lib/sequenced/generator.rb in sequenced-2.0.0 vs lib/sequenced/generator.rb in sequenced-3.0.0

@@ -9,11 +9,13 @@
       @start_at = options[:start_at] || 1
       @skip = options[:skip]
     end
 
     def set
-      record.send(:"#{column}=", next_id) unless id_set? || skip?
+      return if id_set? || skip?
+      lock_table
+      record.send(:"#{column}=", next_id)
     end
 
     def id_set?
       !record.send(column).nil?
     end
@@ -42,10 +44,21 @@
       end.count == 0
     end
 
   private
 
+    def lock_table
+      if postgresql?
+        record.class.connection.execute("LOCK TABLE #{record.class.table_name} IN EXCLUSIVE MODE")
+      end
+    end
+
+    def postgresql?
+      defined?(ActiveRecord::ConnectionAdapters::PostgreSQLAdapter) &&
+        record.class.connection.instance_of?(ActiveRecord::ConnectionAdapters::PostgreSQLAdapter)
+    end
+
     def base_relation
       record.class.base_class.unscoped
     end
 
     def find_last_record
@@ -65,6 +78,6 @@
     def max(*values)
       values.to_a.max
     end
 
   end
-end
\ No newline at end of file
+end