Class: Protocol::Redis::Connection

Inherits:
Object
  • Object
show all
Defined in:
lib/protocol/redis/connection.rb

Constant Summary collapse

CRLF = 
"\r\n".freeze

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(stream) ⇒ Connection

Returns a new instance of Connection.



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# File 'lib/protocol/redis/connection.rb', line 30

def initialize(stream)
	@stream = stream
	
	# Number of requests sent:
	@count = 0
end

Instance Attribute Details

#count ⇒ Object (readonly) 



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

def count
  @count
end

#stream ⇒ Object (readonly)

Returns the value of attribute stream.



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# File 'lib/protocol/redis/connection.rb', line 37

def stream
  @stream
end

Instance Method Details

#close ⇒ Object 



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# File 'lib/protocol/redis/connection.rb', line 42

def close
	@stream.close
end

#closed? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/protocol/redis/connection.rb', line 54

def closed?
	@stream.closed?
end

#flush ⇒ Object 



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# File 'lib/protocol/redis/connection.rb', line 50

def flush
	@stream.flush
end

#read_data(length) ⇒ Object 



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# File 'lib/protocol/redis/connection.rb', line 84

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/protocol/redis/connection.rb', line 93

def read_object
	line = read_line or raise EOFError
	
	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/protocol/redis/connection.rb', line 71

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/protocol/redis/connection.rb', line 59

def write_request(arguments)
	write_lines("*#{arguments.size}")
	
	@count += 1
	
	arguments.each do |argument|
		string = argument.to_s
		
		write_lines("$#{string.bytesize}", string)
	end
end