Performance improvements when rendering

- Fast path for JSON, XML and plain text rendering

render/render.go

@@ -4,103 +4,24 @@
 
 package render
 
-import (
-	"encoding/json"
-	"encoding/xml"
-	"fmt"
-	"html/template"
-	"net/http"
-)
+import "net/http"
 
-type (
-	Render interface {
-		Render(http.ResponseWriter, int, ...interface{}) error
-	}
-
-	jsonRender struct{}
-
-	indentedJSON struct{}
-
-	xmlRender struct{}
-
-	plainTextRender struct{}
-
-	htmlPlainRender struct{}
-
-	redirectRender struct{}
-
-	HTMLRender struct {
-		Template *template.Template
-	}
-)
+type Render interface {
+	Render(http.ResponseWriter, int, ...interface{}) error
+}
 
 var (
-	JSON         = jsonRender{}
-	IndentedJSON = indentedJSON{}
-	XML          = xmlRender{}
-	HTMLPlain    = htmlPlainRender{}
-	Plain        = plainTextRender{}
-	Redirect     = redirectRender{}
+	JSON         Render = jsonRender{}
+	IndentedJSON Render = indentedJSON{}
+	XML          Render = xmlRender{}
+	HTMLPlain    Render = htmlPlainRender{}
+	Plain        Render = plainTextRender{}
+	Redirect     Render = redirectRender{}
+	Data         Render = dataRender{}
+	_            Render = HTMLRender{}
+	_            Render = &HTMLDebugRender{}
 )
 
-func (_ redirectRender) Render(w http.ResponseWriter, code int, data ...interface{}) error {
-	req := data[0].(*http.Request)
-	location := data[1].(string)
-	http.Redirect(w, req, location, code)
-	return nil
-}
-
-func (_ jsonRender) Render(w http.ResponseWriter, code int, data ...interface{}) error {
-	WriteHeader(w, code, "application/json")
-	return json.NewEncoder(w).Encode(data[0])
-}
-
-func (_ indentedJSON) Render(w http.ResponseWriter, code int, data ...interface{}) error {
-	WriteHeader(w, code, "application/json")
-	jsonData, err := json.MarshalIndent(data[0], "", "    ")
-	if err != nil {
-		return err
-	}
-	_, err = w.Write(jsonData)
-	return err
-}
-
-func (_ xmlRender) Render(w http.ResponseWriter, code int, data ...interface{}) error {
-	WriteHeader(w, code, "application/xml")
-	return xml.NewEncoder(w).Encode(data[0])
-}
-
-func (_ plainTextRender) Render(w http.ResponseWriter, code int, data ...interface{}) (err error) {
-	WriteHeader(w, code, "text/plain")
-	format := data[0].(string)
-	args := data[1].([]interface{})
-	if len(args) > 0 {
-		_, err = fmt.Fprintf(w, format, args...)
-	} else {
-		_, err = w.Write([]byte(format))
-	}
-	return
-}
-
-func (_ htmlPlainRender) Render(w http.ResponseWriter, code int, data ...interface{}) (err error) {
-	WriteHeader(w, code, "text/html")
-	format := data[0].(string)
-	args := data[1].([]interface{})
-	if len(args) > 0 {
-		_, err = fmt.Fprintf(w, format, args...)
-	} else {
-		_, err = w.Write([]byte(format))
-	}
-	return
-}
-
-func (html HTMLRender) Render(w http.ResponseWriter, code int, data ...interface{}) error {
-	WriteHeader(w, code, "text/html")
-	file := data[0].(string)
-	args := data[1]
-	return html.Template.ExecuteTemplate(w, file, args)
-}
-
 func WriteHeader(w http.ResponseWriter, code int, contentType string) {
 	contentType = joinStrings(contentType, "; charset=utf-8")
 	w.Header().Set("Content-Type", contentType)