Closes #35692.

The list of commits must be generated from the merge request,
not from a diff of the branches.

Added test to API commits in order to handle cases for authenticated/unauthenticated user in a
private and public project.

Fix the /projects/:id/repository/commits endpoint to handle dots in the ref name when the project full path contains a `/`

Signed-off-by: Rémy Coutable <remy@rymai.me>

This commit introduces the usage of Common Table Expressions (CTEs) to
efficiently retrieve nested group hierarchies, without having to rely on
the "routes" table (which is an _incredibly_ inefficient way of getting
the data). This requires a patch to ActiveRecord (found in the added
initializer) to work properly as ActiveRecord doesn't support WITH
statements properly out of the box.

Unfortunately MySQL provides no efficient way of getting nested groups.
For example, the old routes setup could easily take 5-10 seconds
depending on the amount of "routes" in a database. Providing vastly
different logic for both MySQL and PostgreSQL will negatively impact the
development process. Because of this the various nested groups related
methods return empty relations when used in combination with MySQL.

For project authorizations the logic is split up into two classes:

* Gitlab::ProjectAuthorizations::WithNestedGroups
* Gitlab::ProjectAuthorizations::WithoutNestedGroups

Both classes get the fresh project authorizations (= as they should be
in the "project_authorizations" table), including nested groups if
PostgreSQL is used. The logic of these two classes is quite different
apart from their public interface. This complicates development a bit,
but unfortunately there is no way around this.

This commit also introduces Gitlab::GroupHierarchy. This class can be
used to get the ancestors and descendants of a base relation, or both by
using a UNION. This in turn is used by methods such as:

* Namespace#ancestors
* Namespace#descendants
* User#all_expanded_groups

Again this class relies on CTEs and thus only works on PostgreSQL. The
Namespace methods will return an empty relation when MySQL is used,
while User#all_expanded_groups will return only the groups a user is a
direct member of.

Performance wise the impact is quite large. For example, on GitLab.com
Namespace#descendants used to take around 580 ms to retrieve data for a
particular user. Using CTEs we are able to reduce this down to roughly 1
millisecond, returning the exact same data.

== On The Fly Refreshing

Refreshing of authorizations on the fly (= when
users.authorized_projects_populated was not set) is removed with this
commit. This simplifies the code, and ensures any queries used for
authorizations are not mutated because they are executed in a Rails
scope (e.g. Project.visible_to_user).

This commit includes a migration to schedule refreshing authorizations
for all users, ensuring all of them have their authorizations in place.
Said migration schedules users in batches of 5000, with 5 minutes
between every batch to smear the load around a bit.

== Spec Changes

This commit also introduces some changes to various specs. For example,
some specs for ProjectTeam assumed that creating a personal project
would _not_ lead to the owner having access, which is incorrect. Because
we also no longer refresh authorizations on the fly for new users some
code had to be added to the "empty_project" factory. This chunk of code
ensures that the owner's permissions are refreshed after creating the
project, something that is normally done in Projects::CreateService.

Removed all the unnecessary include of `WaitForAjax` and `ApiHelpers` in the specs.
Removed unnecessary usage of `api:true`

Signed-off-by: Rémy Coutable <remy@rymai.me>

Signed-off-by: Rémy Coutable <remy@rymai.me>

Jordan Ryan Reuter authored 8 years ago and Oswaldo Ferreir committed 7 years ago

`Kaminari.paginate_array` takes some options, most relevant of which is
a `total_count` parameter. Using the `commit_count` for `total_count`
lets us correctly treat the return of `Repository#commits` as a subset
of all the commits we may wish to list.

Addition of a new `Repository#commit_count_for_ref` method was
necessarry to allow the user to start from an arbitrary ref.

Ref #1381

Fixes #23895.

This was because the MR was a bit behind master and the error message
got updated in the meantime by 79aad815.

Signed-off-by: Rémy Coutable <remy@rymai.me>

Restore changes for api spec files

Fix error in rspec Users

Delete extra space Repositories-spec

Signed-off-by: Rémy Coutable <remy@rymai.me>

add docs and tests - add additional validation
allow move without content
updated response

https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/6305#note_15230024