Remove onChangeUpdated method

The onChangeUpdated method is called every time a change is updated.
Its purpose is to iterate over every change in the cache and, if the
updated change is a commit dependency (Depends-On) of the other change,
to set a flag telling the queue processor that changes' dependencies
are out of date and need to be refreshed.  The idea is that if this
happens, the queue processor should notice the dependencies no longer
match and dequeue it.

This became quite slow with the change cache in ZK.

Instead, we can do the following:

* Make sure that every event regarding a change is forwarded to every
  pipeline with that change in it (including non-live changes).

* When processing pipeline trigger events, refresh the dependencies
  of any changes that need to be updated.

There are a few cases that need to be covered in that last point
(but remember, all of this only applies to Depends-on footers which
are in the commit_needs variable):

* Changes to depends-on in gerrit necessarily mean a new patchset
  of the change with the depends-on header, so in the B->A situation,
  if B is updated, it will be re-enqueued.

  * Note that normally the orignal B->A series is dequeued, unless
    dequeue-on-new-patchset is false.  In that case it will remain
    and we will have B->A and B1->A, which is what the user asked for.

  To handle this case, we only need to refresh the deps of the change
  which is updated.

* In a C->B->A situation in gerrit, if B is updated then regardless
  of whether dequeue-on-new-patchset is true or false, the series should
  be dequeued because the dependency changed (and so the test setup
  is incorrect).

  To handle this case, we need to refresh the deps of any change whose
  commit_needs point to the updated change.

* Changes to depends-on in github don't create new patchsets, so we
  only need to refresh the deps of the change which is updated.  Because
  the changes it points to are still valid changes, they will have
  their own deps refreshed in place.

Change-Id: Ifc40ff5583a14c7f015356b963e1ba354974e1c8

1 files changed, 0 insertions, 3 deletions

diff --git a/zuul/driver/github/githubconnection.py b/zuul/driver/github/githubconnection.py
index 690494950..8307990aa 100644
--- a/zuul/driver/github/githubconnection.py
+++ b/zuul/driver/github/githubconnection.py
@@ -1306,9 +1306,6 @@ class GithubConnection(ZKChangeCacheMixin, CachedBranchConnection):
 
                     change = self._change_cache.updateChangeWithRetry(
                         key, change, _update_change)
-
-                    if self.sched:
-                        self.sched.onChangeUpdated(change, event)
                 finally:
                     # We need to remove the lock here again so we don't leak
                     # them.