cnrg.itx.datax
Class ChannelBuffer

java.lang.Object
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  +--cnrg.itx.datax.Channel
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        +--cnrg.itx.datax.ChannelBuffer

class ChannelBuffer

extends Channel

Looks like a channel, actually just a buffer. These are returned on a call to MixerChannel.getNewInput(). They contain all of the channel functionality that a source expects, and buffer data to be read out by the mixer.

Inner Class Summary

private class

ChannelBuffer.BigPipedInputStream

Field Summary

private int	behind The number of bytes our reader dropped from us that we need to eliminate
private int	BUFFER_SIZE The size of the internal buffer.
private long	firstPushTime The time when the first push was executed
private int	iMyInstance Instance number of the current channelbuffer; used for stat output numbering.
(package private) static int	instances Number of instances of the channelbuffer; used for statistics output numbering.
private boolean	isDelinquent True if the last attempt to read from this channel met an empty buffer
private int	MAX_CATCHUP How many consecutive bytes are we willing to cull from a sample to try to catch up
private java.io.PipedInputStream	pis The input stream used to buffer the data.
private java.io.PipedOutputStream	pos The output stream used for buffering data.
private java.io.PrintWriter	pw
private int	SAMPLE_RATE Samples/second
private boolean	started Has our source started sending yet?
private int	totalRead The total number of bytes read out of the buffer

Fields inherited from class cnrg.itx.datax.Channel

closed, destinations, INPUT, mode, OTHER, OUTPUT, pipedInput, pipedOutput, readerThread, running, SAMPLE_SIZE, sampleSize, source

Constructor Summary

ChannelBuffer()
Creates a new ChannelBuffer.

Method Summary

int	available() Returns the number of bytes left in the buffer.
void	close() Closes the BufferChannel.
void	fellBehind(int by) lets the reading channel inform the bufferChannel that it dropped bytes when our buffer was empty.
boolean	getDelinquent() Gets the contents of isDelinquent.
long	getEarlyTime() Returns the number of ms early we are.
Stats	getStatistics() Returns the statistics for this ChannelBuffer, and its destination.
boolean	hasStarted() Returns true if the source has sent data to this channel.
void	open() Starts the channel's source
void	push(byte[] b) Method for the source to feed data to the BufferChannel.
int	read() Method for the mixer to read data out of the buffer.
int	read(byte[] b) Method for the mixer to read data out of the buffer.
int	read(byte[] b, int p1, int p2) Method for the mixer to read data out of the buffer.
void	setDelinquent(boolean delinq) Sets the contents of isDelinquent.

Methods inherited from class cnrg.itx.datax.Channel

addDestination, getMode, getProperties, getSource, mute, removeAllDestinations, removeDestination, run, setMode, setPeerProperties, setProperties, setSource

Methods inherited from class java.lang.Object

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

Field Detail

started

private boolean started

Has our source started sending yet?

firstPushTime

private long firstPushTime

The time when the first push was executed

totalRead

private int totalRead

The total number of bytes read out of the buffer

behind

private int behind

The number of bytes our reader dropped from us that we need to eliminate

pis

private java.io.PipedInputStream pis

The input stream used to buffer the data.

pos

private java.io.PipedOutputStream pos

The output stream used for buffering data.

BUFFER_SIZE

private int BUFFER_SIZE

The size of the internal buffer. Currently, BigPipedInputStream has a buffer of 6400 bytes. We can use up to this amount.

SAMPLE_RATE

private int SAMPLE_RATE

Samples/second

MAX_CATCHUP

private int MAX_CATCHUP

How many consecutive bytes are we willing to cull from a sample to try to catch up

isDelinquent

private boolean isDelinquent

True if the last attempt to read from this channel met an empty buffer

instances

static int instances

Number of instances of the channelbuffer; used for statistics output numbering.

iMyInstance

private int iMyInstance

Instance number of the current channelbuffer; used for stat output numbering.

pw

private java.io.PrintWriter pw

Constructor Detail

ChannelBuffer

public ChannelBuffer()

Creates a new ChannelBuffer. Allocates the internal buffer.

Method Detail

open

public void open()

Starts the channel's source

Overrides:

open in class Channel

push

public void push(byte[] b)

Method for the source to feed data to the BufferChannel. When the buffer runs out of space for a new push() we throw away just enough old data to make room for the new.

Parameters:

b - the byte array to be buffered

Overrides:

push in class Channel

read

public int read()
         throws java.io.IOException

Method for the mixer to read data out of the buffer. Reads out only one byte

read

public int read(byte[] b)
         throws java.io.IOException

Method for the mixer to read data out of the buffer. Trys to fill the given byte array with data from the buffer.

Parameters:

b - the buffer to grab data into

read

public int read(byte[] b,
                int p1,
                int p2)
         throws java.io.IOException

Method for the mixer to read data out of the buffer.

Parameters:

b - The array where the data will go

p1 - the starting index in b

p2 - the number of bytes to read

See Also:

java.io.PipedInputStream.read

available

public int available()
              throws java.io.IOException

Returns the number of bytes left in the buffer.

Throws:

java.io.IOException - thrown when the PipedOutputStream that forms the buffer is broken.

close

public void close()

Closes the BufferChannel. Closes the channel's source and buffer.

Overrides:

close in class Channel

getDelinquent

public boolean getDelinquent()

Gets the contents of isDelinquent.

Returns:

boolean the current state of isDelinquent.

setDelinquent

public void setDelinquent(boolean delinq)

Sets the contents of isDelinquent. This is called with true whenever we need to read, but the buffer does not have enough data.

Parameters:

delinq - the value setDelinquent will set isDelinquent to.

hasStarted

public boolean hasStarted()

Returns true if the source has sent data to this channel.

getEarlyTime

public long getEarlyTime()

Returns the number of ms early we are. If this is negative, we are late. This method assumes that we are late if our samples read by read() method/time elapsed is < SAMPLE_RATE.

fellBehind

public void fellBehind(int by)

lets the reading channel inform the bufferChannel that it dropped bytes when our buffer was empty.

getStatistics

public Stats getStatistics()

Returns the statistics for this ChannelBuffer, and its destination.

Returns:

Stats the stats for this ChannelBuffer -- currently, the number of bytes in the buffer.

Overrides:

getStatistics in class Channel