com.oracle.truffle.api.memory

Class ByteArraySupport

java.lang.Object

com.oracle.truffle.api.memory.ByteArraySupport

public abstract class ByteArraySupport
extends Object

Utility methods to write to and read from arrays of bytes. Singletons of this class are obtained from ByteArraySupport.littleEndian() or ByteArraySupport.bigEndian() respectively to access byte arrays in little-endian or big-endian order.

Since:

20.3

Method Summary

Modifier and Type	Method and Description
static ByteArraySupport	bigEndian() Enables accessing multibyte Java primitives from byte arrays in big-endian order.
abstract byte	getByte(byte[] buffer, int index) Reads the byte at the given index.
abstract double	getDouble(byte[] buffer, int index) Reads the double at the given index.
abstract float	getFloat(byte[] buffer, int index) Reads the float at the given index.
abstract int	getInt(byte[] buffer, int index) Reads the int at the given index.
abstract long	getLong(byte[] buffer, int index) Reads the int at the given index.
abstract short	getShort(byte[] buffer, int index) Reads the short at the given index.
boolean	inBounds(byte[] buffer, int startIndex, int length) Checks if an access is in bounds of the given buffer.
static ByteArraySupport	littleEndian() Enables accessing multibyte Java primitives from byte arrays in little-endian order.
abstract void	putByte(byte[] buffer, int index, byte value) Writes the given byte at the given index.
abstract void	putDouble(byte[] buffer, int index, double value) Writes the given double at the given index.
abstract void	putFloat(byte[] buffer, int index, float value) Writes the given float at the given index.
abstract void	putInt(byte[] buffer, int index, int value) Writes the given int at the given index.
abstract void	putLong(byte[] buffer, int index, long value) Writes the given int at the given index.
abstract void	putShort(byte[] buffer, int index, short value) Writes the given short at the given index.

Methods inherited from class java.lang.Object

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

Method Detail

littleEndian

public static ByteArraySupport littleEndian()

Enables accessing multibyte Java primitives from byte arrays in little-endian order.

Example usage:

 byte[] buffer = new byte[]{0, 0, 0, 0};
 ByteArraySupport.littleEndian().putShort(buffer, 2, (short) 1);
 // buffer[2] == (byte) 1
 // buffer[3] == (byte) 0
 ByteArraySupport.littleEndian().putShort(buffer, 3, (short) 1);
 // throws IndexOutOfBoundsException exception
 

Since:

20.3

bigEndian

public static ByteArraySupport bigEndian()

Enables accessing multibyte Java primitives from byte arrays in big-endian order.

Example usage:

 byte[] buffer = new byte[]{0, 0, 0, 0};
 ByteArraySupport.bigEndian().putShort(buffer, 0, (short) 1);
 // buffer[0] == (byte) 0
 // buffer[1] == (byte) 1
 

Since:

20.3

inBounds

public final boolean inBounds(byte[] buffer,
                              int startIndex,
                              int length)

Checks if an access is in bounds of the given buffer.

If out-of-bounds accesses are expected to happen frequently, it is faster (~1.2x in interpreter mode) to use this method to check for them than catching IndexOutOfBoundsExceptions.

Parameters:

buffer - The byte array

startIndex - The start index of the access

length - The number of bytes accessed

Returns:

True if if the access is in bounds, false otherwise

Since:

20.3

getByte

public abstract byte getByte(byte[] buffer,
                             int index)
                      throws IndexOutOfBoundsException

Reads the byte at the given index.

Parameters:

buffer - The byte array to read from

index - The index from which the byte will be read

Returns:

The byte at the given index

Throws:

IndexOutOfBoundsException - If index is negative or not smaller than the buffer's size

Since:

20.3

putByte

public abstract void putByte(byte[] buffer,
                             int index,
                             byte value)
                      throws IndexOutOfBoundsException

Writes the given byte at the given index.

