field_path.rb in google-cloud-firestore-0.23.0

- old
+ new

@@ -59,19 +59,19 @@
         #     :favorites, :food
         #   )
         #   user_snap.get(nested_field_path) #=> "Pizza"
         #
         def initialize *fields
-          @fields = fields.flatten.map(&:to_s)
-          @fields.each do |field|
-            raise ArgumentError, "empty paths not allowed" if field.empty?
-          end
+          @fields = fields.flatten.map(&:to_s).freeze
+
+          invalid_fields = @fields.detect(&:empty?)
+          raise ArgumentError, "empty paths not allowed" if invalid_fields
         end
 
         ##
         # @private The individual fields representing the nested field path for
-        # document data.
+        # document data. The fields are frozen.
         #
         # @return [Array<String>] The fields.
         #
         # @example
         #   require "google/cloud/firestore"
@@ -127,13 +127,13 @@
         #
         #   # Get a collection reference
         #   cities_col = firestore.col "cities"
         #
         #   # Create a query
-        #   query = cities_col.start_at("NYC").order(
+        #   query = cities_col.order(
         #     Google::Cloud::Firestore::FieldPath.document_id
-        #   )
+        #   ).start_at("NYC")
         #
         #   query.get do |city|
         #     puts "#{city.document_id} has #{city[:population]} residents."
         #   end
         #
@@ -143,10 +143,12 @@
 
         ##
         # @private Creates a field path object representing the nested fields
         # for document data.
         #
+        # The values are memoized to increase performance.
+        #
         # @param [String] dotted_string A string representing the path of the
         #   document data. The string can represent as a string of individual
         #   fields joined by ".". Fields containing `~`, `*`, `/`, `[`, `]`, and
         #   `.` cannot be in a dotted string, and should be created by passing
         #   individual field strings to  {FieldPath.new} instead.
@@ -164,18 +166,26 @@
         #     "favorites.food"
         #   )
         #   field_path.fields #=> ["favorites", "food"]
         #
         def self.parse dotted_string
-          return new dotted_string if dotted_string.is_a? Array
+          # Memoize parsed field paths
+          @memoized_field_paths ||= {}
+          if @memoized_field_paths.key? dotted_string
+            return @memoized_field_paths[dotted_string]
+          end
 
+          if dotted_string.is_a? Array
+            return @memoized_field_paths[dotted_string] = new(dotted_string)
+          end
+
           fields = String(dotted_string).split(".")
-          fields.each do |field|
-            if INVALID_FIELD_PATH_CHARS.match field
-              raise ArgumentError, "invalid character, use FieldPath instead"
-            end
+
+          if fields.grep(INVALID_FIELD_PATH_CHARS).any?
+            raise ArgumentError, "invalid character, use FieldPath instead"
           end
-          new fields
+
+          @memoized_field_paths[dotted_string] = new(fields)
         end
 
         ##
         # @private
         def <=> other