Class: Rack::Chunked

Inherits:
Object
  • Object
show all
Includes:
Utils
Defined in:
lib/rack/chunked.rb

Overview

Middleware that applies chunked transfer encoding to response bodies when the response does not include a Content-Length header.

This supports the Trailer response header to allow the use of trailing headers in the chunked encoding. However, using this requires you manually specify a response body that supports a trailers method. Example:

[200, { 'Trailer' => 'Expires'}, ["Hello", "World"]]
# error raised

body = ["Hello", "World"]
def body.trailers
  { 'Expires' => Time.now.to_s }
end
[200, { 'Trailer' => 'Expires'}, body]
# No exception raised

Defined Under Namespace

Classes: Body, TrailerBody

Constant Summary

Constants included from Utils

Utils::COMMON_SEP, Utils::DEFAULT_SEP, Utils::ESCAPE_HTML, Utils::ESCAPE_HTML_PATTERN, Utils::HTTP_STATUS_CODES, Utils::InvalidParameterError, Utils::KeySpaceConstrainedParams, Utils::NULL_BYTE, Utils::PATH_SEPS, Utils::ParameterTypeError, Utils::STATUS_WITH_NO_ENTITY_BODY, Utils::SYMBOL_TO_STATUS_CODE

Instance Method Summary collapse

Methods included from Utils

add_cookie_to_header, add_remove_cookie_to_header, best_q_match, build_nested_query, build_query, byte_ranges, clean_path_info, #clock_time, delete_cookie_header!, escape, escape_html, escape_path, get_byte_ranges, key_space_limit, key_space_limit=, make_delete_cookie_header, param_depth_limit, param_depth_limit=, parse_cookies, parse_cookies_header, parse_nested_query, parse_query, q_values, rfc2109, rfc2822, secure_compare, select_best_encoding, set_cookie_header!, status_code, unescape, unescape_path, valid_path?

Constructor Details

#initialize(app) ⇒ Chunked

Returns a new instance of Chunked.


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# File 'lib/rack/chunked.rb', line 78

def initialize(app)
  @app = app
end

Instance Method Details

#call(env) ⇒ Object

If the rack app returns a response that should have a body, but does not have Content-Length or Transfer-Encoding headers, modify the response to use chunked Transfer-Encoding.


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# File 'lib/rack/chunked.rb', line 97

def call(env)
  status, headers, body = @app.call(env)
  headers = HeaderHash[headers]

  if chunkable_version?(env[SERVER_PROTOCOL]) &&
     !STATUS_WITH_NO_ENTITY_BODY.key?(status.to_i) &&
     !headers[CONTENT_LENGTH] &&
     !headers[TRANSFER_ENCODING]

    headers[TRANSFER_ENCODING] = 'chunked'
    if headers['Trailer']
      body = TrailerBody.new(body)
    else
      body = Body.new(body)
    end
  end

  [status, headers, body]
end

#chunkable_version?(ver) ⇒ Boolean

Whether the HTTP version supports chunked encoding (HTTP 1.1 does).

Returns:

  • (Boolean)

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# File 'lib/rack/chunked.rb', line 83

def chunkable_version?(ver)
  case ver
  # pre-HTTP/1.0 (informally "HTTP/0.9") HTTP requests did not have
  # a version (nor response headers)
  when 'HTTP/1.0', nil, 'HTTP/0.9'
    false
  else
    true
  end
end