Reuse existing Repository for refs filtering

The git-refs-filter plugin is meant to be used
for repositories that may have millions of refs
associated with hundreds of thousands of changes.

Opening and closing the repository for every change
to be filtered has a significant performance degradation
which could also bring the entire clone to fail for

The Repository object is always the same for the filtering
of all changes and therefore it makes sense to reuse it
instead of wasting CPU cycles in the open/close of the same
repository million of times.

Change-Id: I0e15c6ce53db56486a29a3c009f724f5a92ff300
1 file changed
tree: f5e2cd03df863ddefae89fe58e4f0652dc18bde7
  1. src/
  2. .gitignore
  3. BUILD

Git Ref filter module for Gerrit

Gerrit lib module to allow filtering out refs in the Git advertizing protocol phase.

How to build

Build this module as it was a Gerrit plugin:

  • Clone Gerrit source tree
  • Clone the git-refs-filter source tree
  • Link the git-refs-filter directory to Gerrit /plugins/git-refs-filter
  • From Gerrit source tree run bazel build plugins/git-refs-filter
  • And for running tests bazel test plugins/git-refs-filter:git_refs_filter_tests
  • The git-refs-filter.jar module is generated under /bazel-genfiles/plugins/git-refs-filter/

How install

Copy git-refs-filter.jar library to Gerrit /lib and add the following one extra settings to gerrit.config:

  installModule = com.googlesource.gerrit.modules.gitrefsfilter.RefsFilterModule

How to configure filtering

The refsfilter module defines a new global capability called “Filter out closed changes refs”. By default the capability isn't assigned to any user or group, thus the module installation has no side effects.

Filtering a closed change refs has the following meaning:

  • Merged changes and all their patch-sets
  • Abandoned changes and all their patch-sets
  • Corrupted changes and all their patch-sets
  • All ‘/meta’ refs of all changes

To enable a group of users of getting a “filtered list” of refs (e.g. CI jobs):

  • Define a new group of users (e.g. Builders)
  • Add a user to that group (e.g. Add ‘jenkins’ to the Builders group)
  • Go to the All-Projects ACLs, add the “Filter out closed changes refs” and assign to the group (e.g. Builders)

NOTE Gerrit makes a super-simplified ACL evaluation if all the projects are globally readable (e.g. project has a READ rule to refs/*). To enable the closed changes filtering you need to disable any global read rule for the group that needs refs filtering.