模仿kfifo实现的环形缓冲区

XinLiOV

模仿kfifo实现的环形缓冲区

转载来源：模仿kfifo实现的环形缓冲区


GitHub仓库：https://github.com/XinLiGitHub/RingBuffer
PS：博文不再更新，后续更新会在GitHub仓库进行。

    模仿kfifo实现的环形缓冲区。程序中涉及到环形缓冲区的概念，详细介绍见维基百科[Circular buffer](https://en.wikipedia.org/wiki/Circular_buffer)。

1，开发环境
      1，操作系统：Windows 10 专业版
      2，IDE：Visual Studio 2015 专业版

2，程序源码
      RingBuffer.h文件
[mw_shl_code=c,true]/**
  ******************************************************************************
  * @file    RingBuffer.h
  * @author  XinLi
  * @version v1.0
  * @date    15-January-2018
  * @brief   Header file for RingBuffer.c module.
  ******************************************************************************
  * @attention
  *
  * <h2><center>Copyright &#169; 2018 XinLi</center></h2>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation, either version 3 of the License, or
  * (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  *
  ******************************************************************************
  */

#ifndef __RINGBUFFER_H
#define __RINGBUFFER_H

#ifdef __cplusplus
extern "C" {
#endif

/* Header includes -----------------------------------------------------------*/
#include <stdint.h>
#include <stdbool.h>

/* Macro definitions ---------------------------------------------------------*/
#define RING_BUFFER_MALLOC(size)  malloc(size)
#define RING_BUFFER_FREE(block)   free(block)

/* Type definitions ----------------------------------------------------------*/
typedef struct
{
  uint8_t *buffer;
  uint32_t size;
  uint32_t in;
  uint32_t out;
}RingBuffer;

/* Variable declarations -----------------------------------------------------*/
/* Variable definitions ------------------------------------------------------*/
/* Function declarations -----------------------------------------------------*/
RingBuffer *RingBuffer_Malloc(uint32_t size);
void RingBuffer_Free(RingBuffer *fifo);
uint32_t RingBuffer_In(RingBuffer *fifo, void *in, uint32_t len);
uint32_t RingBuffer_Out(RingBuffer *fifo, void *out, uint32_t len);

/* Function definitions ------------------------------------------------------*/

/**
  * @brief  Removes the entire FIFO contents.
  * @param  [in] fifo: The fifo to be emptied.
  * @return None.
  */
static inline void RingBuffer_Reset(RingBuffer *fifo)
{
  fifo->in = fifo->out = 0;
}

/**
  * @brief  Returns the size of the FIFO in bytes.
  * @param  [in] fifo: The fifo to be used.
  * @return The size of the FIFO.
  */
static inline uint32_t RingBuffer_Size(RingBuffer *fifo)
{
  return fifo->size;
}

/**
  * @brief  Returns the number of used bytes in the FIFO.
  * @param  [in] fifo: The fifo to be used.
  * @return The number of used bytes.
  */
static inline uint32_t RingBuffer_Len(RingBuffer *fifo)
{
  return fifo->in - fifo->out;
}

/**
  * @brief  Returns the number of bytes available in the FIFO.
  * @param  [in] fifo: The fifo to be used.
  * @return The number of bytes available.
  */
static inline uint32_t RingBuffer_Avail(RingBuffer *fifo)
{
  return RingBuffer_Size(fifo) - RingBuffer_Len(fifo);
}

/**
  * @brief  Is the FIFO empty?
  * @param  [in] fifo: The fifo to be used.
  * @retval true:      Yes.
  * @retval false:     No.
  */
static inline bool RingBuffer_IsEmpty(RingBuffer *fifo)
{
  return RingBuffer_Len(fifo) == 0;
}

/**
  * @brief  Is the FIFO full?
  * @param  [in] fifo: The fifo to be used.
  * @retval true:      Yes.
  * @retval false:     No.
  */
static inline bool RingBuffer_IsFull(RingBuffer *fifo)
{
  return RingBuffer_Avail(fifo) == 0;
}

#ifdef __cplusplus
}
#endif

#endif /* __RINGBUFFER_H */
[/mw_shl_code]

      RingBuffer.c文件
[mw_shl_code=c,true]/**
  ******************************************************************************
  * @file    RingBuffer.c
  * @author  XinLi
  * @version v1.0
  * @date    15-January-2018
  * @brief   Ring buffer module source file.
  ******************************************************************************
  * @attention
  *
  * <h2><center>Copyright &#169; 2018 XinLi</center></h2>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation, either version 3 of the License, or
  * (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  *
  ******************************************************************************
  */

