Arc::DataBuffer Class Reference

Represents set of buffers. More...

#include <arc/data/DataBuffer.h>

Public Member Functions
	operator bool () const
	Returns true if DataBuffer object is initialized. More...
	DataBuffer (unsigned int size=1048576, int blocks=3)
	Construct a new DataBuffer object. More...
	DataBuffer (CheckSum *cksum, unsigned int size=1048576, int blocks=3)
	Construct a new DataBuffer object with checksum computation. More...
	~DataBuffer ()
	Destructor. More...
bool	set (CheckSum *cksum=NULL, unsigned int size=1048576, int blocks=3)
	Reinitialize buffers with different parameters. More...
int	add (CheckSum *cksum)
	Add a checksum object which will compute checksum of buffer. More...
char *	operator[] (int n)
	Direct access to buffer by number. More...
bool	for_read (int &handle, unsigned int &length, bool wait)
	Request buffer for READING INTO it. More...
bool	for_read ()
	Check if there are buffers which can be taken by for_read(). More...
bool	is_read (int handle, unsigned int length, unsigned long long int offset)
	Informs object that data was read into buffer. More...
bool	is_read (char *buf, unsigned int length, unsigned long long int offset)
	Informs object that data was read into buffer. More...
bool	for_write (int &handle, unsigned int &length, unsigned long long int &offset, bool wait)
	Request buffer for WRITING FROM it. More...
bool	for_write ()
	Check if there are buffers which can be taken by for_write(). More...
bool	is_written (int handle)
	Informs object that data was written from buffer. More...
bool	is_written (char *buf)
	Informs object that data was written from buffer. More...
bool	is_notwritten (int handle)
	Informs object that data was NOT written from buffer (and releases buffer). More...
bool	is_notwritten (char *buf)
	Informs object that data was NOT written from buffer (and releases buffer). More...
void	eof_read (bool v)
	Informs object if there will be no more request for 'read' buffers. More...
void	eof_write (bool v)
	Informs object if there will be no more request for 'write' buffers. More...
void	error_read (bool v)
	Informs object if error occurred on 'read' side. More...
void	error_write (bool v)
	Informs object if error occurred on 'write' side. More...
bool	eof_read ()
	Returns true if object was informed about end of transfer on 'read' side. More...
bool	eof_write ()
	Returns true if object was informed about end of transfer on 'write' side. More...
bool	error_read ()
	Returns true if object was informed about error on 'read' side. More...
bool	error_write ()
	Returns true if object was informed about error on 'write' side. More...
bool	error_transfer ()
	Returns true if transfer was slower than limits set in speed object. More...
bool	error ()
	Returns true if object was informed about error or internal error occurred. More...
bool	wait_any ()
	Wait (max 60 sec.) till any action happens in object. More...
bool	wait_used ()
	Wait till there are no more used buffers left in object. More...
bool	wait_for_read ()
	Wait till no more buffers taken for "READING INTO" left in object. More...
bool	wait_for_write ()
	Wait till no more buffers taken for "WRITING FROM" left in object. More...
bool	checksum_valid (int index) const
	Returns true if the specified checksum was successfully computed. More...
bool	checksum_valid () const
	Returns true if the checksum was successfully computed. More...
const CheckSum *	checksum_object (int index) const
	Returns CheckSum object at specified index or NULL if index is not in list. More...
const CheckSum *	checksum_object () const
	Returns first checksum object in checksum list or NULL if list is empty. More...
bool	wait_eof_read ()
	Wait until end of transfer happens on 'read' side. Always returns true. More...
bool	wait_read ()
	Wait until end of transfer or error happens on 'read' side. Always returns true. More...
bool	wait_eof_write ()
	Wait until end of transfer happens on 'write' side. Always returns true. More...
bool	wait_write ()
	Wait until end of transfer or error happens on 'write' side. Always returns true. More...
bool	wait_eof ()
	Wait until end of transfer happens on any side. Always returns true. More...
unsigned long long int	eof_position () const
	Returns offset following last piece of data transferred. More...
unsigned int	buffer_size () const
	Returns size of buffer in object. More...

Data Fields
DataSpeed	speed
	This object controls transfer speed. More...

Detailed Description

Represents set of buffers.

This class is used during data transfer using DataPoint classes.

Constructor & Destructor Documentation

DataBuffer() [1/2]

Arc::DataBuffer::DataBuffer	(	unsigned int	size = 1048576,
		int	blocks = 3
	)

Construct a new DataBuffer object.

Parameters

size	size of every buffer in bytes.
blocks	number of buffers.

