#ifndef BUF_H_B87OZOFU
#define BUF_H_B87OZOFU

#include <stdlib.h>

#ifndef NDEBUG
#include "notify.h"
#endif /* NDEBUG */

/*	A simple sliding-window byte buffer. */

typedef struct buf_ {
	size_t buf_sz;
	size_t buf_start;
	size_t buf_used;
	unsigned char buf[];
} *buf_t;
#define BUF_ROOM(__b__) ( (__b__)->buf_sz - ( (__b__)->buf_start + (__b__)->buf_used ) )

#ifndef NDEBUG
/*	For debugging, dump a buffer. */
#define D_BUF(__pre__,__b__,...) do {\
	if ( (__b__) == NULL )\
		NOTIFY_DEBUG(__pre__ "buf:%p", ## __VA_ARGS__, (__b__));\
	else {\
		NOTIFY_DEBUG(__pre__ "buf:%p sz:%zu start:%zu used:%zu free:%zu '%.*s'",\
		             ## __VA_ARGS__,\
		             (__b__),\
		             (__b__)->buf_sz,\
		             (__b__)->buf_start,\
		             (__b__)->buf_used,\
		             BUF_ROOM((__b__)),\
		             (int)(__b__)->buf_used, (__b__)->buf + (__b__)->buf_start);\
		assert( (__b__)->buf_sz >= (__b__)->buf_start + (__b__)->buf_used );\
	}\
} while (0)
#else /* NDEBUG */
#define D_BUF(...)
#endif /* NDEBUG */

/*	buf_new
		Allocate and return a new buf_t capable of holding #sz bytes.
*/
buf_t buf_new(size_t sz);

/*	buf_del
		Deallocate the buf_t pointed to by #pbuf.
*/
void buf_del(buf_t *pbuf);

/*	buf_rebase
		Reclaim any free space from the start of #buf, preserving active content.
*/
void buf_rebase(buf_t buf);

/*	buf_makeroom
		Assures that the buf pointed to by #pbuf has at space to hold #roomfor
	more bytes.
*/
int buf_makeroom(buf_t *pbuf, size_t roomfor);

/*	buf_range_dup_or_append
		Starting at the #src_offset byte of #src, appends the following #n
	bytes to the buffer pointed to by #dstp, which will be re/allocated if
	needed.
*/
int buf_range_dup_or_append(buf_t src, size_t src_offset, size_t n, buf_t *pdst);

/*	buf_flense
		Starting after #src_offset characters, scan through the buffer pointed
	to by #psrc, stopping at the first byte matching #delimiter, whereupon, if
	#pdst is not NULL, all the bytes previous to #delimiter are appended onto
	the buffer pointed to by *#pdst.  The buffer pointed to by #psrc is then
	trimmed to only contain the bytes following #delimiter.  The delimiter byte
	is discarded.
		Returns the number of characters flensed from #src.
*/
ssize_t buf_flense(buf_t *psrc, size_t src_offset, int delimiter, buf_t *pdst);

#endif /* BUF_H_B87OZOFU */