Ring_buffer常用工具使用例子

 

头文件ring_buffer.h

#ifndef _RING_BUF_H_  
#define _RING_BUF_H_  
  
#include   
#include   
#include   
  
#define MAX_SIZE 200

/* ring buffer structure */  
struct ring_buf  
{  
    size_t depth ;             /* maximum element number */  
    size_t width ;             /* sizeof each element */  
    size_t read;            
    size_t write;             
	size_t r_msb;            
    size_t w_msb; 
    void   *buf;  
};  
  
typedef struct ring_buf  ring_buf_t;  
typedef struct ring_buf* ring_buf_p;  
  
bool ring_buf_init (ring_buf_p rbuf, size_t depth, size_t width);  
void ring_buf_free (ring_buf_p rbuf);  
void ring_buf_clear(ring_buf_p rbuf);  
  
bool ring_buf_full (ring_buf_p rbuf);  
bool ring_buf_empty(ring_buf_p rbuf);  
  
bool ring_buf_write(ring_buf_p rbuf, void *wr_data);  
bool ring_buf_read (ring_buf_p rbuf, void *rd_data);  
void *ring_buf_get(ring_buf_p rbuf);
void ring_buf_commit_read(ring_buf_p rbuf);//必须和ring_buf_get连着用，减少一次数据拷贝
  
#endif  

ring_buffer.c源文件

#include "ring_buffer.h"  
#include   
#include   
#include   
#include 
  
bool ring_buf_init(ring_buf_p rbuf, size_t depth, size_t width)  
{  
    assert(depth > 0 && depth <= MAX_SIZE && width > 0);  
  
    rbuf->depth  = depth;  
    rbuf->width  = width;  
    rbuf->read = 0;  
    rbuf->write = 0;  
	rbuf->r_msb = 0;
	rbuf->w_msb = 0;
    rbuf->buf = calloc(depth, width);  
    return rbuf->buf != NULL;  
}  
  
void ring_buf_free(ring_buf_p rbuf)  
{  
    free(rbuf->buf);  
    rbuf->buf = NULL;  
}  
  
void ring_buf_clear(ring_buf_p rbuf)  
{  
    rbuf->read = 0;  
    rbuf->write = 0; 
	rbuf->r_msb = 0;
	rbuf->w_msb = 0;
}  
  
bool ring_buf_is_empty(ring_buf_p rbuf)  
{  
    return rbuf->read == rbuf->write && rbuf->r_msb == rbuf->w_msb;  
}  
  
bool ring_buf_is_full(ring_buf_p rbuf)  
{  
    return rbuf->read == rbuf->write && rbuf->r_msb != rbuf->w_msb; 
}  
  
inline void ring_buf_incr(ring_buf_p rbuf, size_t *p_idx,size_t *msb)  
{  
    *p_idx = *p_idx + 1;
	if (*p_idx == rbuf->depth) {
        *msb ^= 1;
        *p_idx = 0;
    }
}  
  
bool ring_buf_write(ring_buf_p rbuf, void *wr_data)  
{  	
	//printf("ring_buf_write\n");
	if (ring_buf_is_full(rbuf)) {
  		print_dbg("ring buffer is full\n");
        return false; 
    }
    else {  
		//print_dbg("ring_buf_write %d\n",rbuf->width);
        memcpy(rbuf->buf + rbuf->write * rbuf->width, wr_data, rbuf->width);  
        ring_buf_incr(rbuf, &rbuf->write,&rbuf->w_msb);  
  
        return true;  
    }  
}  

bool ring_buf_read(ring_buf_p rbuf, void *rd_data)  
{  
    if (ring_buf_is_empty(rbuf)) {
		print_dbg("ring buffer is empty\n");
		return false;  
    }
    else {  
   		memcpy(rd_data, rbuf->buf + rbuf->read * rbuf->width, rbuf->width);  
        ring_buf_incr(rbuf, &rbuf->read,&rbuf->r_msb);  
        return true;  
    }  
}  

void *ring_buf_get(ring_buf_p rbuf)  
{  
	//printf("ring_buf_get\n");
	void *buffer = NULL;
	if (ring_buf_is_empty(rbuf)) {		
		print_dbg("ring buffer is empty\n");
		return NULL;  
	}
    else {  
		//print_dbg("ring_buf_get %d\n",rbuf->width);
    	buffer = rbuf->buf + rbuf->read* rbuf->width; 
        return (void *)buffer;  
    }  
}  

void ring_buf_commit_read(ring_buf_p rbuf)
{	
	//printf("ring_buf_commit_read \n");
	ring_buf_incr(rbuf, &rbuf->read,&rbuf->r_msb);	
	return;
}

使用实例main.c 

#include 
#include "ring_buffer.h"
int main()
{
	static ring_buf_t rb;
	char *buf;
	if(ring_buf_init(&rb,MAX_SIZE,SIMPLE_SIZE*sizeof(short)) == false)
	{
		printf("ring buffer init fail\n");
		
		return NULL;
	}
	
	/*可以在一个线程中不停的往ring-buffer中写数据*/
	// 从data_buffer中读取数据到rb 
	if(ring_buf_write(&rb,data_buffer) == false)
	{
		printf("ring_buffer is full1！\n")
	}	
	/*可以在另一个线程中不停地从ring-buffer读数据*/
	while(true)
	{
		buf = ring_buf_get(&rb);//从ring_buffer中读数据出来
		if(buf == NULL) {
			usleep(10);
			continue;
		}
		ring_buf_commit_read(&rb);
	}
	
	//if(rb.buf)
	//ring_buf_clear(&rb); //清空ring_buffer
	
	
	
	//使用完记得释放资源
	ring_buf_free(&rb);
}