simtools.util
Class StreamMemoryBuffer.StreamReader

java.lang.Object
  simtools.util.StreamMemoryBuffer.StreamReader

Enclosing class:

StreamMemoryBuffer

public class StreamMemoryBuffer.StreamReader
extends java.lang.Object

A buffer reader

Field Summary

protected long	mark The mark used to perform the writing of the buffer into a channel or into packet buffers
protected java.nio.ByteBuffer	readBuffer The read buffer : an independent view on the write buffer

Constructor Summary

protected

StreamMemoryBuffer.StreamReader() Create a reader

Method Summary

long	bufferize(PacketBufferFactory factory, long timeout) Bufferize the buffer content from the mark to packet buffer
int	getLength(int readIndex) Get the packet length
long	getMinIndex() Get the oldest packet index
long	getNextReadIndex(long timeout, long lastReadIndex) Wait for the next writing on the buffer and return the index of this packet.
long	getReadIndex() Get the last packet index
int	read(long readIndex, int readOffset, int readLength, byte[] b, int offset) Read a packet
void	resetMark() Set the mark location equal to the last received packet
void	resetMark(int margin) Set the mark location wrt the oldest packet to read The mark is initialized with last available index at reader creation time.
long	save(java.nio.channels.ByteChannel channel, long timeout) Save the buffer content from the mark to the last written packet
protected void	validationErrorControl(PacketBufferValidationError e) Default managment of a packet validation error is to send the exception at upper level

Methods inherited from class java.lang.Object

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

Field Detail

readBuffer

protected final java.nio.ByteBuffer readBuffer

The read buffer : an independent view on the write buffer

mark

protected long mark

The mark used to perform the writing of the buffer into a channel or into packet buffers

Constructor Detail

StreamMemoryBuffer.StreamReader

protected StreamMemoryBuffer.StreamReader()

Create a reader

Method Detail

getNextReadIndex

public long getNextReadIndex(long timeout,
                             long lastReadIndex)

Wait for the next writing on the buffer and return the index of this packet. The index is equal to previous index if timeout ellapses. The retuned index is negative if nothing to read or in case of thread interruption.

Parameters:

timeout - the wait timeout

Returns:

the index of the last packet to read

resetMark

public void resetMark()

Set the mark location equal to the last received packet

resetMark

public void resetMark(int margin)

Set the mark location wrt the oldest packet to read The mark is initialized with last available index at reader creation time. To start saving while a unknown number of packets is already written the mark can be set with a margin relative to the oldest packet to read index. For instance margin can be equal to bufferSize/2

Parameters:

margin - the mark location relative to the oldest available packet

bufferize

public long bufferize(PacketBufferFactory factory,
                      long timeout)
               throws java.io.IOException,
                      PacketBufferValidationError

Bufferize the buffer content from the mark to packet buffer

Parameters:

a - packet factory to address the right buffers according to the key read from the packet

timeout - the timeout to wait

Returns:

the number of written bytes

Throws:

java.io.IOException

PacketBufferValidationError

validationErrorControl

protected void validationErrorControl(PacketBufferValidationError e)
                               throws PacketBufferValidationError

Default managment of a packet validation error is to send the exception at upper level

Parameters:

e - the validation error

Throws:

PacketBufferValidationError

save

public long save(java.nio.channels.ByteChannel channel,
                 long timeout)
          throws java.io.IOException

Save the buffer content from the mark to the last written packet

Parameters:

channel - the channel to write into

timeout - the timeout to wait

Returns:

the number of written bytes

Throws:

java.io.IOException

read

public int read(long readIndex,
                int readOffset,
                int readLength,
                byte[] b,
                int offset)

Read a packet

Parameters:

readIndex - the index of the packet to read

readOffset - the offset inside this packet

readLength - the number of bytes to read or -1 if it is up to the packet end

b - the array to which bytes are to be written

offset - the offset within the array of the first byte to be written

Returns:

the number of bytes read

getLength

public int getLength(int readIndex)

Get the packet length

Parameters:

readIndex - the index of the packet

Returns:

the number of bytes in this packet

getReadIndex

public long getReadIndex()

Get the last packet index

Returns:

the index

getMinIndex

public long getMinIndex()

Get the oldest packet index

Returns:

the index