libdar::tuyau Class Reference

pipe implementation under the generic_file interface. More...

#include <tuyau.hpp>

Inheritance diagram for libdar::tuyau:

Collaboration diagram for libdar::tuyau:

Public Member Functions
	tuyau (const std::shared_ptr< user_interaction > &dialog, int fd)
	tuyau (const std::shared_ptr< user_interaction > &dialog, int fd, gf_mode mode)
	tuyau (const std::shared_ptr< user_interaction > &dialog, const std::string &filename, gf_mode mode)
	tuyau (const std::shared_ptr< user_interaction > &dialog)
	creates a anonymous pipe and bind itself to the writing end. The reading end can be obtained by get_read_side() method
	tuyau (const tuyau &ref)=default
	tuyau (tuyau &&ref) noexcept=default
tuyau &	operator= (const tuyau &ref)=default
tuyau &	operator= (tuyau &&ref) noexcept=default
int	get_read_fd () const
void	close_read_fd ()
	closes the read fd of the anonymous pipe (this is to be used by a writer) More...
void	do_not_close_read_fd ()
	ask to not close the read descriptor upon object destruction (the fd survives the object)
virtual bool	skippable (skippability direction, const infinint &amount) override
	whether the implementation is able to skip More...
virtual bool	skip (const infinint &pos) override
	skip at the absolute position More...
virtual bool	skip_to_eof () override
	skip to the end of file
virtual bool	skip_relative (signed int x) override
virtual bool	truncatable (const infinint &pos) const override
	whether the implementation is able to truncate to the given position
virtual infinint	get_position () const override
	get the current read/write position
bool	has_next_to_read ()
Public Member Functions inherited from libdar::generic_file
	generic_file (gf_mode m)
	main constructor
	generic_file (const generic_file &ref)
	copy constructor
	generic_file (generic_file &&ref) noexcept
	move constructor
generic_file &	operator= (const generic_file &ref)
	assignment operator
generic_file &	operator= (generic_file &&ref) noexcept
	move operator
	~generic_file () noexcept(false)
	virtual destructor, More...
void	terminate ()
	destructor-like call, except that it is allowed to throw exceptions
bool	operator== (generic_file &ref)
bool	operator!= (generic_file &ref)
gf_mode	get_mode () const
	retreive the openning mode for this object
void	read_ahead (const infinint &amount)
void	ignore_read_ahead (bool mode)
virtual U_I	read (char *a, U_I size) override
	read data from the generic_file inherited from proto_generic_file
virtual void	write (const char *a, U_I size) override
	write data to the generic_file inherited from proto_generic_file
void	write (const std::string &arg)
	write a string to the generic_file More...
S_I	read_back (char &a)
	skip back one char, read on char and skip back one char
S_I	read_forward (char &a)
	read one char
virtual bool	skip_relative (S_I x)=0
	skip relatively to the current position
virtual void	truncate (const infinint &pos)
	truncate file at the given offset More...
virtual void	copy_to (generic_file &ref)
	copy all data from current position to the object in argument
virtual void	copy_to (generic_file &ref, const infinint &crc_size, crc *&value)
	copy all data from the current position to the object in argument and computes a CRC value of the transmitted data More...
U_32	copy_to (generic_file &ref, U_32 size)
	small copy (up to 4GB) with CRC calculation
infinint	copy_to (generic_file &ref, infinint size)
	copy the given amount to the object in argument
bool	diff (generic_file &f, const infinint &me_read_ahead, const infinint &you_read_ahead, const infinint &crc_size, crc *&value)
	compares the contents with the object in argument More...
bool	diff (generic_file &f, const infinint &me_read_ahead, const infinint &you_read_ahead, const infinint &crc_size, crc *&value, infinint &err_offset)
void	reset_crc (const infinint &width)
	reset CRC on read or writen data More...
bool	crc_status () const
	to known whether CRC calculation is activated or not
crc *	get_crc ()
	get CRC of the transfered date since last reset More...
void	sync_write ()
	write any pending data
void	flush_read ()
	be ready to read at current position, reseting all pending data for reading, cached and in compression engine for example
Public Member Functions inherited from libdar::proto_generic_file
	proto_generic_file (const proto_generic_file &ref)=default
	copy constructor
	proto_generic_file (proto_generic_file &&ref) noexcept=default
	move constructor
proto_generic_file &	operator= (const proto_generic_file &ref)=default
	assignment operator
proto_generic_file &	operator= (proto_generic_file &&ref) noexcept=default
	move operator
virtual	~proto_generic_file () noexcept(false)
	virtual destructor More...
Public Member Functions inherited from libdar::thread_cancellation
	thread_cancellation ()
	the constructor
	thread_cancellation (const thread_cancellation &ref)=default
	copy constructor
	thread_cancellation (thread_cancellation &&ref) noexcept=default
	move constructor
thread_cancellation &	operator= (const thread_cancellation &ref)=default
	assignment operator
thread_cancellation &	operator= (thread_cancellation &&ref) noexcept=default
	move operator
virtual	~thread_cancellation () noexcept(false)
	the destructor
void	check_self_cancellation () const
	Checkpoint test : whether the current libdar call must abort or not. More...
void	block_delayed_cancellation (bool mode)

