Class: NNQ::CLI::Formatter

Inherits:
Object
  • Object
show all
Defined in:
lib/nnq/cli/formatter.rb

Overview

Handles encoding/decoding a single-body message in the configured format. Compression is handled by the NNQ::Zstd decorator around the socket, not by the formatter.

Unlike omq-cli’s Formatter, nnq messages are not multipart — one ‘String` body per message. The API takes and returns a plain `String`.

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(format) ⇒ Formatter

Returns a new instance of Formatter.

Parameters:

  • format (Symbol) —

    wire format (:ascii, :quoted, :raw, :msgpack, :marshal)



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# File 'lib/nnq/cli/formatter.rb', line 14

def initialize(format)
  @format = format
end

Class Method Details

.preview(body) ⇒ String

Formats a message body for human-readable preview (logging).

Parameters:

  • body (String) —

    message body

Returns:

  • (String) —

    truncated preview



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# File 'lib/nnq/cli/formatter.rb', line 84

def self.preview(body)
  body = body.to_s
  "(#{body.bytesize}B) #{preview_body(body)}"
end

.preview_body(body) ⇒ Object 



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# File 'lib/nnq/cli/formatter.rb', line 90

def self.preview_body(body)
  bytes = body.b
  return "''" if bytes.empty?

  sample    = bytes[0, 12]
  printable = sample.count("\x20-\x7e")

  if printable < sample.bytesize / 2
    "[#{bytes.bytesize}B]"
  elsif bytes.bytesize > 12
    "#{sample.gsub(/[^[:print:]]/, ".")}..."
  else
    sample.gsub(/[^[:print:]]/, ".")
  end
end

Instance Method Details

#decode(line) ⇒ String

Decodes a formatted input line into a message body.

Parameters:

  • line (String) —

    input line (newline-terminated)

Returns:

  • (String) —

    message



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# File 'lib/nnq/cli/formatter.rb', line 45

def decode(line)
  case @format
  when :ascii, :marshal
    line.chomp
  when :quoted
    "\"#{line.chomp}\"".undump
  when :raw
    line
  end
end

#decode_marshal(io) ⇒ Object?

Decodes one Marshal object from the given IO stream.

Parameters:

  • io (IO) —

    input stream

Returns:

  • (Object, nil) —

    deserialized object, or nil on EOF



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# File 'lib/nnq/cli/formatter.rb', line 61

def decode_marshal(io)
  Marshal.load(io)
rescue EOFError, TypeError
  nil
end

#decode_msgpack(io) ⇒ Object?

Decodes one MessagePack object from the given IO stream.

Parameters:

  • io (IO) —

    input stream

Returns:

  • (Object, nil) —

    deserialized object, or nil on EOF



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# File 'lib/nnq/cli/formatter.rb', line 72

def decode_msgpack(io)
  @msgpack_unpacker ||= MessagePack::Unpacker.new(io)
  @msgpack_unpacker.read
rescue EOFError
  nil
end

#encode(msg) ⇒ String

Encodes a message body into a printable string for output.

Parameters:

  • msg (String) —

    message body

Returns:

  • (String) —

    formatted output line



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# File 'lib/nnq/cli/formatter.rb', line 24

def encode(msg)
  case @format
  when :ascii
    msg.b.gsub(/[^[:print:]\t]/, ".") << "\n"
  when :quoted
    msg.b.dump[1..-2] << "\n"
  when :raw
    msg # FIXME: are these really the wire bytes?
  when :msgpack
    MessagePack.pack(msg)
  when :marshal
    msg.inspect << "\n"
  end
end