Module: Rack::Utils

Included in:
Chunked, Chunked::Body, ContentLength, ContentType
Defined in:
lib/rack/utils.rb,
lib/rack.rb

Overview

Rack::Utils contains a grab-bag of useful methods for writing web applications adopted from all kinds of Ruby libraries.

Defined Under Namespace

Modules: OkJson Classes: Context, HeaderHash, KeySpaceConstrainedParams

Constant Summary collapse

DEFAULT_SEP = 
/[&;] */n
ESCAPE_HTML = 
{
  "&" => "&",
  "<" => "&lt;",
  ">" => "&gt;",
  "'" => "&#x27;",
  '"' => "&quot;",
  "/" => "&#x2F;"
}
ESCAPE_HTML_PATTERN =

On 1.8, there is a kcode = ‘u’ bug that allows for XSS otherwhise TODO doesn’t apply to jruby, so a better condition above might be preferable?

/#{Regexp.union(*ESCAPE_HTML.keys)}/n
HTTP_STATUS_CODES =

Every standard HTTP code mapped to the appropriate message. Generated with: irb -ropen-uri -rnokogiri > Nokogiri::XML(open(“www.iana.org/assignments/http-status-codes/http-status-codes.xml”)).css(“record”).each{|r|

puts "#{r.css('value').text} => '#Rack::Utils.rr.css('description')r.css('description').text'"}

{
  100 => 'Continue',
  101 => 'Switching Protocols',
  102 => 'Processing',
  200 => 'OK',
  201 => 'Created',
  202 => 'Accepted',
  203 => 'Non-Authoritative Information',
  204 => 'No Content',
  205 => 'Reset Content',
  206 => 'Partial Content',
  207 => 'Multi-Status',
  208 => 'Already Reported',
  226 => 'IM Used',
  300 => 'Multiple Choices',
  301 => 'Moved Permanently',
  302 => 'Found',
  303 => 'See Other',
  304 => 'Not Modified',
  305 => 'Use Proxy',
  306 => 'Reserved',
  307 => 'Temporary Redirect',
  308 => 'Permanent Redirect',
  400 => 'Bad Request',
  401 => 'Unauthorized',
  402 => 'Payment Required',
  403 => 'Forbidden',
  404 => 'Not Found',
  405 => 'Method Not Allowed',
  406 => 'Not Acceptable',
  407 => 'Proxy Authentication Required',
  408 => 'Request Timeout',
  409 => 'Conflict',
  410 => 'Gone',
  411 => 'Length Required',
  412 => 'Precondition Failed',
  413 => 'Request Entity Too Large',
  414 => 'Request-URI Too Long',
  415 => 'Unsupported Media Type',
  416 => 'Requested Range Not Satisfiable',
  417 => 'Expectation Failed',
  422 => 'Unprocessable Entity',
  423 => 'Locked',
  424 => 'Failed Dependency',
  425 => 'Reserved for WebDAV advanced collections expired proposal',
  426 => 'Upgrade Required',
  427 => 'Unassigned',
  428 => 'Precondition Required',
  429 => 'Too Many Requests',
  430 => 'Unassigned',
  431 => 'Request Header Fields Too Large',
  500 => 'Internal Server Error',
  501 => 'Not Implemented',
  502 => 'Bad Gateway',
  503 => 'Service Unavailable',
  504 => 'Gateway Timeout',
  505 => 'HTTP Version Not Supported',
  506 => 'Variant Also Negotiates (Experimental)',
  507 => 'Insufficient Storage',
  508 => 'Loop Detected',
  509 => 'Unassigned',
  510 => 'Not Extended',
  511 => 'Network Authentication Required'
}
STATUS_WITH_NO_ENTITY_BODY =

Responses with HTTP status codes that should not have an entity body

Set.new((100..199).to_a << 204 << 205 << 304)
SYMBOL_TO_STATUS_CODE = 

      
        
Multipart =
          
        

        
Rack::Multipart

      
    

  




  
Class Attribute Summary collapse

  




  
    

      Class Method Summary
      collapse
    


    
  


  

    
Class Attribute Details

    
      
      
      

  

  
    .key_space_limit  ⇒ Object 
  

  

  




  

    

Returns the value of attribute key_space_limit.



