Class: Async::Redis::Protocol::RESP

Inherits:
IO::Protocol::Line
  • Object
show all
Defined in:
lib/async/redis/protocol/resp.rb

Instance Method Summary collapse

Constructor Details

#initialize(stream) ⇒ RESP

Returns a new instance of RESP.



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# File 'lib/async/redis/protocol/resp.rb', line 36

def initialize(stream)
	super(stream, CRLF)
end

Instance Method Details

#closed? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/async/redis/protocol/resp.rb', line 40

def closed?
	@stream.closed?
end

#read_data(length) ⇒ Object 



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# File 'lib/async/redis/protocol/resp.rb', line 70

def read_data(length)
	buffer = @stream.read(length) or @stream.eof!
	
	# Eat trailing whitespace because length does not include the CRLF:
	@stream.read(2) or @stream.eof!
	
	return buffer
end

#read_object ⇒ Object Also known as: read_response 



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# File 'lib/async/redis/protocol/resp.rb', line 79

def read_object
	line = read_line
	token = line.slice!(0, 1)
	
	case token
	when '$'
		length = line.to_i
		
		if length == -1
			return nil
		else
			return read_data(length)
		end
	when '*'
		count = line.to_i
		
		# Null array (https://redis.io/topics/protocol#resp-arrays):
		return nil if count == -1
		
		array = Array.new(count) {read_object}
		
		return array
	when ':'
		return line.to_i
	
	when '-'
		raise ServerError.new(line)
	
	when '+'
		return line
	
	else
		@stream.flush
		
		raise NotImplementedError, "Implementation for token #{token} missing"
	end
	
	# TODO: If an exception (e.g. Async::TimeoutError) propagates out of this function, perhaps @stream should be closed? Otherwise it might be in a weird state.
end

#write_object(object) ⇒ Object 



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# File 'lib/async/redis/protocol/resp.rb', line 57

def write_object(object)
	case object
	when String
		write_lines("$#{object.bytesize}", object)
	when Array
		write_array(object)
	when Integer
		write_lines(":#{object}")
	else
		write_object(object.to_redis)
	end
end

#write_request(arguments) ⇒ Object

The redis server doesn’t want actual objects (e.g. integers) but only bulk strings. So, we inline it for performance.



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# File 'lib/async/redis/protocol/resp.rb', line 45

def write_request(arguments)
	write_lines("*#{arguments.count}")
	
	arguments.each do |argument|
		string = argument.to_s
		
		write_lines("$#{string.bytesize}", string)
	end
	
	@stream.flush
end