知识巩固源码落实之3：缓冲区ringbuffer

在日常业务开发中，使用缓冲区进行临时存储的业务场景也比较多，如tcp每个连接底层都维持一个发送缓冲区和接收缓冲区。

实现一个ringbuffer，做代码备用。(可以考虑如何对ringbuffer进行扩大？)

//实现ringbuffer，其实就是申请一块内存,对塞入数据和取出数据位置分别进行管理
typedef struct RINGBUFF_T{
	void * data;
	unsigned int size;
	unsigned int read_pos;   //数据起始位置
	unsigned int write_pos;  //数据终止位置
}ringbuffer_t;

这里的代码是我为了测试，实现一个ringbuffer进行管理。

这里只考虑了单线程的逻辑实现，多线程需要适配一下。。。

这里在取数据时，有一定的设计，考虑取一个包的数据（可以自己适配调整）。

#ifndef __RINGBUFFER_H_
#define __RINGBUFFER_H_

typedef struct RINGBUFF_T{
	void * data;
	unsigned int size;
	unsigned int read_pos;   //数据起始位置
	unsigned int write_pos;  //数据终止位置
}ringbuffer_t;

//创建ringbuffer
ringbuffer_t * ringbuffer_create(unsigned int size);
//销毁ringbuffer
void ringbuffer_destroy(ringbuffer_t * ring_buffer);

//往ringbuffer中存数据 写入
int ringbuffer_put(ringbuffer_t * ring_buffer, const char* buffer, unsigned int len);
//判断是否是完整的数据  然后进行处理
int ringbuffer_get_len(ringbuffer_t *ring_buffer);
//依赖ringbuffer_get_len 返回值申请内存，取出ring_buffer中的数据
int ringbuffer_get(ringbuffer_t * ring_buffer, char * buffer, unsigned int len);

//基本接口 外部基本不用，但是函数内部有使用
//重置缓冲区
void ringbuffer_reset(ringbuffer_t * ring_buffer);
//ringbuffer已经使用的内存空间的大小
int ringbuffer_use_len(ringbuffer_t * ring_buffer);
//ringbuffer没有使用的内存的大小
int ringbuffer_space_len(ringbuffer_t * ring_buffer);

//基本的判空和判满接口
int ringbuffer_isempty(ringbuffer_t * ring_buffer);
int ringbuffer_isfull(ringbuffer_t * ring_buffer);

// int get_ringbuffer_size(ringbuffer_t * ring_buffer);
#endif //__RINGBUFFER_H_

#include 
#include 
#include 

#include "my_ringbuffer.h"

static inline __attribute__((const))
int is_power_of_2(unsigned long n)
{
	return (n != 0 && ((n & (n - 1)) == 0));
}

static unsigned long roundup_power_of_two(unsigned long n)
{
    if((n & (n-1)) == 0)
        return n;
    
    unsigned long maxulong = (unsigned long)((unsigned long)~0);
    unsigned long andv = ~(maxulong&(maxulong>>1));

    while((andv & n) == 0)
        andv = andv>>1;

    return andv<<1;
}

//创建ringbuffer 
ringbuffer_t * ringbuffer_create(unsigned int size)
{
	//对入参进行校验 并且是2的次方
	if (!is_power_of_2(size)) {
        size = roundup_power_of_two(size);
	}

	ringbuffer_t * ring_buffer;
	ring_buffer = (ringbuffer_t*)malloc(sizeof(*ring_buffer));
	if(ring_buffer == NULL)
	{
		printf("create ringbuffer error n");
		return NULL;
	}

	ring_buffer->data = (void*)malloc(size);
	if(ring_buffer->data == NULL)
	{
		printf("create ringbuffer data error n");
		free(ring_buffer);
		return NULL;
	}

	ring_buffer->size = size;
	ring_buffer->read_pos = 0;
	ring_buffer->write_pos = 0;
	return ring_buffer;
}

