Add a tor_ftruncate to replace ftruncate.

(Windows doesn't have ftruncate, and some ftruncates do not move the
file pointer to the start of the file.)
This commit is contained in:
Nick Mathewson 2014-07-16 13:58:55 +02:00
parent 15e170e01b
commit 867f5e6a76
4 changed files with 73 additions and 2 deletions

View File

@ -1004,6 +1004,23 @@ tor_fd_setpos(int fd, off_t pos)
#endif
}
/** Replacement for ftruncate(fd, 0): move to the front of the file and remove
* all the rest of the file. Return -1 on error, 0 on success. */
int
tor_ftruncate(int fd)
{
/* Rumor has it that some versions of ftruncate do not move the file pointer.
*/
if (tor_fd_setpos(fd, 0) < 0)
return -1;
#ifdef _WIN32
return _chsize(fd, 0);
#else
return ftruncate(fd, 0);
#endif
}
#undef DEBUG_SOCKET_COUNTING
#ifdef DEBUG_SOCKET_COUNTING
/** A bitarray of all fds that should be passed to tor_socket_close(). Only

View File

@ -408,6 +408,7 @@ void tor_lockfile_unlock(tor_lockfile_t *lockfile);
off_t tor_fd_getpos(int fd);
int tor_fd_setpos(int fd, off_t pos);
int tor_fd_seekend(int fd);
int tor_ftruncate(int fd);
#ifdef _WIN32
#define PATH_SEPARATOR "\\"

View File

@ -1305,6 +1305,10 @@ switch_logs_debug(void)
void
truncate_logs(void)
{
for (logfile_t *lf = logfiles; lf; lf = lf->next)
ftruncate(lf->fd, 0);
for (logfile_t *lf = logfiles; lf; lf = lf->next) {
if (lf->fd >= 0) {
tor_ftruncate(lf->fd);
}
}
}

View File

@ -2385,6 +2385,54 @@ test_util_parent_dir(void *ptr)
tor_free(cp);
}
static void
test_util_ftruncate(void *ptr)
{
char *buf = NULL;
const char *fname;
int fd = -1;
const char *message = "Hello world";
const char *message2 = "Hola mundo";
struct stat st;
(void) ptr;
fname = get_fname("ftruncate");
fd = tor_open_cloexec(fname, O_WRONLY|O_CREAT, 0600);
tt_int_op(fd, >=, 0);
/* Make the file be there. */
tt_int_op(strlen(message), ==, write_all(fd, message, strlen(message), 0));
tt_int_op(tor_fd_getpos(fd), ==, strlen(message));
tt_int_op(0, ==, fstat(fd, &st));
tt_int_op(st.st_size, ==, strlen(message));
/* Truncate and see if it got truncated */
tt_int_op(0, ==, tor_ftruncate(fd));
tt_int_op(tor_fd_getpos(fd), ==, 0);
tt_int_op(0, ==, fstat(fd, &st));
tt_int_op(st.st_size, ==, 0);
/* Replace, and see if it got replaced */
tt_int_op(strlen(message2), ==,
write_all(fd, message2, strlen(message2), 0));
tt_int_op(tor_fd_getpos(fd), ==, strlen(message2));
tt_int_op(0, ==, fstat(fd, &st));
tt_int_op(st.st_size, ==, strlen(message2));
close(fd);
fd = -1;
buf = read_file_to_str(fname, 0, NULL);
tt_str_op(message2, ==, buf);
done:
if (fd >= 0)
close(fd);
tor_free(buf);
}
#ifdef _WIN32
static void
test_util_load_win_lib(void *ptr)
@ -3798,6 +3846,7 @@ struct testcase_t util_tests[] = {
UTIL_TEST(asprintf, 0),
UTIL_TEST(listdir, 0),
UTIL_TEST(parent_dir, 0),
UTIL_TEST(ftruncate, 0),
#ifdef _WIN32
UTIL_TEST(load_win_lib, 0),
#endif