Buffered channel organizing data into blocks of predefined size. More...

#include <mdsBlockChannel.h>

Inheritance diagram for mds::mod::CBlockChannel:

[legend]

Public Types
enum	{ DEFAULT_BLOCK_SIZE = 4096 }
	Default block size. More...
enum	{ CLASS_OBJECT }
	Templates that require members of the CObject class can use this enum to check the existence. More...
enum	{ HEAP_OBJECT = 0x70616568 }
	Signature used to recognize objects on the heap. More...
typedef mds::base::CLibraryLockableObject < CChannel >::CLock	tLock
	Lock that have to be used to provide mutual access to write(), read() and etc.
Public Member Functions
	CBlockChannel (int iBlockSize=DEFAULT_BLOCK_SIZE, CChannel *pChannel=NULL)
	Default constructor.
bool	checkMedium (int Medium) const
	Checks if channel medium is equal to a given value.
bool	checkType (int Type) const
	Checks if channel type corresponds to a given value.
virtual bool	connect (unsigned uTimeout=CH_CONNECTION_TIMEOUT)
	Connects to the opposite channel side.
virtual void	disconnect ()
	Disconnects from the opossite channel side.
virtual bool	flush ()
	In case of the output channel, the function writes all remaining data (partially filled or empty block) to the channel.
int	getBlockSize () const
	Returns data block size.
CChannel *	getChannel ()
	Returns pointer to the input/output channel.
int	getMedium () const
	Returns the channel medium.
int	getReferencesCount () const
	Returns the number of references.
int	getType () const
	Method returns the channel type.
virtual bool	isConnected ()
	Method for testing channel errors such as:
bool	isOnHeap () const
	Returns true if the object is allocated on the heap.
virtual bool	listen (unsigned uTimeout=CH_CONNECTION_TIMEOUT)
	Listens for the opposite channel side.
void	lock ()
	Locks the object.
	MDS_SHAREDPTR (CBlockChannel)
	Smart pointer type.
	MDS_SHAREDPTR (CChannel)
	Smart pointer type.
virtual int	read (char *pcData, int iLength)
	Reads data from the input channel.
void	setChannel (CChannel *pChannel)
	Sets the input/output channel.
virtual bool	skip (int iLength)
	Skips a given number of bytes.
void	unlock ()
	Locks the object.
virtual bool	wait (unsigned uTimeout=CH_WAIT_TIMEOUT)
	Waits for data.
virtual bool	write (const char *pcData, int iLength)
	Writes compressed data to the output channel.
virtual	~CBlockChannel ()
	Virtual destructor.
Static Public Member Functions
static CChannel *	create (EChannelType eType, const std::string &sDesc)
	Creation of a channel which is described by a textual string.
static void *	operator new (std::size_t Size)
	Allocates a new object on the heap.
static void	separate (const std::string &sDescs, std::vector< std::string > &Descs)
	Parses a given string and separates descriptions of several channels.
Protected Member Functions
void	addReference () const
	Increase the reference counter.
bool	delReference () const
	Decrease the reference counter.
bool	readBlockHeader (int &iSize)
	Reads and checks the data block header.
bool	writeBlockHeader (int iSize)
	Writes data block header to the channel.
Protected Attributes
bool	m_bFinished
	Flag set to true if an empty or partially filled block was found.
mds::base::CData< char >	m_Buffer
	Internal buffer (data block).
int	m_iBlockSize
	Size of the block.
int	m_iHeapObject
	Flag initialized if the object is on the heap.
int	m_iNumOfBytes
	The number of free (or unread) bytes in the block.
int	m_iReferences
	The number of references to the object.
int	m_Medium
	Channel medium.
char *	m_pcData
	Pointer to the data.
CChannelPtr	m_spChannel
	Output/input channel.
int	m_Type
	Channel type.

Detailed Description

Buffered channel organizing data into blocks of predefined size.

Member Typedef Documentation

typedef mds::base::CLibraryLockableObject<CChannel>::CLock mds::mod::CChannel::tLock [inherited]

Lock that have to be used to provide mutual access to write(), read() and etc.

functions.

Member Enumeration Documentation

anonymous enum

Default block size.

Enumerator:

DEFAULT_BLOCK_SIZE

anonymous enum [inherited]

Templates that require members of the CObject class can use this enum to check the existence.

Enumerator:

CLASS_OBJECT

anonymous enum [inherited]

Signature used to recognize objects on the heap.

Enumerator:

HEAP_OBJECT

Constructor & Destructor Documentation

mds::mod::CBlockChannel::CBlockChannel	(	int	iBlockSize = `DEFAULT_BLOCK_SIZE`,
		CChannel *	pChannel = `NULL`
	)

Default constructor.

Predefined block size.
Pointer to an output/input channel.

mds::mod::CBlockChannel::~CBlockChannel ( ) [virtual]

Virtual destructor.

