Support setting mtime and atime on local files on Windows

Since we (optionally) require nanosecond precision for this
(utimes() is used on *nix), use SetFileTime(), which nominally
has 100ns granularity (actual filesystem might be coarser), instead of
g_utime (), which only has 1-second granularity.
This commit is contained in:
Руслан Ижбулатов 2020-01-19 19:54:26 +00:00
parent d09a6690e4
commit 0550104cf8
2 changed files with 183 additions and 5 deletions

View File

@ -2123,7 +2123,7 @@ get_uint32 (const GFileAttributeValue *value,
return TRUE;
}
#ifdef HAVE_UTIMES
#if defined (HAVE_UTIMES) || defined (G_OS_WIN32)
static gboolean
get_uint64 (const GFileAttributeValue *value,
guint64 *val_out,
@ -2356,7 +2356,180 @@ set_symlink (char *filename,
}
#endif
#ifdef HAVE_UTIMES
#if defined (G_OS_WIN32)
/* From
* https://support.microsoft.com/en-ca/help/167296/how-to-convert-a-unix-time-t-to-a-win32-filetime-or-systemtime
* FT = UT * 10000000 + 116444736000000000.
* Converts unix epoch time (a signed 64-bit integer) to FILETIME.
* Can optionally use a more precise timestamp that has
* a fraction of a second expressed in nanoseconds.
* UT must be between January 1st of year 1601 and December 31st of year 30827.
* nsec must be non-negative and < 1000000000.
* Returns TRUE if conversion succeeded, FALSE otherwise.
*
* The function that does the reverse can be found in
* glib/gstdio.c.
*/
static gboolean
_g_win32_unix_time_to_filetime (gint64 ut,
gint32 nsec,
FILETIME *ft,
GError **error)
{
gint64 result;
/* 1 unit of FILETIME is 100ns */
const gint64 hundreds_of_usec_per_sec = 10000000;
/* The difference between January 1, 1601 UTC (FILETIME epoch) and UNIX epoch
* in hundreds of nanoseconds.
*/
const gint64 filetime_unix_epoch_offset = 116444736000000000;
/* This is the maximum timestamp that SYSTEMTIME can
* represent (last millisecond of the year 30827).
* Since FILETIME and SYSTEMTIME are both used on Windows,
* we use this as a limit (FILETIME can support slightly
* larger interval, up to year 30828).
*/
const gint64 max_systemtime = 0x7fff35f4f06c58f0;
g_return_val_if_fail (ft != NULL, FALSE);
g_return_val_if_fail (error == NULL || *error == NULL, FALSE);
if (nsec < 0)
{
g_set_error (error, G_IO_ERROR,
G_IO_ERROR_INVALID_DATA,
_("Extra nanoseconds %d for UNIX timestamp %lld are negative"),
nsec, ut);
return FALSE;
}
if (nsec >= hundreds_of_usec_per_sec * 100)
{
g_set_error (error, G_IO_ERROR,
G_IO_ERROR_INVALID_DATA,
_("Extra nanoseconds %d for UNIX timestamp %lld reach 1 second"),
nsec, ut);
return FALSE;
}
if (ut >= (G_MAXINT64 / hundreds_of_usec_per_sec) ||
(ut * hundreds_of_usec_per_sec) >= (G_MAXINT64 - filetime_unix_epoch_offset))
{
g_set_error (error, G_IO_ERROR,
G_IO_ERROR_INVALID_DATA,
_("UNIX timestamp %lld does not fit into 64 bits"),
ut);
return FALSE;
}
result = ut * hundreds_of_usec_per_sec + filetime_unix_epoch_offset + nsec / 100;
if (result >= max_systemtime || result < 0)
{
g_set_error (error, G_IO_ERROR,
G_IO_ERROR_INVALID_DATA,
_("UNIX timestamp %lld is outside of the range supported by Windows"),
ut);
return FALSE;
}
ft->dwLowDateTime = (DWORD) (result);
ft->dwHighDateTime = (DWORD) (result >> 32);
return TRUE;
}
static gboolean
set_mtime_atime (const char *filename,
const GFileAttributeValue *mtime_value,
const GFileAttributeValue *mtime_usec_value,