/* Header includes -----------------------------------------------------------*/
#include "RingBuffer.h"
#include <stdlib.h>
#include <string.h>

/* Macro definitions ---------------------------------------------------------*/
/* Type definitions ----------------------------------------------------------*/
/* Variable declarations -----------------------------------------------------*/
/* Variable definitions ------------------------------------------------------*/
/* Function declarations -----------------------------------------------------*/
static bool is_power_of_2(uint32_t x);
static uint32_t roundup_pow_of_two(uint32_t x);

/* Function definitions ------------------------------------------------------*/

/**
  * @brief  Allocates a new FIFO and its internal buffer.
  * @param  [in] size: The size of the internal buffer to be allocated.
  * @note   The size will be rounded-up to a power of 2.
  * @return RingBuffer pointer.
  */
RingBuffer *RingBuffer_Malloc(uint32_t size)
{
  RingBuffer *fifo = RING_BUFFER_MALLOC(sizeof(RingBuffer));

  if(fifo != NULL)
  {
    if(is_power_of_2(size) != true)
    {
      if(size > 0x80000000UL)
      {
        RING_BUFFER_FREE(fifo);
        fifo = NULL;
        return fifo;
      }

      size = roundup_pow_of_two(size);
    }

    fifo->size   = size;
    fifo->in     = 0;
    fifo->out    = 0;
    fifo->buffer = RING_BUFFER_MALLOC(fifo->size);

    if(fifo->buffer == NULL)
    {
      RING_BUFFER_FREE(fifo);
      fifo = NULL;
      return fifo;
    }
  }

  return fifo;
}

/**
  * @brief  Frees the FIFO.
  * @param  [in] fifo: The fifo to be freed.
  * @return None.
  */
void RingBuffer_Free(RingBuffer *fifo)
{
  RING_BUFFER_FREE(fifo->buffer);
  RING_BUFFER_FREE(fifo);
  fifo = NULL;
}

/**
  * @brief  Puts some data into the FIFO.
  * @param  [in] fifo: The fifo to be used.
  * @param  [in] in:   The data to be added.
  * @param  [in] len:  The length of the data to be added.
  * @return The number of bytes copied.
  * @note   This function copies at most @len bytes from the @in into
  *         the FIFO depending on the free space, and returns the number
  *         of bytes copied.
  */
uint32_t RingBuffer_In(RingBuffer *fifo, void *in, uint32_t len)
{
  len = min(len, RingBuffer_Avail(fifo));

  /* First put the data starting from fifo->in to buffer end. */
  uint32_t l = min(len, fifo->size - (fifo->in & (fifo->size - 1)));
  memcpy(fifo->buffer + (fifo->in & (fifo->size - 1)), in, l);

  /* Then put the rest (if any) at the beginning of the buffer. */
  memcpy(fifo->buffer, (uint8_t *)in + l, len - l);

  fifo->in += len;

  return len;
}

/**
  * @brief  Gets some data from the FIFO.
  * @param  [in] fifo: The fifo to be used.
  * @param  [in] out:  Where the data must be copied.
  * @param  [in] len:  The size of the destination buffer.
  * @return The number of copied bytes.
  * @note   This function copies at most @len bytes from the FIFO into
  *         the @out and returns the number of copied bytes.
  */
uint32_t RingBuffer_Out(RingBuffer *fifo, void *out, uint32_t len)
{
  len = min(len, RingBuffer_Len(fifo));

  /* First get the data from fifo->out until the end of the buffer. */
  uint32_t l = min(len, fifo->size - (fifo->out & (fifo->size - 1)));
  memcpy(out, fifo->buffer + (fifo->out & (fifo->size - 1)), l);

  /* Then get the rest (if any) from the beginning of the buffer. */
  memcpy((uint8_t *)out + l, fifo->buffer, len - l);

  fifo->out += len;

  return len;
}

/**
  * @brief  Determine whether some value is a power of two.
  * @param  [in] x: The number to be confirmed.
  * @retval true:   Yes.
  * @retval false:  No.
  * @note   Where zero is not considered a power of two.
  */
static bool is_power_of_2(uint32_t x)
{
  return (x != 0) && ((x & (x - 1)) == 0);
}

/**
  * @brief  Round the given value up to nearest power of two.
  * @param  [in] x: The number to be converted.
  * @return The power of two.
  */
static uint32_t roundup_pow_of_two(uint32_t x)
{
  uint32_t b = 0;

  for(int i = 0; i < 32; i++)
  {
    b = 1UL << i;

    if(x <= b)
    {
      break;
    }
  }

  return b;
}
[/mw_shl_code]