//销毁ringbuffer
void ringbuffer_destroy(ringbuffer_t * ring_buffer)
{
	if(ring_buffer)
	{
		if(ring_buffer->data)
		{
			free(ring_buffer->data);
			ring_buffer->data = NULL;
		}
		free(ring_buffer);
		ring_buffer = NULL;
	}
}

//往ringbuffer中存数据 写入
int ringbuffer_put(ringbuffer_t * ring_buffer, const char* buffer, unsigned int len)
{
	if(ring_buffer->write_pos >=ring_buffer->read_pos &&(len <(ring_buffer->size - ring_buffer->write_pos +ring_buffer->read_pos)))
	{
		//进行拷贝
		if(ring_buffer->size - ring_buffer->write_pos >len)
		{
			memcpy(ring_buffer->data + ring_buffer->write_pos, buffer, len);
			ring_buffer->write_pos += len;
		}else
		{
			unsigned int right_space_len = ring_buffer->size - ring_buffer->write_pos;
			memcpy(ring_buffer->data + ring_buffer->write_pos, buffer, right_space_len);
			memcpy(ring_buffer->data, buffer+right_space_len, len - right_space_len);
			ring_buffer->write_pos = len - right_space_len;
		}
		return 0;
	}

	if(ring_buffer->write_pos read_pos && (ring_buffer->read_pos - ring_buffer->write_pos) >len)
	{
		memcpy(ring_buffer->data + ring_buffer->write_pos, buffer, len);
		ring_buffer->write_pos += len;
		return 0;
	}

	return -1;
}

//判断是否是完整的数据  然后进行处理
int ringbuffer_get_len(ringbuffer_t *ring_buffer)
{
	//对ringbuffer中的数据做判断解析  如果是完整的数据  则提取出去
	if(ringbuffer_use_len(ring_buffer) < strlen("FFFF0D0A
0D0AFEFE"))
	{
		printf("ringbuffer data is error [%d], [%ld]n", ringbuffer_use_len(ring_buffer),  strlen("FFFF0D0A
0D0AFEFE"));
		return -1;
	}
	//判断是否是终结的字段
	const char* end_str = "0D0AFEFE";
	char check_end_str[20] = {0};
	if(ring_buffer->write_pos >strlen(end_str))
	{
		memcpy(check_end_str, ring_buffer->data+ring_buffer->write_pos - (strlen(end_str)),  strlen(end_str));
	}else
	{
		unsigned int left_len = ring_buffer->write_pos;
		memcpy(check_end_str, ring_buffer->data +ring_buffer->size - (strlen(end_str) - left_len), ring_buffer->size - (strlen(end_str) - left_len));
		memcpy(check_end_str + (strlen(end_str) - left_len), ring_buffer->data, left_len);
	}
	printf("get check_end_str is %s n", check_end_str);


	char * ret_addr = strstr(check_end_str, end_str);
	if(ret_addr == NULL)
	{
		return -1;
	}

	if(check_end_str - ret_addr != 0)
	{
		printf("DDDDD :why end string is error");
		return -1;
	}

	return ringbuffer_use_len(ring_buffer);
}

//从ringbuffer中取数据做处理, 判断接收到的字符是否是终结符号，就可以去做处理
//取完数据后重置ringbuffer的位置  读取
int ringbuffer_get(ringbuffer_t * ring_buffer, char * buffer, unsigned int len)
{
	//这里建立在ringbuffer_get_len 的基础上，传入入参，取出数据
	int data_len = ringbuffer_use_len(ring_buffer);
	if(data_len >= len)
	{
		printf("para buffer is not enough space n");
		return -1;
	}

