| .. | ||
| converter.py | ||
| docker-setup.sh | ||
| read-json.py | ||
| README.md | ||
| requirements.txt | ||
| sync-to-github.sh | ||
This folder contains scripts to sync the WebRender code from
mozilla-central to Github. The scripts in this folder were derived
from the code at https://github.com/staktrace/wrupdater; the main
difference is that the versions in this folder are designed to run
as a taskcluster task. The versions in this folder are the canonical
version going forward; the staktrace/wrupdater Github repo will
continue to exist only as a historical archive.
The main entry point is the sync-to-github.sh script. It creates a
staging directory at ~/.wrupdater if one doesn't already exist,
and clones the webrender repo into it. The script also requires the
GECKO_PATH environment variable to point to a mercurial clone of
mozilla-central, and access to the taskcluster secrets service to
get a Github API token.
The script does some setup steps but the bulk of the actual work
is done by the converter.py script. This script scans the mercurial
repository for new changes to the gfx/wr folder, and adds commits to
the git repository corresponding to those changes. There are some
details in the implementation that make it more robust than simply
exporting patches and attempting to reapply them; in particular it
builds a commit tree structure that mirrors what is found in the
mozilla-central repository with respect to branches and merges. So
if conflicting changes land on autoland and inbound, and then get
merged, the git repository commits will have the same structure with
a fork/merge in the commit history. This was discovered to be
necessary after a previous version ran into multiple cases where
the simple patch approach didn't really work.
Once the converter is done converting, the sync-to-github.sh script
finishes the process by pushing the new commits to moz-gfx/webrender
and generating a pull request against servo/webrender. It also
leaves a comment on the PR that triggers testing and merge of the PR.
If there is already a pull request (perhaps from a previous run) the
pre-existing PR is force-updated instead. This allows for graceful
handling of scenarios where the PR failed to get merged (e.g. due to
CI failures on the Github side).
The script is intended to by run by taskcluster for any changes that
touch the gfx/wr folder that land on mozilla-central. This may mean
that multiple instances of this script run concurrently, or even out
of order (i.e. the task for an older m-c push runs after the task for
a newer m-c push). The script was written with these possibilities in
mind and should be able to eventually recover from any such scenario
automatically (although it may take additional changes to mozilla-central
for such recovery to occur).