/*********************************************************************************
 *      Copyright:  (C) 2023 LingYun IoT System Studio.
 *                  All rights reserved.
 *
 *       Filename:  ringbuf.h
 *    Description:  This file is common ring buffer API functions
 *
 *        Version:  1.0.0(11/08/23)
 *         Author:  Guo Wenxue <guowenxue@gmail.com>
 *      ChangeLog:  1, Release initial version on "11/08/23 16:18:43"
 *
 ********************************************************************************/

#ifndef  _RINGBUF_H_
#define  _RINGBUF_H_

struct ring_buffer
{
    unsigned char      *buffer;
    int                 wr_pointer;
    int                 rd_pointer;
    int                 size;
};


/* Initial the ring buffer */
void rb_init(struct ring_buffer *rb, unsigned char *buf, int size);

/* Clear the ring buffer data  */
void rb_clear(struct ring_buffer *rb);

/* Get data size in the ring buffer  */
int rb_data_size(struct ring_buffer *rb);

/* Get ring buffer left free size  */
int rb_free_size(struct ring_buffer *rb);

/* Read a specify $index byte data in ring buffer $rb  */
unsigned char rb_peek(struct ring_buffer *rb, int index);

/*  Description: Write $len bytes data in $buf into ring buffer $rb
 * Return Value: The actual written into ring buffer data size, if ring buffer
 * left space size small than $len, then only part of the data be written into.
 */
int rb_write(struct ring_buffer *rb, unsigned char *buf, int len);

/* Read $bytes data from ring buffer $rb to $buf */
int rb_read(struct ring_buffer *rb, unsigned char *buf, int bytes);

/* Read $bytes data from ring buffer $rb to $buf, but not drain */
int rb_copy(struct ring_buffer *rb, unsigned char *buf, int bytes);

#endif   /* ----- #ifndef _RINGBUF_H_  ----- */