diff options
Diffstat (limited to 'activerecord/lib/active_record/attribute_methods/read.rb')
-rw-r--r-- | activerecord/lib/active_record/attribute_methods/read.rb | 118 |
1 files changed, 64 insertions, 54 deletions
diff --git a/activerecord/lib/active_record/attribute_methods/read.rb b/activerecord/lib/active_record/attribute_methods/read.rb index 964c4123ef..846ac03d82 100644 --- a/activerecord/lib/active_record/attribute_methods/read.rb +++ b/activerecord/lib/active_record/attribute_methods/read.rb @@ -58,78 +58,88 @@ module ActiveRecord end protected - # We want to generate the methods via module_eval rather than define_method, - # because define_method is slower on dispatch and uses more memory (because it - # creates a closure). - # - # But sometimes the database might return columns with characters that are not - # allowed in normal method names (like 'my_column(omg)'. So to work around this - # we first define with the __temp__ identifier, and then use alias method to - # rename it to what we want. - def define_method_attribute(attr_name) - cast_code = attribute_cast_code(attr_name) - - generated_attribute_methods.module_eval <<-STR, __FILE__, __LINE__ + 1 - def __temp__ - #{internal_attribute_access_code(attr_name, cast_code)} - end - alias_method '#{attr_name}', :__temp__ - undef_method :__temp__ - STR - - generated_external_attribute_methods.module_eval <<-STR, __FILE__, __LINE__ + 1 - def __temp__(v, attributes, attributes_cache, attr_name) - #{external_attribute_access_code(attr_name, cast_code)} - end - alias_method '#{attr_name}', :__temp__ - undef_method :__temp__ - STR - end - - private - def cacheable_column?(column) - attribute_types_cached_by_default.include?(column.type) - end - - def internal_attribute_access_code(attr_name, cast_code) - access_code = "(v=@attributes[attr_name]) && #{cast_code}" - - unless attr_name == primary_key - access_code.insert(0, "missing_attribute(attr_name, caller) unless @attributes.has_key?(attr_name); ") + # We want to generate the methods via module_eval rather than define_method, + # because define_method is slower on dispatch and uses more memory (because it + # creates a closure). + # + # But sometimes the database might return columns with characters that are not + # allowed in normal method names (like 'my_column(omg)'. So to work around this + # we first define with the __temp__ identifier, and then use alias method to + # rename it to what we want. + def define_method_attribute(attr_name) + cast_code = attribute_cast_code(attr_name) + + generated_attribute_methods.module_eval <<-STR, __FILE__, __LINE__ + 1 + def __temp__ + #{internal_attribute_access_code(attr_name, cast_code)} end + alias_method '#{attr_name}', :__temp__ + undef_method :__temp__ + STR - if cache_attribute?(attr_name) - access_code = "@attributes_cache[attr_name] ||= (#{access_code})" + generated_external_attribute_methods.module_eval <<-STR, __FILE__, __LINE__ + 1 + def __temp__(v, attributes, attributes_cache, attr_name) + #{external_attribute_access_code(attr_name, cast_code)} end + alias_method '#{attr_name}', :__temp__ + undef_method :__temp__ + STR + end - "attr_name = '#{attr_name}'; #{access_code}" + private + def cacheable_column?(column) + if attribute_types_cached_by_default == ATTRIBUTE_TYPES_CACHED_BY_DEFAULT + ! serialized_attributes.include? column.name + else + attribute_types_cached_by_default.include?(column.type) end + end - def external_attribute_access_code(attr_name, cast_code) - access_code = "v && #{cast_code}" + def internal_attribute_access_code(attr_name, cast_code) + "read_attribute('#{attr_name}') { |n| missing_attribute(n, caller) }" + end - if cache_attribute?(attr_name) - access_code = "attributes_cache[attr_name] ||= (#{access_code})" - end + def external_attribute_access_code(attr_name, cast_code) + access_code = "v && #{cast_code}" - access_code + if cache_attribute?(attr_name) + access_code = "attributes_cache[attr_name] ||= (#{access_code})" end - def attribute_cast_code(attr_name) - columns_hash[attr_name].type_cast_code('v') - end + access_code + end + + def attribute_cast_code(attr_name) + columns_hash[attr_name].type_cast_code('v') + end end # Returns the value of the attribute identified by <tt>attr_name</tt> after it has been typecast (for example, # "2004-12-12" in a data column is cast to a date object, like Date.new(2004, 12, 12)). def read_attribute(attr_name) - self.class.type_cast_attribute(attr_name, @attributes, @attributes_cache) + # If it's cached, just return it + @attributes_cache.fetch(attr_name) { |name| + column = @columns_hash.fetch(name) { + return self.class.type_cast_attribute(name, @attributes, @attributes_cache) + } + + value = @attributes.fetch(name) { + return block_given? ? yield(name) : nil + } + + if self.class.cache_attribute?(name) + @attributes_cache[name] = column.type_cast(value) + else + column.type_cast value + end + } end private - def attribute(attribute_name) - read_attribute(attribute_name) - end + + def attribute(attribute_name) + read_attribute(attribute_name) + end end end end |