Arc::FileAccess Class Reference

Defines interface for accessing filesystems. More...

#include <arc/FileAccess.h>

Data Structures
struct	header_t
	Internal struct used for communication between processes. More...

Public Member Functions
	FileAccess (void)
	New FileAccess object.
	~FileAccess (void)
	Shuts down any spawned executable.
bool	ping (void)
	Check if communication with proxy works.
bool	fa_setuid (int uid, int gid)
	Modify user uid and gid. More...
bool	fa_mkdir (const std::string &path, mode_t mode)
	Make a directory and assign it specified mode.
bool	fa_mkdirp (const std::string &path, mode_t mode)
	Make a directory and assign it specified mode. More...
bool	fa_link (const std::string &oldpath, const std::string &newpath)
	Create hard link.
bool	fa_softlink (const std::string &oldpath, const std::string &newpath)
	Create symbolic (aka soft) link.
bool	fa_copy (const std::string &oldpath, const std::string &newpath, mode_t mode)
	Copy file to new location. More...
bool	fa_rename (const std::string &oldpath, const std::string &newpath)
	Rename file.
bool	fa_chmod (const std::string &path, mode_t mode)
	Change mode of filesystem object.
bool	fa_stat (const std::string &path, struct stat &st)
	stat file.
bool	fa_lstat (const std::string &path, struct stat &st)
	stat symbolic link or file.
bool	fa_fstat (struct stat &st)
	stat open file.
bool	fa_ftruncate (off_t length)
	Truncate open file.
off_t	fa_fallocate (off_t length)
	Allocate disk space for open file.
bool	fa_readlink (const std::string &path, std::string &linkpath)
	Read content of symbolic link.
bool	fa_remove (const std::string &path)
	Remove file system object.
bool	fa_unlink (const std::string &path)
	Remove file.
bool	fa_rmdir (const std::string &path)
	Remove directory (if empty).
bool	fa_rmdirr (const std::string &path)
	Remove directory recursively.
bool	fa_opendir (const std::string &path)
	Open directory. Only one directory may be open at a time.
bool	fa_closedir (void)
	Close open directory.
bool	fa_readdir (std::string &name)
	Read relative name of object in open directory.
bool	fa_open (const std::string &path, int flags, mode_t mode)
	Open file. Only one file may be open at a time.
bool	fa_close (void)
	Close open file.
bool	fa_mkstemp (std::string &path, mode_t mode)
	Open new temporary file for writing. More...
off_t	fa_lseek (off_t offset, int whence)
	Change current position in open file.
ssize_t	fa_read (void *buf, size_t size)
	Read from open file.
ssize_t	fa_write (const void *buf, size_t size)
	Write to open file.
ssize_t	fa_pread (void *buf, size_t size, off_t offset)
	Read from open file at specified offset.
ssize_t	fa_pwrite (const void *buf, size_t size, off_t offset)
	Write to open file at specified offset.
int	geterrno ()
	Get errno of last operation. Every operation resets errno.
	operator bool (void)
	Returns true if this instance is in useful condition.
bool	operator! (void)
	Returns true if this instance is not in useful condition.

Static Public Member Functions
static FileAccess *	Acquire (void)
	Constructor which takes already existing object from global cache.
static void	Release (FileAccess *fa)
	Destructor which returns object into global cache.
static void	testtune (void)
	Special method for using in unit tests.

Detailed Description

Defines interface for accessing filesystems.

This class accesses the local filesystem through a proxy executable which allows switching user id in multithreaded systems without introducing conflict with other threads. Its methods are mostly replicas of corresponding POSIX functions with some convenience tweaking.

Member Function Documentation

bool Arc::FileAccess::fa_copy	(	const std::string &	oldpath,
		const std::string &	newpath,
		mode_t	mode
	)

Copy file to new location.

If new file is created it is assigned specified mode.

bool Arc::FileAccess::fa_mkdirp	(	const std::string &	path,
		mode_t	mode
	)

Make a directory and assign it specified mode.

If missing all intermediate directories are created too.

bool Arc::FileAccess::fa_mkstemp	(	std::string &	path,
		mode_t	mode
	)

Open new temporary file for writing.

On input path contains template of file name ending with XXXXXX. On output path is path to created file.

bool Arc::FileAccess::fa_setuid	(	int	uid,
		int	gid
	)

Modify user uid and gid.

If any is set to 0 then executable is switched to original uid/gid.

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

• FileAccess.h