	if(ring_buffer->write_pos >ring_buffer->read_pos )
	{
		printf("get data from ringbuffer len: [%d] n", ring_buffer->write_pos - ring_buffer->read_pos);
		memcpy(buffer, ring_buffer->data + ring_buffer->read_pos, data_len);
	}else
	{
		memcpy(buffer, ring_buffer->data+ring_buffer->read_pos, ring_buffer->size - ring_buffer->read_pos);
		memcpy(buffer+ring_buffer->size - ring_buffer->read_pos, ring_buffer->data, data_len - (ring_buffer->size - ring_buffer->read_pos));
	}

	ring_buffer->write_pos = 0;
	ring_buffer->read_pos = 0;
	return 0;
}

//直接从socket中读数据放入ringbuffer中也可以
int ringbuffer_get_from_dev()
{
	return 0;
}
//直接从ringbuffer中取数据用socket进行发送
int ringbuffer_put_to_dev()
{
	return 0;
}

void ringbuffer_reset(ringbuffer_t * ring_buffer)
{
	ring_buffer->read_pos = ring_buffer->write_pos = 0;
}

int ringbuffer_use_len(ringbuffer_t * ring_buffer)
{
	if(ring_buffer->write_pos >= ring_buffer->read_pos)
	{
		return ring_buffer->write_pos-ring_buffer->read_pos;
	}

	return ring_buffer->write_pos + ring_buffer->size - ring_buffer->read_pos;
}

int ringbuffer_space_len(ringbuffer_t * ring_buffer)
{
	if(ring_buffer->write_pos >= ring_buffer->read_pos)
	{
		return ring_buffer->read_pos +(ring_buffer->size - ring_buffer->write_pos);
	}

	return ring_buffer->read_pos - ring_buffer->write_pos;
}

int ringbuffer_isempty(ringbuffer_t * ring_buffer)
{
	return ringbuffer_use_len(ring_buffer) == 0? 0 :-1;
}

int ringbuffer_isfull(ringbuffer_t * ring_buffer)
{
	return ringbuffer_space_len(ring_buffer) == 0? 0 :-1;
}

// int get_ringbuffer_size(ringbuffer_t * ring_buffer)
// {
// 	return ring_buffer->size;
// }

#include 
#include 
#include 
#include "tcp_ringbuffer.h"

int main()
{
	//申请一个ringbuffer 
	ringbuffer_t * ringbuff = ringbuffer_create(128);
	printf("ringbuffer_create size is : %d n", ringbuff->size);
	printf("ringbuffer isempty [%d] n", ringbuffer_isempty(ringbuff));
	printf("ringbuffer isfull [%d] n", ringbuffer_isfull(ringbuff));
	printf("ringbuffer used len is [%d] n",ringbuffer_use_len(ringbuff));
	printf("ringbuffer space len is [%d] n", ringbuffer_space_len(ringbuff));
	ringbuffer_destroy(ringbuff);
	//判断基本的条件
	ringbuff = ringbuffer_create(129);
	printf("ringbuffer_create size is : %d n", ringbuff->size);
	printf("ringbuffer isempty [%d] n", ringbuffer_isempty(ringbuff));
	printf("ringbuffer isfull [%d] n", ringbuffer_isfull(ringbuff));
	printf("ringbuffer used len is [%d] n",ringbuffer_use_len(ringbuff));
	printf("ringbuffer space len is [%d] n", ringbuffer_space_len(ringbuff));
	ringbuffer_destroy(ringbuff);

