#include "buff.h"
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
int buff_Iint(Pbuffer buffer,u16 size)
{
  //判断参数合法性
  if(buffer==NULL||size==0)
  {
    return -1;
  }
  if(buffer->fifo==NULL)
  {
    buffer->fifo=(u8*)malloc(size);//申请空间
    if(buffer->fifo==NULL)//申请空间失败
    {
      return -1;
    }
  }
  //对缓冲区进行初始化
  buffer->pr=buffer->pw=0;
  buffer->buf_size=size;
  return 0;
}
int buffer_write(Pbuffer buffer,const u8 data)
{
  //判断参数合法性
  if(buffer==NULL||buffer->fifo==NULL)
  {
    return -1;
  }
  //写入数据
  if((buffer->pw+1)%buffer->buf_size!=buffer->pr)
  {    
    buffer->fifo[buffer->pw]=data;
    buffer->pw=(buffer->pw+1)%buffer->buf_size;
    return 0;
  }
  return -1;
}
int buffer_writeBytes(Pbuffer buffer,u8 *data_strea,u8 len)
{
  int i=0;
  //判断参数合法性
  if(buffer==NULL||buffer->fifo==NULL)
  {
    return -1;
  }
  if(data_strea==NULL)
  {
    return -1;
  }
  if(len==0)
  {
    return -1;
  }
  for(i=0;i<len;i++)
  {
      if(buffer_write(buffer,data_strea[i])!=0)
      {    
            break;
      }
  }
  return i;
}
int buffer_read(Pbuffer buffer,u8 *data)
{
  //判断参数合法性
  if(buffer==NULL||buffer->fifo==NULL)
  {
    return -1;
  }
  if(buffer->pr!=buffer->pw)
  {
    *data=buffer->fifo[buffer->pr];
    buffer->pr=(buffer->pr+1)%buffer->buf_size;
    return 0;
  }
  return 0;
}
int buffer_readBytes(Pbuffer buffer,u8 *data_strea,u8 len)
{
  int i=0;
  //判断参数合法性
  if(buffer==NULL||buffer->fifo==NULL)
  {
    return -1;
  }
  if(data_strea==NULL)
  {
    return -1;
  }
  if(len==0)
  {
    return -1;
  }
  for(i=0;i<len;i++)
  {
      if(buffer_read(buffer,&data_strea[i])!=0)
      {    
            break;
      }
  }
  return i;
}
int buffer_clean(Pbuffer buffer)
{
  //判断参数合法性
  if(buffer==NULL||buffer->fifo==NULL)
  {
    return -1;
  }
  memset(buffer->fifo,0,sizeof(buffer->buf_size));//数据全部清0
  buffer->pr=buffer->pw=0;//读写置0
  return 0;
}

#ifndef _BUFF_H_
#define _BUFF_H_
#include "main.h"
#define u8 unsigned char
#define u16 unsigned short
#define u32 unsigned int
typedef struct
{
  u8 *fifo;
  u16 pw;//读指针
  u16 pr;//写指针
  u16 buf_size;//环形缓冲区大小
}buffer,*Pbuffer;
int buff_Iint(Pbuffer buffer,u16 size);
int buffer_write(Pbuffer buffer,u8 data);
int buffer_read(Pbuffer buffer,u8 *data);
int buffer_clean(Pbuffer buffer);
int buffer_writeBytes(Pbuffer buffer,u8 *data_strea,u8 len);
int buffer_readBytes(Pbuffer buffer,u8 *data_strea,u8 len);
#endif