Parent

Celluloid::IO::DNSResolver

Asynchronous DNS resolver using Celluloid::IO::UDPSocket

Constants

DNS_PORT
RESOLV_CONF

Public Class Methods

generate_id() click to toggle source
# File lib/celluloid/io/dns_resolver.rb, line 13
def self.generate_id
  @mutex.synchronize { @identifier = (@identifier + 1) & 0xFFFF }
end
nameservers(config = RESOLV_CONF) click to toggle source
# File lib/celluloid/io/dns_resolver.rb, line 17
def self.nameservers(config = RESOLV_CONF)
  File.read(config).scan(/^\s*nameserver\s+([0-9.:]+)/).flatten
end
new() click to toggle source
# File lib/celluloid/io/dns_resolver.rb, line 21
def initialize
  @nameservers = self.class.nameservers

  # TODO: fall back on other nameservers if the first one is unavailable
  @server = @nameservers.first

  # The non-blocking secret sauce is here, as this is actually a
  # Celluloid::IO::UDPSocket
  @socket = UDPSocket.new
end

Public Instance Methods

resolve(hostname) click to toggle source
# File lib/celluloid/io/dns_resolver.rb, line 32
def resolve(hostname)
  if host = resolve_hostname(hostname)
    unless ip_address = resolve_host(host)
      raise Resolv::ResolvError, "invalid entry in hosts file: #{host}"
    end
    return ip_address
  end

  query = build_query(hostname)
  @socket.send query.encode, 0, @server, DNS_PORT
  data, _ = @socket.recvfrom(512)
  response = Resolv::DNS::Message.decode(data)

  addrs = []
  # The answer might include IN::CNAME entries so filters them out
  # to include IN::A & IN::AAAA entries only.
  response.each_answer { |name, ttl, value| addrs << value.address if value.respond_to?(:address) }

  return if addrs.empty?
  return addrs.first if addrs.size == 1
  addrs
end

[Validate]

Generated with the Darkfish Rdoc Generator 2.