I was looking at ostree performance, and a surprising amount of time was spent in `glnx_gen_temp_name()`. We end up calling it from the main loop, and the iteration here shows up in my perf profiles. The glibc algorithm here that we adopted is *very* dated; let's switch to use `GRand`, which gives us a better algorithm. It'd be even better of course to use `getrandom()`, but we should do that in glib at some point. While I had the patient open, I extended the charset with lowercase, to better avoid collisions.
libglnx is the successor to libgsystem: https://git.gnome.org/browse/libgsystem
It is for modules which depend on both GLib and Linux, intended to be used as a git submodule.
Features:
- File APIs which use
openat()like APIs, but also take aGCancellableto support dynamic cancellation - APIs also have a
GErrorparameter - High level "shutil", somewhat inspired by Python's
- A "console" API for tty output
- A backport of the GLib cleanup macros for projects which can't yet take a dependency on 2.40.
Why?
There are multiple projects which have a hard dependency on Linux and GLib, such as NetworkManager, ostree, xdg-app, etc. It makes sense for them to be able to share Linux-specific APIs.
This module also contains some code taken from systemd, which has very high quality LGPLv2+ shared library code, but most of the internal shared library is private, and not namespaced.
One could also compare this project to gnulib; the salient differences there are that at least some of this module is eventually destined for inclusion in GLib.
Porting from libgsystem
For all of the filesystem access code, libglnx exposes only
fd-relative API, not GFile*. It does use GCancellable where
applicable.
For local allocation macros, you should start using the g_auto
macros from GLib. A backport is included in libglnx. There are a few
APIs not defined in GLib yet, such as glnx_fd_close.
gs_transfer_out_value is replaced by g_steal_pointer.
Contributing
Currently there is not a Bugzilla product - one may be created in the future. You can submit PRs against the Github mirror:
https://github.com/GNOME/libglnx/pulls
Or alternatively, email one of the maintainers directly.