class Rack::Multipart::Parser

Rack::Multipart::Parser handles parsing of multipart/form-data requests.

File Parameter Contents

When processing file uploads, the parser returns a hash containing information about uploaded files. For file parameters, the hash includes:

:filename - The original filename, already URL decoded by the parser
:type - The content type of the uploaded file
:name - The parameter name from the form
:tempfile - A Tempfile object containing the uploaded data
:head - The raw header content for this part

Constants

BUFSIZE
CHARSET
CONTENT_DISPOSITION_MAX_BYTES
CONTENT_DISPOSITION_MAX_PARAMS
EMPTY
MultipartInfo
REENCODE_DUMMY_ENCODINGS
TEMPFILE_FACTORY
TEXT_PLAIN

Attributes

state [R]

Public Class Methods

new (boundary, tempfile, bufsize, query_parser) Show source

# File lib/rack/multipart/parser.rb, line 260
def initialize(boundary, tempfile, bufsize, query_parser)
  @query_parser   = query_parser
  @params         = query_parser.make_params
  @bufsize        = bufsize

  @state = :FAST_FORWARD
  @mime_index = 0
  @body_retained = nil
  @retained_size = 0
  @total_bytes_read = (0 if PARSER_BYTESIZE_LIMIT)
  @content_disposition_quoted_escapes = 0
  @collector = Collector.new tempfile

  @sbuf = StringScanner.new("".b)
  @body_regex = /(?:#{EOL}|\A)--#{Regexp.quote(boundary)}(?:#{EOL}|--)/m
  @body_regex_at_end = /#{@body_regex}\z/m
  @end_boundary_size = boundary.bytesize + 4 # (-- at start, -- at finish)
  @rx_max_size = boundary.bytesize + 6 # (\r\n-- at start, either \r\n or -- at finish)
  @head_regex = /(.*?#{EOL})#{EOL}/m
end

parse (io, content_length, content_type, tmpfile, bufsize, qp) Show source

# File lib/rack/multipart/parser.rb, line 137
def self.parse(io, content_length, content_type, tmpfile, bufsize, qp)
  return EMPTY if 0 == content_length

  boundary = parse_boundary content_type
  return EMPTY unless boundary

  if PARSER_BYTESIZE_LIMIT && content_length && content_length > PARSER_BYTESIZE_LIMIT
    raise Error, "multipart Content-Length #{content_length} exceeds limit of #{PARSER_BYTESIZE_LIMIT} bytes"
  end

  if boundary.length > 70
    # RFC 1521 Section 7.2.1 imposes a 70 character maximum for the boundary.
    # Most clients use no more than 55 characters.
    raise BoundaryTooLongError, "multipart boundary size too large (#{boundary.length} characters)"
  end

  io = BoundedIO.new(io, content_length) if content_length

  parser = new(boundary, tmpfile, bufsize, qp)
  parser.parse(io)

  parser.result
end

parse_boundary (content_type) Show source

# File lib/rack/multipart/parser.rb, line 122
def self.parse_boundary(content_type)
  return unless content_type
  data = content_type.match(MULTIPART)
  return unless data

  unless data[1].empty?
    raise Error, "whitespace between boundary parameter name and equal sign"
  end
  if data.post_match.match?(/boundary\s*=/i)
    raise BoundaryTooLongError, "multiple boundary parameters found in multipart content type"
  end

  data[2]
end

Public Instance Methods

parse (io) Show source

# File lib/rack/multipart/parser.rb, line 281
def parse(io)
  @total_bytes_read &&= nil if io.is_a?(BoundedIO)
  outbuf = String.new
  read_data(io, outbuf)

  loop do
    status =
      case @state
      when :FAST_FORWARD
        handle_fast_forward
      when :CONSUME_TOKEN
        handle_consume_token
      when :MIME_HEAD
        handle_mime_head
      when :MIME_BODY
        handle_mime_body
      else # when :DONE
        return
      end

    read_data(io, outbuf) if status == :want_read
  end
end

result () Show source

# File lib/rack/multipart/parser.rb, line 305
def result
  @collector.each do |part|
    part.get_data do |data|
      tag_multipart_encoding(part.filename, part.content_type, part.name, data)
      name, data = handle_dummy_encoding(part.name, data)
      @query_parser.normalize_params(@params, name, data)
    end
  end
  MultipartInfo.new @params.to_params_hash, @collector.find_all(&:file?).map(&:body)
end