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.

>
> 1. 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).

> 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.

>
> 2. 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.

>
> 3. 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.