Add Project.where_paths_in
What does this MR do?
This MR adds the method Project.where_paths_in which can be used to find multiple projects by a list of full paths.
Are there points in the code the reviewer needs to double check?
No.
Why was this MR needed?
In https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/4410 I'm working on reducing the SQL queries needed to render Markdown. One reason for the large amount of queries is executing a large number of queries needed to find projects and related data. Basically Project.find_with_namespace is called in a loop and then any relations have to be retrieved separately.
By using Project.where_paths_in we can work around this by doing something like:
project_paths = [...] # populated by some method
projects = Project.where_paths_in(project_paths).includes(:namespace, ...)