Improve diff lines count efficiency

Previously, we called the `peek_enabled?` method like so:

    prepend_before_action :set_peek_request_id, if: :peek_enabled?

Now we don't have a `set_peek_request_id` method, so we don't need that
line. However, the `peek_enabled?` part had a side-effect: it would also
populate the request store cache for whether the performance bar was
enabled for the current request or not.

This commit makes that side-effect explicit, and replaces all uses of
`peek_enabled?` with the more explicit
`Gitlab::PerformanceBar.enabled_for_request?`. There is one spec that
still sets `SafeRequestStore[:peek_enabled]` directly, because it is
contrasting behaviour with and without a request store enabled.

The upshot is:

1. We still set the value in one place. We make it more explicit that
   that's what we're doing.
2. Reading that value uses a consistent method so it's easier to find in
   future.

This will help diagnose the source of excessive I/O from Rugged
calls. To implement this, we need to obtain the full list of arguments
sent to each request method.

Igor Drozdov authored 5 years ago and Nick Thomas committed 5 years ago

This is part of migration of Folder View to Vue

Whenever we use the rugged implementation, we are going straight to disk
so we want to bypass the disk access check.

Add a module we use as a singleton to determine whether or not rails is
able to access the disk

Currently, MergeToRefService is specifically designed for
createing merge commits from source branch and target branch of
merge reqeusts. We extend this behavior to source branch and any
target ref paths.

GitalyBot authored 5 years ago and Bob Van Landuyt :neckbeard: committed 5 years ago

The setup was wrong, and due to Gitaly being a bit more strict it had to
match up. The test is now accurate and passing again.

CE port of https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/13460

It used to be the case that GitLab created symlinks for each repository
to one copy of the Git hooks, so these ran when required. This changed
to set the hooks dynamically on Gitaly when invoking Git.

The side effect is that we didn't need all these symlinks anymore, which
Gitaly doesn't create anymore either. Now that means that the tests in
GitLab-Rails should test for it either.

Related: https://gitlab.com/gitlab-org/gitaly/issues/1392#note_175619926

Attempting to use the API endpoint
/projects/:id/repository/tree?recursive=true would only return a subset
of the results since the full recursive list wasn't actually being
returned.

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/61979

DisconnectGitAlternates is a Gitaly RPC that will delete a repository's
objects/info/alternates file. This commit adds client support for that
RPC.

Gitaly's FetchIntoObjectPool RPC will idempotently fetch objects into an
object pool. If the pool doesn't exist, it will create an empty pool
before attempting the fetch. This change adds client code as well as
specs to cover this behavior.