makes a segment of a generic_file appear like a real generic_file More...

#include <tronc.hpp>

Inheritance diagram for libdar::tronc:

Collaboration diagram for libdar::tronc:

Public Member Functions
	tronc (generic_file *f, const infinint &offset, const infinint &size, bool own_f=false)
	constructor More...

	tronc (generic_file *f, const infinint &offset, const infinint &size, gf_mode mode, bool own_f=false)

	tronc (generic_file *f, const infinint &offset, bool own_f=false)

	tronc (generic_file *f, const infinint &offset, gf_mode mode, bool own_f=false)

	tronc (const tronc &ref)=delete

	tronc (tronc &&ref) noexcept=delete

tronc &	operator= (const tronc &ref)=delete

tronc &	operator= (tronc &&ref)=delete

	~tronc ()
	destructor More...

void	modify (const infinint &new_offset, const infinint &new_size)
	modify the tronc object to zoom on another (size limited) portion of the underlying object

void	modify (const infinint &new_offset)
	modify the tronc object to zoom on another (size unlimited) portion of the underlying object

void	modify ()
	modify the tronc object to become transparent and allow unrestricted access to the underlyuing object More...

virtual bool	skippable (skippability direction, const infinint &amount) override
	inherited from generic_file More...

virtual bool	skip (const infinint &pos) override
	inherited from generic_file More...

virtual bool	skip_to_eof () override
	inherited from generic_file More...

virtual bool	skip_relative (S_I x) override
	inherited from generic_file More...

virtual bool	truncatable (const infinint &pos) const override
	inherited from generic_file More...

virtual infinint	get_position () const override
	get the current read/write position More...

void	check_underlying_position_while_reading_or_writing (bool mode)

Public Member Functions inherited from libdar::generic_file
	generic_file (gf_mode m)
	main constructor More...

	generic_file (const generic_file &ref)
	copy constructor More...

	generic_file (generic_file &&ref) noexcept
	move constructor More...

generic_file &	operator= (const generic_file &ref)
	assignment operator More...

generic_file &	operator= (generic_file &&ref) noexcept
	move operator More...

	~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 More...

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 More...

virtual void	write (const char *a, U_I size) override
	write data to the generic_file inherited from proto_generic_file More...

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 More...

virtual bool	skippable (skippability direction, const infinint &amount)=0
	whether the implementation is able to skip More...

virtual bool	skip (const infinint &pos)=0
	skip at the absolute position More...

virtual bool	skip_to_eof ()=0
	skip to the end of file More...

virtual bool	skip_relative (S_I x)=0
	skip relatively to the current position More...

virtual bool	truncatable (const infinint &pos) const =0
	whether the implementation is able to truncate to the given position More...

virtual void	truncate (const infinint &pos)
	truncate file at the given offset More...

virtual infinint	get_position () const =0
	get the current read/write position More...

virtual void	copy_to (generic_file &ref)
	copy all data from current position to the object in argument More...

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 More...

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...

virtual U_I	read (char *a, U_I size)=0
	read data from the proto_generic_file More...

virtual void	write (const char *a, U_I size)=0
	write data to the proto_generic_file More...

Protected Member Functions
virtual void	inherited_read_ahead (const infinint &amount) override
	inherited from generic_file More...

virtual U_I	inherited_read (char *a, U_I size) override
	inherited from generic_file More...

virtual void	inherited_write (const char *a, U_I size) override
	inherited from generic_file 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)

virtual void	inherited_read_ahead (const infinint &amount)=0
	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)=0
	implementation of read() operation More...

virtual void	inherited_write (const char *a, U_I size)=0
	implementation of the write() operation More...

virtual void	inherited_truncate (const infinint &pos)=0
	truncate file at the give offset More...

virtual void	inherited_sync_write ()=0
	write down any pending data More...

virtual void	inherited_flush_read ()=0
	reset internal engine, flush caches in order to read the data at current position More...

virtual void	inherited_terminate ()=0
	destructor-like call, except that it is allowed to throw exceptions More...

bool	is_terminated () const

Private Member Functions
void	set_back_current_position ()

void	detruit () noexcept

Private Attributes
infinint	start
	offset in the global generic file to start at More...

infinint	sz
	length of the portion to consider More...

generic_file *	ref
	global generic file of which to take a piece More...

infinint	current
	inside position of the next read or write More...

bool	own_ref
	whether we own ref (and must destroy it when no more needed) More...

bool	limited
	whether the sz argument is to be considered More...

bool	check_pos
	whether to check and eventually adjust (seek) the position of the underlying layer at each read or write More...

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

Detailed Description

makes a segment of a generic_file appear like a real generic_file

Definition at line 43 of file tronc.hpp.

Constructor & Destructor Documentation

◆ tronc() [1/2]

libdar::tronc::tronc	(	generic_file *	f,
		const infinint &	offset,
		const infinint &	size,
		bool	own_f = `false`
	)

constructor

Parameters

f	is the file to take the segment from
offset	is the position of the beginning of the segment
size	is the size of the segment
own_f	is true if this object has to own and must destroy the 'f' object at tronc's destruction time

◆ tronc() [2/2]

libdar::tronc::tronc	(	generic_file *	f,
		const infinint &	offset,
		bool	own_f = `false`
	)

other constructor, the end of the segment is the end of the underlying generic_file only data before offset is inaccessible

◆ ~tronc()

libdar::tronc::~tronc ( )

inline

destructor

Definition at line 66 of file tronc.hpp.

