net.sf.mmm.util.io.impl
Class DetectorStreamBufferImpl

java.lang.Object
  net.sf.mmm.util.io.impl.DetectorStreamBufferImpl

All Implemented Interfaces:

ByteBuffer, ByteIterator, ByteProvider, ComposedByteBuffer, DetectorStreamBuffer

public class DetectorStreamBufferImpl
extends Object
implements DetectorStreamBuffer

This is the implementation of the DetectorStreamBuffer interface.
It is based on the idea that each DetectorStreamProcessor in the chain has its own DetectorStreamBuffer instance. Therefore it holds the according DetectorStreamProcessor building a pair of buffer+processor. Further it holds an instance of the predecessor and thereby represents the chain itself.

Author:

Joerg Hohwiller (hohwille at users.sourceforge.net)

Nested Class Summary

protected class	DetectorStreamBufferImpl.CurrentByteArray This inner class is a view on the current ByteArray.
protected static class	DetectorStreamBufferImpl.SeekMode Enum with available modes for a seek.

Field Summary

private LinkedList<ByteArray>	arrayQueue The Queue of available DetectorStreamBufferImpl.CurrentByteArrays that have NOT yet been processed.
private ByteArrayPool	byteArrayPool The ByteArrayPool.
private DetectorStreamBufferImpl	chainSuccessor The successor in the chain or null if this is the last.
private byte[]	currentArray The current DetectorStreamBufferImpl.CurrentByteArray to work on.
private int	currentArrayIndex The index in currentArray.
private int	currentArrayMax The maximum index in currentArray.
private int	currentArrayMin The start-index in currentArray.
private ByteArray	currentArrayView
private ByteArray	currentByteArray
private DetectorStreamProcessor	processor The actual processor served by this buffer.
private long	seekCount
private DetectorStreamBufferImpl.SeekMode	seekMode
private long	streamPosition

Constructor Summary

DetectorStreamBufferImpl(DetectorStreamProcessor processor, DetectorStreamBufferImpl successor, ByteArrayPool byteArrayPool)
The constructor.

Method Summary

protected void	append(ByteArray nextArray) This method queues the given DetectorStreamBufferImpl.CurrentByteArray at the end of this buffer.
int	fill(byte[] buffer, int offset, int length) This method fills the given buffer starting at offset with the next bytes from this ComposedByteBuffer.
ByteArray	getByteArray(int index) This method gets the ByteArray at the given index.
int	getByteArrayCount() This method gets the number of ByteArrays currently available via ComposedByteBuffer.getByteArray(int).
int	getBytesAvailable() This method gets the number of bytes available.
long	getStreamPosition() This method gets the absolute position of the current pointer in the logical stream (the data provided by this interface that origins from the previous member of the chain).
boolean	hasNext() This method determines if there is a next byte available.
void	insert(byte... data) This method inserts the given bytes at the current position into the stream.
void	insert(ByteArray data) This method inserts the given data at the current position into the stream.
byte	next() This method gets the current byte in the iteration.
private boolean	nextArray() This method switches over to the next internal byte-array.
byte	peek() This method gets the current byte in the iteration.
void	process(Map<String,Object> metadata, boolean eos)
protected void	release(ByteArray byteArray) This method is called when a DetectorStreamBufferImpl.CurrentByteArray is wiped out of the chain.
void	remove(long byteCount) This method removes the number of bytes given by byteCount from the stream starting at the current position.
protected void	seek(long byteCount, DetectorStreamBufferImpl.SeekMode mode) This method removes or skips the given number of bytes.
long	skip() This method skips all bytes available in this buffer.
long	skip(long byteCount) This method skips the number of bytes given by byteCount in the stream starting at the current position.