	//给ringbuff中塞入一定的数据查看相关的基本信息
	ringbuff = ringbuffer_create(129);
	const char* str_data = "FFFF0D0A
0D0AFEFE";
	//给ringbuffer中塞入一定的数据，进行获取查看
	ringbuffer_put(ringbuff, str_data, strlen(str_data));
	printf("set data size is : %lu, ringbuff size is %d n", strlen(str_data), ringbuff->size);
	printf("ringbuffer isempty [%d] n", ringbuffer_isempty(ringbuff));
	printf("ringbuffer isfull [%d] n", ringbuffer_isfull(ringbuff));
	printf("ringbuffer used len is [%d] n",ringbuffer_use_len(ringbuff));
	printf("ringbuffer space len is [%d] n", ringbuffer_space_len(ringbuff));
	int data_len = ringbuffer_get_len(ringbuff);
	if(data_len == -1)
	{
		printf("error of ringbuff data n");
	}else
	{
		printf("ringbuff data len is %d n", data_len);
	}
	char * data_exec;
	data_exec = (char*)malloc(data_len +1);
	memset(data_exec, 0, data_len +1);
	printf("sizeof data_exec is %lu n", sizeof(data_exec));
	ringbuffer_get(ringbuff, data_exec, data_len +1);
	printf("ringbuff get data is :%s n",data_exec);
	printf("ringbuffer isempty [%d] n", ringbuffer_isempty(ringbuff));
	printf("ringbuffer isfull [%d] n", ringbuffer_isfull(ringbuff));
	printf("ringbuffer used len is [%d] n",ringbuffer_use_len(ringbuff));
	printf("ringbuffer space len is [%d] n", ringbuffer_space_len(ringbuff));
	ringbuffer_destroy(ringbuff);
	if(data_exec !=NULL)
	{
		free(data_exec);
		data_exec = NULL;
	}


	printf("******************test of more package check***********************n");
	const char* data_str_test = "FFFF0D0A
0D0AFEFE";
	const char* data_str_test1 = "FFFF0D0A
1110D0AFEFE";
	const char* data_str_test2 = "FFFF0D0A
2220D0AFEFE";
	const char* data_str_test3 = "FFFF0D0A
0D0AFEFE";
	const char* data_str_test4 = "FFFF0D0A
0D0AFEFE";
	const char* data_str_error = "FFFF0D0A
test error";
	//试着塞多个数据 能取出来吗？
	ringbuff = ringbuffer_create(129);
	ringbuffer_put(ringbuff, data_str_test, strlen(data_str_test));
	printf("put one data. ringbuffer used len is [%d] n",ringbuffer_use_len(ringbuff));
	printf("put one data.  ringbuffer space len is [%d] n", ringbuffer_space_len(ringbuff));
	ringbuffer_put(ringbuff, data_str_test1, strlen(data_str_test1));
	printf("put two data. ringbuffer used len is [%d] n",ringbuffer_use_len(ringbuff));
	printf("put two data.  ringbuffer space len is [%d] n", ringbuffer_space_len(ringbuff));
	ringbuffer_put(ringbuff, data_str_test2, strlen(data_str_test2));
	printf("put three data. ringbuffer used len is [%d] n",ringbuffer_use_len(ringbuff));
	printf("put three data.  ringbuffer space len is [%d] n", ringbuffer_space_len(ringbuff));
	printf("ringbuffer is not empty [%d] n", ringbuffer_isempty(ringbuff));
	printf("ringbuffer is not full [%d] n", ringbuffer_isfull(ringbuff));
	int test_get_len = ringbuffer_get_len(ringbuff);
	if(test_get_len == -1)
	{
		printf("error of ringbuff data n");
	}else
	{
		printf("get ringbuff has data len is %d n", test_get_len);
	}
	data_exec = (char*)malloc(test_get_len +1);
	memset(data_exec, 0, test_get_len +1);
	ringbuffer_get(ringbuff, data_exec, test_get_len +1);
	printf("ringbuff get data is :%s n",data_exec);
	printf("get all data used len is [%d] n",ringbuffer_use_len(ringbuff));
	printf("get all data space len is [%d] n", ringbuffer_space_len(ringbuff));
	printf("ringbuffer isempty [%d] n", ringbuffer_isempty(ringbuff));
	printf("ringbuffer is not full [%d] n", ringbuffer_isfull(ringbuff));
	ringbuffer_destroy(ringbuff);
	if(data_exec !=NULL)
	{
		free(data_exec);
		data_exec = NULL;
	}

