commit 03fc0306cd943a65c987730dfc48b70ad2020ef3
author Edwin Kempin <ekempin@google.com> Wed Jun 23 10:43:24 2021 +0200
committer Edwin Kempin <ekempin@google.com> Tue Jun 29 16:38:24 2021 +0200
tree b64bb7c2872b4d0674afed88ab2cf0dceeb9fe44
parent a792738fa92720a04eb375f6af8b22b015ca7fa0

Make all callers of ChangedFiles go through getOrCompute

Earlier it was required to pass in the RevWalk instance into
ChangedFiles when validating newly created commits, because commits
that were newly created in the CreateChange REST endpoint where only
visible through the specific RevWalk instance that was used when
creating the commit (any newly created RevWalk instance was not seeing
the commit and any attempt to look it up failed with a
MissingObjectException). Due to this the validation could not use the
new diff cache (aka DiffOperations), as the new diff cache didn't allow
to pass in a RevWalk instance.

Since passing in a RevWalk instance is no longer needed (see change
Ie8d447b79 and change I489c26ac3) we can now also use the new diff cache
for the validation.

With this change all callers of ChangedFiles use the getOrCompute
methods now. The getOrCompute methods will either retrieve the changed
files from the new diff cache or compute them newly depending on the
setting for the CodeOwnersExperimentFeaturesConstants#USE_DIFF_CACHE
experiment flag. At the moment using the new diff cache is disabled by
default, but once we are sure that its performance is fine, we will make
the switch to always use it. Then we will also want to drop the code for
computing changed files on our own.

While we are at this, remove the PatchListNotAvailableException from the
method signatures as this exception is never thrown.

Signed-off-by: Edwin Kempin <ekempin@google.com>
Change-Id: Ie703498f2ad39e8a9802c143364e63b5a7ac6b2a