c和c++的循环buffer

自已项目上一直用的循环buffer的源码，可用于中断。

c文件

#include "buffer.h"

#if C_CODE  //c code

void DataBufferInit(DataBuffer *intance)
{
    if(NULL == intance){
        return;
    }

    intance->last_recv_time = 0;
    intance->first = 0;
    intance->last = 0;
    intance->full = 0;
}

uint16_t BufferAvailable(DataBuffer *intance)
{
    if(NULL == intance){
        return 0;
    }

    uint16_t len = 0;
    if(intance->last > intance->first)
    {
        len = intance->last - intance->first;
    }else if(intance->last < intance->first)
    {
        len = (BUFFER_DAT_LEN - intance->first) + intance->last;
    }else if(intance->last == intance->first)
    {
        len = 0;
    }

    return len;
}

uint8_t BufferRead(DataBuffer *intance)
{
    if(NULL == intance){
        return 0;
    }

    uint8_t dat = 0;
    if( BufferAvailable(intance