  





  



  

    
      


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# File 'lib/rack/utils.rb', line 54

def key_space_limit
  @key_space_limit
end

    		
  





    
      
      
      

  

  
    .multipart_part_limit  ⇒ Object 
  

  

  




  

    

Returns the value of attribute multipart_part_limit.



  





  



  

    
      


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# File 'lib/rack/utils.rb', line 56

def multipart_part_limit
  @multipart_part_limit
end

    		
  





    
      
      
      

  

  
    .param_depth_limit  ⇒ Object 
  

  

  




  

    

Returns the value of attribute param_depth_limit.



  





  



  

    
      


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# File 'lib/rack/utils.rb', line 55

def param_depth_limit
  @param_depth_limit
end

    		
  





    
  



  

    
Class Method Details


    
      

  

  
    .best_q_match(q_value_header, available_mimes)  ⇒ Object 
  

  

  




  

    
      


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# File 'lib/rack/utils.rb', line 195

def best_q_match(q_value_header, available_mimes)
  values = q_values(q_value_header)

  values.map do |req_mime, quality|
    match = available_mimes.first { |am| Rack::Mime.match?(am, req_mime) }
    next unless match
    [match, quality]
  end.compact.sort_by do |match, quality|
    (match.split('/', 2).count('*') * -10) + quality
  end.last.first
end

    		
  





    
      

  

  
    .build_nested_query(value, prefix = nil)  ⇒ Object 
  

  

  




  

    
      


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# File 'lib/rack/utils.rb', line 164

def build_nested_query(value, prefix = nil)
  case value
  when Array
    value.map { |v|
      build_nested_query(v, "#{prefix}[]")
    }.join("&")
  when Hash
    value.map { |k, v|
      build_nested_query(v, prefix ? "#{prefix}[#{escape(k)}]" : escape(k))
    }.join("&")
  when String
    raise ArgumentError, "value must be a Hash" if prefix.nil?
    "#{prefix}=#{escape(value)}"
  else
    prefix
  end
end

    		
  





    
      

  

  
    .build_query(params)  ⇒ Object 
  

  

  




  

    
      


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# File 'lib/rack/utils.rb', line 153

def build_query(params)
  params.map { |k, v|
    if v.class == Array
      build_query(v.map { |x| [k, x] })
    else
      v.nil? ? escape(k) : "#{escape(k)}=#{escape(v)}"
    end
  }.join("&")
end

    		
  





    
      

  

  
    .byte_ranges(env, size)  ⇒ Object 
  

  

  




  

    

Parses the “Range:” header, if present, into an array of Range objects. Returns nil if the header is missing or syntactically invalid. Returns an empty array if none of the ranges are satisfiable.



  





  



  

    
      


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# File 'lib/rack/utils.rb', line 381

def byte_ranges(env, size)
  # See <http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.35>
  http_range = env['HTTP_RANGE']
  return nil unless http_range && http_range =~ /bytes=([^;]+)/
  ranges = []
  $1.split(/,\s*/).each do |range_spec|
    return nil  unless range_spec =~ /(\d*)-(\d*)/
    r0,r1 = $1, $2
    if r0.empty?
      return nil  if r1.empty?
      # suffix-byte-range-spec, represents trailing suffix of file
      r0 = size - r1.to_i
      r0 = 0  if r0 < 0
      r1 = size - 1
    else
      r0 = r0.to_i
      if r1.empty?
        r1 = size - 1
      else
        r1 = r1.to_i
        return nil  if r1 < r0  # backwards range is syntactically invalid
        r1 = size-1  if r1 >= size
      end
    end
    ranges << (r0..r1)  if r0 <= r1
  end
  ranges
end

