def call(env)
status, headers, body = @app.call(env)
request = Request.new(env)
encoding = Utils.select_best_encoding(%w(gzip deflate identity), request.accept_encoding)
case encoding
when "gzip"
mtime = headers["Last-Modified"] || Time.now
[status, headers.merge("Content-Encoding" => "gzip"), self.class.gzip(body, mtime)]
when "deflate"
[status, headers.merge("Content-Encoding" => "deflate"), self.class.deflate(body)]
when "identity"
[status, headers, body]
when nil
message = "An acceptable encoding for the requested resource #{request.fullpath} could not be found."
[406, {"Content-Type" => "text/plain"}, message]
end
end