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 = 
{
  'gzip' => Body::Deflate.method(:for)
}
DEFAULT_CONTENT_TYPES = 
%r{^(text/.*?)|(.*?/json)|(.*?/javascript)$}

Constants inherited from Methods

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

Instance Attribute Summary

Attributes inherited from Middleware

#delegate

Instance Method Summary collapse

Methods inherited from Middleware

build, #close

Methods inherited from Methods

each, valid?

Constructor Details

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

Returns a new instance of ContentEncoding.



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# File 'lib/protocol/http/content_encoding.rb', line 38

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

Instance Method Details

#call(request) ⇒ Object 



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# File 'lib/protocol/http/content_encoding.rb', line 45

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?
  
  # Ensure that caches are aware we are varying the response based on the accept-encoding request header:
  response.headers.add('vary', 'accept-encoding')
  
  # TODO use http-accept and sort by priority
  if !response.body.empty? and accept_encoding = request.headers['accept-encoding']
    
    if content_type = response.headers['content-type'] and @content_types =~ content_type
      body = response.body
      
      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