fsaccess.c File Reference

#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include "fsaccess.h"
#include "compiler.h"
#include "file.h"
#include "navigation.h"
#include "ctrl_access.h"

Functions
bool	b_fsaccess_init (void)
	This function initializes mutex and navigators. More...
int	close (int fd)
	This function closes a file. More...
long	fsaccess_alloc_nav_id (void)
	This function returns a free navigator id. More...
size_t	fsaccess_file_get_size (int fd)
	This function returns the opened file size. More...
void	fsaccess_free_nav_id (int fd)
	This function frees a navigator id. More...
void	fsaccess_give_mutex (void)
	This function frees the mutex. More...
int8_t	fsaccess_IsDirPresent (const char *pcStringDirName)
	Is a directory present? More...
void	fsaccess_take_mutex (void)
	This function gives the mutex to the caller. More...
int	open (const char *pathname, int flags,...)
	Mutex to access the File System. More...
ssize_t	read (int fd, void *buf, size_t count)
	This function reads from a file. More...
ssize_t	write (int fd, const void *buf, size_t count)
	This function writes to a file. More...

Variables
static unsigned int	pvNavUsed = 0
	bitfield for navigator currently used. bit[0..31] is 1 if used, 0 if not. More...

bool b_fsaccess_init

(

void

)

This function initializes mutex and navigators.

References nav_reset().

Referenced by main().

int close

(

int

fd

)

This function closes a file.

Parameters

fd	file descriptor.

Returns

int : -1 if error, 0 otherwise

References file_close(), fsaccess_free_nav_id(), fsaccess_give_mutex(), fsaccess_take_mutex(), and nav_select().

Referenced by fsaccess_example_read(), and fsaccess_example_write().

long fsaccess_alloc_nav_id

(

void

)

This function returns a free navigator id.

Returns

long : Id navigator allocated or -1 if none free

References FS_NB_NAVIGATOR, FS_NB_RESERVED_NAV, pvNavUsed, Set_bits, and Tst_bits.

Referenced by fsaccess_IsDirPresent(), and open().

size_t fsaccess_file_get_size

(

int

fd

)

This function returns the opened file size.

Parameters

fd	file descriptor.

Returns

size_t : size of the file pointed to by the descriptor

References fsaccess_give_mutex(), fsaccess_take_mutex(), nav_file_lgt(), and nav_select().

Referenced by fsaccess_example_read(), and fsaccess_example_write().

void fsaccess_free_nav_id

(

int

fd

)

This function frees a navigator id.

Parameters

fd	file descriptor.

References Clr_bits, and pvNavUsed.

Referenced by close(), fsaccess_IsDirPresent(), and open().

void fsaccess_give_mutex

(

void

)

This function frees the mutex.

Referenced by close(), fsaccess_file_get_size(), fsaccess_IsDirPresent(), open(), read(), and write().

int8_t fsaccess_IsDirPresent

(

const char *

pcStringDirName

)

Is a directory present?

Parameters

pcStringDirName

Input. Directory name string.

Returns

1 if the directory exists, 0 if the directory doesn't exist, else -1

References false, fsaccess_alloc_nav_id(), fsaccess_free_nav_id(), fsaccess_give_mutex(), fsaccess_take_mutex(), nav_select(), and nav_setcwd().

void fsaccess_take_mutex

(

void

)

This function gives the mutex to the caller.

Referenced by close(), fsaccess_file_get_size(), fsaccess_IsDirPresent(), open(), read(), and write().

int open	(	const char *	pathname,
		int	flags,
			...
	)

Mutex to access the File System.

This function opens a file.

This function opens a file.

Parameters

pathname	path of the file to open.
flags	flags to give file access rights should be O_CREAT : create file if not exist O_APPEND : add data to the end of file O_RDONLY : Read Only O_WRONLY : Write Only O_RDWR : Read/Write

Returns

int : file descriptor (>= 0 if OK (NavID), -1 otherwise)

References file_open(), FOPEN_MODE_APPEND, FOPEN_MODE_R, FOPEN_MODE_R_PLUS, FOPEN_MODE_W, fsaccess_alloc_nav_id(), fsaccess_free_nav_id(), fsaccess_give_mutex(), fsaccess_take_mutex(), nav_select(), nav_setcwd(), O_APPEND, O_CREAT, O_RDWR, and O_WRONLY.

Referenced by fsaccess_example_read(), and fsaccess_example_write().

ssize_t read	(	int	fd,
		void *	buf,
		size_t	count
	)

This function reads from a file.

Parameters

fd	file descriptor.
buf	pointer for data that are read.
count	amount of bytes to read

Returns

ssize_t : amount of data read (-1 if error)

References file_eof(), file_read_buf(), fsaccess_give_mutex(), fsaccess_take_mutex(), and nav_select().

Referenced by fsaccess_example_read(), and fsaccess_example_write().

ssize_t write	(	int	fd,
		const void *	buf,
		size_t	count
	)

This function writes to a file.

Parameters

fd	file descriptor.
buf	pointer from where data are written.
count	amount of bytes to write

Returns

ssize_t : amount of data written (-1 if error)

References file_write_buf(), fsaccess_give_mutex(), fsaccess_take_mutex(), and nav_select().

Referenced by fsaccess_example_write().

unsigned int pvNavUsed = 0

static

bitfield for navigator currently used. bit[0..31] is 1 if used, 0 if not.

Referenced by fsaccess_alloc_nav_id(), and fsaccess_free_nav_id().