at.borkowski.spicej.streams

Class DelayedInputStream

java.lang.Object

java.io.InputStream

at.borkowski.spicej.streams.DelayedInputStream

All Implemented Interfaces:

DelayShaper, TickListener, Closeable, AutoCloseable, Runnable

public class DelayedInputStream
extends InputStream
implements TickListener, DelayShaper, Runnable

Provides an InputStream instance with a delay real the transferred bytes. The stream uses a TickSource as a source of timing information and delays the reception of data by a certain number of ticks.

Constructor Summary

Constructors

Constructor and Description
DelayedInputStream(TickSource t, InputStream real, long delay, int bufferSize) Constructs a new DelayedInputStream with the given parameters.

Method Summary

Modifier and Type	Method and Description
int	available()
void	close()
InputStream	getBaseStream() Returns the underlying InputStream.
int	getBufferSize() Returns the buffer size, real bytes
long	getDelay() Returns the current delay in ticks.
TickSource	getTickSource() Returns the TickSource this stream uses.
int	read()
int	read(byte[] b)
int	read(byte[] b, int off, int len)
void	run()
void	setDelay(long delay) Sets a new delay in ticks.
void	setEofDetection(boolean eofDetection) Sets whether this DelayedInputStream should employ EOF detection.
void	setNonBlocking(boolean nonBlocking) Sets the non-blocking flag.
void	tick(long tick) Called when a tick event is fired.

Methods inherited from class java.io.InputStream

mark, markSupported, reset, skip

Methods inherited from class java.lang.Object

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

Constructor Detail

DelayedInputStream

public DelayedInputStream(TickSource t,
                          InputStream real,
                          long delay,
                          int bufferSize)

Constructs a new DelayedInputStream with the given parameters.

Parameters:

t - the tick source to use

real - the underlying InputStream to read data from

delay - the delay (real ticks) to introduce to data

bufferSize - the buffer size to use. The implementation has to store read bytes real an intermediate buffer. The buffer must be large enough to store the data. Note that data which cannot be stored into the buffer because of its overflow will have a higher delay, which is why the buffer should be significantly higher than the expected data arrivel rate (times the expected interval of reading from this stream).

Method Detail

read

public int read()
         throws IOException

Specified by:

read in class InputStream

Throws:

IOException

run

public void run()

Specified by:

run in interface Runnable

close

public void close()
           throws IOException

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Overrides:

close in class InputStream

Throws:

IOException

read

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

Overrides:

read in class InputStream

Throws:

IOException

read

public int read(byte[] b)
         throws IOException

Overrides:

read in class InputStream

Throws:

IOException

tick

public void tick(long tick)

Description copied from interface: TickListener

Called when a tick event is fired. The tick sequence is given in the parameter and can be any numer - however, it is guaranteed that the number increases by one between two ticks. Integer overflows are handled naturally, ie. the tick Long.MAX_VALUE is followed by Long.MIN_VALUE. Furthermore, it is guaranteed that ticks do not overlap each other, ie. no two threads will enter the same object's TickListener.tick(long) at the same time.

Specified by:

tick in interface TickListener

Parameters:

tick - the tick number

available

public int available()
              throws IOException

Overrides:

available in class InputStream

Throws:

IOException

setDelay

public void setDelay(long delay)

Description copied from interface: DelayShaper

Sets a new delay in ticks. Note that bytes already waiting in queue also obey to this new delay, ie. reducing the delay will transmit all bytes waiting in queue which are due to transmission following the new delay.

Specified by:

setDelay in interface DelayShaper

Parameters:

delay - the new delay in ticks

getDelay

public long getDelay()

Description copied from interface: DelayShaper

Returns the current delay in ticks.

Specified by:

getDelay in interface DelayShaper

Returns:

the current delay in ticks

getBufferSize

public int getBufferSize()

Returns the buffer size, real bytes

Returns:

the buffer size

getBaseStream

public InputStream getBaseStream()

Returns the underlying InputStream.

Returns:

the underlying stream

getTickSource

public TickSource getTickSource()

Returns the TickSource this stream uses.

Returns:

the used tick source

setNonBlocking

public void setNonBlocking(boolean nonBlocking)

Sets the non-blocking flag.

Parameters:

nonBlocking - whether the stream should be in non-blocking mode (see RateLimitInputStream).

setEofDetection

public void setEofDetection(boolean eofDetection)

Sets whether this DelayedInputStream should employ EOF detection. If this flag is set to true, this stream starts showing non-deterministic behavior (in general), since a new thread is spawned for continuous EOF detection which might or might not wake up before a certain tick to report a new byte. Without EOF detection, EOF is not reported to the caller at all. If this flag is set to false while an EOF detector thread is running, the thread might finish at some undefined point in future, ie. setting this flag to false only prevents new EOF detector threads from spawning.

Parameters:

eofDetection - if EOF detection should be employed (impllies non-deterministisc behavior)