`class AcceptEncoding`

A middleware that sets the accept-encoding header and decodes the response according to the content-encoding header.

Definitions

`ACCEPT_ENCODING = "accept-encoding".freeze`

The header used to request encodings.

`CONTENT_ENCODING = "content-encoding".freeze`

The header used to specify encodings.

`DEFAULT_WRAPPERS = {...}`

The default wrappers to use for decoding content.

Implementation

DEFAULT_WRAPPERS = {
	"gzip" => Body::Inflate.method(:for),
	"identity" => ->(body) {body}, # Identity means no encoding
	
	# There is no point including this:
	# 'identity' => ->(body){body},
}

`def initialize(delegate, wrappers = DEFAULT_WRAPPERS)`

Initialize the middleware with the given delegate and wrappers.

Signature

parameter　delegate　Protocol::HTTP::Middleware: The delegate middleware.
parameter　wrappers　Hash: A hash of encoding names to wrapper functions.

Implementation

def initialize(delegate, wrappers = DEFAULT_WRAPPERS)
	super(delegate)
	
	@accept_encoding = wrappers.keys.join(", ")
	@wrappers = wrappers
end

`def call(request)`

Set the accept-encoding header and decode the response body.

Signature

parameter　request　Protocol::HTTP::Request: The request to modify.
returns　Protocol::HTTP::Response: The response.

Implementation

def call(request)
	request.headers[ACCEPT_ENCODING] = @accept_encoding
	
	response = super
	
	if body = response.body and !body.empty?
		if content_encoding = response.headers[CONTENT_ENCODING]
			# Process encodings in reverse order and remove them when they are decoded:
			while name = content_encoding.last
				# Look up wrapper with case-insensitive matching:
				wrapper = @wrappers[name.downcase]
				
				if wrapper
					body = wrapper.call(body)
					# Remove the encoding we just processed:
					content_encoding.pop
				else
					# Unknown encoding - stop processing here:
					break
				end
			end
			
			# Update the response body:
			response.body = body
			
			# Remove the content-encoding header if we decoded all encodings:
			if content_encoding.empty?
				response.headers.delete(CONTENT_ENCODING)
			end
		end
	end
	
	return response
end