Methods inherited from class java.lang.Object

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

Field Detail

processor

private DetectorStreamProcessor processor

The actual processor served by this buffer.

chainSuccessor

private DetectorStreamBufferImpl chainSuccessor

The successor in the chain or null if this is the last.

streamPosition

private long streamPosition

See Also:

getStreamPosition()

seekCount

private long seekCount

See Also:

seek(long, SeekMode)

seekMode

private DetectorStreamBufferImpl.SeekMode seekMode

See Also:

seek(long, SeekMode)

currentByteArray

private ByteArray currentByteArray

See Also:

getByteArray(int)

currentArray

private byte[] currentArray

The current DetectorStreamBufferImpl.CurrentByteArray to work on.

currentArrayMin

private int currentArrayMin

The start-index in currentArray.

currentArrayIndex

private int currentArrayIndex

The index in currentArray.

currentArrayMax

private int currentArrayMax

The maximum index in currentArray.

arrayQueue

private final LinkedList<ByteArray> arrayQueue

The Queue of available DetectorStreamBufferImpl.CurrentByteArrays that have NOT yet been processed.

currentArrayView

private final ByteArray currentArrayView

See Also:

getByteArray(int)

byteArrayPool

private ByteArrayPool byteArrayPool

The ByteArrayPool.

Constructor Detail

DetectorStreamBufferImpl

public DetectorStreamBufferImpl(DetectorStreamProcessor processor,
                                DetectorStreamBufferImpl successor,
                                ByteArrayPool byteArrayPool)

The constructor.

Parameters:

processor - is the DetectorStreamProcessor served by this buffer.

successor - is the successor in the chain or null if this is the last buffer/processor pair in the chain.

byteArrayPool - is the ByteArrayPool to use.

Method Detail

skip

public long skip(long byteCount)

This method skips the number of bytes given by byteCount in the stream starting at the current position. The given number of bytes will be untouched in stream (queued for the next processor in the chain).

Specified by:

skip in interface ByteIterator

Specified by:

skip in interface DetectorStreamBuffer

Parameters:

byteCount - is the number of bytes to ignore. This value can be greater than the currently available bytes. You may supply Long.MAX_VALUE to ignore to the end of the stream.

Returns:

the given byteCount.

See Also:

InputStream.skip(long)

skip

public long skip()

This method skips all bytes available in this buffer. This is logically the same as skip(ByteProvider.getBytesAvailable()) but more efficient.

Specified by:

skip in interface DetectorStreamBuffer

Returns:

the number of bytes that have been skipped.

getByteArray

public ByteArray getByteArray(int index)

This method gets the ByteArray at the given index. The DetectorStreamBuffer is composed out of ByteArrays. This method allows efficient processing of bytes from byte[] rather then calling ByteIterator.hasNext() and ByteIterator.next() and repetitive. Additionally this way allows full lookahead up to the end of the buffer without consuming the data.
ATTENTION:
Consuming operations such as ByteIterator.next() or ByteIterator.skip(long) will invalidate the returned ByteArray. Please do NOT call these methods while working with ByteArrays.

Specified by:

getByteArray in interface ComposedByteBuffer

Parameters:

index - is the index of the requested ByteArray. It has to be in the range from 0 to ComposedByteBuffer.getByteArrayCount() - 1. A value of 0 indicates the current ByteArray this buffer is currently pointing to. For that current buffer ByteArray.getBytes()[ByteArray.getCurrentIndex()] will have the same result as ByteIterator.peek().

Returns:

the requested ByteArray.

See Also:

ComposedByteBuffer.getByteArrayCount()

getByteArrayCount

public int getByteArrayCount()

This method gets the number of ByteArrays currently available via ComposedByteBuffer.getByteArray(int).
ATTENTION:
Consuming operations such as ByteIterator.next() or ByteIterator.skip(long) will invalidate the returned ByteArray. Please do NOT call these methods while working with ByteArrays.

Specified by:

getByteArrayCount in interface ComposedByteBuffer

Returns:

the number of currently available ByteArrays.

getBytesAvailable

public int getBytesAvailable()

This method gets the number of bytes available.

Specified by:

getBytesAvailable in interface ByteProvider

Returns:

the bytes left.

hasNext

public boolean hasNext()

This method determines if there is a next byte available.

Specified by:

hasNext in interface ByteIterator

Returns:

true if there is a next byte available, false otherwise (if the end of this buffer has been reached).

release

protected void release(ByteArray byteArray)

This method is called when a DetectorStreamBufferImpl.CurrentByteArray is wiped out of the chain.

