iobuf: I/O Buffer Management

Data Structures
struct	iobuf

Common
typedef struct iobuf	iobuf
int	iobuf_init (iobuf *io, int fd, unsigned bufsize, char *buffer, unsigned flags)
int	iobuf_close (iobuf *io)
int	iobuf_timeout (iobuf *io, int poll_out)
#define	IOBUF_SET_ERROR(io)
#define	iobuf_closed(io)
#define	iobuf_error(io)
#define	iobuf_timedout(io)
#define	iobuf_bad(io)

Status Flags
unsigned	iobuf_bufsize
#define	IOBUF_EOF   1
#define	IOBUF_ERROR   2
#define	IOBUF_TIMEOUT   4
#define	IOBUF_BADFLAGS   0xf
#define	IOBUF_SEEKABLE   0x10
#define	IOBUF_NEEDSCLOSE   0x20
#define	IOBUF_NEEDSFREE   0x40
#define	IOBUF_NEEDSMUNMAP   0x80

Mass copying functions.
int	iobuf_copy (ibuf *in, obuf *out)
int	iobuf_copyflush (ibuf *in, obuf *out)
int	ibuf_copytofd (ibuf *in, int out)
int	obuf_copyfromfd (int in, obuf *out)

Detailed Description

Calling Convention

Unless otherwise specified, the return value is non-zero (true) if the entire requested operation completed, and 0 (false) otherwise.

Macro Definition Documentation

iobuf_bad

#define iobuf_bad

(

io

)

Value:

((io)->flags & IOBUF_BADFLAGS)

True if the iobuf is in a "bad" state.

Referenced by ibuf_refill(), obuf_flush(), obuf_putc(), obuf_seek(), obuf_write(), and obuf_write_large().

IOBUF_BADFLAGS

#define IOBUF_BADFLAGS   0xf

Mask of all the error type flags.

iobuf_closed

#define iobuf_closed

(

io

)

Value:

((io)->fd == -1)

True if the iobuf has been closed.

IOBUF_EOF

#define IOBUF_EOF   1

Reading reached end of file.

Referenced by ibuf_eof(), ibuf_read_large(), ibuf_refill(), and ibuf_seek().

IOBUF_ERROR

#define IOBUF_ERROR   2

The iobuf has encountered an error.

Referenced by obuf_seek().

iobuf_error

#define iobuf_error

(

io

)

Value:

((io)->flags & IOBUF_ERROR)

True if the iobuf has an error flag.

IOBUF_NEEDSCLOSE

#define IOBUF_NEEDSCLOSE   0x20

The file descriptor needs to be closed.

Referenced by ibuf_open(), iobuf_close(), and obuf_open().

IOBUF_NEEDSFREE

#define IOBUF_NEEDSFREE   0x40

The buffer needs to be deallocated with free

Referenced by iobuf_close(), and iobuf_init().

IOBUF_NEEDSMUNMAP

#define IOBUF_NEEDSMUNMAP   0x80

The buffer needs to be deallocated with munmap

Referenced by iobuf_close(), and iobuf_init().

IOBUF_SEEKABLE

#define IOBUF_SEEKABLE   0x10

lseek is possible on the file descriptor.

Referenced by ibuf_open(), and obuf_open().

IOBUF_SET_ERROR

#define IOBUF_SET_ERROR

(

io

)

Value:

do{ \
  io->flags |= IOBUF_ERROR; \
  io->errnum = errno; \
  return 0; \
}while(0)

Set the error flag, save errno, and return false.

Referenced by ibuf_read_large(), ibuf_refill(), ibuf_seek(), iobuf_timeout(), obuf_flush(), obuf_sync(), and obuf_write_large().

iobuf_timedout

#define iobuf_timedout

(

io

)

Value:

((io)->flags & IOBUF_TIMEOUT)

True if the input or output to the iobuf previously timed out.

IOBUF_TIMEOUT

#define IOBUF_TIMEOUT   4

The timeout expired before the read or write could be completed.

Referenced by iobuf_timeout().

Function Documentation

ibuf_copytofd()

int ibuf_copytofd	(	ibuf *	in,
		int	out )

Copy all the data from an ibuf to an output file descriptor.

References iobuf::buffer, iobuf::buflen, iobuf::bufstart, ibuf::count, ibuf_eof(), ibuf_error, ibuf_refill(), and ibuf::io.

iobuf_close()

int iobuf_close

(

iobuf *

io

)

Close an iobuf and deallocate the buffer.

References iobuf::buffer, iobuf::bufsize, iobuf::fd, iobuf::flags, IOBUF_NEEDSCLOSE, IOBUF_NEEDSFREE, and IOBUF_NEEDSMUNMAP.

Referenced by obuf_close().

iobuf_copy()

int iobuf_copy	(	ibuf *	in,
		obuf *	out )

Copy all the data from an ibuf to an obuf.

References iobuf::buffer, iobuf::buflen, iobuf::bufstart, ibuf_eof(), ibuf_error, ibuf_refill(), ibuf::io, obuf_error, and obuf_write_large().

Referenced by iobuf_copyflush().

iobuf_copyflush()

int iobuf_copyflush	(	ibuf *	in,
		obuf *	out )

Copy all the data from an ibuf to an obuf, and flush the obuf after writing is completed.

References iobuf_copy(), and obuf_flush().

iobuf_init()

int iobuf_init	(	iobuf *	io,
		int	fd,
		unsigned	bufsize,
		char *	buffer,
		unsigned	flags )

Initialize an iobuf structure.

References iobuf::buffer, iobuf::bufsize, iobuf::fd, iobuf::flags, iobuf_bufsize, IOBUF_NEEDSFREE, and IOBUF_NEEDSMUNMAP.

Referenced by ibuf_init(), and obuf_init().

iobuf_timeout()

int iobuf_timeout	(	iobuf *	io,
		int	poll_out )

Wait for a file descriptor to be ready for reading or writing.

References iobuf::fd, iobuf::flags, IOBUF_SET_ERROR, IOBUF_TIMEOUT, and iobuf::timeout.

Referenced by ibuf_read_large(), ibuf_refill(), obuf_flush(), and obuf_write_large().

obuf_copyfromfd()

int obuf_copyfromfd	(	int	in,
		obuf *	out )

Copy all the data from an input file descriptor to an obuf.

References iobuf::buffer, iobuf::buflen, obuf::bufpos, iobuf::bufsize, obuf::count, obuf::io, obuf_error, and obuf_flush().

Variable Documentation

iobuf_bufsize

unsigned iobuf_bufsize

extern

The default iobuf buffer size, defaults to 8192.

Referenced by iobuf_init().