DataBuffer() [2/2]

Arc::DataBuffer::DataBuffer	(	CheckSum *	cksum,
		unsigned int	size = 1048576,
		int	blocks = 3
	)

Construct a new DataBuffer object with checksum computation.

Parameters

size	size of every buffer in bytes.
blocks	number of buffers.
cksum	object which will compute checksum. Should not be destroyed until DataBuffer itself.

~DataBuffer()

Arc::DataBuffer::~DataBuffer

(

)

Destructor.

Member Function Documentation

add()

int Arc::DataBuffer::add

(

CheckSum *

cksum

)

Add a checksum object which will compute checksum of buffer.

Parameters

cksum

object which will compute checksum. Should not be destroyed until DataBuffer itself.

Returns

integer position in the list of checksum objects.

buffer_size()

unsigned int Arc::DataBuffer::buffer_size

(

)

const

Returns size of buffer in object.

If not initialized then this number represents size of default buffer.

checksum_object() [1/2]

const CheckSum* Arc::DataBuffer::checksum_object

(

int

index

)

const

Returns CheckSum object at specified index or NULL if index is not in list.

Parameters

index

of the checksum in question.

checksum_object() [2/2]

const CheckSum* Arc::DataBuffer::checksum_object

(

)

const

Returns first checksum object in checksum list or NULL if list is empty.

checksum_valid() [1/2]

bool Arc::DataBuffer::checksum_valid

(

int

index

)

const

Returns true if the specified checksum was successfully computed.

Parameters

index

of the checksum in question.

Returns

false if index is not in list

checksum_valid() [2/2]

bool Arc::DataBuffer::checksum_valid

(

)

const

Returns true if the checksum was successfully computed.

eof_position()

unsigned long long int Arc::DataBuffer::eof_position ( ) const

inline

Returns offset following last piece of data transferred.

eof_read() [1/2]

void Arc::DataBuffer::eof_read

(

bool

v

)

Informs object if there will be no more request for 'read' buffers.

Parameters

v	true if no more requests.

eof_read() [2/2]

bool Arc::DataBuffer::eof_read

(

)

Returns true if object was informed about end of transfer on 'read' side.

eof_write() [1/2]

void Arc::DataBuffer::eof_write

(

bool

v

)

Informs object if there will be no more request for 'write' buffers.

Parameters

v	true if no more requests.

eof_write() [2/2]

bool Arc::DataBuffer::eof_write

(

)

Returns true if object was informed about end of transfer on 'write' side.

error()

bool Arc::DataBuffer::error

(

)

Returns true if object was informed about error or internal error occurred.

error_read() [1/2]

void Arc::DataBuffer::error_read

(

bool

v

)

Informs object if error occurred on 'read' side.

Parameters

v	true if error

error_read() [2/2]

bool Arc::DataBuffer::error_read

(

)

Returns true if object was informed about error on 'read' side.

error_transfer()

bool Arc::DataBuffer::error_transfer

(

)

Returns true if transfer was slower than limits set in speed object.

error_write() [1/2]

void Arc::DataBuffer::error_write

(

bool

v

)

Informs object if error occurred on 'write' side.

Parameters

v	true if error

error_write() [2/2]

bool Arc::DataBuffer::error_write

(

)

Returns true if object was informed about error on 'write' side.

for_read() [1/2]

bool Arc::DataBuffer::for_read	(	int &	handle,
		unsigned int &	length,
		bool	wait
	)

Request buffer for READING INTO it.

Should be called when data is being read from a source. The calling code should write data into the returned buffer and then call is_read().

Parameters

handle	filled with buffer's number.
length	filled with size of buffer
wait	if true and there are no free buffers, method will wait for one.

Returns

true on success For python bindings pattern of this method is (bool, handle, length) for_read(wait). Here buffer for reading to be provided by external code and provided to DataBuffer object through is_read() method. Content of buffer must not exceed provided length.

Python interface deviation

Method is unavailable in Python interface

for_read() [2/2]

bool Arc::DataBuffer::for_read

(

)

Check if there are buffers which can be taken by for_read().

This function checks only for buffers and does not take eof and error conditions into account.

Returns

true if buffers are available

for_write() [1/2]

bool Arc::DataBuffer::for_write	(	int &	handle,
		unsigned int &	length,
		unsigned long long int &	offset,
		bool	wait
	)

Request buffer for WRITING FROM it.

Should be called when data is being written to a destination. The calling code should write the data contained in the returned buffer and then call is_written().

Parameters

handle	returns buffer's number.
length	returns size of buffer
offset	returns buffer offset
wait	if true and there are no available buffers, method will wait for one.

