Add mm_futimens() and mm_utimens() API

Provides API to set access and modification timestamp of a file through
either its path or a file descriptor.

Change-Id: Ifa099932f53b6e3fb61eefa28a4b851c9d572115

Author: nbourdau

src/file-posix.c

@@ -666,6 +666,82 @@ int mm_stat(const char* path, struct mm_stat* buf, int flags)
 }
 
 
+/**
+ * mm_futimens() - set file access and modification times of an opened file
+ * @fd:         file descriptor of an open file whose times must be changed
+ * @ts:         array of 2 timestamps (access and modification time). If NULL,
+ *              both time are set to current time.
+ *
+ * This set the access and modification times of a file associated with the
+ * file description @fd to the values of the @ts argument. The file's relevant
+ * timestamp is set to the greatest value supported by the file system that is
+ * not greater than the specified time.
+ *
+ * The @ts argument is an array of two timespec structures. The first array
+ * member @ts[0] represents the date and time of last access, and the second
+ * member @ts[1] represents the date and time of last modification. The times
+ * in the mmm_timespec structure are measured in seconds and nanoseconds since
+ * the Epoch.
+ *
+ * If the tv_nsec field of a mm_timespec structure has the special value
+ * UTIME_NOW, the file's relevant timestamp is set to the greatest value
+ * supported by the file system that is not greater than the current time. If
+ * the tv_nsec field has the special value UTIME_OMIT, the file's relevant
+ * timestamp is not changed. In either case, the tv_sec field shall be ignored.
+ *
+ * If the @ts argument is a null pointer, both the access and modification
+ * timestamps are set to the greatest value supported by the file system that
+ * is not greater than the current time.
+ *
+ * Return: 0 in case of success, -1 otherwise with error state set.
+ */
+API_EXPORTED
+int mm_futimens(int fd, const struct mm_timespec ts[2])
+{
+	if (futimens(fd, (const struct timespec*)ts))
+		return mm_raise_from_errno("futimens(%i) failed", fd);
+
+	return 0;
+}
+
+
+/**
+ * mm_utimens() - set file access and modification times
+ * @path:       path to file whose times must be changed
+ * @ts:         array of 2 timestamps (access and modification time). If NULL,
+ *              both time are set to current time.
+ * @flags       0 or MM_NOFOLLOW
+ *
+ * This does the same as mm_futimes excepting that file is refered through its
+ * file path while with mm_futimens() it must be refered though a file
+ * descriptor.
+ *
+ * See documentation of mm_futimens() for the documentation of @ts argument.
+ *
+ * If @flags is 0, the time are set to the target if @path refers to a symlink.
+ * Otherwise, if MM_NOFOLLOW is set in @flags, the times of the symlink itself
+ * are set.
+ *
+ * Return: 0 in case of success, -1 otherwise with error state set.
+ */
+API_EXPORTED
+int mm_utimens(const char* path, const struct mm_timespec ts[2], int flags)
+{
+	int uflags = 0;
+
+	if (flags & ~MM_NOFOLLOW)
+		return mm_raise_error(EINVAL, "invalid flags (0x%08x)", flags);
+
+	if (flags & MM_NOFOLLOW)
+		uflags |= AT_SYMLINK_NOFOLLOW;
+
+	if (utimensat(AT_FDCWD, path, (const struct timespec*)ts, uflags))
+		return mm_raise_from_errno("utimensat(%s) failed", path);
+
+	return 0;
+}
+
+
 /**
  * mm_readlink() - read value of a symbolic link
  * @path:       pathname of symbolic link

