StreamBuffer Class Reference

The stream buffer is a small object collecting object data. More...

#include <GaudiKernel/StreamBuffer.h>

Collaboration diagram for StreamBuffer:

Classes
class	ContainedLink
	Definition of the contained link set. More...
class	DataIO
	A small base class to handle generic data streaming. More...
class	IdentifiedLink
	Definition of the contained link set. More...
class	Istream
	Reader for standard input streams. More...
class	Ostream
	Writer for standard output streams. More...

Public Types
enum	Mode { UNINITIALIZED, READING, WRITING }
	Streamer mode. More...
enum	SwapAction { SINGLE_BYTE, SWAP, NOSWAP }
	Data Sawp actions. More...
enum	State { INVALID =-1, VALID }
	Link state defintions. More...
typedef std::vector < ContainedLink >	ContainedLinks
typedef std::vector < IdentifiedLink >	IdentifiedLinks
	Definition of the identifiable link set.
typedef void(*	AnalyzeFunction )(const void *data, int siz, const std::type_info &type)
	Definition of the buffer analyzer.

Public Member Functions
	StreamBuffer (bool do_swap=true)
	Standard constructor.
virtual	~StreamBuffer ()
	Standard destructor.
const char *	data () const
	Read access to data buffer.
char *	data ()
	write access to data buffer
void	erase ()
	Reset the buffer.
void	reserve (long len)
	Reserve buffer space; Default: 16 k buffer size.
void	extend (long len)
	Extend the buffer.
long	size () const
	Total buffer size.
ContainedLinks &	containedLinks ()
	Access to contained links.
const ContainedLinks &	containedLinks () const
	CONST Access to contained links.
IdentifiedLinks &	identifiedLinks ()
	Access to identified links.
const IdentifiedLinks &	identifiedLinks () const
	CONST Access to identified links.
void	setMode (Mode m)
	Set mode of the stream and allocate buffer.
bool	isReading () const
	Get stream buffer state.
bool	isWriting () const
	Get stream buffer state.
long	buffPointer () const
	Retrieve current buffer pointer.
void	setBuffPointer (long ptr)
	Retrieve current buffer pointer.
void	setAnalyzer (AnalyzeFunction fun=0)
	Enable user analysis function.
void	swapToBuffer (const void *source, int siz)
	Swap buffers: int, long, short, float and double.
void	swapFromBuffer (void *target, int siz)
	Swap buffers: int, long, short, float and double.
StreamBuffer &	writeBytes (const char *str, long len)
	Write string to output stream.
void	getIdentifiedLink (DataObject *&pObject, long &hint)
void	addIdentifiedLink (const DataObject *pObject, long hint)
void	getContainedLink (ContainedObject *&pObject, long &hint, long &link)
void	addContainedLink (const ContainedObject *pObject, long hint, long link)
StreamBuffer &	operator<< (longlong data)
	Output Streamer.
StreamBuffer &	operator>> (longlong &data)
	Input Streamer.
StreamBuffer &	operator<< (int data)
	Output Streamer.
StreamBuffer &	operator>> (int &data)
	Input Streamer.
StreamBuffer &	operator<< (unsigned int data)
	Output Streamer.
StreamBuffer &	operator>> (unsigned int &data)
	Input Streamer.
StreamBuffer &	operator<< (long data)
	Output Streamer.
StreamBuffer &	operator>> (long &data)
	Input Streamer.
StreamBuffer &	operator<< (unsigned long data)
	Output Streamer.
StreamBuffer &	operator>> (unsigned long &data)
	Input Streamer.
StreamBuffer &	operator<< (short data)
	Output Streamer.
StreamBuffer &	operator>> (short &data)
	Input Streamer.
StreamBuffer &	operator<< (unsigned short data)
	Output Streamer.
StreamBuffer &	operator>> (unsigned short &data)
	Input Streamer.
StreamBuffer &	operator<< (char data)
	Output Streamer.
StreamBuffer &	operator>> (char &data)
	Input Streamer.
StreamBuffer &	operator<< (unsigned char data)
	Output Streamer.
StreamBuffer &	operator>> (unsigned char &data)
	Input Streamer.
StreamBuffer &	operator<< (float data)
	Output Streamer.
StreamBuffer &	operator>> (float &data)
	Input Streamer.
StreamBuffer &	operator<< (double data)
	Output Streamer.
StreamBuffer &	operator>> (double &data)
	Input Streamer.
StreamBuffer &	operator>> (char *data)
	Streamer to read strings in (char*) format.
StreamBuffer &	operator<< (const char *data)
	Streamer to write strings in (char*) format.
StreamBuffer &	operator>> (std::string &data)
	Streamer to read strings in (std::string) format.
StreamBuffer &	operator<< (const std::string &data)
	Streamer to write strings in (std::string) format.
template<class TYPE >
StreamBuffer &	operator>> (TYPE *&refpObject)
	Streamer to read links to contained or identified objects.
StreamBuffer &	operator<< (const ContainedObject *pObject)
	Streamer to write links to contained objects.
StreamBuffer &	operator<< (const DataObject *pObject)
	Streamer to write links to identified objects.
void	serialize (DataIO &ioObject)
	Serialize the buffer using an IO object.