	ringbuff = ringbuffer_create(129);
	ringbuffer_put(ringbuff, data_str_test, strlen(data_str_test));
	ringbuffer_put(ringbuff, data_str_error, strlen(data_str_error));
	test_get_len = ringbuffer_get_len(ringbuff);
	if(test_get_len == -1)
	{
		printf("error of ringbuff data n");
	}else
	{
		printf("get ringbuff has data len is %d n", test_get_len);
	}
	ringbuffer_put(ringbuff, data_str_test, strlen(data_str_test));
	test_get_len = ringbuffer_get_len(ringbuff);
	if(test_get_len == -1)
	{
		printf("error of ringbuff data n");
	}else
	{
		printf("get ringbuff has data len is %d n", test_get_len);
	}
	data_exec = (char*)malloc(test_get_len +1);
	memset(data_exec, 0, test_get_len +1);
	ringbuffer_get(ringbuff, data_exec, test_get_len +1);
	printf("ringbuff get data is :%s n",data_exec);
	printf("get all data used len is [%d] n",ringbuffer_use_len(ringbuff));
	printf("get all data space len is [%d] n", ringbuffer_space_len(ringbuff));
	ringbuffer_destroy(ringbuff);
	if(data_exec !=NULL)
	{
		free(data_exec);
		data_exec = NULL;
	}
	//根本不会有write追到read的场景，除非这里的设计做成不是全部取出，或者多线程处理
	printf("******************* check n");

	return 0;
}

这里我使用的gcc进行编译，没有用makefile

这里是为了符合特定的业务格式，有“FFFF0D0A

写这个测试代码主要是为了针对tcp接收缓冲区业务处理考虑的。

hlp@ubuntu:~/220107/0：test_ringbuffer_tcp_Stickybag$ ./ringbuffer 
ringbuffer_create size is : 128 
ringbuffer isempty [0] 
ringbuffer isfull [-1] 
ringbuffer used len is [0] 
ringbuffer space len is [128] 
ringbuffer_create size is : 256 
ringbuffer isempty [0] 
ringbuffer isfull [-1] 
ringbuffer used len is [0] 
ringbuffer space len is [256] 
set data size is : 30, ringbuff size is 256 
ringbuffer isempty [-1] 
ringbuffer isfull [-1] 
ringbuffer used len is [30] 
ringbuffer space len is [226] 
get check_end_str is 0D0AFEFE 
ringbuff data len is 30 
sizeof data_exec is 8 
get data from ringbuffer len: [30] 
ringbuff get data is :FFFF0D0A
0D0AFEFE 
ringbuffer isempty [0] 
ringbuffer isfull [-1] 
ringbuffer used len is [0] 
ringbuffer space len is [256] 
******************test of more package check***********************
put one data. ringbuffer used len is [30] 
put one data.  ringbuffer space len is [226] 
put two data. ringbuffer used len is [63] 
put two data.  ringbuffer space len is [193] 
put three data. ringbuffer used len is [96] 
put three data.  ringbuffer space len is [160] 
ringbuffer is not empty [-1] 
ringbuffer is not full [-1] 
get check_end_str is 0D0AFEFE 
get ringbuff has data len is 96 
get data from ringbuffer len: [96] 
ringbuff get data is :FFFF0D0A
0D0AFEFEFFFF0D0A
1110D0AFEFEFFFF0D0A
2220D0AFEFE 
get all data used len is [0] 
get all data space len is [256] 
ringbuffer isempty [0] 
ringbuffer is not full [-1] 
get check_end_str is der>test error 
error of ringbuff data 
get check_end_str is 0D0AFEFE 
get ringbuff has data len is 86 
get data from ringbuffer len: [86] 
ringbuff get data is :FFFF0D0A
0D0AFEFEFFFF0D0A
test errorFFFF0D0A
0D0AFEFE 
get all data used len is [0] 
get all data space len is [256] 
******************* check

我开始试着积累一些常用代码：自己代码库中备用

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