accesslog middleware: add total bytes received and sent

relative to: https://github.com/kataras/iris/issues/1601

context/response_recorder.go

@@ -1,8 +1,13 @@
 package context
 
 import (
+	"bytes"
 	"errors"
+	"fmt"
+	"io/ioutil"
 	"net/http"
+	"net/textproto"
+	"strconv"
 	"sync"
 )
 
@@ -38,6 +43,8 @@ type ResponseRecorder struct {
 	chunks []byte
 	// the saved headers
 	headers http.Header
+
+	result *http.Response
 }
 
 var _ ResponseWriter = (*ResponseRecorder)(nil)
@@ -53,6 +60,7 @@ func (w *ResponseRecorder) Naive() http.ResponseWriter {
 func (w *ResponseRecorder) BeginRecord(underline ResponseWriter) {
 	w.ResponseWriter = underline
 	w.headers = underline.Header()
+	w.result = nil
 	w.ResetBody()
 }
 
@@ -288,3 +296,66 @@ func (w *ResponseRecorder) Push(target string, opts *http.PushOptions) (err erro
 
 	return ErrPushNotSupported
 }
+
+// Result returns the response generated by the handler.
+// It does set all provided headers.
+//
+// Result must only be called after the handler has finished running.
+func (w *ResponseRecorder) Result() *http.Response { // a modified copy of net/http/httptest
+	if w.result != nil {
+		return w.result
+	}
+
+	headers := w.headers.Clone()
+
+	for k, v := range w.ResponseWriter.Header() {
+		headers[k] = v
+	}
+	/*
+		dateFound := false
+		for k := range headers {
+			if strings.ToLower(k) == "date" {
+				dateFound = true
+				break
+			}
+		}
+
+		if !dateFound {
+			headers["Date"] = []string{time.Now().Format(http.TimeFormat)}
+		}
+	*/
+
+	res := &http.Response{
+		Proto:      "HTTP/1.1",
+		ProtoMajor: 1,
+		ProtoMinor: 1,
+		StatusCode: w.StatusCode(),
+		Header:     headers,
+	}
+	if res.StatusCode == 0 {
+		res.StatusCode = 200
+	}
+	res.Status = fmt.Sprintf("%03d %s", res.StatusCode, http.StatusText(res.StatusCode))
+	if w.chunks != nil {
+		res.Body = ioutil.NopCloser(bytes.NewReader(w.chunks))
+	} else {
+		res.Body = http.NoBody
+	}
+	res.ContentLength = parseContentLength(res.Header.Get("Content-Length"))
+
+	w.result = res
+	return res
+}
+
+// copy of net/http/httptest
+func parseContentLength(cl string) int64 {
+	cl = textproto.TrimString(cl)
+	if cl == "" {
+		return -1
+	}
+	n, err := strconv.ParseUint(cl, 10, 63)
+	if err != nil {
+		return -1
+	}
+	return int64(n)
+}