Skip to content
This repository
file 135 lines (110 sloc) 3.703 kb
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134
require 'time'
require 'rack/utils'
require 'rack/mime'

module Rack
  # Rack::File serves files below the +root+ directory given, according to the
  # path info of the Rack request.
  # e.g. when Rack::File.new("/etc") is used, you can access 'passwd' file
  # as http://localhost:9292/passwd
  #
  # Handlers can detect if bodies are a Rack::File, and use mechanisms
  # like sendfile on the +path+.

  class File
    ALLOWED_VERBS = %w[GET HEAD OPTIONS]
    ALLOW_HEADER = ALLOWED_VERBS.join(', ')

    attr_accessor :root
    attr_accessor :path
    attr_accessor :cache_control

    alias :to_path :path

    def initialize(root, headers={}, default_mime = 'text/plain')
      @root = root
      @headers = headers
      @default_mime = default_mime
    end

    def call(env)
      dup._call(env)
    end

    F = ::File

    def _call(env)
      unless ALLOWED_VERBS.include? env["REQUEST_METHOD"]
        return fail(405, "Method Not Allowed", {'Allow' => ALLOW_HEADER})
      end

      path_info = Utils.unescape(env["PATH_INFO"])
      clean_path_info = Utils.clean_path_info(path_info)

      @path = F.join(@root, clean_path_info)

      available = begin
        F.file?(@path) && F.readable?(@path)
      rescue SystemCallError
        false
      end

      if available
        serving(env)
      else
        fail(404, "File not found: #{path_info}")
      end
    end

    def serving(env)
      if env["REQUEST_METHOD"] == "OPTIONS"
       return [200, {'Allow' => ALLOW_HEADER, 'Content-Length' => '0'}, []]
      end
      last_modified = F.mtime(@path).httpdate
      return [304, {}, []] if env['HTTP_IF_MODIFIED_SINCE'] == last_modified

      headers = { "Last-Modified" => last_modified }
      mime = Mime.mime_type(F.extname(@path), @default_mime)
      headers["Content-Type"] = mime if mime

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

      response = [ 200, headers, env["REQUEST_METHOD"] == "HEAD" ? [] : self ]

      # NOTE:
      # 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.
      size = F.size?(@path) || Utils.bytesize(F.read(@path))

      ranges = Rack::Utils.byte_ranges(env, 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[1]["Content-Length"] = size.to_s
      response
    end

    def each
      F.open(@path, "rb") do |file|
        file.seek(@range.begin)
        remaining_len = @range.end-@range.begin+1
        while remaining_len > 0
          part = file.read([8192, remaining_len].min)
          break unless part
          remaining_len -= part.length

          yield part
        end
      end
    end

    private

    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

  end
end
Something went wrong with that request. Please try again.