file_object.h File Reference

#include "common.h"

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Functions
void	file_object_init (void)
	Initializes this module and must be called before using any other function of this module.
void	file_object_close (void)
	Releases all used resources and should be called on shutdown.
file_object *	file_object_new (int fd, const char *pathname, int accmode)
	Acquires a new file object for a given pathname.
file_object *	file_object_open (const char *pathname, int accmode)
	Acquires a file object for a given pathname and access mode.
ssize_t	file_object_pwrite (const struct file_object *fo, const void *data, size_t buf, filesize_t offset)
	Write the given data to a file object at the given offset.
ssize_t	file_object_pwritev (const struct file_object *fo, const struct iovec *iov, int iov_cnt, filesize_t offset)
	Write the given data to a file object at the given offset.
ssize_t	file_object_pread (const struct file_object *fo, void *data, size_t size, filesize_t pos)
	Read data from the file object from the given offset.
ssize_t	file_object_preadv (const struct file_object *fo, struct iovec *iov, int iov_cnt, filesize_t offset)
	Read data from a file object from the given offset.
int	file_object_get_fd (const struct file_object *fo)
	Get the file descriptor associated with a file object.
const char *	file_object_get_pathname (const struct file_object *fo)
	Get the pathname associated with a file object.
void	file_object_release (struct file_object **fo_ptr)
	Releases a file object and frees its memory.
void	file_object_revoke (const char *pathname)
	Revokes all file objects associated with the pathname.

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Function Documentation

void file_object_close (  void   )

Releases all used resources and should be called on shutdown. Note: Still existing file objects are not destroyed.

int file_object_get_fd (  const struct file_object *const   fo  )

Get the file descriptor associated with a file object. This should not be used lightly and the returned file descriptor should not be cached. Future versions might open/close the file descriptor on demand or dynamically. Parameters: An  initialized file object. Returns: The file descriptor of the file object.

const char* file_object_get_pathname (  const struct file_object *const   fo  )

Get the pathname associated with a file object. Parameters: An  initialized file object. Returns: The pathname of the file object.

void file_object_init (  void   )

Initializes this module and must be called before using any other function of this module.

struct file_object* file_object_new (  const int  fd, const char *const   pathname, int  accmode )

Acquires a new file object for a given pathname. There must not be any file object registered for this pathname already. Parameters: pathname  An absolute pathname. Returns: On failure NULL is returned. On success a file object is returned.

struct file_object* file_object_open (  const char *const   pathname, int  accmode )

Acquires a file object for a given pathname and access mode. If no matching file object exists, NULL is returned. Parameters: pathname  An absolute pathname. Returns: On failure NULL is returned. On success a file object is returned.

ssize_t file_object_pread (  const struct file_object *const   fo, void *const   data, const size_t  size, const filesize_t  pos )

Read data from the file object from the given offset. Parameters: fo  An initialized file object. data  A buffer for holding the data to be read. size  The amount of bytes to read (i.e., the size of data). offset  The file offset from which to start reading data. Returns: On failure -1 is returned and errno is set. On success the amount of bytes read is returned.

ssize_t file_object_preadv (  const struct file_object *const   fo, struct iovec *const   iov, const int  iov_cnt, const filesize_t  pos )

Read data from a file object from the given offset. Parameters: fo  An initialized file object. iov  An initialized I/O vector buffer. iov_cnt  The number of initialized buffer in iov (i.e., its size). offset  The file offset at which to start reading data. Returns: On failure -1 is returned and errno is set. On success the amount of data bytes read is returned.

ssize_t file_object_pwrite (  const struct file_object *const   fo, const void *const   data, const size_t  size, const filesize_t  pos )

Write the given data to a file object at the given offset. Parameters: fo  An initialized file object. data  An initialized buffer holding the data to write. size  The amount of bytes to write (i.e., the size of data). offset  The file offset at which to start writing the data. Returns: On failure -1 is returned and errno is set. On success the amount of bytes written is returned.

ssize_t file_object_pwritev (  const struct file_object *const   fo, const struct iovec *const   iov, const int  iov_cnt, const filesize_t  pos )

Write the given data to a file object at the given offset. Parameters: fo  An initialized file object. iov  An initialized I/O vector buffer. iov_cnt  The number of initialized buffer in iov (i.e., its size). offset  The file offset at which to start writing the data. Returns: On failure -1 is returned and errno is set. On success the amount of data bytes written is returned.

void file_object_release (  struct file_object **  fo_ptr  )

Releases a file object and frees its memory. The underlying file descriptor however is not closed unless no other file object references it. The pointer is nullified. Parameters: fo_ptr  If pointing to NULL, nothing happens. Otherwise, it must point to an initialized file_object.

void file_object_revoke (  const char *const   pathname  )

Revokes all file objects associated with the pathname. This is useful after moving a file to prevent that file_object_open() returns a file object associated with the now removed file. Parameters: pathname  An absolute pathname.

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