class Rack::Chunked

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

Public Class Methods

new (app)

# File lib/rack/chunked.rb, line 82
def initialize(app)
  @app = app
end

Public Instance Methods

call (env)

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.

# File lib/rack/chunked.rb, line 101
def call(env)
  status, headers, body = response = @app.call(env)

  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']
      response[2] = TrailerBody.new(body)
    else
      response[2] = Body.new(body)
    end
  end

  response
end

chunkable_version? (ver)

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

# File lib/rack/chunked.rb, line 87
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