    		
  





    
      

  

  
    .bytesize(string)  ⇒ Object 
  

  

  




  

    
      


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# File 'lib/rack/utils.rb', line 347

def bytesize(string)
  string.bytesize
end

    		
  





    
      

  

  
    .delete_cookie_header!(header, key, value = {})  ⇒ Object 
  

  

  




  

    
      


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# File 'lib/rack/utils.rb', line 313

def delete_cookie_header!(header, key, value = {})
  case header["Set-Cookie"]
  when nil, ''
    cookies = []
  when String
    cookies = header["Set-Cookie"].split("\n")
  when Array
    cookies = header["Set-Cookie"]
  end

  cookies.reject! { |cookie|
    if value[:domain]
      cookie =~ /\A#{escape(key)}=.*domain=#{value[:domain]}/
    elsif value[:path]
      cookie =~ /\A#{escape(key)}=.*path=#{value[:path]}/
    else
      cookie =~ /\A#{escape(key)}=/
    end
  }

  header["Set-Cookie"] = cookies.join("\n")

  set_cookie_header!(header, key,
             {:value => '', :path => nil, :domain => nil,
               :max_age => '0',
               :expires => Time.at(0) }.merge(value))

  nil
end

    		
  





    
      

  

  
    .escape(s)  ⇒ Object 
  

  

  




  

    

URI escapes. (CGI style space to +)



  





  



  

    
      


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# File 'lib/rack/utils.rb', line 26

def escape(s)
  URI.encode_www_form_component(s)
end

    		
  





    
      

  

  
    .escape_html(string)  ⇒ Object 
  

  

  




  

    

Escape ampersands, brackets and quotes to their HTML/XML entities.



  





  



  

    
      


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# File 'lib/rack/utils.rb', line 225

def escape_html(string)
  string.to_s.gsub(ESCAPE_HTML_PATTERN){|c| ESCAPE_HTML[c] }
end

    		
  





    
      

  

  
    .escape_path(s)  ⇒ Object 
  

  

  




  

    

Like URI escaping, but with %20 instead of +. Strictly speaking this is true URI escaping.



  





  



  

    
      


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# File 'lib/rack/utils.rb', line 33

def escape_path(s)
  escape(s).gsub('+', '%20')
end

    		
  





    
      

  

  
    .normalize_params(params, name, v = nil, depth = Utils.param_depth_limit)  ⇒ Object 
  

  

  




  

    

  





  

Raises:


    
  
    
  • 
      
      
        (RangeError)
      
      
      
    
    • 
  





  

    
      


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# File 'lib/rack/utils.rb', line 114

def normalize_params(params, name, v = nil, depth = Utils.param_depth_limit)
  raise RangeError if depth <= 0

  name =~ %r(\A[\[\]]*([^\[\]]+)\]*)
  k = $1 || ''
  after = $' || ''

  return if k.empty?

  if after == ""
    params[k] = v
  elsif after == "[]"
    params[k] ||= []
    raise TypeError, "expected Array (got #{params[k].class.name}) for param `#{k}'" unless params[k].is_a?(Array)
    params[k] << v
  elsif after =~ %r(^\[\]\[([^\[\]]+)\]$) || after =~ %r(^\[\](.+)$)
    child_key = $1
    params[k] ||= []
    raise TypeError, "expected Array (got #{params[k].class.name}) for param `#{k}'" unless params[k].is_a?(Array)
    if params_hash_type?(params[k].last) && !params[k].last.key?(child_key)
      normalize_params(params[k].last, child_key, v, depth - 1)
    else
      params[k] << normalize_params(params.class.new, child_key, v, depth - 1)
    end
  else
    params[k] ||= params.class.new
    raise TypeError, "expected Hash (got #{params[k].class.name}) for param `#{k}'" unless params_hash_type?(params[k])
    params[k] = normalize_params(params[k], after, v, depth - 1)
  end

  return params
end

    		
  





