Class: Protocol::HTTP::ContentEncoding

Inherits:
Middleware show all
Defined in:
lib/protocol/http/content_encoding.rb

Overview

Encode a response according the the request’s acceptable encodings.

Constant Summary collapse

DEFAULT_WRAPPERS =

The default wrappers to use for encoding content.

{
  "gzip" => Body::Deflate.method(:for)
}
DEFAULT_CONTENT_TYPES =

The default content types to apply encoding to.

%r{^(text/.*?)|(.*?/json)|(.*?/javascript)$}

Constants inherited from Methods

Methods::CONNECT, Methods::DELETE, Methods::GET, Methods::HEAD, Methods::OPTIONS, Methods::PATCH, Methods::POST, Methods::PUT, Methods::TRACE

Instance Attribute Summary

Attributes inherited from Middleware

#delegate

Instance Method Summary collapse

Methods inherited from Middleware

#The delegate object that is used for passing along requests that are not handled by *this* middleware.=, build, #close, for

Methods inherited from Methods

each, valid?

Constructor Details

#initialize(delegate, content_types = DEFAULT_CONTENT_TYPES, wrappers = DEFAULT_WRAPPERS) ⇒ ContentEncoding

Initialize the content encoding middleware.



28
29
30
31
32
33
 
# File 'lib/protocol/http/content_encoding.rb', line 28

def initialize(delegate, content_types = DEFAULT_CONTENT_TYPES, wrappers = DEFAULT_WRAPPERS)
  super(delegate)
  
  @content_types = content_types
  @wrappers = wrappers
end

Instance Method Details

#call(request) ⇒ Object

Encode the response body according to the request’s acceptable encodings.



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
 
# File 'lib/protocol/http/content_encoding.rb', line 39

def call(request)
  response = super
  
  # Early exit if the response has already specified a content-encoding.
  return response if response.headers["content-encoding"]
  
  # This is a very tricky issue, so we avoid it entirely.
  # https://lists.w3.org/Archives/Public/ietf-http-wg/2014JanMar/1179.html
  return response if response.partial?
  
  body = response.body
  
  # If there is no response body, there is nothing to encode:
  return response if body.nil? or body.empty?
  
  # Ensure that caches are aware we are varying the response based on the accept-encoding request header:
  response.headers.add("vary", "accept-encoding")
  
  if accept_encoding = request.headers["accept-encoding"]
    if content_type = response.headers["content-type"] and @content_types =~ content_type
      accept_encoding.each do |name|
        if wrapper = @wrappers[name]
          response.headers["content-encoding"] = name
          
          body = wrapper.call(body)
          
          break
        end
      end
      
      response.body = body
    end
  end
  
  return response
end