Module: Bencode

Defined in:

lib/bencode.rb

Class Method Summary

• .dump(obj) ⇒ Object
• .load(str) ⇒ Object
• .load_file(path) ⇒ Object
• .parse(scanner) ⇒ Object

  :nodoc:.

Class Method Details

.dump(obj) ⇒ Object

# File 'lib/bencode.rb', line 154

def dump(obj)
  obj.bencode
end

.load(str) ⇒ Object

Raises:

• (BdecodeError)

# File 'lib/bencode.rb', line 158

def load(str)
  require 'strscan'

  scanner = StringScanner.new(str)
  obj = parse(scanner)
  raise BdecodeError unless scanner.eos?
  return obj
end

.load_file(path) ⇒ Object

# File 'lib/bencode.rb', line 167

def load_file(path)
  load(File.open(path).read)
end

.parse(scanner) ⇒ Object

:nodoc:

# File 'lib/bencode.rb', line 171

def parse(scanner) # :nodoc:
  case token = scanner.scan(/[ild]|\d+:|\s/)
  when nil
    raise BdecodeError, scanner.pos
  when "i"
    number = scanner.scan(/0|(?:-?[1-9][0-9]*)/)
    unless number and scanner.scan(/e/)
      raise BdecodeError, scanner.pos
    end
    return number.to_i
  when "l"
    ary = []
    until scanner.peek(1) == "e"
      ary.push(parse(scanner))
    end
    scanner.pos += 1
    return ary
  when "d"
    hsh = {}
    until scanner.peek(1) == "e"
      key, value = parse(scanner), parse(scanner)
      unless key.is_a? String
        raise BdecodeError, "error at #{scanner.pos}: " + 
                            "key must be a string"
      end
      hsh.store(key, value)
    end
    scanner.pos += 1
    return hsh
  when /\d+:/
    length = token.chop.to_i
    str = scanner.peek(length)
    scanner.pos += length
    return str
  when /\s/
    nil
  else
    raise BdecodeError, scanner.pos
  end
end