On Wed, Aug 19, 2015 at 12:43 PM, Lex Trotman elextr@gmail.com wrote:
On 19 August 2015 at 19:48, Jiří Techet techet@gmail.com wrote:
Hi,
after some time spent debugging
https://github.com/geany/geany/issues/605
I think the file saving options are a bit confusing and misleading and should be simplified.
Agree the usability is poor with several options that interact with each other.
- Both g_file_set_contents() and g_file_replace_contents() do absolutely
the same thing (saving to temporary file, then renaming the file),
No they are not the same, set_contents does not work on file systems where rename is not available or is not allowed over existing files (windows), and it creates a new file with new file metadata (eg permissions), whereas replace_contents is much more complex than set, it tries to compensate for these issues but can do several copies of the data during the attempt, which is very costly on slow remote filesystems and has a bug (see below).
I meant "same" in the sense they both should be safe. Yes, you are right, g_file_replace_contents() tries to mitigate the problems of g_file_set_contents(). By the way g_file_set_contents() works on Windows, it just isn't atomic:
https://github.com/bratsche/glib/blob/master/glib/gfileutils.c#L1087
the only difference is the first uses POSIX calls while the second GIO. The use_gio_unsafe_file_saving name is very confusing because it's not
unsafe in
any way.
It is unsafe due to a long standing bug where a failure deletes the copy of the original data without copying it back to the original file, so you are left with a truncated original file and no backup of the original data. You still have the new data in the Geany buffer of course. But it regularly has caught people out if they closed the buffer after a failure assuming they had the original data safe.
Uh, just checked the code and it really seems to be the case. Might fix that if I have time.
- It is now possible to set
use_gio_unsafe_file_saving=true use_atomic_file_saving=true
and to users it's unclear which of the options will be actually used
(it's
the use_atomic_file_saving case because it's checked first in the code).
Yeah, an enum not a set of bools would be better, IIUC the current system grew all the options over time rather than being planned. For sure cleaning it up would be good.
- The fallback "ordinary" file saving when
use_gio_unsafe_file_saving=false use_atomic_file_saving=false
doesn't bring any benefit compared to the two above
It just overwrites the file, nothing else, one data transfer, fast, no rename, works on *all* filesystems, keeps the files metadata. Whilst its not in any way "safe" its got the best performance.
OK, might make sense to keep it then.
Jiri