    
      

  

  
    .params_hash_type?(obj)  ⇒ Boolean 
  

  

  




  

    

  





  

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        (Boolean)
      
      
      
    
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# File 'lib/rack/utils.rb', line 148

def params_hash_type?(obj)
  obj.kind_of?(KeySpaceConstrainedParams) || obj.kind_of?(Hash)
end

    		
  





    
      

  

  
    .parse_nested_query(qs, d = nil)  ⇒ Object 
  

  

  




  

    
      


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# File 'lib/rack/utils.rb', line 101

def parse_nested_query(qs, d = nil)
  params = KeySpaceConstrainedParams.new

  (qs || '').split(d ? /[#{d}] */n : DEFAULT_SEP).each do |p|
    k, v = p.split('=', 2).map { |s| unescape(s) }

    normalize_params(params, k, v)
  end

  return params.to_params_hash
end

    		
  





    
      

  

  
    .parse_query(qs, d = nil, &unescaper)  ⇒ Object 
  

  

  




  

    

Stolen from Mongrel, with some small modifications: Parses a query string by breaking it up at the ‘&’ and ‘;’ characters.  You can also use this to parse cookies by changing the characters used in the second parameter (which defaults to ‘&;’).



  





  



  

    
      


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# File 'lib/rack/utils.rb', line 77

def parse_query(qs, d = nil, &unescaper)
  unescaper ||= method(:unescape)

  params = KeySpaceConstrainedParams.new

  (qs || '').split(d ? /[#{d}] */n : DEFAULT_SEP).each do |p|
    next if p.empty?
    k, v = p.split('=', 2).map(&unescaper)

    if cur = params[k]
      if cur.class == Array
        params[k] << v
      else
        params[k] = [cur, v]
      end
    else
      params[k] = v
    end
  end

  return params.to_params_hash
end

    		
  





    
      

  

  
    .q_values(q_value_header)  ⇒ Object 
  

  

  




  

    
      


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# File 'lib/rack/utils.rb', line 183

def q_values(q_value_header)
  q_value_header.to_s.split(/\s*,\s*/).map do |part|
    value, parameters = part.split(/\s*;\s*/, 2)
    quality = 1.0
    if md = /\Aq=([\d.]+)/.match(parameters)
      quality = md[1].to_f
    end
    [value, quality]
  end
end

    		
  





    
      

  

  
    .rfc2109(time)  ⇒ Object 
  

  

  




  

    

Modified version of stdlib time.rb Time#rfc2822 to use ‘%d-%b-%Y’ instead of ‘% %b %Y’. It assumes that the time is in GMT to comply to the RFC 2109.



NOTE: I’m not sure the RFC says it requires GMT, but is ambigous enough that I’m certain someone implemented only that option. Do not use %a and %b from Time.strptime, it would use localized names for weekday and month.



  





  



  

    
      


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# File 'lib/rack/utils.rb', line 371

def rfc2109(time)
  wday = Time::RFC2822_DAY_NAME[time.wday]
  mon = Time::RFC2822_MONTH_NAME[time.mon - 1]
  time.strftime("#{wday}, %d-#{mon}-%Y %H:%M:%S GMT")
end

    		
  





    
      

  

  
    .rfc2822(time)  ⇒ Object 
  

  

  




  

    
      


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# File 'lib/rack/utils.rb', line 357

def rfc2822(time)
  time.rfc2822
end

    		
  





    
      

  

  
    .secure_compare(a, b)  ⇒ Object 
  

  

  




  

    

Constant time string comparison.



