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.



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# 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.



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# 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