Contents

# frozen_string_literal: true

module Dalli
  module Protocol
    ##
    # Dalli::Protocol::ServerConfigParser parses a server string passed to
    # a Dalli::Protocol::Binary instance into the hostname, port, weight, and
    # socket_type.
    ##
    class ServerConfigParser
      # TODO: Revisit this, especially the IP/domain part.  Likely
      # can limit character set to LDH + '.'.  Hex digit section
      # appears to have been added to support IPv6, but as far as
      # I can tell it doesn't work
      SERVER_CONFIG_REGEXP = /\A(\[([\h:]+)\]|[^:]+)(?::(\d+))?(?::(\d+))?\z/.freeze

      DEFAULT_PORT = 11_211
      DEFAULT_WEIGHT = 1

      def self.parse(str)
        res = deconstruct_string(str)

        hostname = normalize_hostname(str, res)
        if hostname.start_with?('/')
          socket_type = :unix
          port, weight = attributes_for_unix_socket(res)
        else
          socket_type = :tcp
          port, weight = attributes_for_tcp_socket(res)
        end
        [hostname, port, weight, socket_type]
      end

      def self.deconstruct_string(str)
        mtch = str.match(SERVER_CONFIG_REGEXP)
        raise Dalli::DalliError, "Could not parse hostname #{str}" if mtch.nil? || mtch[1] == '[]'

        mtch
      end

      def self.attributes_for_unix_socket(res)
        # in case of unix socket, allow only setting of weight, not port
        raise Dalli::DalliError, "Could not parse hostname #{res[0]}" if res[4]

        [nil, normalize_weight(res[3])]
      end

      def self.attributes_for_tcp_socket(res)
        [normalize_port(res[3]), normalize_weight(res[4])]
      end

      def self.normalize_hostname(str, res)
        raise Dalli::DalliError, "Could not parse hostname #{str}" if res.nil? || res[1] == '[]'

        res[2] || res[1]
      end

      def self.normalize_port(port)
        Integer(port || DEFAULT_PORT)
      end

      def self.normalize_weight(weight)
        Integer(weight || DEFAULT_WEIGHT)
      end
    end
  end
end

Version data entries

1 entries across 1 versions & 1 rubygems

Version	Path
dalli-3.0.4	lib/dalli/protocol/server_config_parser.rb