#include <fileflow.h>

Inheritance diagram for scopira::tool::fileflow:

Public Types
enum	{ append_c = 1024, trunc_c = 2048, linked_c = 4096, existing_c = 8192 }
	access levels More...

enum	{ stdin_c = -1, stdout_c = -2, stderr_c = -3 }
	special file descriptor (fd) numbers More...

enum	seek_dir_t { seek_start_c = 0, seek_end_c = 1, seek_cur_c }

typedef ::off_t	offset_t

Public Types inherited from scopira::tool::flow_i
enum	{ input_c = 1, output_c = 2 }

typedef scopira::tool::byte_t	byte_t

typedef int	mode_t

Public Member Functions
	fileflow (void)

	fileflow (const std::string &filename, mode_t mode)

	fileflow (int fd, mode_t mode)

virtual bool	failed (void) const

virtual size_t	read (byte_t *_buf, size_t _maxsize)

virtual size_t	write (const byte_t *_buf, size_t _size)

void	open (const std::string &filename, mode_t mode)

void	open (int fd, mode_t mode)

void	close (void)

int	get_os_handle (void) const

offset_t	seek (offset_t howmuch, seek_dir_t dir=seek_start_c)
	seekers

void	seek_reset (void)
	seeks to the start

offset_t	tell (void) const
	tells the current location of the file pointer

bool	resize (offset_t newsz)

void	read_lock (void)

bool	try_read_lock (void)

void	write_lock (void)

bool	try_write_lock (void)

void	unlock (void)

Public Member Functions inherited from scopira::tool::iflow_i
virtual size_t	read_byte (byte_t &out)

template<class TT >
size_t	read_array (TT *_buf, size_t _numelem)

size_t	read_void (void *_buf, size_t _maxsize)

Public Member Functions inherited from scopira::tool::object
virtual	~object ()

int	add_ref (void) const

bool	sub_ref (void) const

void	auto_ref (void) const

int	current_ref (void) const

virtual scopira::tool::oflow_i &	print (scopira::tool::oflow_i &o) const

virtual bool	load (scopira::tool::iobjflow_i &in)

virtual void	save (scopira::tool::oobjflow_i &out) const

bool	is_alive_object (void) const

bool	is_dead_object (void) const

Public Member Functions inherited from scopira::tool::oflow_i
virtual size_t	write_byte (byte_t b)

template<class TT >
size_t	write_array (const TT *_buf, size_t _numelem)

size_t	write_void (const void *_buf, size_t _size)

Protected Attributes
mode_t	dm_mode
	current modes, 0 for no-file

int	dm_hand
	the file handle

bool	dm_fail
	currently failed?

Additional Inherited Members
Protected Member Functions inherited from scopira::tool::object
	object (void)

	object (bool neverusecounter)

Detailed Description

The is a binary/raw flow stream object that reads and writes files to disk.

This class is often the base of many chains, and can also be used by itself for basic file reading and writing.

See also: Input/output flows

Author: Aleksander Demko

Member Enumeration Documentation

◆ anonymous enum

anonymous enum

access levels

Enumerator
append_c	append to any existing file
trunc_c	this is the default, for output files
linked_c	internal, you dont need to specifiy this
existing_c	open an existinf file. do not trunc. do not append.

◆ anonymous enum

anonymous enum

special file descriptor (fd) numbers

Enumerator
stdin_c	this file descriptor represents the standard input stream, stdin
stdout_c	this file descriptor represents the standard output stream, stdout
stderr_c	this file descriptor represents the standard error stream, stderr

Constructor & Destructor Documentation

◆ fileflow() [1/3]

scopira::tool::fileflow::fileflow ( void )

The default constructor.

You should then use open() to open a file.

Author: Aleksander Demko

◆ fileflow() [2/3]

scopira::tool::fileflow::fileflow	(	const std::string &	filename,
		mode_t	mode
	)

A constructor that also opens a file. See the corresponding open() call for parameter information.

Author: Aleksander Demko

◆ fileflow() [3/3]

scopira::tool::fileflow::fileflow	(	int	fd,
		mode_t	mode
	)

A constructor that also opens a file. See the corresponding open() call for parameter information.

Parameters

fd	the file descriptor (OS specific)
mode	the file mode to use

Author: Aleksander Demko

Member Function Documentation

◆ close()

void scopira::tool::fileflow::close ( void )

Close the currently opened file.

You normally do not need to call this as the file will be closed automatically if you:

try to open() another file
the fileflow object is destroyed

Author: Aleksander Demko

Referenced by scopira::tool::filememory::c_array().

