1 files changed, 60 insertions, 0 deletions
diff --git a/lib/gitlab/database/query_analyzer.rb b/lib/gitlab/database/query_analyzer.rb
new file mode 100644
index 00000000000..830ad1383c0
--- /dev/null
+++ b/lib/gitlab/database/query_analyzer.rb
@@ -0,0 +1,60 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module Database
+    # The purpose of this class is to implement a various query analyzers based on `pg_query`
+    # And process them all via `Gitlab::Database::QueryAnalyzers::*`
+    class QueryAnalyzer
+      ANALYZERS = [].freeze
+
+      Parsed = Struct.new(
+        :sql, :connection, :pg
+      )
+
+      def hook!
+        @subscriber = ActiveSupport::Notifications.subscribe('sql.active_record') do |event|
+          process_sql(event.payload[:sql], event.payload[:connection])
+        end
+      end
+
+      private
+
+      def process_sql(sql, connection)
+        analyzers = enabled_analyzers(connection)
+        return unless analyzers.any?
+
+        parsed = parse(sql, connection)
+        return unless parsed
+
+        analyzers.each do |analyzer|
+          analyzer.analyze(parsed)
+        rescue => e # rubocop:disable Style/RescueStandardError
+          # We catch all standard errors to prevent validation errors to introduce fatal errors in production
+          Gitlab::ErrorTracking.track_and_raise_for_dev_exception(e)
+        end
+      end
+
+      def enabled_analyzers(connection)
+        ANALYZERS.select do |analyzer|
+          analyzer.enabled?(connection)
+        rescue StandardError => e # rubocop:disable Style/RescueStandardError
+          # We catch all standard errors to prevent validation errors to introduce fatal errors in production
+          Gitlab::ErrorTracking.track_and_raise_for_dev_exception(e)
+        end
+      end
+
+      def parse(sql, connection)
+        parsed = PgQuery.parse(sql)
+        return unless parsed
+
+        normalized = PgQuery.normalize(sql)
+        Parsed.new(normalized, connection, parsed)
+      rescue PgQuery::ParseError => e
+        # Ignore PgQuery parse errors (due to depth limit or other reasons)
+        Gitlab::ErrorTracking.track_exception(e)
+
+        nil
+      end
+    end
+  end
+end