class Rack::File

Rack::File serves files below the root directory given, according to the path info of the Rack request. e.g. when ::new(“/etc”) is used, you can access 'passwd' file as localhost:9292/passwd

Handlers can detect if bodies are a Rack::File, and use mechanisms like sendfile on the path.

Constants

ALLOWED_VERBS
ALLOW_HEADER

Attributes

root[R]

Public Class Methods

new(root, headers={}, default_mime = 'text/plain') click to toggle source
# File lib/rack/file.rb, line 22
def initialize(root, headers={}, default_mime = 'text/plain')
  @root = root
  @headers = headers
  @default_mime = default_mime
  @head = Rack::Head.new(lambda { |env| get env })
end

Public Instance Methods

call(env) click to toggle source
# File lib/rack/file.rb, line 29
def call(env)
  # HEAD requests drop the response body, including 4xx error messages.
  @head.call env
end
get(env) click to toggle source
# File lib/rack/file.rb, line 34
def get(env)
  request = Rack::Request.new env
  unless ALLOWED_VERBS.include? request.request_method
    return fail(405, "Method Not Allowed", {'Allow' => ALLOW_HEADER})
  end

  path_info = Utils.unescape_path request.path_info
  return fail(400, "Bad Request") unless Utils.valid_path?(path_info)

  clean_path_info = Utils.clean_path_info(path_info)
  path = ::File.join(@root, clean_path_info)

  available = begin
    ::File.file?(path) && ::File.readable?(path)
  rescue SystemCallError
    false
  end

  if available
    serving(request, path)
  else
    fail(404, "File not found: #{path_info}")
  end
end
serving(request, path) click to toggle source
# File lib/rack/file.rb, line 59
def serving(request, path)
  if request.options?
    return [200, {'Allow' => ALLOW_HEADER, CONTENT_LENGTH => '0'}, []]
  end
  last_modified = ::File.mtime(path).httpdate
  return [304, {}, []] if request.get_header('HTTP_IF_MODIFIED_SINCE') == last_modified

  headers = { "Last-Modified" => last_modified }
  mime_type = mime_type path, @default_mime
  headers[CONTENT_TYPE] = mime_type if mime_type

  # Set custom headers
  @headers.each { |field, content| headers[field] = content } if @headers

  response = [ 200, headers ]

  size = filesize path

  range = nil
  ranges = Rack::Utils.get_byte_ranges(request.get_header('HTTP_RANGE'), size)
  if ranges.nil? || ranges.length > 1
    # No ranges, or multiple ranges (which we don't support):
    # TODO: Support multiple byte-ranges
    response[0] = 200
    range = 0..size-1
  elsif ranges.empty?
    # Unsatisfiable. Return error, and file size:
    response = fail(416, "Byte range unsatisfiable")
    response[1]["Content-Range"] = "bytes */#{size}"
    return response
  else
    # Partial content:
    range = ranges[0]
    response[0] = 206
    response[1]["Content-Range"] = "bytes #{range.begin}-#{range.end}/#{size}"
    size = range.end - range.begin + 1
  end

  response[2] = [response_body] unless response_body.nil?

  response[1][CONTENT_LENGTH] = size.to_s
  response[2] = make_body request, path, range
  response
end

Private Instance Methods

fail(status, body, headers = {}) click to toggle source
# File lib/rack/file.rb, line 140
def fail(status, body, headers = {})
  body += "\n"

  [
    status,
    {
      CONTENT_TYPE   => "text/plain",
      CONTENT_LENGTH => body.size.to_s,
      "X-Cascade" => "pass"
    }.merge!(headers),
    [body]
  ]
end
filesize(path) click to toggle source
# File lib/rack/file.rb, line 159
def filesize path
  # If response_body is present, use its size.
  return Rack::Utils.bytesize(response_body) if response_body

  #   We check via File::size? whether this file provides size info
  #   via stat (e.g. /proc files often don't), otherwise we have to
  #   figure it out by reading the whole file into memory.
  ::File.size?(path) || ::File.read(path).bytesize
end
make_body(request, path, range) click to toggle source
# File lib/rack/file.rb, line 132
def make_body request, path, range
  if request.head?
    []
  else
    Iterator.new path, range
  end
end
mime_type(path, default_mime) click to toggle source

The MIME type for the contents of the file located at @path

# File lib/rack/file.rb, line 155
def mime_type path, default_mime
  Mime.mime_type(::File.extname(path), default_mime)
end
response_body() click to toggle source

By default, the response body for file requests is nil. In this case, the response body will be generated later from the file at @path

# File lib/rack/file.rb, line 172
def response_body
  nil
end