Create statistics tablesm-efficient-counters

4 files changed, 67 insertions, 1 deletions

diff --git a/app/models/namespace.rb b/app/models/namespace.rb
index 4a6627d3ca1..7e60f9e299c 100644
--- a/app/models/namespace.rb
+++ b/app/models/namespace.rb
@@ -24,6 +24,7 @@ class Namespace < ActiveRecord::Base
 
   has_many :projects, dependent: :destroy # rubocop:disable Cop/ActiveRecordDependent
   has_many :project_statistics
+  has_many :statistics
 
   has_many :runner_namespaces, inverse_of: :namespace, class_name: 'Ci::RunnerNamespace'
   has_many :runners, through: :runner_namespaces, source: :runner, class_name: 'Ci::Runner'
diff --git a/app/models/project.rb b/app/models/project.rb
index d87fc1e4b86..5efa1ce9155 100644
--- a/app/models/project.rb
+++ b/app/models/project.rb
@@ -226,7 +226,8 @@ class Project < ActiveRecord::Base
 
   has_one :import_data, class_name: 'ProjectImportData', inverse_of: :project, autosave: true
   has_one :project_feature, inverse_of: :project
-  has_one :statistics, class_name: 'ProjectStatistics'
+  # has_one :statistics, class_name: 'ProjectStatistics'
+  has_one :statistics, foreign_key: 'project_id', class_name: 'Statistic'
 
   has_one :cluster_project, class_name: 'Clusters::Project'
   has_many :clusters, through: :cluster_project, class_name: 'Clusters::Cluster'
diff --git a/app/models/statistic.rb b/app/models/statistic.rb
new file mode 100644
index 00000000000..902ed429704
--- /dev/null
+++ b/app/models/statistic.rb
@@ -0,0 +1,47 @@
+# frozen_string_literal: true
+
+class Statistic < ActiveRecord::Base
+  belongs_to :project
+
+  before_save :update_storage_size
+
+  enum key: {
+    commit_count: 0,
+    repository_size: 1,
+    lfs_objects_size: 2,
+    job_artifacts_size: 3,
+    repositories_count: 4
+  }
+
+  validates :key, presence: true
+
+  def self.increment_project_statistic(project, key, amount)
+    raise ArgumentError, "Cannot increment attribute: #{key}" unless keys.key?(key)
+    return if amount == 0
+
+    ActiveRecord::Base.transaction do
+      project.statistic.public_send(key).increment(amount)
+    end
+  end
+
+  def self.increment(amount)
+    self.value ||= 0
+    self.value += amount
+    save
+  end
+
+  def storage_size
+    query = <<~SQL
+      SELECT sum(v) from
+      (
+        SELECT value AS v FROM statistics WHERE project_id = #{project.id} AND key = #{keys[:repository_size]} LIMIT 1
+        union all
+        SELECT value AS v FROM statistics WHERE project_id = #{project.id} AND key = #{keys[:lfs_objects_size]} LIMIT 1
+        union all
+        SELECT value AS v FROM statistics WHERE project_id = #{project.id} AND key = #{keys[:job_artifacts_size]} LIMIT 1
+      )
+    SQL
+
+    ActiveRecord::Base.connection.select_all(query).first
+  end
+end
diff --git a/db/migrate/20181114193339_create_statistics_table.rb b/db/migrate/20181114193339_create_statistics_table.rb
new file mode 100644
index 00000000000..e8d0206c9a6
--- /dev/null
+++ b/db/migrate/20181114193339_create_statistics_table.rb
@@ -0,0 +1,17 @@
+# frozen_string_literal: true
+
+class CreateStatisticsTable < ActiveRecord::Migration
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+
+  def change
+    create_table :statistics, id: :bigserial do |t|
+      t.references :project, null: false, foreign_key: { on_delete: :cascade }
+      t.integer :key, null: false
+      t.bigint :value, null: false
+
+      t.index [:project_id, :key], unique: true
+    end
+  end
+end