Protected Member Functions
virtual void	inherited_read_ahead (const infinint &amount) override
	tells the object that several calls to read() will follow to probably obtain at least the given amount of data More...
virtual U_I	inherited_read (char *a, U_I size) override
	implementation of read() operation More...
virtual void	inherited_write (const char *a, U_I size) override
	implementation of the write() operation More...
virtual void	inherited_truncate (const infinint &pos) override
	truncate file at the give offset More...
virtual void	inherited_sync_write () override
	write down any pending data More...
virtual void	inherited_flush_read () override
	reset internal engine, flush caches in order to read the data at current position More...
virtual void	inherited_terminate () override
	destructor-like call, except that it is allowed to throw exceptions More...
Protected Member Functions inherited from libdar::generic_file
void	set_mode (gf_mode x)
bool	is_terminated () const
Protected Member Functions inherited from libdar::mem_ui
user_interaction &	get_ui () const
	get access to the user_interaction object More...
std::shared_ptr< user_interaction >	get_pointer () const
	get access to the shared_ptr pointing to the user_interaction
	mem_ui (const std::shared_ptr< user_interaction > &dialog)
	constructor More...
	mem_ui (const mem_ui &ref)=default
	the copy constructor More...
	mem_ui (mem_ui &&ref) noexcept=default
	the move constructor
mem_ui &	operator= (const mem_ui &ref)=default
	assignement operator More...
mem_ui &	operator= (mem_ui &&ref) noexcept=default
	move operator
virtual	~mem_ui () noexcept(false)
	destructor More...

Private Types
enum	{ pipe_fd , pipe_path , pipe_both }

Private Member Functions
void	ouverture ()
bool	read_and_drop (infinint byte)
	skip forward by reading data More...
bool	read_to_eof ()
	skip to eof by reading data

Private Attributes
enum libdar::tuyau:: { ... }	pipe_mode
	defines how the object's status (which possible values defined by the anonymous enum above)
infinint	position
	recorded position in the stream
int	filedesc
	file descriptors of the pipe
int	other_end_fd
	in pipe_both mode, this holds the reading side of the anonymous pipe
std::string	chemin
	in pipe_path mode only, this holds the named pipe to be open
bool	has_one_to_read
	if true, the next char to read is placed in "next_to_read"
char	next_to_read
	when has_one_to_read is true, contains the next to read byte

Additional Inherited Members
Public Types inherited from libdar::generic_file
enum	skippability { skip_backward , skip_forward }
Static Public Member Functions inherited from libdar::thread_cancellation
static U_I	count ()
	method for debugging/control purposes

Detailed Description

pipe implementation under the generic_file interface.

Definition at line 48 of file tuyau.hpp.

Member Enumeration Documentation

anonymous enum

anonymous enum

private

Enumerator
pipe_fd	holds a single file descriptor for the pipe
pipe_path	holds a filename to be openned (named pipe)
pipe_both	holds a pair of file descriptors

Definition at line 104 of file tuyau.hpp.

Constructor & Destructor Documentation

tuyau() [1/3]

libdar::tuyau::tuyau	(	const std::shared_ptr< user_interaction > &	dialog,
		int	fd
	)

Parameters

dialog	for user interaction
fd	fd is the filedescriptor of a pipe extremity already openned

tuyau() [2/3]

libdar::tuyau::tuyau	(	const std::shared_ptr< user_interaction > &	dialog,
		int	fd,
		gf_mode	mode
	)

Parameters

dialog	for user interaction
fd	fd is the filedescriptor of a pipe extremity already openned
mode	forces the mode if possible

tuyau() [3/3]

libdar::tuyau::tuyau	(	const std::shared_ptr< user_interaction > &	dialog,
		const std::string &	filename,
		gf_mode	mode
	)

Parameters

dialog	for user interaction
filename	named pipe to open
mode	forces the mode if possible

Member Function Documentation

close_read_fd()

void libdar::tuyau::close_read_fd

(

)

closes the read fd of the anonymous pipe (this is to be used by a writer)

Note

to ensure a proper behavior of the 'eof', the writer must close the read fd this call let this be done, assuming the read has already fetched the fd and forked in a new process

get_read_fd()

int libdar::tuyau::get_read_fd

(

)

const

provides the reading end of the anonymous pipe when the current object has created it (no filedesc, no path given to constructor).

