org.yamcs.parameterarchive

Class BitBuffer

java.lang.Object

org.yamcs.parameterarchive.BitBuffer

public class BitBuffer
extends Object

BitBuffer allows to write individual bits or group of bits into a buffer backed by an long[] array. All the writings/readings are performed to/from a temporary field which is stored/retrieve from the backing array when it is "full"

Author:

nm

Constructor Summary

Constructors

Constructor and Description
BitBuffer(byte[] b)

Method Summary

Modifier and Type	Method and Description
long[]	getArray() flush the temporary field to the array and return the backing array
int	getSize() get the size of the backing array containing data
int	read(int numBits)
long	readLong(int numBits)
void	rewind()
byte[]	toByteArray() flush the temporary field to the backing array and return a byte[] copy of the backing long array
void	write(int x, int numBits) write the least significant numBits of x into the BitBuffer Note that there is no check that the bits will actually fit into the allocated buffer, they will be stored in the temporary field.

Methods inherited from class java.lang.Object

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

Constructor Detail

BitBuffer

public BitBuffer(byte[] b)

Method Detail

write

public void write(int x,
                  int numBits)

write the least significant numBits of x into the BitBuffer Note that there is no check that the bits will actually fit into the allocated buffer, they will be stored in the temporary field. A buffer overflow exception will happen when the temporary field is full and flushed to the array (so the buffer is exceeded by 64 bits)

Parameters:

x -

numBits -

readLong

public long readLong(int numBits)

read

public int read(int numBits)

getArray

public long[] getArray()

flush the temporary field to the array and return the backing array

Returns:

the backing array

getSize

public int getSize()

get the size of the backing array containing data

Returns:

the size of the backing array

rewind

public void rewind()

toByteArray

public byte[] toByteArray()

flush the temporary field to the backing array and return a byte[] copy of the backing long array

Returns:

a byte[] copy of the backing long array