add bmp/webm thumbnailing support

Thumbnailer.go

@@ -2,15 +2,19 @@ package thumbnail
 
 import (
 	"errors"
+	"image"
 	"image/gif"
 	"image/jpeg"
 	"image/png"
+	"io"
 	"mime"
 	"os"
 	"path/filepath"
 	"strings"
 
 	lru "github.com/hashicorp/golang-lru"
+	"golang.org/x/image/bmp"
+	"golang.org/x/image/webp"
 )
 
 type OutputFormat uint8
@@ -105,7 +109,10 @@ func (this *Thumbnailer) RenderFile(absPath string) ([]byte, error) {
 
 func FiletypeSupported(ext string) bool {
 	switch strings.ToLower(ext) {
-	case ".jpg", ".jpeg", ".png", ".gif", ".avi", ".mkv", ".mp4", ".ogm", ".wmv", ".flv", ".rm", ".rmvb":
+	case
+		".jpg", ".jpeg", ".png", ".gif",
+		".avi", ".mkv", ".mp4", ".ogm", ".wmv", ".flv", ".rm", ".rmvb",
+		".bmp", ".webp":
 		return true
 	default:
 		return false
@@ -124,24 +131,17 @@ func (this *Thumbnailer) RenderFile_NoCache_MimeType(absPath, mimeType string) (
 	}
 	defer fh.Close()
 
-	if mimeType == `image/jpeg` {
-		src, err := jpeg.Decode(fh)
-		if err != nil {
-			return nil, err
-		}
+	type imageDecoder func(io.Reader) (image.Image, error)
+	imageDecoders := map[string]imageDecoder{
+		`image/jpeg`: jpeg.Decode,
+		`image/png`:  png.Decode,
+		`image/gif`:  gif.Decode,
+		`image/webp`: webp.Decode,
+		`image/bmp`:  bmp.Decode,
+	}
 
-		return this.RenderScaledImage(src)
-
-	} else if mimeType == `image/png` {
-		src, err := png.Decode(fh)
-		if err != nil {
-			return nil, err
-		}
-
-		return this.RenderScaledImage(src)
-
-	} else if mimeType == `image/gif` {
-		src, err := gif.Decode(fh)
+	if fn, ok := imageDecoders[mimeType]; ok {
+		src, err := fn(fh)
 		if err != nil {
 			return nil, err
 		}