/* ex: set ff=dos ts=2 et: */
/* $Id$ */
/*
 * Copyright 2008 Ryan Flynn
 * All rights reserved.
 */
/*
 * standard interface for reading, passing and consuming network data
 */

#ifndef BUF_H
#define BUF_H

#include <stddef.h> /* size_t */
#include "types.h"

typedef struct {
  size_t buflen, /* how much data is in */
         start, /* where the start of the current data is */
	       len; /* how much more data has been received than processed */
  u8    *data;
} buf;

void    buf_init        (buf *, u8*, size_t);
size_t  buf_after       (const buf *, const u8 *);
size_t  buf_append      (buf *, const u8 *, size_t);
size_t  buf_append_circ (buf *, const u8 *, size_t);
size_t  buf_data_contig (buf *);
size_t  buf_space_contig(buf *);
void    buf_consume     (buf *, size_t);
void    buf_lengthen    (buf *, size_t);
void    buf_shift       (buf *);
void    buf_clr         (buf *);

#define buf_start(b)    ((b)->data + (b)->start)
#define buf_end(b)      (buf_start(b) + (b)->len)
#define buf_space(b)    ((size_t)((b)->buflen - ((b)->start + (b)->len))) /* space left */
#define buf_len(b)      ((b)->len)
/* amount of contiguous data after start (for buf which may be circular) */
#define buf_buflen(b)   ((b)->buflen)

#endif