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 28

def initialize(stream)
  @stream = stream
end

Instance Attribute Details

#stream ⇒ Object (readonly)

Returns the value of attribute stream.



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# File 'lib/protocol/redis/connection.rb', line 32

def stream
  @stream
end

Instance Method Details

#close ⇒ Object 



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# File 'lib/protocol/redis/connection.rb', line 34

def close
  @stream.close
end

#closed? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/protocol/redis/connection.rb', line 46

def closed?
  @stream.closed?
end

#flush ⇒ Object 



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

def flush
  @stream.flush
end

#read_data(length) ⇒ Object 



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# File 'lib/protocol/redis/connection.rb', line 74

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 83

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 61

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 51

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