musicbrainz/lib/musicbrainz/client_modules/caching_proxy.rb

# -*- encoding : utf-8 -*-
module MusicBrainz
  module ClientModules
    module CachingProxy
      def cache_path
        MusicBrainz.config.cache_path
      end

      def clear_cache
        FileUtils.rm_r(cache_path) if cache_path && File.exist?(cache_path)
      end

      def get_contents(url)
        return super unless caching?

        hash = Digest::SHA256.hexdigest(url)
        dir_path = [cache_path, *(0..2).map{ |i| hash.slice(2*i, 2) }].join(?/)
        file_path = [dir_path, '/', hash.slice(6, 58), '.xml'].join

        response = { body: nil, status: 500 }

        if File.exist?(file_path)
          response = {
            body: File.open(file_path, 'rb').gets,
            status: 200
          }
        else
          response = super
          if response[:status] == 200
            FileUtils.mkpath(dir_path)
            File.open(file_path, 'wb') do |f|
              f.puts(response[:body])
              f.chmod(0755)
              f.close
            end
          end
        end

        response
      end

      def caching?
        MusicBrainz.config.perform_caching
      end
    end
  end
end