tree 3e4cf00411631cb4651b2525be0dd1e2a76fe180
parent ec6956dac5c5ebcc9212ad1a54c777e737a2baf5
author Antonio Barone <syntonyze@gmail.com> 1641218949 +0100
committer Antonio Barone <syntonyze@gmail.com> 1641305267 +0100

Introduce cache for open changes

Git-refs-filter plugin relies on change_notes when filtering for open
changes.

In order to speed up access to them, it is advised to enable caching for
change_notes, as documented in the README.md.

Whilst this improves the _accessing_ of the change note, it does nothing
to speed up the parsing of the change itself, in order to gather the
change status information, needed to assess whether the change is
actually open.

Introduce an additional in-memory cache to store previously computed
open/close change statuses to avoid processing them over and over
again.

Explicit cache invalidation is not necessary, since the change revision
is part of the cache key, so that previous entries automatically become
obsolete once a change status is updated.

Bug: Issue 15484
Change-Id: I36467dbd7c1ce646d97be410acbae564fa4a675f