◆ failed()

virtual bool scopira::tool::fileflow::failed ( void ) const

virtual

Check if the file stream is in a failed state.

Returns: true if the stream is in a failed state.

Author: Aleksander Demko

Implements scopira::tool::flow_i.

◆ open() [1/2]

void scopira::tool::fileflow::open	(	const std::string &	filename,
		mode_t	mode
	)

Opens the given on disk file.

The mode is a bitmask (or-ed) of file modes.

It usually contains either (or both) of:

input_c (for reading from a file)
output_c (for writing to a file)

And possible some of:

append_c (append to any existing file)
trunc_c (truncate - delete - any existing file)
existing_c (open an existinf file, and fail if it doesn't exist)

Use failed() to check if the open was successfull.

Parameters

filename	is the filename
mode	is the file mode

Author: Aleksander Demko

Referenced by scopira::tool::filememory::c_array().

◆ open() [2/2]

void scopira::tool::fileflow::open	(	int	fd,
		mode_t	mode
	)

Opens a file via an existing OS file descriptor. File descriptors are typically low level OS objects that you typically do not want to use. This method is provided for the few times users would want streams that reflect into standard OS file descriptors.

You can either pass it a file descriptor (fd) or one of the standard (std*_c) file descriptors. If you pass one of the standard streams (std*._c), mode is ignored)

Use failed() to check if the open was successfull.

Parameters

fd	the file descriptor (OS specific)
mode	the file mode to use

Author: Aleksander Demko

◆ read()

virtual size_t scopira::tool::fileflow::read	(	byte_t *	_buf,
		size_t	_maxsize
	)

virtual

Reads a raw array of bytes from the file.

Parameters

_buf	the buffer to read into.
_maxsize	the maximum number of bytes to read

Returns: the actual number of bytes read

Author: Aleksander Demko

Implements scopira::tool::iflow_i.

◆ read_lock()

void scopira::tool::fileflow::read_lock ( void )

Locks the (whole) file for (shared) reading. Blocks until the lock is acquired. Don't forget to unlock! File must be open for reading!

Author: Aleksander Demko

Referenced by scopira::tool::read_flocker::read_flocker(), and seek_reset().

◆ resize()

bool scopira::tool::fileflow::resize ( offset_t newsz )

Resize the file (see ftruncate).

Returns true on success.

Author: Aleksander Demko

Referenced by seek_reset().

◆ try_read_lock()

bool scopira::tool::fileflow::try_read_lock ( void )

Checks if a read lock is doable, right now. Returns true if a read lock is doable. Never blocks. File must be open for reading!

Author: Aleksander Demko

Referenced by seek_reset().

◆ try_write_lock()

bool scopira::tool::fileflow::try_write_lock ( void )

Checks if a write lock is doable, right now. Returns true if a write lock is doable. Never blocks. File must be open for writing!

Author: Aleksander Demko

Referenced by seek_reset().

◆ unlock()

void scopira::tool::fileflow::unlock ( void )

Unlocks the current write or read lock. File must be open!

Author: Aleksander Demko

Referenced by seek_reset(), scopira::tool::read_flocker::~read_flocker(), and scopira::tool::write_flocker::~write_flocker().

◆ write()

virtual size_t scopira::tool::fileflow::write	(	const byte_t *	_buf,
		size_t	_size
	)

virtual

Writes a raw array of bytes from the file.

Parameters

_buf	the buffer to write from.
_size	the size of the buffer

Returns: the actual number of bytes written

Author: Aleksander Demko

Implements scopira::tool::oflow_i.

◆ write_lock()

void scopira::tool::fileflow::write_lock ( void )

Locks the (whole) file for (exclusive) writing. Blocks until the lock is acquired. Don't forget to unlock! File must be open for writing!

Author: Aleksander Demko

Referenced by seek_reset(), and scopira::tool::write_flocker::write_flocker().

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

fileflow.h

Public Types

Public Member Functions

Protected Attributes

Additional Inherited Members

Detailed Description

Member Enumeration Documentation

◆ anonymous enum

◆ anonymous enum

Constructor & Destructor Documentation

◆ fileflow() [1/3]

◆ fileflow() [2/3]

◆ fileflow() [3/3]

Member Function Documentation

◆ close()

◆ failed()

◆ open() [1/2]

◆ open() [2/2]

◆ read()

◆ read_lock()

◆ resize()

◆ try_read_lock()

◆ try_write_lock()

◆ unlock()

◆ write()

◆ write_lock()