1 files changed, 90 insertions, 0 deletions
diff --git a/lib/gitlab/database/async_indexes/index_base.rb b/lib/gitlab/database/async_indexes/index_base.rb
new file mode 100644
index 00000000000..bde75e12295
--- /dev/null
+++ b/lib/gitlab/database/async_indexes/index_base.rb
@@ -0,0 +1,90 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module Database
+    module AsyncIndexes
+      class IndexBase
+        include AsyncDdlExclusiveLeaseGuard
+        extend ::Gitlab::Utils::Override
+
+        TIMEOUT_PER_ACTION = 1.day
+
+        def initialize(async_index)
+          @async_index = async_index
+        end
+
+        def perform
+          try_obtain_lease do
+            if preconditions_met?
+              log_index_info("Starting async index #{action_type}")
+              execute_action_with_error_handling
+              log_index_info("Finished async index #{action_type}")
+            else
+              log_index_info(skip_log_message)
+              async_index.destroy!
+            end
+          end
+        end
+
+        private
+
+        attr_reader :async_index
+
+        delegate :connection, :connection_db_config, to: :async_index
+
+        def preconditions_met?
+          raise NotImplementedError, 'must implement preconditions_met?'
+        end
+
+        def action_type
+          raise NotImplementedError, 'must implement action_type'
+        end
+
+        def execute_action_with_error_handling
+          around_execution { execute_action }
+        rescue StandardError => error
+          async_index.handle_exception!(error)
+
+          Gitlab::ErrorTracking.track_and_raise_for_dev_exception(error)
+          Gitlab::AppLogger.error(message: error.message, **logging_options)
+        end
+
+        def around_execution
+          yield
+        end
+
+        def execute_action
+          connection.execute(async_index.definition)
+          async_index.destroy!
+        end
+
+        def index_exists?
+          connection.indexes(async_index.table_name).any? do |index|
+            index.name == async_index.name
+          end
+        end
+
+        def lease_timeout
+          TIMEOUT_PER_ACTION
+        end
+
+        def log_index_info(message)
+          Gitlab::AppLogger.info(message: message, **logging_options)
+        end
+
+        def skip_log_message
+          "Skipping index #{action_type} since preconditions are not met. " \
+            "The queuing entry will be deleted"
+        end
+
+        def logging_options
+          {
+            table_name: async_index.table_name,
+            index_name: async_index.name,
+            class: self.class.name.to_s
+          }
+        end
+      end
+    end
+  end
+end