Member Function Documentation

◆ check_underlying_position_while_reading_or_writing()

void libdar::tronc::check_underlying_position_while_reading_or_writing ( bool mode )

inline

when a tronc is used over a compressor, it becomes necessary to disable position check

Note: by default, before each read or write, the tronc object check that the underlying object is at adhoc position in regard to where the cursor is currently in the tronc. Disabling that check let ignore possible position mismatch (which are normal when a compressor is found below) while reading or writing but keep seeking the underlying object to the requested position upon any call to tronc::skip_* familly methods.

Definition at line 94 of file tronc.hpp.

References check_pos.

◆ detruit()

void libdar::tronc::detruit ( )

inlineprivatenoexcept

Definition at line 119 of file tronc.hpp.

◆ get_position()

virtual infinint libdar::tronc::get_position ( ) const

inlineoverridevirtual

get the current read/write position

Implements libdar::generic_file.

Definition at line 85 of file tronc.hpp.

References current.

◆ inherited_flush_read()

virtual void libdar::tronc::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 106 of file tronc.hpp.

◆ inherited_read()

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

overrideprotectedvirtual

inherited from generic_file

Implements libdar::generic_file.

◆ inherited_read_ahead()

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

overrideprotectedvirtual

inherited from generic_file

Implements libdar::generic_file.

◆ inherited_sync_write()

virtual void libdar::tronc::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 105 of file tronc.hpp.

References ref, and libdar::generic_file::sync_write().

◆ inherited_terminate()

virtual void libdar::tronc::inherited_terminate ( )

inlineoverrideprotectedvirtual

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.

Definition at line 107 of file tronc.hpp.

References own_ref, ref, and libdar::generic_file::terminate().

◆ inherited_truncate()

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

overrideprotectedvirtual

inherited from generic_file

Implements libdar::generic_file.

◆ modify()

void libdar::tronc::modify ( )

inline

modify the tronc object to become transparent and allow unrestricted access to the underlyuing object

Definition at line 73 of file tronc.hpp.

References modify().

Referenced by modify().

◆ skip()

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

overridevirtual

inherited from generic_file

Implements libdar::generic_file.

◆ skip_relative()

virtual bool libdar::tronc::skip_relative ( S_I x )

overridevirtual

inherited from generic_file

Implements libdar::generic_file.

◆ skip_to_eof()

virtual bool libdar::tronc::skip_to_eof ( )

overridevirtual

inherited from generic_file

Implements libdar::generic_file.

◆ skippable()

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

overridevirtual

inherited from generic_file

Implements libdar::generic_file.

◆ truncatable()

virtual bool libdar::tronc::truncatable ( const infinint & pos ) const

inlineoverridevirtual

inherited from generic_file

Implements libdar::generic_file.

Definition at line 84 of file tronc.hpp.

References ref, start, and libdar::generic_file::truncatable().

Member Data Documentation

◆ check_pos

bool libdar::tronc::check_pos

private

whether to check and eventually adjust (seek) the position of the underlying layer at each read or write

Definition at line 116 of file tronc.hpp.

Referenced by check_underlying_position_while_reading_or_writing().

◆ current

infinint libdar::tronc::current

private

inside position of the next read or write

Definition at line 113 of file tronc.hpp.

Referenced by get_position().

◆ limited

bool libdar::tronc::limited

private

whether the sz argument is to be considered

Definition at line 115 of file tronc.hpp.

◆ own_ref

bool libdar::tronc::own_ref

private

whether we own ref (and must destroy it when no more needed)

Definition at line 114 of file tronc.hpp.

Referenced by inherited_terminate().

◆ ref

generic_file* libdar::tronc::ref

private

global generic file of which to take a piece

Definition at line 112 of file tronc.hpp.

Referenced by inherited_sync_write(), inherited_terminate(), and truncatable().

◆ start

infinint libdar::tronc::start

private

offset in the global generic file to start at

Definition at line 110 of file tronc.hpp.

Referenced by truncatable().

◆ sz

infinint libdar::tronc::sz

private

length of the portion to consider

Definition at line 111 of file tronc.hpp.

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

tronc.hpp

Public Member Functions

Protected Member Functions

Private Member Functions

Private Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ tronc() [1/2]

◆ tronc() [2/2]

◆ ~tronc()

Member Function Documentation

◆ check_underlying_position_while_reading_or_writing()

◆ detruit()

◆ get_position()

◆ inherited_flush_read()

◆ inherited_read()

◆ inherited_read_ahead()

◆ inherited_sync_write()

◆ inherited_terminate()

◆ inherited_truncate()

◆ inherited_write()

◆ modify()

◆ skip()

◆ skip_relative()

◆ skip_to_eof()

◆ skippable()

◆ truncatable()

Member Data Documentation

◆ check_pos

◆ current

◆ limited

◆ own_ref

◆ ref

◆ start

◆ sz