Optimise CI status accessor

app/models/ci/commit.rb

@@ -44,8 +44,12 @@ module Ci
       sha[0...8]
     end
 
+    def self.stages
+      CommitStatus.where(commit: all).stages
+    end
+
     def stages
-      statuses.group(:stage).order(:stage_idx).pluck(:stage)
+      statuses.stages
     end
 
     def project_id

app/models/commit_status.rb

@@ -49,6 +49,7 @@ class CommitStatus < ActiveRecord::Base
 
   scope :latest, -> { where(id: unscope(:select).select('max(id)').group(:name, :commit_id)) }
   scope :ordered, -> { order(:ref, :stage_idx, :name) }
+  scope :ignored, -> { where(allow_failure: true, status: [:failed, :canceled]) }
 
   AVAILABLE_STATUSES = ['pending', 'running', 'success', 'failed', 'canceled']
 
@@ -84,6 +85,40 @@ class CommitStatus < ActiveRecord::Base
 
   delegate :before_sha, :sha, :short_sha, to: :commit, prefix: false
 
+  def self.stages
+    order_by = 'max(stage_idx)'
+    group('stage').order(order_by).pluck(:stage, order_by).map(&:first).compact
+  end
+
+  def self.status_sql
+    builds = all.select('count(id)').to_sql
+    success = all.success.select('count(id)').to_sql
+    ignored = all.failed.where(allow_failure: true).select('count(id)').to_sql if all.try(:ignored)
+    ignored ||= '0'
+    pending = all.pending.select('count(id)').to_sql
+    running = all.running.select('count(id)').to_sql
+    canceled = all.canceled.select('count(id)').to_sql
+
+    deduce_status = "(CASE
+      WHEN (#{builds})=0 THEN 'skipped'
+      WHEN (#{builds})=(#{success})+(#{ignored}) THEN 'success'
+      WHEN (#{builds})=(#{pending}) THEN 'pending'
+      WHEN (#{builds})=(#{canceled}) THEN 'canceled'
+      WHEN (#{running})+(#{pending})>0 THEN 'running'
+      ELSE 'failed'
+    END)"
+
+    deduce_status
+  end
+
+  def self.status
+    pluck(self.status_sql).first
+  end
+
+  def self.stages_status
+    Hash[group(:stage).pluck(:stage, self.status_sql)]
+  end
+
   def ignored?
     allow_failure? && (failed? || canceled?)
   end

app/models/concerns/ci_status.rb

@@ -43,6 +43,7 @@ module CiStatus
     scope :pending, -> { where(status: 'pending') }
     scope :success, -> { where(status: 'success') }
     scope :failed, -> { where(status: 'failed')  }
+    scope :canceled, -> { where(status: 'canceled')  }
     scope :running_or_pending, -> { where(status: [:running, :pending]) }
     scope :finished, -> { where(status: [:success, :failed, :canceled]) }
   end

db/migrate/20160412174954_add_ci_commit_indexes.rb

+class AddCiCommitIndexes < ActiveRecord::Migration
+  def change
+    add_index :ci_commits, [:gl_project_id, :sha]
+    add_index :ci_commits, [:gl_project_id, :status]
+    add_index :ci_commits, [:status]
+  end
+end

db/migrate/20160412175417_update_ci_commit.rb

+class UpdateCiCommit < ActiveRecord::Migration
+  def change
+    execute("UPDATE ci_commits SET status=#{status}, ref=#{ref}, tag=#{tag} WHERE status IS NULL")
+  end
+
+  def status
+    builds = '(SELECT COUNT(*) FROM ci_builds WHERE ci_builds.commit_id=ci_commits.id)'
+    success = "(SELECT COUNT(*) FROM ci_builds WHERE ci_builds.commit_id=ci_commits.id AND status='success')"
+    ignored = "(SELECT COUNT(*) FROM ci_builds WHERE ci_builds.commit_id=ci_commits.id AND (status='failed' OR status='canceled') AND allow_failure)"
+    pending = "(SELECT COUNT(*) FROM ci_builds WHERE ci_builds.commit_id=ci_commits.id AND status='pending')"
+    running = "(SELECT COUNT(*) FROM ci_builds WHERE ci_builds.commit_id=ci_commits.id AND status='running')"
+    canceled = "(SELECT COUNT(*) FROM ci_builds WHERE ci_builds.commit_id=ci_commits.id AND status='canceled')"
+
+    "(CASE
+      WHEN #{builds}=0 THEN 'skipped'
+      WHEN #{builds}=#{success}+#{ignored} THEN 'success'
+      WHEN #{builds}=#{pending} THEN 'pending'
+      WHEN #{builds}=#{canceled} THEN 'canceled'
+      WHEN #{running}+#{pending}>0 THEN 'running'
+      ELSE 'failed'
+    END)"
+  end
+
+  def ref
+    '(SELECT ref FROM ci_builds WHERE ci_builds.commit_id=ci_commits.id ORDER BY id DESC LIMIT 1)'
+  end
+
+  def tag
+    '(SELECT tag FROM ci_builds WHERE ci_builds.commit_id=ci_commits.id ORDER BY id DESC LIMIT 1)'
+  end
+end