one.util
Class RubberPipedInputStream

java.lang.Object
  |
  +--java.io.InputStream
        |
        +--one.util.RubberPipedInputStream

public class RubberPipedInputStream

extends InputStream

RubberPipedInputStream and RubberPipedOutputStream allow data to be piped between two or more threads, similar to PipedInputStream and PipedOutputStream. However, RubberPipedInputStream grows its internal buffer rather than blocking when the buffer is full. It also supports mark(int) and reset().

A RubberPipedInputStream is useful when data must be written to a stream in response to one event and read from a stream in response to another event, for instance, when reassembling the contents of Chunks into a byte stream.

Version:

$Revision: 1.2 $

See Also:

RubberPipedOutputStream

Field Summary

protected byte[]	buffer The circular buffer into which incoming data is placed.
protected boolean	closed Is this rubber piped input stream closed?
protected boolean	connected Is this rubber piped input stream connected?
protected int	in The index of the position in the circular buffer at which the next byte of data will be stored when received from the connected piped output stream.
protected static int	INITIAL_SIZE The initial buffer size.
protected int	mark The mark position.
protected int	out The index of the position in the circular buffer at which the next byte of data will be read by this piped input stream.

Constructor Summary

RubberPipedInputStream()
Constructs a new rubber piped input stream.

RubberPipedInputStream(RubberPipedOutputStream out)
Constructs a new rubber piped input stream connected to the specified rubber piped output stream.

Method Summary

int	available() Returns the number of bytes that can be read from this input stream without blocking.
protected void	checkConnected() Check to see if the pipe is connected.
void	close() Closes this rubber piped input stream.
void	connect(RubberPipedOutputStream out) Connects this rubber piped input stream to the specified rubber piped output stream.
protected int	freespace() Computes the amount of free space in the buffer.
protected void	grow() Doubles the size of the internal buffer.
static void	main(String[] args) A simple test program.
void	mark(int readlimit) Marks the current position in this input stream.
boolean	markSupported() Tests if this input stream supports the mark and reset methods.
int	read() Reads one byte of data from this rubber piped input stream.
int	read(byte[] b, int off, int len) Reads up to len bytes of data from this rubber piped input stream into an array of bytes.
protected void	receive1(byte[] b, int off, int len) Receives data from an array of bytes.
protected void	receive1(int b) Receives a single byte.
void	reset() Repositions this stream to the position at the time the mark method was last called on this input stream.

Methods inherited from class java.io.InputStream

read, skip

Methods inherited from class java.lang.Object

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

Field Detail

INITIAL_SIZE

protected static final int INITIAL_SIZE

The initial buffer size.

buffer

protected byte[] buffer

The circular buffer into which incoming data is placed.

in

protected int in

The index of the position in the circular buffer at which the next byte of data will be stored when received from the connected piped output stream. in<0 implies the buffer is empty, in==out implies the buffer is full.

out

protected int out

The index of the position in the circular buffer at which the next byte of data will be read by this piped input stream.

Since:

JDK1.1

mark

protected int mark

The mark position.

connected

protected boolean connected

Is this rubber piped input stream connected?

closed

protected boolean closed

Is this rubber piped input stream closed?

Constructor Detail

RubberPipedInputStream

public RubberPipedInputStream()

Constructs a new rubber piped input stream. It must be connected using connect(RubberPipedOutputStream) or RubberPipedOutputStream.RubberPipedOutputStream(RubberPipedInputStream) before it can be used; otherwise, an IOException will result.

RubberPipedInputStream

public RubberPipedInputStream(RubberPipedOutputStream out)
                       throws IOException

Constructs a new rubber piped input stream connected to the specified rubber piped output stream.

Parameters:

out - The output stream to connect to.

Throws:

IOException - if out is already connected.

Method Detail

connect

public void connect(RubberPipedOutputStream out)
             throws IOException

Connects this rubber piped input stream to the specified rubber piped output stream. This is equivalent to

   out.connect(this)
 

Parameters:

out - The output stream to connect to.

Throws:

IOException - if either endpoint is already connected.

checkConnected

protected void checkConnected()
                       throws IOException

Check to see if the pipe is connected.

Throws:

IOException - if the pipe is closed or is not connected.

grow

protected void grow()

Doubles the size of the internal buffer.

freespace

protected int freespace()

Computes the amount of free space in the buffer.

available

public int available()

Returns the number of bytes that can be read from this input stream without blocking.

Overrides:

available in class InputStream

Returns:

The number of bytes that can be read without blocking.

receive1

protected void receive1(int b)
                 throws IOException

Receives a single byte. If no space is available, the buffer will be thrown.

Parameters:

b - The byte to receive.

Throws:

IOException - if the pipe is closed or is not connected.

receive1

protected void receive1(byte[] b,
                        int off,
                        int len)
                 throws IOException

Receives data from an array of bytes. If no space is available, the buffer will be grown.

Parameters:

b - The buffer from which the data is received.

off - The start offset of the data.

len - The number of bytes to receive.

Throws:

IOException - if the pipe is closed or is not connected.

read

public int read()
         throws IOException

Reads one byte of data from this rubber piped input stream. This method blocks until at least one byte of input is available.

Overrides:

read in class InputStream

Throws:

IOException - if the pipe is closed or is not connected.

read

public int read(byte[] b,
                int off,
                int len)
         throws IOException

Reads up to len bytes of data from this rubber piped input stream into an array of bytes. Less than len bytes will be read if the end of the data stream is reached. This method blocks until at least one byte of input is available.

Overrides:

read in class InputStream

Parameters:

b - the buffer into which the data is read.

off - the start offset of the data.

len - the maximum number of bytes read.

Returns:

the total number of bytes read into the buffer, or -1 if there is no more data because the end of the stream has been reached.

Throws:

IOException - if an I/O error occurs.

mark

public void mark(int readlimit)

Marks the current position in this input stream. A subsequent call to the reset method repositions this stream at the last marked position so that subsequent reads re-read the same bytes.

Overrides:

mark in class InputStream

Parameters:

readlimit - The maximum limit of bytes that can be read before the mark position becomes invalid.

reset

public void reset()
           throws IOException

Repositions this stream to the position at the time the mark method was last called on this input stream.

Overrides:

reset in class InputStream

Throws:

IOException - if no mark has been set.

markSupported

public boolean markSupported()

Tests if this input stream supports the mark and reset methods. The markSupported method of RubberPipedInputStream returns true.

Overrides:

markSupported in class InputStream

close

public void close()

Closes this rubber piped input stream.

Overrides:

close in class InputStream

main

public static void main(String[] args)
                 throws IOException

A simple test program.