Returns

true on success For python bindings pattern of this method is (bool, handle, length, offset, buffer) for_write(wait). Here buffer is string with content of buffer provided by DataBuffer object.

Python interface deviation

Method is unavailable in Python interface

for_write() [2/2]

bool Arc::DataBuffer::for_write

(

)

Check if there are buffers which can be taken by for_write().

This function checks only for buffers and does not take eof and error conditions into account.

Returns

true if buffers are available

is_notwritten() [1/2]

bool Arc::DataBuffer::is_notwritten

(

int

handle

)

Informs object that data was NOT written from buffer (and releases buffer).

Parameters

handle

buffer's number.

Returns

true if buffer was successfully informed

is_notwritten() [2/2]

bool Arc::DataBuffer::is_notwritten

(

char *

buf

)

Informs object that data was NOT written from buffer (and releases buffer).

Parameters

buf	- address of buffer

Returns

true if buffer was successfully informed

Python interface deviation

Method is unavailable in Python interface

is_read() [1/2]

bool Arc::DataBuffer::is_read	(	int	handle,
		unsigned int	length,
		unsigned long long int	offset
	)

Informs object that data was read into buffer.

Parameters

handle	buffer's number.
length	amount of data.
offset	offset in stream, file, etc.

Returns

true if buffer was successfully informed For python bindings pattern of that method is bool is_read(handle,buffer,offset). Here buffer is string containing content of buffer to be passed to DataBuffer object.

Python interface deviation

Method is unavailable in Python interface

is_read() [2/2]

bool Arc::DataBuffer::is_read	(	char *	buf,
		unsigned int	length,
		unsigned long long int	offset
	)

Informs object that data was read into buffer.

Parameters

buf	address of buffer
length	amount of data.
offset	offset in stream, file, etc.

Returns

true if buffer was successfully informed

Python interface deviation

Method is unavailable in Python interface

is_written() [1/2]

bool Arc::DataBuffer::is_written

(

int

handle

)

Informs object that data was written from buffer.

Parameters

handle

buffer's number.

Returns

true if buffer was successfully informed

is_written() [2/2]

bool Arc::DataBuffer::is_written

(

char *

buf

)

Informs object that data was written from buffer.

Parameters

buf	- address of buffer

Returns

true if buffer was successfully informed

Python interface deviation

Method is unavailable in Python interface

operator bool()

Arc::DataBuffer::operator bool ( ) const

inline

Returns true if DataBuffer object is initialized.

operator[]()

char* Arc::DataBuffer::operator[]

(

int

n

)

Direct access to buffer by number.

Parameters

n	buffer number

Returns

buffer content

Python interface deviation

Method is unavailable in Python interface

set()

bool Arc::DataBuffer::set	(	CheckSum *	cksum = NULL,
		unsigned int	size = 1048576,
		int	blocks = 3
	)

Reinitialize buffers with different parameters.

Parameters

size	size of every buffer in bytes.
blocks	number of buffers.
cksum	object which will compute checksum. Should not be destroyed until DataBuffer itself.

Returns

true if buffers were successfully initialized

wait_any()

bool Arc::DataBuffer::wait_any

(

)

Wait (max 60 sec.) till any action happens in object.

Returns

true if action is eof on any side

wait_eof()

bool Arc::DataBuffer::wait_eof

(

)

Wait until end of transfer happens on any side. Always returns true.

wait_eof_read()

bool Arc::DataBuffer::wait_eof_read

(

)

Wait until end of transfer happens on 'read' side. Always returns true.

wait_eof_write()

bool Arc::DataBuffer::wait_eof_write

(

)

Wait until end of transfer happens on 'write' side. Always returns true.

wait_for_read()

bool Arc::DataBuffer::wait_for_read

(

)

Wait till no more buffers taken for "READING INTO" left in object.

Returns

true if an error occurred while waiting

wait_for_write()

bool Arc::DataBuffer::wait_for_write

(

)

Wait till no more buffers taken for "WRITING FROM" left in object.

Returns

true if an error occurred while waiting

wait_read()

bool Arc::DataBuffer::wait_read

(

)

Wait until end of transfer or error happens on 'read' side. Always returns true.

wait_used()

bool Arc::DataBuffer::wait_used

(

)

Wait till there are no more used buffers left in object.

Returns

true if an error occurred while waiting

wait_write()

bool Arc::DataBuffer::wait_write

(

)

Wait until end of transfer or error happens on 'write' side. Always returns true.

Field Documentation

speed

DataSpeed Arc::DataBuffer::speed

This object controls transfer speed.

---

The documentation for this class was generated from the following file:

• DataBuffer.h