Class: EM::Tycoon::Protocol::Message

Inherits:
Object
  • Object
show all
Defined in:
lib/em/tycoon/protocol/message.rb

Overview

Represents a Kyoto Tycoon binary protocol message See KT docs : fallabs.com/kyototycoon/spex.html#protocol

Constant Summary collapse

MAGIC = 
{:set => 0xB8,
:get => 0xBA,
:remove => 0xB9,
:play_script => 0xB4,
:replication => 0xB1,
:error => 0xBF}
MSG_TYPES = 
MAGIC.invert
FLAGS = 
{:no_reply => 0x01}
DEFAULT_OPTS = 
{
  :no_reply => false
}
NO_EXPIRATION_TIME = 
0x7FFFFFFFFFFFFFFF
PARSE_PHASES = 
[:magic,:item_count]
NO_XT_HEX = 
"7#{'F'*15}"
KV_PACK_FMT = 
"nNNH*a*a*"

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(type, data = nil) ⇒ Message

Create a new KT message object to parse a response from KT or to serialize one to send, type indicates the message type being created, as defined by the keys of Message::MAGIC (e.g. :set, :get, etc.), and the optional data parameter can be used to specify the initial contents of the message, specific to the message type



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# File 'lib/em/tycoon/protocol/message.rb', line 43

def initialize(type,data=nil)
  self.class.check_msg_type(type)
  self.type = type
  @data = data
  @bytes_per_record = 0
  @bytes_expected = 5
  @keysize = @valuesize = 0
  @parsed = false
  @buffer = String.new
  @parse_phase = PARSE_PHASES.first
end

Instance Attribute Details

#buffer ⇒ Object (readonly)

Returns the value of attribute buffer.



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# File 'lib/em/tycoon/protocol/message.rb', line 24

def buffer
  @buffer
end

#bytes_expected ⇒ Object (readonly)

Returns the value of attribute bytes_expected.



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# File 'lib/em/tycoon/protocol/message.rb', line 24

def bytes_expected
  @bytes_expected
end

#data ⇒ Object (readonly)

The data payload of the KT message, which can either be empty, contain a hash of KV pairs, or a list of keys



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# File 'lib/em/tycoon/protocol/message.rb', line 37

def data
  @data
end

#item_count ⇒ Object (readonly)

Number of items/KV pairs contained in KT message



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# File 'lib/em/tycoon/protocol/message.rb', line 30

def item_count
  @item_count
end

#keysize ⇒ Object (readonly)

Total size, in bytes, of all key data contained in KT message



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# File 'lib/em/tycoon/protocol/message.rb', line 32

def keysize
  @keysize
end

#magic ⇒ Object (readonly)

“Magic” number header from KT message, indicating message type



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# File 'lib/em/tycoon/protocol/message.rb', line 28

def magic
  @magic
end

#parse_phase ⇒ Object (readonly)

Returns the value of attribute parse_phase.



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# File 'lib/em/tycoon/protocol/message.rb', line 24

def parse_phase
  @parse_phase
end

#parsed ⇒ Object (readonly)

Returns the value of attribute parsed.



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# File 'lib/em/tycoon/protocol/message.rb', line 24

def parsed
  @parsed
end

#type ⇒ Object

The human-readable symbol version of the KT message type, as defined in the keys of Message::MAGIC



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# File 'lib/em/tycoon/protocol/message.rb', line 26

def type
  @type
end

#valuesize ⇒ Object (readonly)

Total size, in bytes, of all value data contained in KT message



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# File 'lib/em/tycoon/protocol/message.rb', line 34

def valuesize
  @valuesize
end

Class Method Details

.check_msg_type(type) ⇒ Object

Raises:

  • (ArgumentError) 


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# File 'lib/em/tycoon/protocol/message.rb', line 135

def check_msg_type(type)
  raise ArgumentError.new("Unknown message type #{type.inspect}") unless MAGIC.has_key?(type.downcase.to_sym)
end

.generate(type, data, opts = {}) ⇒ Object 



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# File 'lib/em/tycoon/protocol/message.rb', line 128

def generate(type, data, opts={})
  check_msg_type(type)
  opts=DEFAULT_OPTS.merge(opts)
  classname = type.to_s.gsub(/^[a-z]|_[a-z]/) {|c| c.upcase}.gsub('_','') + "Message"
  Binary.const_get(classname).generate(data,opts)
end

.message_for(data) ⇒ Object

Raises:

  • (ArgumentError) 


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# File 'lib/em/tycoon/protocol/message.rb', line 116

def message_for(data)
  msgtype = msg_type_for(data)
  raise ArgumentError.new("Unknown magic byte 0x#{('%02X' % data[0])}") unless msgtype
  classname = msgtype.to_s.gsub(/^[a-z]|_[a-z]/) {|c| c.upcase}.gsub('_','') + "Message"
  Binary.const_get(classname).new(data)
end

.msg_type_for(data) ⇒ Object 



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# File 'lib/em/tycoon/protocol/message.rb', line 123

def msg_type_for(data)
  magic = data.unpack("C").first
  MSG_TYPES[magic]
end

Instance Method Details

#[](key) ⇒ Object 



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# File 'lib/em/tycoon/protocol/message.rb', line 109

def [](key)
  @data[key]
end

#parse(data) ⇒ Object

Parse an arbitrary blob of data, possibly containing an entire message, possibly part of it, possibly more than 1 returns the number of bytes from the buffer that were actually parsed and updates the #bytes_expected property accordingly



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# File 'lib/em/tycoon/protocol/message.rb', line 65

def parse(data)
  return 0 unless data && data.bytesize > 0
  if data.bytesize < @bytes_expected
    @buffer << data
    @bytes_expected -= data.bytesize
    return data.bytesize
  else
    @buffer << data[0..@bytes_expected]
    bytes_parsed = parse_chunk(@buffer)
    return 0 if bytes_parsed == 0 # This is an error
    @bytes_expected -= bytes_parsed
    @buffer = String.new
    if @bytes_expected == 0
      @parsed = true
    elsif (data.bytesize-bytes_parsed) > 0
      bytes_parsed += parse(data[bytes_parsed..-1])
    end
    return bytes_parsed 
  end
end

#parse_chunk(data) ⇒ Object

Parse a Kyoto Tycoon binary protocol message part into this Message instance, returning the number of bytes parsed. Default implementation supports standard magic+hits or just magic (in case of error message) messages



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# File 'lib/em/tycoon/protocol/message.rb', line 89

def parse_chunk(data)
  return 0 if data.nil?
  return 0 unless data.bytesize == @bytes_expected
  bytes_parsed = 0
  if @bytes_expected > 1
    @magic,@item_count = data.unpack("CN")
    bytes_parsed = 5
  else
    @magic = data.unpack("C").first
    bytes_parsed = 1
  end
  @data = @item_count
  @parse_phase = :item_count
  return bytes_parsed
end

#parsed? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/em/tycoon/protocol/message.rb', line 105

def parsed?
  @parsed
end