tree f8b28261b77762df00522df836f07674170f02e3
parent b81a9aa509675d3cdfab5ff4701af9ee5eeb15a7
author David Ostrovsky <david@ostrovsky.org> 1573299493 +0100
committer Matthias Sohn <matthias.sohn@sap.com> 1575418763 +0100

Replace guava caches with caffeine

Replacing Guava caches with Caffeine reduces the chances of having the
deadlocks and improves the cache performance.

This was already attempted in: I8d2b17a94d0, but got reverted in:
If65560b4a9b due to recursion in PatchListLoader. This recursion issue
is present on current master. While this change replaces all caches
with Caffeine backend, the follow-up change in this series will switch
back to using Guava backend for PatchListCache implementation.

For seamless integration, the caffeine-guava adapter library is used.
Given that the final artifact for the adapter is also called guava,
there is only the version number that differentiates that artifact from
the guava library itself so that we have a danger for naming collision.
To avoid potential naming collision risk, rename the library name to
caffeine-guava.jar during the fetch from Maven Central.

Alternatives considered is not to use the caffeine-guava adapter
library. But then the Cache and LoadingCache classes and friends would
change the package name from com.google.common.cache package to
com.github.benmanes.caffeine.cache package and this change would also
affect some gerrit plugins and thus considered to be a quite intrusive
change.  Still we can consider to do this change in one of the future
gerrit releases.

Bug: Issue 7645
Bug: Issue 11484
Change-Id: I6af4c15d6c15f438becd62409b7d233c309be8de
(cherry picked from commit 0050a9b5f61da67a9f33fda0bb170f8b1df6080a)