Parameters:

byteArray - is the array to release.

nextArray

private boolean nextArray()

This method switches over to the next internal byte-array.

Returns:

true if a new buffer is available, false if the buffer queue is empty.

next

public byte next()
          throws NoSuchElementException

This method gets the current byte in the iteration. After the call of this method this ByteIterator points to the next byte in the iteration or to the end if there is no such byte available.
ATTENTION:
You should only call this method if ByteIterator.hasNext() returns true.

Specified by:

next in interface ByteIterator

Returns:

the current byte in the iteration.

Throws:

NoSuchElementException - if there is no such byte available.

See Also:

Iterator.next()

peek

public byte peek()
          throws NoSuchElementException

This method gets the current byte in the iteration. Unlike ByteIterator.next() this method does NOT modify the state of this ByteIterator. Therefore the peeked byte does NOT get consumed and repetitive calls will return the same value.
ATTENTION:
You should only call this method if ByteIterator.hasNext() returns true.

Specified by:

peek in interface ByteIterator

Returns:

the current byte in the iteration.

Throws:

NoSuchElementException - if there is no such byte available.

See Also:

ByteIterator.next()

insert

public void insert(byte... data)

This method inserts the given bytes at the current position into the stream.
It is only a convenience-method for DetectorStreamBuffer.insert(ByteArray).

Specified by:

insert in interface DetectorStreamBuffer

Parameters:

data - is a ByteArray with the data to insert.

insert

public void insert(ByteArray data)

This method inserts the given data at the current position into the stream.

Specified by:

insert in interface DetectorStreamBuffer

Parameters:

data - is a ByteArray with the data to insert.

seek

protected void seek(long byteCount,
                    DetectorStreamBufferImpl.SeekMode mode)

This method removes or skips the given number of bytes.

Parameters:

byteCount - is the number of bytes to seek.

mode - is the DetectorStreamBufferImpl.SeekMode.

remove

public void remove(long byteCount)

This method removes the number of bytes given by byteCount from the stream starting at the current position.

Specified by:

remove in interface DetectorStreamBuffer

Parameters:

byteCount - is the number of bytes to remove. This value can be greater than the currently available bytes. You may supply Long.MAX_VALUE to remove the rest of the stream.

See Also:

DetectorStreamBuffer.skip(long)

getStreamPosition

public long getStreamPosition()

This method gets the absolute position of the current pointer in the logical stream (the data provided by this interface that origins from the previous member of the chain). The value represents the number of bytes that have been consumed. It excludes the number of bytes that have been inserted.

Specified by:

getStreamPosition in interface DetectorStreamBuffer

Returns:

the current position in the stream.

append

protected void append(ByteArray nextArray)

This method queues the given DetectorStreamBufferImpl.CurrentByteArray at the end of this buffer.

Parameters:

nextArray - is the DetectorStreamBufferImpl.CurrentByteArray to append.

process

public void process(Map<String,Object> metadata,
                    boolean eos)
             throws IOException

Parameters:

metadata - is the Map with the meta-data.

eos - - true if the end of the stream has been reached and the given buffer has to be

Throws:

IOException - in case of an Input/Output error. Should only be used internally.

See Also:

DetectorStreamProcessor.process(DetectorStreamBuffer, Map, boolean)

fill

public int fill(byte[] buffer,
                int offset,
                int length)

This method fills the given buffer starting at offset with the next bytes from this ComposedByteBuffer. The bytes that are filled into the given buffer will therefore be consumed. This method can be used to write data from this buffer to an OutputStream or supply it to the consumer of an InputStream.

Specified by:

fill in interface ComposedByteBuffer

Parameters:

buffer - is the buffer to fill.

offset - is the index in the given buffer where to fill in the first byte. See ByteArray.getCurrentIndex().

length - is the expected number of bytes to fill into buffer. Has to be positive and less or equal to buffer.length - offset. However at most the number of available bytes can be filled even if length is greater.

Returns:

the number of bytes that have actually been filled into the buffer. Will be positive and less or equal to the given length. Should be only less than maxLength if NOT enough bytes are available.