshift()

Instantiates bitshift tool

Returns:

bitshift tool instance

isUnsafe

public abstract boolean isUnsafe()

Whether current tool instance uses sun.misc.Unsafe

Returns:

whether unsafe

getByte

public abstract byte getByte(byte[] data,
           int offset)

Gets byte

Parameters:

data - byte array

offset - byte array index

Returns:

byte

putByte

public abstract void putByte(byte[] data,
           int offset,
           byte value)

Puts byte

Parameters:

data - byte array

offset - byte array index

value - value

getUnsignedByte

public abstract short getUnsignedByte(byte[] data,
                    int offset)

Gets one byte (stored as one signed byte), converts it to unsigned and returns it as short

Parameters:

data - byte array

offset - byte array index

Returns:

unsigned byte as short

putUnsignedByte

public abstract void putUnsignedByte(byte[] data,
                   int offset,
                   short value)

Puts short with value from 0 to 255 inclusive into byte array as one signed byte

Parameters:

data - byte array

offset - byte array index

value - unsigned byte

getShort

public abstract short getShort(byte[] data,
             int offset)

Gets two bytes as short

Parameters:

data - byte array

offset - byte array offset

Returns:

short value

putShort

public abstract void putShort(byte[] data,
            int offset,
            short value)

Puts short as two bytes

Parameters:

data - byte array

offset - byte array offset

value - short value

getUnsignedShort

public abstract int getUnsignedShort(byte[] data,
                   int offset)

Gets unsigned short (stored as two bytes) and returns it as int

Parameters:

data - byte array

offset - byte array offset

Returns:

unsigned short as int

putUnsignedShort

public abstract void putUnsignedShort(byte[] data,
                    int offset,
                    int value)

Puts int with value from 0 to 65535 inclusive as two bytes

Parameters:

data - byte array

offset - byte array offset

value - unsigned short as int

getInt

public abstract int getInt(byte[] data,
         int offset)

Gets four bytes as int

Parameters:

data - byte array

offset - byte array offset

Returns:

int value

putInt

public abstract void putInt(byte[] data,
          int offset,
          int value)

Puts int as four bytes

Parameters:

data - byte array

offset - byte array offset

value - int value

getUnsignedInt

public abstract long getUnsignedInt(byte[] data,
                  int offset)

Gets unsigned int (stored as 4 bytes) and returns it as long

Parameters:

data - byte array

offset - byte array offset

Returns:

unsigned int as long

putUnsignedInt

public abstract void putUnsignedInt(byte[] data,
                  int offset,
                  long value)

Puts long value from 0 to 4294967295 inclusive as four bytes

Parameters:

data - byte array

offset - byte array offset

value - unsigned int as long

getLong

public abstract long getLong(byte[] data,
           int offset)

Gets long

Parameters:

data - byte array

offset - byte array offset

Returns:

long value

putLong

public abstract void putLong(byte[] data,
           int offset,
           long value)

Puts long as eight bytes

Parameters:

data - byte array

offset - byte array offset

value - long value

copy

public abstract void copy(byte[] src,
        int srcPos,
        byte[] dest,
        int destPos,
        int length)

Copies part of one array into another. Unsafe implementation has less bounds checks (if assertions are disabled in runtime) then System.arraycopy(Object, int, Object, int, int) that is used by fallback implementation uses

Parameters:

src - source array

srcPos - source array position

dest - destination array

destPos - destination array position

length - length to copy