  





  



  

    
      


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# File 'lib/rack/utils.rb', line 412

def secure_compare(a, b)
  return false unless bytesize(a) == bytesize(b)

  l = a.unpack("C*")

  r, i = 0, -1
  b.each_byte { |v| r |= v ^ l[i+=1] }
  r == 0
end

    		
  





    
      

  

  
    .select_best_encoding(available_encodings, accept_encoding)  ⇒ Object 
  

  

  




  

    
      


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# File 'lib/rack/utils.rb', line 230

def select_best_encoding(available_encodings, accept_encoding)
  # http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html

  expanded_accept_encoding =
    accept_encoding.map { |m, q|
      if m == "*"
        (available_encodings - accept_encoding.map { |m2, _| m2 }).map { |m2| [m2, q] }
      else
        [[m, q]]
      end
    }.inject([]) { |mem, list|
      mem + list
    }

  encoding_candidates = expanded_accept_encoding.sort_by { |_, q| -q }.map { |m, _| m }

  unless encoding_candidates.include?("identity")
    encoding_candidates.push("identity")
  end

  expanded_accept_encoding.find_all { |m, q|
    q == 0.0
  }.each { |m, _|
    encoding_candidates.delete(m)
  }

  return (encoding_candidates & available_encodings)[0]
end

    		
  





    
      

  

  
    .set_cookie_header!(header, key, value)  ⇒ Object 
  

  

  




  

    
      


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# File 'lib/rack/utils.rb', line 260

def set_cookie_header!(header, key, value)
  case value
  when Hash
    domain  = "; domain="  + value[:domain] if value[:domain]
    path    = "; path="    + value[:path]   if value[:path]
    max_age = "; max-age=" + value[:max_age] if value[:max_age]
    # There is an RFC mess in the area of date formatting for Cookies. Not
    # only are there contradicting RFCs and examples within RFC text, but
    # there are also numerous conflicting names of fields and partially
    # cross-applicable specifications.
    #
    # These are best described in RFC 2616 3.3.1. This RFC text also
    # specifies that RFC 822 as updated by RFC 1123 is preferred. That is a
    # fixed length format with space-date delimeted fields.
    #
    # See also RFC 1123 section 5.2.14.
    #
    # RFC 6265 also specifies "sane-cookie-date" as RFC 1123 date, defined
    # in RFC 2616 3.3.1. RFC 6265 also gives examples that clearly denote
    # the space delimited format. These formats are compliant with RFC 2822.
    #
    # For reference, all involved RFCs are:
    # RFC 822
    # RFC 1123
    # RFC 2109
    # RFC 2616
    # RFC 2822
    # RFC 2965
    # RFC 6265
    expires = "; expires=" +
      rfc2822(value[:expires].clone.gmtime) if value[:expires]
    secure = "; secure"  if value[:secure]
    httponly = "; HttpOnly" if value[:httponly]
    value = value[:value]
  end
  value = [value] unless Array === value
  cookie = escape(key) + "=" +
    value.map { |v| escape v }.join("&") +
    "#{domain}#{path}#{max_age}#{expires}#{secure}#{httponly}"

  case header["Set-Cookie"]
  when nil, ''
    header["Set-Cookie"] = cookie
  when String
    header["Set-Cookie"] = [header["Set-Cookie"], cookie].join("\n")
  when Array
    header["Set-Cookie"] = (header["Set-Cookie"] + [cookie]).join("\n")
  end

  nil
end

    		
  





    
      

  

  
    .status_code(status)  ⇒ Object 
  

  

  




  

    
      


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# File 'lib/rack/utils.rb', line 629

def status_code(status)
  if status.is_a?(Symbol)
    SYMBOL_TO_STATUS_CODE[status] || 500
  else
    status.to_i
  end
end

    		
  





    
      

  

  
    .unescape(s, encoding = nil)  ⇒ Object 
  

  

  




  

    
      


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# File 'lib/rack/utils.rb', line 41

def unescape(s, encoding = Encoding::UTF_8)
  URI.decode_www_form_component(s, encoding)
end