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 }
headers[CONTENT_TYPE] = mime_type if mime_type
# Set custom headers
@headers.each { |field, content| headers[field] = content } if @headers
response = [ 200, headers, env[REQUEST_METHOD] == "HEAD" ? [] : self ]
size = filesize
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[2] = [response_body] unless response_body.nil?
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
# The MIME type for the contents of the file located at @path
def mime_type
Mime.mime_type(F.extname(@path), @default_mime)
end
def filesize
# 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.
F.size?(@path) || Utils.bytesize(F.read(@path))
end
# 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
def response_body
nil
end
end
end
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