XinLiOV

      main.c文件
[mw_shl_code=c,true]/**
  ******************************************************************************
  * @file    main.c
  * @author  XinLi
  * @version v1.0
  * @date    15-January-2018
  * @brief   Main program body.
  ******************************************************************************
  * @attention
  *
  * <h2><center>Copyright &copy; 2018 XinLi</center></h2>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation, either version 3 of the License, or
  * (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  *
  ******************************************************************************
  */

/* Header includes -----------------------------------------------------------*/
#include "RingBuffer.h"
#include <stdio.h>
#include <windows.h>

/* Macro definitions ---------------------------------------------------------*/
/* Type definitions ----------------------------------------------------------*/
/* Variable declarations -----------------------------------------------------*/
/* Variable definitions ------------------------------------------------------*/
/* Function declarations -----------------------------------------------------*/
/* Function definitions ------------------------------------------------------*/

/**
  * @brief  Main program.
  * @param  None.
  * @return None.
  */
int main(void)
{
  uint8_t data[256] = {0};

  for(int i = 0; i < sizeof(data); i++)
  {
    data = i;
  }

  RingBuffer *fifo = RingBuffer_Malloc(sizeof(data));

  if(fifo != NULL)
  {
    printf("FIFO创建成功，FIFO大小：%d，使用大小：%d，剩余大小：%d\n",
           RingBuffer_Size(fifo), RingBuffer_Len(fifo), RingBuffer_Avail(fifo));

    if(RingBuffer_IsFull(fifo) == true)
    {
      printf("FIFO满了！！！\n");
    }
    else
    {
      printf("FIFO没满！！！\n");
    }

    if(RingBuffer_IsEmpty(fifo) == true)
    {
      printf("FIFO空了！！！\n");
    }
    else
    {
      printf("FIFO没空！！！\n");
    }

    printf("\n");

    for(;;)
    {
      {
        if(RingBuffer_In(fifo, data, sizeof(data) / 2) > 0)
        {
          printf("FIFO写入成功，FIFO大小：%d，使用大小：%d，剩余大小：%d\n",
                 RingBuffer_Size(fifo), RingBuffer_Len(fifo), RingBuffer_Avail(fifo));
        }
        else
        {
          printf("FIFO写入失败，FIFO大小：%d，使用大小：%d，剩余大小：%d\n",
                 RingBuffer_Size(fifo), RingBuffer_Len(fifo), RingBuffer_Avail(fifo));
        }

        if(RingBuffer_IsFull(fifo) == true)
        {
          printf("FIFO满了！！！\n");
        }
        else
        {
          printf("FIFO没满！！！\n");
        }

        if(RingBuffer_IsEmpty(fifo) == true)
        {
          printf("FIFO空了！！！\n");
        }
        else
        {
          printf("FIFO没空！！！\n");
        }
      }

      printf("\n");

      {
        uint8_t rdata[64] = {0};
        uint8_t len       = RingBuffer_Out(fifo, rdata, sizeof(rdata));

        if(len > 0)
        {
          printf("从FIFO中读出的数据，长度：%d\n", len);

          for(int i = 0; i < len; i++)
          {
            printf("%d ", rdata);
          }

          printf("\n");

          printf("FIFO读取成功，FIFO大小：%d，使用大小：%d，剩余大小：%d\n",
                 RingBuffer_Size(fifo), RingBuffer_Len(fifo), RingBuffer_Avail(fifo));
        }
        else
        {
          printf("FIFO读取失败，FIFO大小：%d，使用大小：%d，剩余大小：%d\n",
                 RingBuffer_Size(fifo), RingBuffer_Len(fifo), RingBuffer_Avail(fifo));
        }

        if(RingBuffer_IsFull(fifo) == true)
        {
          printf("FIFO满了！！！\n");
        }
        else
        {
          printf("FIFO没满！！！\n");
        }

        if(RingBuffer_IsEmpty(fifo) == true)
        {
          printf("FIFO空了！！！\n");
        }
        else
        {
          printf("FIFO没空！！！\n");
        }
      }

      printf("\n");

      {
        RingBuffer_Reset(fifo);
        printf("FIFO清空成功，FIFO大小：%d，使用大小：%d，剩余大小：%d\n",
               RingBuffer_Size(fifo), RingBuffer_Len(fifo), RingBuffer_Avail(fifo));

        if(RingBuffer_IsFull(fifo) == true)
        {
          printf("FIFO满了！！！\n");
        }
        else
        {
          printf("FIFO没满！！！\n");
        }

        if(RingBuffer_IsEmpty(fifo) == true)
        {
          printf("FIFO空了！！！\n");
        }
        else
        {
          printf("FIFO没空！！！\n");
        }
      }

      printf("\n");

