io.h File Reference

C wrapper for I/O interfaces. More...

#include "dmlite.h"
#include "any.h"
#include "pool.h"
#include <sys/uio.h>
#include <unistd.h>

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Macros
#define	O_INSECURE   010

Typedefs
typedef struct dmlite_fd	dmlite_fd

Functions
dmlite_fd *	dmlite_fopen (dmlite_context *context, const char *path, int flags, const dmlite_any_dict *extra,...)
	Opens a file.
int	dmlite_fclose (dmlite_fd *fd)
	Closes a file.
int	dmlite_fstat (dmlite_fd *fd, struct stat *buf)
	Gets information about a file descriptor.
int	dmlite_fseek (dmlite_fd *fd, off_t offset, int whence)
	Sets the file position.
off_t	dmlite_ftell (dmlite_fd *fd)
	Returns the cursor position.
ssize_t	dmlite_fread (dmlite_fd *fd, void *buffer, size_t count)
	Reads from a file.
ssize_t	dmlite_fwrite (dmlite_fd *fd, const void *buffer, size_t count)
	Writes to a file.
ssize_t	dmlite_freadv (dmlite_fd *fd, const struct iovec *vector, size_t count)
	Reads from a file into multiple buffers.
ssize_t	dmlite_fwritev (dmlite_fd *fd, const struct iovec *vector, size_t count)
	Reads from a file into multiple buffers.
ssize_t	dmlite_fpread (dmlite_fd *fd, void *buffer, size_t count, off_t offset)
	Reads up to count bytes starting at the given offset. Does not change internal offset.
ssize_t	dmlite_fpwrite (dmlite_fd *fd, const void *buffer, size_t count, off_t offset)
	Writes count bytes starting at the given offset. Does not change internal offset.
int	dmlite_feof (dmlite_fd *fd)
	Returns 1 if EOF.
int	dmlite_ferrno (dmlite_fd *fd)
	Returns the last errror code.
const char *	dmlite_ferror (dmlite_fd *fd)
	Returns the last error message.
int	dmlite_donewriting (dmlite_context *context, const dmlite_location *loc)
	Finishes a PUT.
int	dmlite_fileno (dmlite_fd *fd)
	Returns the system file descriptor if available.

Detailed Description

C wrapper for I/O interfaces.

Author

Alejandro Álvarez Ayllon aalva.nosp@m.rez@.nosp@m.cern..nosp@m.ch

Macro Definition Documentation

O_INSECURE

#define O_INSECURE   010

Use this flag in addition to the standard ones to skip any security check (i.e. token validation)

Typedef Documentation

dmlite_fd

typedef struct dmlite_fd dmlite_fd

Handle for a file descriptor.

Function Documentation

dmlite_donewriting()

int dmlite_donewriting	(	dmlite_context *	context,
		const dmlite_location *	loc
	)

Finishes a PUT.

Parameters

context	The DM context.
loc	The location as returned by dmlite_put.

Returns

0 on success, error code otherwise.

dmlite_fclose()

int dmlite_fclose

(

dmlite_fd *

fd

)

Closes a file.

Parameters

fd	The file descriptor as returned by dmlite_open.

Returns

0 on success, error code otherwise.

dmlite_feof()

int dmlite_feof

(

dmlite_fd *

fd

)

Returns 1 if EOF.

Parameters

fd	The file descriptor.

Returns

0 if there is more to read. 1 if EOF.

dmlite_ferrno()

int dmlite_ferrno

(

dmlite_fd *

fd

)

Returns the last errror code.

Parameters

fd	The file descriptor.

Returns

The last error code.

dmlite_ferror()

const char * dmlite_ferror

(

dmlite_fd *

fd

)

Returns the last error message.

Parameters

fd	The file descriptor.

Returns

A pointer to an internal buffer with the last error message.

Note

This buffer is specific to each file descriptor.

dmlite_fileno()

int dmlite_fileno

(

dmlite_fd *

fd

)

Returns the system file descriptor if available.

Parameters

fd	The file descriptor.

Returns

The file descriptor, -1 if it can not be retrieved.

Note

Support depends on the plugin providing the file.

Calling dmlite_fclose will close the file descriptor returned by this.

dmlite_fopen()

dmlite_fd * dmlite_fopen	(	dmlite_context *	context,
		const char *	path,
		int	flags,
		const dmlite_any_dict *	extra,
			...
	)

Opens a file.

Parameters

context	The DM context.
path	The path to open.
flags	See open()
extra	The key-value pairs.
...	Should be mode_t when called with O_CREAT.

Returns

An opaque handler for the file, NULL on failure.

dmlite_fpread()

ssize_t dmlite_fpread	(	dmlite_fd *	fd,
		void *	buffer,
		size_t	count,
		off_t	offset
	)

Reads up to count bytes starting at the given offset. Does not change internal offset.

Parameters

fd	File descriptor.
buffer	Buffer where to put the data.
count	Number of bytes to read.
offset	Read offset.

Returns

Number of bytes actually read on success. -1 on failure.

dmlite_fpwrite()

ssize_t dmlite_fpwrite	(	dmlite_fd *	fd,
		const void *	buffer,
		size_t	count,
		off_t	offset
	)

Writes count bytes starting at the given offset. Does not change internal offset.

Parameters

fd	File descriptor.
buffer	Data to write.
count	Number of bytes to read.
offset	Write offset.

Returns

Number of bytes actually write on success. -1 on failure.

dmlite_fread()

ssize_t dmlite_fread	(	dmlite_fd *	fd,
		void *	buffer,
		size_t	count
	)

Reads from a file.

Parameters

fd	The file descriptor.
buffer	Where to put the data.
count	Number of bytes to read.

Returns

Number of bytes actually read on success. -1 on failure.

dmlite_freadv()

ssize_t dmlite_freadv	(	dmlite_fd *	fd,
		const struct iovec *	vector,
		size_t	count
	)

Reads from a file into multiple buffers.

Parameters

fd	The file descriptor.
vector	Array of buffers.
count	Number of elements in the array of buffers.

Returns

Number of bytes actually read on success. -1 on failure.

dmlite_fseek()

int dmlite_fseek	(	dmlite_fd *	fd,
		off_t	offset,
		int	whence
	)

Sets the file position.

Parameters

fd	The file descriptor.
offset	The offset.
whence	See fseek()

Returns

0 on success, error code otherwise.

dmlite_fstat()

int dmlite_fstat	(	dmlite_fd *	fd,
		struct stat *	buf
	)

Gets information about a file descriptor.

Parameters

fd	The file descriptor.
buf	Where to put the information.

Returns

0 on success, error code otherwise.

Note

Not all plug-ins will fill all the fields, but st_size is a reasonable expectation.

dmlite_ftell()

off_t dmlite_ftell

(

dmlite_fd *

fd

)

Returns the cursor position.

Parameters

fd	The file descriptor.

Returns

The cursor position, or -1 on error.

dmlite_fwrite()

ssize_t dmlite_fwrite	(	dmlite_fd *	fd,
		const void *	buffer,
		size_t	count
	)

Writes to a file.

Parameters

fd	The file descriptor.
buffer	A pointer to the data.
count	Number of bytes to write.

Returns

Number of bytes actually written. -1 on failure.

dmlite_fwritev()

ssize_t dmlite_fwritev	(	dmlite_fd *	fd,
		const struct iovec *	vector,
		size_t	count
	)

Reads from a file into multiple buffers.

Parameters

fd	The file descriptor.
vector	Array of buffers.
count	Number of elements in the array of buffers.

Returns

Number of bytes actually read on success. -1 on failure.