Module: Sensu::Redis::Parser

Included in:
Client
Defined in:
lib/sensu/redis/parser.rb

Overview

Sensu Module for parsing RESP (REdis Serialization Protocol). You can read about RESP @ redis.io/topics/protocol This module calls methods provided by other Sensu Redis modules:

Sensu::Redis::Processor.dispatch_error()
Sensu::Redis::Processor.dispatch_response()
Sensu::Redis::Processor.begin_multibulk()
Sensu::Redis::Connection.error()

Instance Method Summary collapse

Instance Method Details

#parse_line(line) ⇒ Object

Parse a RESP line.

Parameters:

  • line (String) 


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# File 'lib/sensu/redis/parser.rb', line 17

def parse_line(line)
  # Trim off the response type and delimiter (\r\n).
  response = line.slice(1..-3)
  # First character indicates response type.
  case line[0, 1]
  when MINUS # Error, e.g. -ERR
    dispatch_error(response)
  when PLUS # String, e.g. +OK
    dispatch_response(response)
  when DOLLAR # Bulk string, e.g. $3\r\nfoo\r\n
    response_size = Integer(response)
    if response_size == -1 # No data, return nil.
      dispatch_response(nil)
    elsif @buffer.size >= response_size + 2 # Complete data.
      dispatch_response(@buffer.slice!(0, response_size))
      @buffer.slice!(0,2) # Discard delimeter (\r\n).
    else # Incomplete, have data pushed back into buffer.
      return INCOMPLETE
    end
  when COLON # Integer, e.g. :8
    dispatch_response(Integer(response))
  when ASTERISK # Array, e.g. *2\r\n$3\r\foo\r\n$3\r\nbar\r\n
    multibulk_count = Integer(response)
    if multibulk_count == -1 || multibulk_count == 0 # No data, return [].
      dispatch_response(EMPTY_ARRAY)
    else
      begin_multibulk(multibulk_count) # Accumulate responses.
    end
  else
    error(ProtocolError, "response type not recognized: #{line.strip}")
  end
end

#receive_data(data) ⇒ Object

EM connection receive data, parse incoming data using RESP (‘parse_line()`).

Parameters:

  • data (String) 


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# File 'lib/sensu/redis/parser.rb', line 54

def receive_data(data)
  (@buffer ||= '') << data
  while index = @buffer.index(DELIM)
    line = @buffer.slice!(0, index+2)
    if parse_line(line) == INCOMPLETE
      @buffer[0...0] = line
      break
    end
  end
end