1 files changed, 24 insertions, 18 deletions
diff --git a/app/models/ci/pipeline.rb b/app/models/ci/pipeline.rb
index aeee7f0a5d2..9512ba42f67 100644
--- a/app/models/ci/pipeline.rb
+++ b/app/models/ci/pipeline.rb
@@ -58,15 +58,9 @@ module Ci
 
     after_create :keep_around_commits, unless: :importing?
 
-    enum_with_nil source: {
-      unknown: nil,
-      push: 1,
-      web: 2,
-      trigger: 3,
-      schedule: 4,
-      api: 5,
-      external: 6
-    }
+    # We use `Ci::PipelineEnums.sources` here so that EE can more easily extend
+    # this `Hash` with new values.
+    enum_with_nil source: ::Ci::PipelineEnums.sources
 
     enum_with_nil config_source: {
       unknown_source: nil,
@@ -74,10 +68,9 @@ module Ci
       auto_devops_source: 2
     }
 
-    enum failure_reason: {
-      unknown_failure: 0,
-      config_error: 1
-    }
+    # We use `Ci::PipelineEnums.failure_reasons` here so that EE can more easily
+    # extend this `Hash` with new values.
+    enum failure_reason: ::Ci::PipelineEnums.failure_reasons
 
     state_machine :status, initial: :created do
       event :enqueue do
@@ -181,22 +174,31 @@ module Ci
     #
     # ref - The name (or names) of the branch(es)/tag(s) to limit the list of
     #       pipelines to.
-    def self.newest_first(ref = nil)
+    # limit - This limits a backlog search, default to 100.
+    def self.newest_first(ref: nil, limit: 100)
       relation = order(id: :desc)
+      relation = relation.where(ref: ref) if ref
 
-      ref ? relation.where(ref: ref) : relation
+      if limit
+        ids = relation.limit(limit).select(:id)
+        # MySQL does not support limit in subquery
+        ids = ids.pluck(:id) if Gitlab::Database.mysql?
+        relation = relation.where(id: ids)
+      end
+
+      relation
     end
 
     def self.latest_status(ref = nil)
-      newest_first(ref).pluck(:status).first
+      newest_first(ref: ref).pluck(:status).first
     end
 
     def self.latest_successful_for(ref)
-      newest_first(ref).success.take
+      newest_first(ref: ref).success.take
     end
 
     def self.latest_successful_for_refs(refs)
-      relation = newest_first(refs).success
+      relation = newest_first(ref: refs).success
 
       relation.each_with_object({}) do |pipeline, hash|
         hash[pipeline.ref] ||= pipeline
@@ -238,6 +240,10 @@ module Ci
       end
     end
 
+    def self.latest_successful_ids_per_project
+      success.group(:project_id).select('max(id) as id')
+    end
+
     def self.truncate_sha(sha)
       sha[0...8]
     end