Protected Member Functions
SwapAction	swapBuffer (int siz) const
	Check for byte swapping.
template<class TYPE >
StreamBuffer &	getObjectPointer (const DataObject *, TYPE *&refpObject)
	Helper to distinguish between identified pointers and contained pointers.
template<class TYPE >
StreamBuffer &	getObjectPointer (const ContainedObject *, TYPE *&refpObject)
	Helper to distinguish between identified pointers and contained pointers.

Protected Attributes
Mode	m_mode
	Boolean indicating wether the stream is in read or write mode.
long	m_pointer
	Current buffer pointer.
long	m_length
	Total buffer length.
char *	m_buffer
	Pointer to heap buffer.
bool	m_swapEnabled
	Flag indicating swapping.
ContainedLinks	m_containedLinks
	Container with links to contained objects.
IdentifiedLinks	m_identifiedLinks
	Container with links to contained objects.
AnalyzeFunction	m_analyzer
	Hook function for analysis of data to the stream.

Friends
class	DataObject
	DataObject is friend.

Detailed Description

The stream buffer is a small object collecting object data.

The basic idea behind the StreamBuffer is generic object conversion. The StreamBuffer acts as a byte stream (hence inheriting from a std::string) and stores any information streamed to the buffer. Since the information must be represented in a generic way on the fly byte swapping is performed. However, not only primitive data can be stored in the buffer, but also pointers to DataObjects (symbolic links) and pointers to contained objects. Automatically during serialization the persistent references to the corresponding objects and containers must be stored. These objects are accessible from the StreamBuffer object.

"On the fly" data conversion to non persistent

Author

M.Frank

Definition at line 40 of file StreamBuffer.h.

Member Typedef Documentation

typedef void(* StreamBuffer::AnalyzeFunction)(const void *data, int siz, const std::type_info &type)

Definition of the buffer analyzer.

Definition at line 153 of file StreamBuffer.h.

typedef std::vector<ContainedLink> StreamBuffer::ContainedLinks

Definition at line 149 of file StreamBuffer.h.

typedef std::vector<IdentifiedLink> StreamBuffer::IdentifiedLinks

Definition of the identifiable link set.

Definition at line 151 of file StreamBuffer.h.

Member Enumeration Documentation

enum StreamBuffer::Mode

Streamer mode.

Enumerator:

UNINITIALIZED
READING
WRITING

Definition at line 114 of file StreamBuffer.h.

{UNINITIALIZED, READING, WRITING};

enum StreamBuffer::State

Link state defintions.

Enumerator:

INVALID
VALID

Definition at line 118 of file StreamBuffer.h.

{INVALID=-1, VALID };

enum StreamBuffer::SwapAction

Data Sawp actions.

Enumerator:

SINGLE_BYTE
SWAP
NOSWAP

Definition at line 116 of file StreamBuffer.h.

{SINGLE_BYTE, SWAP, NOSWAP};

Constructor & Destructor Documentation

StreamBuffer::StreamBuffer ( bool  do_swap = true )

inline

Standard constructor.

Definition at line 207 of file StreamBuffer.h.

                                  :
    m_mode(UNINITIALIZED),
    m_pointer(0),
    m_length(0),
    m_buffer(0),
    m_swapEnabled(do_swap)
  {
    m_analyzer = 0;