/**
 * my implementation of a ringbuffer.
 * It maps a shared memory object twice directly following
 * thus make it possible to read and write from any
 * position within the buffer without the nasty wrap
 * calculations.
 * This is achived because the same memory region is mapped
 * at the two addresses.
 */
#ifndef __RINGBUFFER_H__
#define __RINGBUFFER_H__

#include <ctype.h>
#include <string.h>
#include <sys/types.h>

#include "class.h"

#define ECBUFOVFL		100

#ifndef TRUE
#define TRUE	((void *)1)
#endif

#ifndef FALSE
#define FALSE	((void *)0)
#endif

CLASS(Cbuf) {
	char * shm_name;  // shared memory identifier

	char * data;
	void * lock;

	size_t bsize;
	size_t bused;

	size_t write;
	size_t read;
};

ssize_t cbufRead(Cbuf, int fd);
ssize_t cbufWrite(Cbuf, int fd);

char *  cbufGetLine(Cbuf);
char *  cbufGetData(Cbuf, size_t);
char *  cbufSetData(Cbuf, const void *, size_t);
void    cbufEmpty(Cbuf);

char *  cbufGetRead(Cbuf this);
char *  cbufGetWrite(Cbuf this);
char *  cbufMemchr(Cbuf this, int c);
size_t  cbufAddrIndex(Cbuf this, const void * c);
void    cbufIncRead(Cbuf this, size_t n);
void    cbufIncWrite(Cbuf this, size_t n);
size_t  cbufGetFree(Cbuf this);
char    cbufIsEmpty(Cbuf this);
void    cbufSkipNonAlpha(Cbuf this);
void *  cbufIsLocked(Cbuf this);
void    cbufLock(Cbuf this);
void    cbufRelease(Cbuf this);

#endif // __RINGBUFFER_H__

// vim: set ts=4 sw=4: