# File lib/rubygems/source_info_cache.rb, line 103
  def refresh
    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

      cache_entry.refresh source_uri
    end
    update
    flush
  end