com.siemens.ct.exi.core.io

Class BitOutputStream

java.lang.Object

java.io.OutputStream

com.siemens.ct.exi.core.io.BitOutputStream

All Implemented Interfaces:

Closeable, Flushable, AutoCloseable

public class BitOutputStream
extends OutputStream

Write bits and bytes to an underlying output stream.

Author:

Daniel.Peintner.EXT@siemens.com, Richard.Kuntschke@siemens.com

Field Summary

Fields

Modifier and Type	Field and Description
static int	BITS_IN_BYTE
protected int	buffer Internal buffer represented as an int.
protected int	capacity Unused capacity of the internal buffer in bits.
protected int	len Fully-written bytes

Constructor Summary

Constructors

Constructor and Description
BitOutputStream(OutputStream ostream) Constructs an instance of this class.

Method Summary

Modifier and Type	Method and Description
void	align() If there are some unwritten bits, pad them if necessary and write them out.
void	flush() If there are some unwritten bits, pad them if necessary and write them out.
protected void	flushBuffer() If buffer is full, write it out and reset internal state.
int	getBitsInBuffer() Returns the number of bits that haven't been flushed.
int	getLength() Returns the number of bytes written.
OutputStream	getUnderlyingOutputStream() Returns a reference to underlying output stream.
boolean	isByteAligned() Returns true if stream is on a byte boundary, i.e. if no bits have been buffered since the last byte was written to underlying stream.
void	write(int b)
protected void	writeBit(int b) Write the least significant bit of parameter b into the internal buffer, flushing it if necessary.
void	writeBit0() Write a single bit 0.
void	writeBit1() Write a single bit 1.
void	writeBits(int b, int n) Write the n least significant bits of parameter b starting with the most significant, i.e. from left to right.
protected void	writeDirectByte(int b) Ignore current buffer, and write a byte directly to the underlying stream.
protected void	writeDirectBytes(byte[] b, int off, int len) Ignore current buffer, and write a sequence of bytes directly to the underlying stream.

Methods inherited from class java.io.OutputStream

close, write, write

Methods inherited from class java.lang.Object

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

Field Detail

BITS_IN_BYTE

public static final int BITS_IN_BYTE

See Also:

Constant Field Values

buffer

protected int buffer

Internal buffer represented as an int. Only the least significant byte is used. An int is used instead of a byte int-to-byte conversions in the VM.

capacity

protected int capacity

Unused capacity of the internal buffer in bits.

len

protected int len

Fully-written bytes

Constructor Detail

BitOutputStream

public BitOutputStream(OutputStream ostream)

Constructs an instance of this class.

Parameters:

ostream - output stream

Method Detail

getUnderlyingOutputStream

public OutputStream getUnderlyingOutputStream()

Returns a reference to underlying output stream.

Returns:

underlying output stream

getLength

public int getLength()

Returns the number of bytes written.

Returns:

number of bytes

flushBuffer

protected void flushBuffer()
                    throws IOException

If buffer is full, write it out and reset internal state.

Throws:

IOException - IO exception

isByteAligned

public boolean isByteAligned()

Returns true if stream is on a byte boundary, i.e. if no bits have been buffered since the last byte was written to underlying stream.

Returns:

whether stream is aligned

getBitsInBuffer

public int getBitsInBuffer()

Returns the number of bits that haven't been flushed. When the buffer is full, it is automatically flushed, so the number returned by this method is in [0, 7].

Returns:

bits in buffer

flush

public void flush()
           throws IOException

If there are some unwritten bits, pad them if necessary and write them out. Note that this method does flush the underlying stream.

Specified by:

flush in interface Flushable

Overrides:

flush in class OutputStream

Throws:

IOException

align

public void align()
           throws IOException

If there are some unwritten bits, pad them if necessary and write them out.

Throws:

IOException - IO exception

writeBit0

public void writeBit0()
               throws IOException

Write a single bit 0.

Throws:

IOException - IO exception

writeBit1

public void writeBit1()
               throws IOException

Write a single bit 1.

Throws:

IOException - IO exception

writeBit

protected void writeBit(int b)
                 throws IOException

Write the least significant bit of parameter b into the internal buffer, flushing it if necessary.

Parameters:

b - bit

Throws:

IOException - IO exception

writeBits

public void writeBits(int b,
                      int n)
               throws IOException

Write the n least significant bits of parameter b starting with the most significant, i.e. from left to right.

Parameters:

b - bits

n - number of bits

Throws:

IOException - IO exception

writeDirectByte

protected void writeDirectByte(int b)
                        throws IOException

Ignore current buffer, and write a byte directly to the underlying stream.

Parameters:

b - byte

Throws:

IOException - IO exception

writeDirectBytes

protected void writeDirectBytes(byte[] b,
                                int off,
                                int len)
                         throws IOException

Ignore current buffer, and write a sequence of bytes directly to the underlying stream.

Parameters:

b - byte array

off - byte array offset

len - byte array length

Throws:

IOException - IO exception

write

public void write(int b)
           throws IOException

Specified by:

write in class OutputStream

Throws:

IOException