const GFileAttributeValue *atime_value,
const GFileAttributeValue *atime_usec_value,
GError **error)
{
BOOL res;
guint64 val = 0;
guint32 val_usec = 0;
gunichar2 *filename_utf16;
SECURITY_ATTRIBUTES sec = { sizeof (SECURITY_ATTRIBUTES), NULL, FALSE };
HANDLE file_handle;
FILETIME mtime;
FILETIME atime;
FILETIME *p_mtime = NULL;
FILETIME *p_atime = NULL;
DWORD gle;
/* ATIME */
if (atime_value)
{
if (!get_uint64 (atime_value, &val, error))
return FALSE;
val_usec = 0;
if (atime_usec_value &&
!get_uint32 (atime_usec_value, &val_usec, error))
return FALSE;
if (!_g_win32_unix_time_to_filetime (val, val_usec, &atime, error))
return FALSE;
p_atime = &atime;
}
/* MTIME */
if (mtime_value)
{
if (!get_uint64 (mtime_value, &val, error))
return FALSE;
val_usec = 0;
if (mtime_usec_value &&
!get_uint32 (mtime_usec_value, &val_usec, error))
return FALSE;
if (!_g_win32_unix_time_to_filetime (val, val_usec, &mtime, error))
return FALSE;
p_mtime = &mtime;
}
filename_utf16 = g_utf8_to_utf16 (filename, -1, NULL, NULL, error);
if (filename_utf16 == NULL)
{
g_prefix_error (error,
_("File name “%s” cannot be converted to UTF-16"),
filename);
return FALSE;
}
file_handle = CreateFileW (filename_utf16,
FILE_WRITE_ATTRIBUTES,
FILE_SHARE_WRITE | FILE_SHARE_READ | FILE_SHARE_DELETE,
&sec,
OPEN_EXISTING,
FILE_FLAG_BACKUP_SEMANTICS,
NULL);
gle = GetLastError ();
g_clear_pointer (&filename_utf16, g_free);
if (file_handle == INVALID_HANDLE_VALUE)
{
g_set_error (error, G_IO_ERROR,
g_io_error_from_errno (gle),
_("File “%s” cannot be opened: Windows Error %lu"),
filename, gle);
return FALSE;
}
res = SetFileTime (file_handle, NULL, p_atime, p_mtime);
gle = GetLastError ();
CloseHandle (file_handle);
if (!res)
g_set_error (error, G_IO_ERROR,
g_io_error_from_errno (gle),
_("Error setting modification or access time for file “%s”: %lu"),
filename, gle);
return res;
}
#elif defined (HAVE_UTIMES)
static int
lazy_stat (char *filename,
struct stat *statbuf,
@ -2536,7 +2709,7 @@ _g_local_file_info_set_attribute (char *filename,
return set_symlink (filename, &value, error);
#endif
#ifdef HAVE_UTIMES
#if defined (HAVE_UTIMES) || defined (G_OS_WIN32)
else if (strcmp (attribute, G_FILE_ATTRIBUTE_TIME_MODIFIED) == 0)
return set_mtime_atime (filename, &value, NULL, NULL, NULL, error);
else if (strcmp (attribute, G_FILE_ATTRIBUTE_TIME_MODIFIED_USEC) == 0)
@ -2603,9 +2776,11 @@ _g_local_file_info_set_attributes (char *filename,
GFileAttributeValue *value;
#ifdef G_OS_UNIX
GFileAttributeValue *uid, *gid;
#ifdef HAVE_UTIMES
#endif
#if defined (HAVE_UTIMES) || defined (G_OS_WIN32)
GFileAttributeValue *mtime, *mtime_usec, *atime, *atime_usec;
#endif
#if defined (G_OS_UNIX) || defined (G_OS_WIN32)
GFileAttributeStatus status;
#endif
gboolean res;
@ -2676,7 +2851,7 @@ _g_local_file_info_set_attributes (char *filename,
}
#ifdef HAVE_UTIMES
#if defined (HAVE_UTIMES) || defined (G_OS_WIN32)
/* Group all time settings into one call
* Change times as the last thing to avoid it changing due to metadata changes
*/

View File

@ -166,6 +166,9 @@ _g_win32_fix_mode (wchar_t *mode)
* UT = (FT - 116444736000000000) / 10000000.
* Converts FILETIME to unix epoch time in form
* of a signed 64-bit integer (can be negative).
*
* The function that does the reverse can be found in
* gio/glocalfileinfo.c.
*/
static gint64
_g_win32_filetime_to_unix_time (const FILETIME *ft,