libdar::pile Class Reference

stores a stack of generic_files writing/reading on each others More...

#include <pile.hpp>

Inheritance diagram for libdar::pile:

Collaboration diagram for libdar::pile:

Public Member Functions
	pile ()
	the constructor More...
	pile (const pile &ref)=delete
	pile (pile &&ref) noexcept=delete
pile &	operator= (const pile &ref)=delete
pile &	operator= (pile &&ref) noexcept=delete
void	push (generic_file *f, const std::string &label="", bool extend_mode=false)
	add a generic_file on the top More...
generic_file *	pop ()
	remove the top generic_file from the top More...
template<class T >
bool	pop_and_close_if_type_is (T *ptr)
	remove the top generic_file and destroy it More...
generic_file *	top () const
	returns the address of the top generic_file
generic_file *	bottom () const
	returns the address of the bottom generic_file
U_I	size () const
	returns the number of objects in the stack
bool	is_empty () const
	returns true if the stack is empty, false otherwise.
void	clear ()
	clears the stack
template<class T >
void	find_first_from_top (T *&ref) const
	this template let the class user find out the higher object on the stack of the given type More...
template<class T >
void	find_first_from_bottom (T *&ref) const
	this template is similar to the template "find_first_from_top" except that the search is started from the bottom of the stack
generic_file *	get_below (const generic_file *ref)
	return the generic_file object just below the given object or nullptr if the object is at the bottom of the stack or is not in the stack
generic_file *	get_above (const generic_file *ref)
	return the generic_file object just above the given object or nullptr if the object is at the bottom of the stack or is not in the stack
generic_file *	get_by_label (const std::string &label)
	find the object associated to a given label More...
void	clear_label (const std::string &label)
	if label is associated to a member of the stack, makes this member of the stack an anoymous member (the label is no more associated to this object, while this object stays in the stack untouched More...
void	add_label (const std::string &label)
	associate a additional label to the object currently at the top of the stack More...
void	sync_write_above (generic_file *ptr)
	call the generic_file::sync_write() method of all object found above ptr in the stack
void	flush_read_above (generic_file *ptr)
	call the generic_file::flush_read() method of all objects found above ptr in the stack
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 (S_I x) override
	skip relatively to the current position
virtual bool	truncatable (const infinint &amount) 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
void	copy_to (generic_file &ref) override
	copy all data from current position to the object in argument
void	copy_to (generic_file &ref, const infinint &crc_size, crc *&value) override
	copy all data from the current position to the object in argument and computes a CRC value of the transmitted data More...
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 void	truncate (const infinint &pos)
	truncate file at the given offset 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...

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

Private Member Functions
void	detruit ()
std::deque< face >::iterator	look_for_label (const std::string &label)

Private Attributes
std::deque< face >	stack

Additional Inherited Members
Public Types inherited from libdar::generic_file
enum	skippability { skip_backward , skip_forward }

Detailed Description

stores a stack of generic_files writing/reading on each others

Definition at line 43 of file pile.hpp.

Constructor & Destructor Documentation

pile()

libdar::pile::pile ( )

inline

the constructor

Note

the mode (gf_mode) of the pile is the one of the first object pushed on the stack, thus when empty we choose the arbitrary gf_read_only value, because the stack is empty.

Definition at line 51 of file pile.hpp.

Member Function Documentation

add_label()

void libdar::pile::add_label

(

const std::string &

label

)

associate a additional label to the object currently at the top of the stack

Parameters

[in]

label

the label to add

Note

this does not remove an eventually existing label that had been added either by push() or add_label() previously

an object of the stack can thus be refered by several different labels

clear_label()

void libdar::pile::clear_label

(

const std::string &

label

)

if label is associated to a member of the stack, makes this member of the stack an anoymous member (the label is no more associated to this object, while this object stays in the stack untouched

Parameters

[in]

label

the label to clear, empty string is not a valid label an exception is thrown if used here

Note

no exception is thrown else, even if the label is not present in the stack

copy_to()

void libdar::pile::copy_to ( generic_file &  ref, const infinint &  crc_size, crc *&  value  )

overridevirtual

copy all data from the current position to the object in argument and computes a CRC value of the transmitted data

Parameters

[in]	ref	defines where to copy the data to
[in]	crc_size	tell the width of the crc to compute on the copied data
[out]	value	points to a newly allocated crc object containing the crc value

Note

value has to be deleted by the caller when no more needed

Reimplemented from libdar::generic_file.

get_by_label()

generic_file* libdar::pile::get_by_label

(

const std::string &

label

)

find the object associated to a given label

Parameters

[in]

label

is the label to look for, empty string is forbidden

Returns

the object associated to label, else an exception is thrown

inherited_flush_read()

virtual void libdar::pile::inherited_flush_read ( )

overrideprotectedvirtual

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.

inherited_read()

virtual U_I libdar::pile::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::pile::inherited_read_ahead ( const infinint &  amount )

overrideprotectedvirtual

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.

inherited_sync_write()

virtual void libdar::pile::inherited_sync_write ( )

overrideprotectedvirtual

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.

inherited_terminate()

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

overrideprotectedvirtual

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.

inherited_write()

virtual void libdar::pile::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.

pop()

generic_file* libdar::pile::pop

(

)

remove the top generic_file from the top

Returns

the address of the object that has been poped from the stack or nullptr if the stack is empty

Note

this is now the duty of the caller to release this object memory when the object is no more needed

push()

void libdar::pile::push	(	generic_file *	f,
		const std::string &	label = "",
		bool	extend_mode = false
	)

add a generic_file on the top

Parameters

[in]	f	is the address of the object to add to the stack
[in]	label	unique label associated to this object in the current stack, exception thrown if label already used in stack
[in]	extend_mode	allow the new object to have more read/write permission than the already placed object, which have the effect to change the read/write permission of the stack itself, future push() will accept wider permission even if extend_mode is not set

Note

once added, the object memory allocation is managed by the pile object the pile is responsible of destroying this object if its destructor is called however, the pile object releases its responsibility about any object that will be poped (see pop() below) from the stack.

empty label (empty string) is the only identical value that can be used for several objects of the stack

skip()

virtual bool libdar::pile::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::pile::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:

• pile.hpp