C语言日志和事务API—libjio
libjio是一个C库做日志,交易为导向的I/O它提供了一个类UNIX的文件操作功能(如打开,读取和写入) ,这是装在一个交易框架,以使文件操作可以提交或回滚是必要的。这是非侵入性,原子,和线程安全的,具有快速崩溃恢复。
示例代码:
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
#include <string.h>
#include <libjio.h>
#define FILENAME "test1"
#define TEXT "Hello world!\n"
int main(void)
{
int r;
struct jfs file;
struct jtrans trans;
struct jfsck_result result;
/* check the file is OK */
jfsck(FILENAME, NULL, &result);
jfsck_cleanup(FILENAME, NULL);
/* and open it */
r = jopen(&file, FILENAME, O_RDWR | O_CREAT | O_TRUNC, 0600, 0);
if (r < 0) {
perror("jopen");
return 1;
}
/* write two "Hello world"s next to each other */
jtrans_init(&file, &trans);
jtrans_add(&trans, TEXT, strlen(TEXT), 0);
jtrans_add(&trans, TEXT, strlen(TEXT), strlen(TEXT));
r = jtrans_commit(&trans);
if (r < 0) {
perror("jtrans_commit");
return 1;
}
/* at this point the file has "Hello world!\nHello world!\n" */
/* now we rollback */
r = jtrans_rollback(&trans);
if (r < 0) {
perror("jtrans_rollback");
return 1;
}
/* and now the file is empty! */
jtrans_free(&trans);
jclose(&file);
return 0;
}
示例代码:
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
#include <string.h>
#include <libjio.h>
#define FILENAME "test1"
#define TEXT "Hello world!\n"
int main(void)
{
int r;
struct jfs file;
struct jtrans trans;
struct jfsck_result result;
/* check the file is OK */
jfsck(FILENAME, NULL, &result);
jfsck_cleanup(FILENAME, NULL);
/* and open it */
r = jopen(&file, FILENAME, O_RDWR | O_CREAT | O_TRUNC, 0600, 0);
if (r < 0) {
perror("jopen");
return 1;
}
/* write two "Hello world"s next to each other */
jtrans_init(&file, &trans);
jtrans_add(&trans, TEXT, strlen(TEXT), 0);
jtrans_add(&trans, TEXT, strlen(TEXT), strlen(TEXT));
r = jtrans_commit(&trans);
if (r < 0) {
perror("jtrans_commit");
return 1;
}
/* at this point the file has "Hello world!\nHello world!\n" */
/* now we rollback */
r = jtrans_rollback(&trans);
if (r < 0) {
perror("jtrans_rollback");
return 1;
}
/* and now the file is empty! */
jtrans_free(&trans);
jclose(&file);
return 0;
}