Merge branch 'zj-gitaly-pipelines-n-1' into 'master'

Improve performance of Pipelines#index.json

See merge request gitlab-org/gitlab-ce!14846

3 files changed, 36 insertions, 9 deletions

diff --git a/app/models/ci/pipeline.rb b/app/models/ci/pipeline.rb
index 28f154581a9..d4690da3be6 100644
--- a/app/models/ci/pipeline.rb
+++ b/app/models/ci/pipeline.rb
@@ -287,8 +287,12 @@ module Ci
       Ci::Pipeline.truncate_sha(sha)
     end
 
+    # NOTE: This is loaded lazily and will never be nil, even if the commit
+    # cannot be found.
+    #
+    # Use constructs like: `pipeline.commit.present?`
     def commit
-      @commit ||= project.commit_by(oid: sha)
+      @commit ||= Commit.lazy(project, sha)
     end
 
     def branch?
@@ -338,12 +342,9 @@ module Ci
     end
 
     def latest?
-      return false unless ref
-
-      commit = project.commit(ref)
-      return false unless commit
+      return false unless ref && commit.present?
 
-      commit.sha == sha
+      project.commit(ref) == commit
     end
 
     def retried
diff --git a/app/models/commit.rb b/app/models/commit.rb
index 13c31111134..2be07ca7d3c 100644
--- a/app/models/commit.rb
+++ b/app/models/commit.rb
@@ -86,6 +86,20 @@ class Commit
     def valid_hash?(key)
       !!(/\A#{COMMIT_SHA_PATTERN}\z/ =~ key)
     end
+
+    def lazy(project, oid)
+      BatchLoader.for({ project: project, oid: oid }).batch do |items, loader|
+        items_by_project = items.group_by { |i| i[:project] }
+
+        items_by_project.each do |project, commit_ids|
+          oids = commit_ids.map { |i| i[:oid] }
+
+          project.repository.commits_by(oids: oids).each do |commit|
+            loader.call({ project: commit.project, oid: commit.id }, commit) if commit
+          end
+        end
+      end
+    end
   end
 
   attr_accessor :raw
@@ -103,7 +117,7 @@ class Commit
   end
 
   def ==(other)
-    (self.class === other) && (raw == other.raw)
+    other.is_a?(self.class) && raw == other.raw
   end
 
   def self.reference_prefix
@@ -224,8 +238,8 @@ class Commit
     notes.includes(:author)
   end
 
-  def method_missing(m, *args, &block)
-    @raw.__send__(m, *args, &block) # rubocop:disable GitlabSecurity/PublicSend
+  def method_missing(method, *args, &block)
+    @raw.__send__(method, *args, &block) # rubocop:disable GitlabSecurity/PublicSend
   end
 
   def respond_to_missing?(method, include_private = false)
diff --git a/app/models/repository.rb b/app/models/repository.rb
index 4ec8ec9c8b2..387428d90a6 100644
--- a/app/models/repository.rb
+++ b/app/models/repository.rb
@@ -118,6 +118,18 @@ class Repository
     @commit_cache[oid] = find_commit(oid)
   end
 
+  def commits_by(oids:)
+    return [] unless oids.present?
+
+    commits = Gitlab::Git::Commit.batch_by_oid(raw_repository, oids)
+
+    if commits.present?
+      Commit.decorate(commits, @project)
+    else
+      []
+    end
+  end
+
   def commits(ref, path: nil, limit: nil, offset: nil, skip_merges: false, after: nil, before: nil)
     options = {
       repo: raw_repository,