You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: sendfile.go
    path of file: ./repos/gitlabhq/workhorse/internal/sendfile
    
    the code of the file until where you have to start completion: /*
The xSendFile middleware transparently sends static files in HTTP responses
via the X-Sendfile mechanism. All that is needed in the Rails c
    
func countSendFileMetrics(size int64, r *http.Request) {
	var requestType string
	switch {
	case artifactsSendFile.MatchString(r.RequestURI):
		requestType = "artifacts"
	default:
		requestType = "other"
	}

	sendFileRequests.WithLabelValues(requestType).Inc()
	sendFileBytes.WithLabelValues(requestType).Add(float64(size))
}