src/file-win32.c

@@ -1620,6 +1620,84 @@ int mm_fstat(int fd, struct mm_stat* buf)
 }
 
 
+static
+int hnd_utimens(HANDLE hnd, const struct mm_timespec ts[2])
+{
+	FILETIME aft;
+	FILETIME mft;
+	FILETIME now;
+
+	if (!ts || ts[0].tv_nsec == UTIME_NOW || ts[1].tv_nsec == UTIME_NOW)
+		GetSystemTimePreciseAsFileTime(&now);
+
+	// Set access filetime
+	if (!ts || ts[0].tv_nsec == UTIME_NOW)
+		aft = now;
+	else if (ts[0].tv_nsec == UTIME_OMIT)
+		aft = (FILETIME) {0};
+	else
+		aft = timespec_to_filetime(ts[0]);
+
+	// Set modification filetime
+	if (!ts || ts[1].tv_nsec == UTIME_NOW)
+		mft = now;
+	else if (ts[1].tv_nsec == UTIME_OMIT)
+		mft = (FILETIME) {0};
+	else
+		mft = timespec_to_filetime(ts[1]);
+
+	return SetFileTime(hnd, NULL, &aft, &mft) ? 0 : -1;
+}
+
+
+/* doc in posix implementation */
+API_EXPORTED
+int mm_futimens(int fd, const struct mm_timespec ts[2])
+{
+	HANDLE hnd, hnd_new;
+	int rv;
+
+	if (unwrap_handle_from_fd(&hnd, fd))
+		return -1;
+
+	hnd_new = ReOpenFile(hnd, FILE_WRITE_ATTRIBUTES, FILE_SHARE_ALL, 0);
+	if (hnd_new == INVALID_HANDLE_VALUE)
+		goto exit;
+
+	rv = hnd_utimens(hnd_new, ts);
+	CloseHandle(hnd_new);
+
+exit:
+	if (rv)
+		mm_raise_from_w32err("Cannot change times of fd %i", fd);
+	return rv;
+}
+
+
+/* doc in posix implementation */
+API_EXPORTED
+int mm_utimens(const char* path, const struct mm_timespec ts[2], int flags)
+{
+	HANDLE hnd;
+	int rv;
+
+	if (flags & ~MM_NOFOLLOW)
+		return mm_raise_error(EINVAL, "invalid flags (0x%08x)", flags);
+
+	hnd = open_handle(path, FILE_WRITE_ATTRIBUTES,
+	                  OPEN_EXISTING, NULL, flags);
+	if (hnd == INVALID_HANDLE_VALUE)
+		return mm_raise_from_w32err("Cannot open %s", path);
+
+	rv = hnd_utimens(hnd, ts);
+	if (rv)
+		mm_raise_from_w32err("Cannot change times of %s", path);
+
+	CloseHandle(hnd);
+	return rv;
+}
+
+
 /* doc in posix implementation */
 API_EXPORTED
 int mm_readlink(const char* path, char* buf, size_t bufsize)

src/libmmlib.map

@@ -60,6 +60,7 @@ MMLIB_1.0 {
 		mm_fstat;
 		mm_fsync;
 		mm_ftruncate;
+		mm_futimens;
 		mm_get_basedir;
 		mm_get_environ;
 		mm_get_lasterror_desc;
@@ -122,6 +123,7 @@ MMLIB_1.0 {
 		mm_unlink;
 		mm_unmap;
 		mm_unsetenv;
+		mm_utimens;
 		mm_wait_process;
 		mm_write;
 		mm_arg_complete_path;

src/mmsysio.h

@@ -188,6 +188,9 @@ extern "C" {
 #define R_OK 0x04
 #endif
 
+#define UTIME_NOW       (-1L)
+#define UTIME_OMIT      (-2L)
+
 #endif /* _WIN32 */
 
 /* file types returned when scanning a directory */
@@ -248,6 +251,9 @@ MMLIB_API mm_off_t mm_seek(int fd, mm_off_t offset, int whence);
 MMLIB_API int mm_ftruncate(int fd, mm_off_t length);
 MMLIB_API int mm_fstat(int fd, struct mm_stat* buf);
 MMLIB_API int mm_stat(const char* path, struct mm_stat* buf, int flags);
+MMLIB_API int mm_futimens(int fd, const struct mm_timespec ts[2]);
+MMLIB_API int mm_utimens(const char* path,
+                         const struct mm_timespec ts[2], int flags);
 MMLIB_API int mm_check_access(const char* path, int amode);
 MMLIB_API int mm_isatty(int fd);
 

src/utils-win32.h

@@ -294,6 +294,22 @@ time_t filetime_to_time(FILETIME ft)
 }
 
 
+static inline
+FILETIME timespec_to_filetime(struct mm_timespec ts)
+{
+	ULARGE_INTEGER time_int;
+
+	time_int.QuadPart = ((LONGLONG)ts.tv_sec) * 10000000;
+	time_int.QuadPart += (ts.tv_nsec / 100);
+	time_int.QuadPart += FT_EPOCH;
+
+	return (FILETIME) {
+		.dwLowDateTime = time_int.LowPart,
+		.dwHighDateTime = time_int.HighPart,
+	};
+}
+
+
 /**************************************************************************
  *                                                                        *
  *                         thread related utils                           *