Class: RubyDNS::Resolver::Request

Inherits:
Object
  • Object
show all
Includes:
EventMachine::Deferrable
Defined in:
lib/rubydns/resolver.rb

Overview

Manages a single DNS question message across one or more servers.

Defined Under Namespace

Modules: TCPRequestHandler, UDPRequestHandler

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(message, servers, options = {}, &block) ⇒ Request

Returns a new instance of Request.



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# File 'lib/rubydns/resolver.rb', line 96

def initialize(message, servers, options = {}, &block)
	@message = message
	@packet = message.encode
	
	@servers = servers.dup
	
	# We select the protocol based on the size of the data:
	if @packet.bytesize > UDP_TRUNCATION_SIZE
		@servers.delete_if{|server| server[0] == :udp}
	end
	
	# Measured in seconds:
	@timeout = options[:timeout] || 5
	
	@logger = options[:logger]
end

Instance Attribute Details

#logger ⇒ Object (readonly)

Returns the value of attribute logger.



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# File 'lib/rubydns/resolver.rb', line 115

def logger
  @logger
end

#message ⇒ Object (readonly)

Returns the value of attribute message.



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# File 'lib/rubydns/resolver.rb', line 113

def message
  @message
end

#packet ⇒ Object (readonly)

Returns the value of attribute packet.



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# File 'lib/rubydns/resolver.rb', line 114

def packet
  @packet
end

Class Method Details

.fetch(*args) ⇒ Object 



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# File 'lib/rubydns/resolver.rb', line 80

def self.fetch(*args)
	request = self.new(*args)
	
	request.callback do |message|
		yield message
	end
	
	request.errback do |error|
		# In the case of a timeout, error will be nil, so we make one up.
		
		yield error
	end
	
	request.run!
end

Instance Method Details

#process_response!(response) ⇒ Object

Once either an exception or message is received, we update the status of this request.



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# File 'lib/rubydns/resolver.rb', line 122

def process_response!(response)
	finish_request!
	
	if Exception === response
		@logger.warn "[#{@message.id}] Failure while processing response #{response}!" if @logger
		RubyDNS.log_exception(@logger, response) if @logger
		
		try_next_server!
	elsif response.tc != 0
		@logger.warn "[#{@message.id}] Received truncated response!" if @logger
		
		try_next_server!
	elsif response.id != @message.id
		@logger.warn "[#{@message.id}] Received response with incorrect message id: #{response.id}" if @logger
		
		try_next_server!
	else
		@logger.debug "[#{@message.id}] Received valid response #{response.inspect}" if @logger
		
		succeed response
	end
end

#run! ⇒ Object 



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# File 'lib/rubydns/resolver.rb', line 117

def run!
	try_next_server!
end