Parameters:

buffer - The byte array to write in

index - The index at which the byte will be written

value - The byte value to be written

Throws:

IndexOutOfBoundsException - If index is negative or not smaller than the buffer's size

Since:

20.3

getShort

public abstract short getShort(byte[] buffer,
                               int index)
                        throws IndexOutOfBoundsException

Reads the short at the given index.

Parameters:

buffer - The byte array to read from

index - The index from which the short will be read

Returns:

The short at the given index

Throws:

IndexOutOfBoundsException - If index is negative or not smaller than the buffer's size minus one

Since:

20.3

putShort

public abstract void putShort(byte[] buffer,
                              int index,
                              short value)
                       throws IndexOutOfBoundsException

Writes the given short at the given index.

Parameters:

buffer - The byte array to write in

index - The index at which the short will be written

value - The short value to be written

Throws:

IndexOutOfBoundsException - If index is negative or not smaller than the buffer's size minus one

Since:

20.3

getInt

public abstract int getInt(byte[] buffer,
                           int index)
                    throws IndexOutOfBoundsException

Reads the int at the given index.

Parameters:

buffer - The byte array to read from

index - The index from which the int will be read

Returns:

The int at the given index

Throws:

IndexOutOfBoundsException - If index is negative or not smaller than the buffer's size minus three

Since:

20.3

putInt

public abstract void putInt(byte[] buffer,
                            int index,
                            int value)
                     throws IndexOutOfBoundsException

Writes the given int at the given index.

Parameters:

buffer - The byte array to write in

index - The index at which the int will be written

value - The int value to be written

Throws:

IndexOutOfBoundsException - If index is negative or not smaller than the buffer's size minus three

Since:

20.3

getLong

public abstract long getLong(byte[] buffer,
                             int index)
                      throws IndexOutOfBoundsException

Reads the int at the given index.

Parameters:

buffer - The byte array to read from

index - The index from which the int will be read

Returns:

The int at the given index

Throws:

IndexOutOfBoundsException - If index is negative or not smaller than the buffer's size minus seven

Since:

20.3

putLong

public abstract void putLong(byte[] buffer,
                             int index,
                             long value)
                      throws IndexOutOfBoundsException

Writes the given int at the given index.

Parameters:

buffer - The byte array to write in

index - The index at which the int will be written

value - The int value to be written

Throws:

IndexOutOfBoundsException - If index is negative or not smaller than the buffer's size minus seven

Since:

20.3

getFloat

public abstract float getFloat(byte[] buffer,
                               int index)
                        throws IndexOutOfBoundsException

Reads the float at the given index.

Parameters:

buffer - The byte array to read from

index - The index from which the float will be read

Returns:

The float at the given index

Throws:

IndexOutOfBoundsException - If index is negative or not smaller than the buffer's size minus three

Since:

20.3

putFloat

public abstract void putFloat(byte[] buffer,
                              int index,
                              float value)
                       throws IndexOutOfBoundsException

Writes the given float at the given index.

Parameters:

buffer - The byte array to write in

index - The index at which the float will be written

value - The float value to be written

Throws:

IndexOutOfBoundsException - If index is negative or not smaller than the buffer's size minus three

Since:

20.3

getDouble

public abstract double getDouble(byte[] buffer,
                                 int index)
                          throws IndexOutOfBoundsException

Reads the double at the given index.

Parameters:

buffer - The byte array to read from

index - The index from which the double will be read

Returns:

The double at the given index

Throws:

IndexOutOfBoundsException - If index is negative or not smaller than the buffer's size minus seven

Since:

20.3

putDouble

public abstract void putDouble(byte[] buffer,
                               int index,
                               double value)
                        throws IndexOutOfBoundsException

Writes the given double at the given index.

Parameters:

buffer - The byte array to write in

index - The index at which the double will be written

value - The double value to be written

Throws:

IndexOutOfBoundsException - If index is negative or not smaller than the buffer's size minus seven

Since:

20.3