      {
        if(RingBuffer_In(fifo, data, sizeof(data)) > 0)
        {
          printf("FIFO写入成功，FIFO大小：%d，使用大小：%d，剩余大小：%d\n",
                 RingBuffer_Size(fifo), RingBuffer_Len(fifo), RingBuffer_Avail(fifo));
        }
        else
        {
          printf("FIFO写入失败，FIFO大小：%d，使用大小：%d，剩余大小：%d\n",
                 RingBuffer_Size(fifo), RingBuffer_Len(fifo), RingBuffer_Avail(fifo));
        }

        if(RingBuffer_IsFull(fifo) == true)
        {
          printf("FIFO满了！！！\n");
        }
        else
        {
          printf("FIFO没满！！！\n");
        }

        if(RingBuffer_IsEmpty(fifo) == true)
        {
          printf("FIFO空了！！！\n");
        }
        else
        {
          printf("FIFO没空！！！\n");
        }
      }

      printf("\n");

      {
        if(RingBuffer_In(fifo, data, sizeof(data)) > 0)
        {
          printf("FIFO写入成功，FIFO大小：%d，使用大小：%d，剩余大小：%d\n",
                 RingBuffer_Size(fifo), RingBuffer_Len(fifo), RingBuffer_Avail(fifo));
        }
        else
        {
          printf("FIFO写入失败，FIFO大小：%d，使用大小：%d，剩余大小：%d\n",
                 RingBuffer_Size(fifo), RingBuffer_Len(fifo), RingBuffer_Avail(fifo));
        }

        if(RingBuffer_IsFull(fifo) == true)
        {
          printf("FIFO满了！！！\n");
        }
        else
        {
          printf("FIFO没满！！！\n");
        }

        if(RingBuffer_IsEmpty(fifo) == true)
        {
          printf("FIFO空了！！！\n");
        }
        else
        {
          printf("FIFO没空！！！\n");
        }
      }

      printf("\n");

      {
        uint8_t  rdata[256] = {0};
        uint16_t len        = RingBuffer_Out(fifo, rdata, sizeof(rdata));

        if(len > 0)
        {
          printf("从FIFO中读出的数据，长度：%d\n", len);

          for(int i = 0; i < len; i++)
          {
            printf("%d ", rdata);
          }

          printf("\n");

          printf("FIFO读取成功，FIFO大小：%d，使用大小：%d，剩余大小：%d\n",
                 RingBuffer_Size(fifo), RingBuffer_Len(fifo), RingBuffer_Avail(fifo));
        }
        else
        {
          printf("FIFO读取失败，FIFO大小：%d，使用大小：%d，剩余大小：%d\n",
                 RingBuffer_Size(fifo), RingBuffer_Len(fifo), RingBuffer_Avail(fifo));
        }

        if(RingBuffer_IsFull(fifo) == true)
        {
          printf("FIFO满了！！！\n");
        }
        else
        {
          printf("FIFO没满！！！\n");
        }

        if(RingBuffer_IsEmpty(fifo) == true)
        {
          printf("FIFO空了！！！\n");
        }
        else
        {
          printf("FIFO没空！！！\n");
        }
      }

      printf("\n");

      {
        uint8_t  rdata[256] = {0};
        uint16_t len        = RingBuffer_Out(fifo, rdata, sizeof(rdata));

        if(len > 0)
        {
          printf("从FIFO中读出的数据，长度：%d\n", len);

          for(int i = 0; i < len; i++)
          {
            printf("%d ", rdata);
          }

          printf("\n");

          printf("FIFO读取成功，FIFO大小：%d，使用大小：%d，剩余大小：%d\n",
                 RingBuffer_Size(fifo), RingBuffer_Len(fifo), RingBuffer_Avail(fifo));
        }
        else
        {
          printf("FIFO读取失败，FIFO大小：%d，使用大小：%d，剩余大小：%d\n",
                 RingBuffer_Size(fifo), RingBuffer_Len(fifo), RingBuffer_Avail(fifo));
        }

        if(RingBuffer_IsFull(fifo) == true)
        {
          printf("FIFO满了！！！\n");
        }
        else
        {
          printf("FIFO没满！！！\n");
        }

        if(RingBuffer_IsEmpty(fifo) == true)
        {
          printf("FIFO空了！！！\n");
        }
        else
        {
          printf("FIFO没空！！！\n");
        }
      }

      printf("\n\n\n");
      Sleep(5000);
    }
  }
  else
  {
    printf("FIFO创建失败\n");
  }

  for(;;)
  {

  }
}
[/mw_shl_code]

XinLiOV

3，运行效果

八度空间

厉害了，谢谢分享！！！

XinLiOV

可以直接移植到嵌入式端，非常方便。