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;
- }