    # File lib/rubygems/source_info_cache.rb, line 241
      def refresh(all)
        Gem.sources.each do |source_uri|
          cache_entry = cache_data[source_uri]
          if cache_entry.nil? then
            cache_entry = Gem::SourceInfoCacheEntry.new nil, 0
            cache_data[source_uri] = cache_entry
          end

          update if cache_entry.refresh source_uri, all
        end

        flush
      end