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diff --git a/third_party/gerrit-queue/README.md b/third_party/gerrit-queue/README.md deleted file mode 100644 index 9ffb81b8d26d..000000000000 --- a/third_party/gerrit-queue/README.md +++ /dev/null @@ -1,80 +0,0 @@ -# gerrit-queue - -This daemon automatically rebases and submits changesets from a Gerrit -instance, ensuring they still pass CI. - -In a usual gerrit setup with a linear master history, different developers -await CI feedback on a rebased changeset, then one clicks submit, and -effectively makes everybody else rebase again. `gerrit-queue` is meant to -remove these races to master. - -Developers can set the `Autosubmit` label to `+1` on all changesets in a series, -and if all preconditions on are met ("submittable" in gerrit speech, this -usually means passing CI and passing Code Review), `gerrit-queue` takes care of -rebasing and submitting it to master - -## How it works -Gerrit only knows about Changesets (and some relations to other changesets), -but usually developers think in terms of multiple changesets. - -### Fetching changesets -`gerrit-queue` fetches all changesets from gerrit, and tries to identify these -chains of changesets. We call them `Series`. All changesets need to have strict -parent/child relationships to be detected (so if only half of the stack gets -rebased by the Gerrit Web interface, these are considered individual series. - -Series are sorted by the number of changesets in them. This ensures longer -series are merged faster, and less rebases are triggered. In the future, this -might be extended to other metrics. - -### Submitting changesets -The submitqueue has a Trigger() function, which gets periodically executed. - -It can keep a reference to one single serie across multiple runs. This is -necessary if it previously rebased one serie to current HEAD and needs to wait -some time until CI feedback is there. If it wouldn't keep that state, it would -pick another series (with +1 from CI) and trigger a rebase on that one, so -depending on CI run times and trigger intervals, if not keepig this information -it'd end up rebasing all unrebased changesets on the same HEAD, and then just -pick one, instead of waiting for the one to finish. - -The Trigger() function first instructs the gerrit client to fetch changesets -and assemble series. -If there is a `wipSerie` from a previous run, we check if it can still be found -in the newly assembled list of series (it still needs to contain the same -number of series. Commit IDs may differ, because the code doesn't reassemble a -`wipSerie` after scheduling a rebase. -If the `wipSerie` could be refreshed, we update the pointer with the newly -assembled series. If we couldn't find it, we drop it. - -Now, we enter the main for loop. The first half of the loop checks various -conditions of the current `wipSerie`, and if successful, does the submit -("Submit phase"), the second half will pick a suitable new `wipSerie`, and -potentially do a rebase ("Pick phase"). - -#### Submit phase -We check if there is an existing `wipSerie`. If there isn't, we immediately go to -the "pick" phase. - -The `wipSerie` still needs to be rebased on `HEAD` (otherwise, the submit queue -advanced outside of gerrit), and should not fail CI (logical merge conflict) - -otherwise we discard it, and continue with the picking phase. - -If the `wipSerie` still contains a changeset awaiting CI feedback, we `return` -from the `Trigger()` function (and go back to sleep). - -If the changeset is "submittable" in gerrit speech, and has the necessary -submit queue tag set, we submit it. - -#### Pick phase -The pick phase finds a new `wipSerie`. It'll first try to find one that already -is rebased on the current `HEAD` (so the loop can just continue, and the next -submit phase simply submit), and otherwise fall back to a not-yet-rebased -serie. Because the rebase mandates waiting for CI, the code `return`s the -`Trigger()` function, so it'll be called again after waiting some time. - -## Compile and Run -```sh -go generate -GERRIT_PASSWORD=mypassword go run main.go --url https://gerrit.mydomain.com --username myuser --project myproject -``` |