iobuf: I/O Buffer Management

Data Structures
struct	iobuf
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
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)   ((io)->fd == -1)
#define	iobuf_error(io)   ((io)->flags & IOBUF_ERROR)
#define	iobuf_timedout(io)   ((io)->flags & IOBUF_TIMEOUT)
#define	iobuf_bad(io)   ((io)->flags & IOBUF_BADFLAGS)
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)

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Detailed Description

Calling Convention

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

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Define Documentation

#define iobuf_bad

(

io

)

((io)->flags & IOBUF_BADFLAGS)

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

#define IOBUF_BADFLAGS   0xf

Mask of all the error type flags.

#define iobuf_closed

(

io

)

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

True if the iobuf has been closed.

#define IOBUF_EOF   1

Reading reached end of file.

#define iobuf_error

(

io

)

((io)->flags & IOBUF_ERROR)

True if the iobuf has an error flag.

#define IOBUF_ERROR   2

The iobuf has encountered an error.

#define IOBUF_NEEDSCLOSE   0x20

The file descriptor needs to be closed.

#define IOBUF_NEEDSFREE   0x40

The buffer needs to be deallocated with free

#define IOBUF_NEEDSMUNMAP   0x80

The buffer needs to be deallocated with munmap

#define IOBUF_SEEKABLE   0x10

lseek is possible on the file descriptor.

#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.

#define iobuf_timedout

(

io

)

((io)->flags & IOBUF_TIMEOUT)

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

#define IOBUF_TIMEOUT   4

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

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Function Documentation

int ibuf_copytofd	(	ibuf *	in,
		int	out
	)

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

int iobuf_close

(

iobuf *

io

)

Close an iobuf and deallocate the buffer.

int iobuf_copy	(	ibuf *	in,
		obuf *	out
	)

Copy all the data from an ibuf to an obuf.

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.

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

Initialize an iobuf structure.

int iobuf_timeout	(	iobuf *	io,
		int	poll_out
	)

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

int obuf_copyfromfd	(	int	in,
		obuf *	out
	)

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

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Variable Documentation

unsigned iobuf_bufsize

The default iobuf buffer size, defaults to 8192.

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