Performance and memory optimizations

Co-authored-by: Sutou Kouhei <[email protected]>

lib/rexml/attribute.rb

@@ -1,4 +1,4 @@
-# frozen_string_literal: false
+# frozen_string_literal: true
 require_relative "namespace"
 require_relative 'text'
 
@@ -119,10 +119,13 @@ def hash
     #  b = Attribute.new( "ns:x", "y" )
     #  b.to_string     # -> "ns:x='y'"
     def to_string
+      value = to_s
       if @element and @element.context and @element.context[:attribute_quote] == :quote
-        %Q^#@expanded_name="#{to_s().gsub(/"/, '"')}"^
+        value = value.gsub('"', '"') if value.include?('"')
+        %Q^#@expanded_name="#{value}"^
       else
-        "#@expanded_name='#{to_s().gsub(/'/, ''')}'"
+        value = value.gsub("'", ''') if value.include?("'")
+        "#@expanded_name='#{value}'"
       end
     end
 
@@ -192,7 +195,7 @@ def node_type
     end
 
     def inspect
-      rv = ""
+      rv = +""
       write( rv )
       rv
     end

lib/rexml/entity.rb

@@ -132,24 +132,34 @@ def to_s
     # then:
     #  doctype.entity('yada').value   #-> "nanoo bar nanoo"
     def value
-      if @value
-        matches = @value.scan(PEREFERENCE_RE)
-        rv = @value.clone
-        if @parent
-          sum = 0
-          matches.each do |entity_reference|
-            entity_value = @parent.entity( entity_reference[0] )
-            if sum + entity_value.bytesize > Security.entity_expansion_text_limit
-              raise "entity expansion has grown too large"
-            else
-              sum += entity_value.bytesize
-            end
-            rv.gsub!( /%#{entity_reference.join};/um, entity_value )
+      @resolved_value ||= resolve_value
+    end
+
+    def parent=(other)
+      @resolved_value = nil
+      super
+    end
+
+    private
+    def resolve_value
+      return nil if @value.nil?
+      return @value unless @value.match?(PEREFERENCE_RE)
+
+      matches = @value.scan(PEREFERENCE_RE)
+      rv = @value.clone
+      if @parent
+        sum = 0
+        matches.each do |entity_reference|
+          entity_value = @parent.entity( entity_reference[0] )
+          if sum + entity_value.bytesize > Security.entity_expansion_text_limit
+            raise "entity expansion has grown too large"
+          else
+            sum += entity_value.bytesize
           end
+          rv.gsub!( /%#{entity_reference.join};/um, entity_value )
         end
-        return rv
       end
-      nil
+      rv
     end
   end
 

lib/rexml/formatters/pretty.rb

@@ -1,4 +1,4 @@
-# frozen_string_literal: false
+# frozen_string_literal: true
 require_relative 'default'
 
 module REXML
@@ -58,7 +58,7 @@ def write_element(node, output)
           skip = false
           if compact
             if node.children.inject(true) {|s,c| s & c.kind_of?(Text)}
-              string = ""
+              string = +""
               old_level = @level
               @level = 0
               node.children.each { |child| write( child, string ) }

lib/rexml/namespace.rb

@@ -1,4 +1,4 @@
-# frozen_string_literal: false
+# frozen_string_literal: true
 
 require_relative 'xmltokens'
 
@@ -10,21 +10,25 @@ module Namespace
     # The expanded name of the object, valid if name is set
     attr_accessor :prefix
     include XMLTokens
+    NAME_WITHOUT_NAMESPACE = /\A#{NCNAME_STR}\z/
     NAMESPLIT = /^(?:(#{NCNAME_STR}):)?(#{NCNAME_STR})/u
 
     # Sets the name and the expanded name
     def name=( name )
       @expanded_name = name
-      case name
-      when NAMESPLIT
+      if name.match?(NAME_WITHOUT_NAMESPACE)
+        @prefix = ""
+        @namespace = ""
+        @name = name
+      elsif name =~ NAMESPLIT
         if $1
           @prefix = $1
         else
           @prefix = ""
           @namespace = ""
         end
         @name = $2
-      when ""
+      elsif name == ""
         @prefix = nil
         @namespace = nil
         @name = nil

lib/rexml/text.rb

@@ -1,4 +1,4 @@
-# frozen_string_literal: false
+# frozen_string_literal: true
 require_relative 'security'
 require_relative 'entity'
 require_relative 'doctype'
@@ -131,7 +131,7 @@ def parent= parent
     def Text.check string, pattern, doctype
 
       # illegal anywhere
-      if string !~ VALID_XML_CHARS
+      if !string.match?(VALID_XML_CHARS)
         if String.method_defined? :encode
           string.chars.each do |c|
             case c.ord
@@ -371,7 +371,7 @@ def Text::normalize( input, doctype=nil, entity_filter=nil )
       copy = input.to_s
       # Doing it like this rather than in a loop improves the speed
       #copy = copy.gsub( EREFERENCE, '&' )
-      copy = copy.gsub( "&", "&" )
+      copy = copy.gsub( "&", "&" ) if copy.include?("&")
       if doctype
         # Replace all ampersands that aren't part of an entity
         doctype.entities.each_value do |entity|
@@ -382,7 +382,9 @@ def Text::normalize( input, doctype=nil, entity_filter=nil )
       else
         # Replace all ampersands that aren't part of an entity
         DocType::DEFAULT_ENTITIES.each_value do |entity|
-          copy = copy.gsub(entity.value, "&#{entity.name};" )
+          if copy.include?(entity.value)
+            copy = copy.gsub(entity.value, "&#{entity.name};" )
+          end
         end
       end
       copy

test/test_core.rb

@@ -1423,7 +1423,7 @@ def test_ticket_91
       d.root.add_element( "bah" )
       p=REXML::Formatters::Pretty.new(2)
       p.compact = true    # Don't add whitespace to text nodes unless necessary
-      p.write(d,out="")
+      p.write(d,out=+"")
       assert_equal( expected, out )
     end
 

test/test_document.rb

@@ -166,11 +166,9 @@ def test_empty_value
 <cd></cd>
 EOF
 
-          assert_raise(REXML::ParseException) do
-            REXML::Document.new(xml)
-          end
-          REXML::Security.entity_expansion_limit = 100
-          assert_equal(100, REXML::Security.entity_expansion_limit)
+          REXML::Document.new(xml)
+          REXML::Security.entity_expansion_limit = 90
+          assert_equal(90, REXML::Security.entity_expansion_limit)
           assert_raise(REXML::ParseException) do
             REXML::Document.new(xml)
           end