1：背景介绍：
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;
2：测试代码：
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）。
2.1：my_ringbuffer.h
#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ringbufferringbuffer_t * ringbuffer_create(unsigned int size);//销毁ringbuffervoid 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_
2.2：my_ringbuffer.c
#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ringbuffervoid 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("FFFF0D0A0D0AFEFE")){printf("ringbuffer data is error [%d], [%ld]n", ringbuffer_use_len(ring_buffer), strlen("FFFF0D0A0D0AFEFE"));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;// }
2.3：my_ringbuffer_test.c
#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 = "FFFF0D0A0D0AFEFE";//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 = "FFFF0D0A0D0AFEFE";const char* data_str_test1 = "FFFF0D0A1110D0AFEFE";const char* data_str_test2 = "FFFF0D0A2220D0AFEFE";const char* data_str_test3 = "FFFF0D0A0D0AFEFE";const char* data_str_test4 = "FFFF0D0A0D0AFEFE";const char* data_str_error = "FFFF0D0Atest 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;}
3：运行结果
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
”和“0D0AFEFE”进行标识的数据才认为是一个完整的数据。 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 :FFFF0D0A0D0AFEFE 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 :FFFF0D0A0D0AFEFEFFFF0D0A1110D0AFEFEFFFF0D0A2220D0AFEFE 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 :FFFF0D0A0D0AFEFEFFFF0D0Atest errorFFFF0D0A0D0AFEFE 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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