From e24b9c2502613cc0df5b2a676236d1c36c02bca4 Mon Sep 17 00:00:00 2001 From: Stan Hu Date: Thu, 22 Aug 2019 00:19:44 -0700 Subject: Eliminate Gitaly N+1 queries with notes API Similar to https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/31834, we see that in https://gitlab.com/gitlab-org/gitlab-ce/issues/65957 there can be hundreds, even thousands, of Gitaly requests in the `/api/:version/projects/:id/merge_requests/:noteable_id/notes` endpoint. Previously, the API to retrieve notes generated hundreds of Gitaly calls to determine whether a system note should be shown to the user. It did this by: 1. Rendering the Markdown 2. Extracting cross-references from the Markdown 3. Issuing a Gitaly `FindCommit` RPC for every reference to validate that the commit exists. The last step is unnecessary because we don't need to display a commit if the user doesn't have access to the project in the first place. `RendersNotes#prepare_notes_for_rendering` is already used in `MergeRequestsController`, which is why we don't see N+1 Gitaly calls there. We use it here to optimize the note redaction process. --- lib/api/helpers/notes_helpers.rb | 2 ++ lib/api/notes.rb | 13 +++++++------ 2 files changed, 9 insertions(+), 6 deletions(-) (limited to 'lib') diff --git a/lib/api/helpers/notes_helpers.rb b/lib/api/helpers/notes_helpers.rb index 6bf9057fad7..b2bf6bf7417 100644 --- a/lib/api/helpers/notes_helpers.rb +++ b/lib/api/helpers/notes_helpers.rb @@ -3,6 +3,8 @@ module API module Helpers module NotesHelpers + include ::RendersNotes + def self.noteable_types # This is a method instead of a constant, allowing EE to more easily # extend it. diff --git a/lib/api/notes.rb b/lib/api/notes.rb index 9381f045144..84563d66ee8 100644 --- a/lib/api/notes.rb +++ b/lib/api/notes.rb @@ -36,12 +36,13 @@ module API # page can have less elements than :per_page even if # there's more than one page. raw_notes = noteable.notes.with_metadata.reorder(order_options_with_tie_breaker) - notes = - # paginate() only works with a relation. This could lead to a - # mismatch between the pagination headers info and the actual notes - # array returned, but this is really a edge-case. - paginate(raw_notes) - .reject { |n| n.cross_reference_not_visible_for?(current_user) } + + # paginate() only works with a relation. This could lead to a + # mismatch between the pagination headers info and the actual notes + # array returned, but this is really a edge-case. + notes = paginate(raw_notes) + notes = prepare_notes_for_rendering(notes) + notes = notes.reject { |n| n.cross_reference_not_visible_for?(current_user) } present notes, with: Entities::Note end # rubocop: enable CodeReuse/ActiveRecord -- cgit v1.2.1