Class: Cae::MultipartParser::Part::Body

Inherits:
Object
  • Object
show all
Defined in:
lib/cae/multipart_parser/part/body.rb

Instance Method Summary collapse

Constructor Details

#initialize(fh, read_limit, read_buffer = nil) ⇒ Body

Returns a new instance of Body.



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# File 'lib/cae/multipart_parser/part/body.rb', line 7

def initialize(fh, read_limit, read_buffer = nil)
  # Backing filehandle
  @fh = fh

  # After we've read this amount, act like the backing filehandle is empty
  @read_limit = read_limit

  # If anything is in this, we'll return it on the first read()
  @read_buffer = read_buffer
end

Instance Method Details

#read(length, outbuf = nil) ⇒ Object 



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# File 'lib/cae/multipart_parser/part/body.rb', line 18

def read(length, outbuf = nil)
  # Check we're not trying to read more bytes than are available
  length = @read_limit > length ? length : @read_limit

  # Early nil return if there's nothing available. This technically
  # breaks compatibility with IO#read, but I don't care.
  # (IO#read returns an empty string if passed length is 0; we'll return nil)
  return nil if length == 0

  # if there's anything in @read_buffer, return it before doing a real read
  if @read_buffer
    # initialise outbuf if it wasn't passed in.
    outbuf ||= String.new

    # copy contents into outbuf, being careful NOT to change the object_id
    outbuf.clear
    outbuf << @read_buffer[0, length]

    # advance buffer pointer; if there's none left, @read_buffer will be nil
    @read_limit -= outbuf.length
    @read_buffer = @read_buffer[length, @read_limit]

    return outbuf
  end

  @fh.read(length, outbuf).tap{|o| @read_limit -= o.length }
end