Member Function Documentation

void mds::base::CObject::addReference ( ) const [protected, inherited]

Increase the reference counter.

bool mds::mod::CChannel::checkMedium ( int Medium ) const [inherited]

Checks if channel medium is equal to a given value.

bool mds::mod::CChannel::checkType ( int Type ) const [inherited]

Checks if channel type corresponds to a given value.

virtual bool mds::mod::CBlockChannel::connect ( unsigned uTimeout = CH_CONNECTION_TIMEOUT ) [virtual]

Connects to the opposite channel side.

Returns false on failure and/or timeout elapsed.

Implements mds::mod::CChannel.

CChannel * mds::mod::CChannel::create	(	EChannelType	eType,
		const std::string &	sDesc
	)		`[static, inherited]`

Creation of a channel which is described by a textual string.

String has the form: "chmedium[:chattrib1[:chattrib2[:...]]]".
Actually, the channel medium can be "stdio", "file", "pipe" and "shm".
Channel attributes depend on the medium.
"stdio" has empty attributes, "file" (:filename), "pipe" (:pipename) and "shm" (:shmname).
Throws CCannotCreate exception on failure!

bool mds::base::CObject::delReference ( ) const [protected, inherited]

Decrease the reference counter.

Returns true if the decremented number of references is lower or equal to zero and object must be deleted.

virtual void mds::mod::CBlockChannel::disconnect ( ) [virtual]

Disconnects from the opossite channel side.

Returns false on failure.

Implements mds::mod::CChannel.

bool mds::mod::CBlockChannel::flush ( ) [virtual]

In case of the output channel, the function writes all remaining data (partially filled or empty block) to the channel.

Otherwise, it skips the remaining data in the channel until en empty data block or partially filled block is found.

Implements mds::mod::CChannel.

int mds::mod::CBlockChannel::getBlockSize ( ) const

Returns data block size.

CChannel* mds::mod::CBlockChannel::getChannel ( )

Returns pointer to the input/output channel.

int mds::mod::CChannel::getMedium ( ) const [inherited]

Returns the channel medium.

int mds::base::CObject::getReferencesCount ( ) const [inherited]

Returns the number of references.

int mds::mod::CChannel::getType ( ) const [inherited]

Method returns the channel type.

bool mds::mod::CBlockChannel::isConnected ( ) [virtual]

Method for testing channel errors such as:

Disconnected or broken channel.
Reading after end of input.

Implements mds::mod::CChannel.

bool mds::base::CObject::isOnHeap ( ) const [inherited]

Returns true if the object is allocated on the heap.

virtual bool mds::mod::CBlockChannel::listen ( unsigned uTimeout = CH_CONNECTION_TIMEOUT ) [virtual]

Listens for the opposite channel side.

Returns false on failure and/or timeout elapsed.

Implements mds::mod::CChannel.

void mds::base::CLockableObject< CChannel >::lock ( ) [inherited]

Locks the object.

mds::mod::CBlockChannel::MDS_SHAREDPTR ( CBlockChannel )

Smart pointer type.

mds::mod::CChannel::MDS_SHAREDPTR ( CChannel ) [inherited]

Smart pointer type.

static void* mds::base::CObject::operator new ( std::size_t Size ) [static, inherited]

Allocates a new object on the heap.

int mds::mod::CBlockChannel::read	(	char *	pcData,
		int	iLength
	)		`[virtual]`

Reads data from the input channel.

In case of error or reading after end of input the number of successfully readed bytes is returned.

Implements mds::mod::CChannel.

bool mds::mod::CBlockChannel::readBlockHeader ( int & iSize ) [protected]

Reads and checks the data block header.

Returns false on failure.

void mds::mod::CChannel::separate	(	const std::string &	sDescs,
		std::vector< std::string > &	Descs
	)		`[static, inherited]`

Parses a given string and separates descriptions of several channels.

Channels are separated by two successive colons "::" in the string.
Example: "chmedium1[:chattribs1][::chmedium2[:chattribs2][::...]]".

void mds::mod::CBlockChannel::setChannel ( CChannel * pChannel )

Sets the input/output channel.

bool mds::mod::CChannel::skip ( int iLength ) [virtual, inherited]

Skips a given number of bytes.

If the channel is open for readinpg, the data are discarded. Otherwise, zeros are written to the output channel.
This method cannot be used if the channel is opened for reading and writting simultaneously!

Reimplemented in mds::mod::CSharedMemChannel, and mds::mod::CMemoryChannel.

void mds::base::CLockableObject< CChannel >::unlock ( ) [inherited]

Locks the object.

virtual bool mds::mod::CBlockChannel::wait ( unsigned uTimeout = CH_WAIT_TIMEOUT ) [virtual]