Note

this methid cannot be called more than once.

inherited_flush_read()

virtual void libdar::tuyau::inherited_flush_read ( )

inlineoverrideprotectedvirtual

reset internal engine, flush caches in order to read the data at current position

Note

when the object relies on external object or system object to fetch the data from for reading, when a call to (inherited_)flush_read() occurs, the current object must not assume that any previously read data is still valid if it has internal buffers or the like and it should flush them asap. This call must not propagate the flush_read to any other gneric_file object it could rely on

Implements libdar::generic_file.

Definition at line 100 of file tuyau.hpp.

inherited_read()

virtual U_I libdar::tuyau::inherited_read ( char *  a, U_I  size  )

overrideprotectedvirtual

implementation of read() operation

Parameters

[in,out]	a	where to put the data to read
[in]	size	says how much data to read

Returns

the exact amount of data read and put into 'a'

Note

read as much byte as requested, up to end of file stays blocked if not enough data is available and EOF not yet met. May return less data than requested only if EOF as been reached. in other worlds, EOF is reached when returned data is stricly less than the requested data Any problem shall be reported by throwing an exception.

Implements libdar::generic_file.

inherited_read_ahead()

virtual void libdar::tuyau::inherited_read_ahead ( const infinint &  amount )

inlineoverrideprotectedvirtual

tells the object that several calls to read() will follow to probably obtain at least the given amount of data

Parameters

[in]

amount

is the maximum expected amount of data that is known to be read

Note

this call may be implemented as a do-nothing call, its presence is only to allow optimization when possible, like in multi-threaded environment

Implements libdar::generic_file.

Definition at line 95 of file tuyau.hpp.

inherited_sync_write()

virtual void libdar::tuyau::inherited_sync_write ( )

inlineoverrideprotectedvirtual

write down any pending data

Note

called after sanity checks from generic_file::sync_write() this method's role is to write down any data pending for writing in the current object it has not to be propagated to other gneric_file object this object could rely on

Implements libdar::generic_file.

Definition at line 99 of file tuyau.hpp.

inherited_terminate()

virtual void libdar::tuyau::inherited_terminate ( )

overrideprotectedvirtual

destructor-like call, except that it is allowed to throw exceptions

Note

this method must never be called directly but using terminate() instead, generic_file class manages it to never be called more than once

Implements libdar::generic_file.

inherited_truncate()

virtual void libdar::tuyau::inherited_truncate ( const infinint &  pos )

inlineoverrideprotectedvirtual

truncate file at the give offset

Note

if pos is greater than the current file size, this call may do nothing (not even enlarging the file)

this call should always fail on a read-only generic_file

implementation must throw exception if truncate is not possible for other reason than read/write access mode

Implements libdar::generic_file.

Definition at line 98 of file tuyau.hpp.

References position.

inherited_write()

virtual void libdar::tuyau::inherited_write ( const char *  a, U_I  size  )

overrideprotectedvirtual

implementation of the write() operation

Parameters

[in]	a	what data to write
[in]	size	amount of data to write

Note

must either write all data or report an error by throwing an exception

Implements libdar::generic_file.

read_and_drop()

bool libdar::tuyau::read_and_drop ( infinint  byte )

private

skip forward by reading data

Parameters

[in]

byte

is the amount of byte to skip forward

Returns

true if the given amount of byte could be read, false otherwise (reached EOF).

skip()

virtual bool libdar::tuyau::skip ( const infinint &  pos )

overridevirtual

skip at the absolute position

Parameters

[in]

pos

the offset in byte where next read/write operation must start

Returns

true if operation was successfull and false if the requested position is not valid (after end of file)

Note

if requested position is not valid the reading/writing cursor must be set to the closest valid position

Implements libdar::generic_file.

skippable()

virtual bool libdar::tuyau::skippable ( skippability  direction, const infinint &  amount  )

overridevirtual

whether the implementation is able to skip

Note

the capability to skip does not mean that skip_relative() or skip() will succeed, but rather that the inherited class implementation does not by construction forbid the requested skip (like inherited class providing a generic_file interface of an anonymous pipe for example)

Implements libdar::generic_file.

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

• tuyau.hpp