doc: README

.hgtags

@@ -0,0 +1 @@
+efd7b407177086c57e8c086605c2c8d1cee23840 release-1.0

Thumbnailer.go

@@ -5,6 +5,7 @@ import (
 	"image/gif"
 	"image/jpeg"
 	"image/png"
+	"mime"
 	"os"
 	"path/filepath"
 	"strings"
@@ -21,9 +22,10 @@ const (
 	OUTPUT_JPG       OutputFormat = 3
 	OUTPUT__DEFAULT               = OUTPUT_PNG_CRUSH
 
-	ASPECT_PADDED   AspectFormat = 80
-	ASPECT_SVELTE   AspectFormat = 81
-	ASPECT__DEFAULT              = ASPECT_PADDED
+	ASPECT_PAD_TO_DIMENSIONS          AspectFormat = 80
+	ASPECT_RESPECT_MAX_DIMENSION_ONLY AspectFormat = 81
+	ASPECT_CROP_TO_DIMENSIONS         AspectFormat = 82
+	ASPECT__DEFAULT                                = ASPECT_PAD_TO_DIMENSIONS
 
 	SCALEFMT_NN       ScaleFormat = 120
 	SCALEFMT_BILINEAR ScaleFormat = 121
@@ -42,35 +44,51 @@ type Thumbnailer struct {
 	afmt   AspectFormat
 	sfmt   ScaleFormat
 
-	thumbCache *lru.Cache // threadsafe
+	thumbCache *lru.Cache // threadsafe, might be nil
 }
 
-func NewThumbnailer(Width, Height, MaxCacheSize int) *Thumbnailer {
+func NewThumbnailer(Width, Height int, MaxCacheSize uint) *Thumbnailer {
 	return NewThumbnailerEx(Width, Height, MaxCacheSize, OUTPUT__DEFAULT, ASPECT__DEFAULT, SCALEFMT__DEFAULT)
 }
 
-func NewThumbnailerEx(Width, Height, MaxCacheSize int, of OutputFormat, af AspectFormat, sf ScaleFormat) *Thumbnailer {
-	thumbCache, err := lru.New(MaxCacheSize)
-	if err != nil {
-		panic(err)
-	}
+func NewThumbnailerEx(Width, Height int, MaxCacheSize uint, of OutputFormat, af AspectFormat, sf ScaleFormat) *Thumbnailer {
 
-	return &Thumbnailer{
+	ret := &Thumbnailer{
 		width:      Width,
 		height:     Height,
 		ofmt:       of,
 		afmt:       af,
 		sfmt:       sf,
-		thumbCache: thumbCache,
+		thumbCache: nil,
 	}
+
+	if MaxCacheSize > 0 {
+		thumbCache, err := lru.New(int(MaxCacheSize))
+		if err != nil {
+			panic(err)
+		}
+		ret.thumbCache = thumbCache
+	}
+
+	return ret
+}
+
+func (this *Thumbnailer) Width() int {
+	return this.width
+}
+
+func (this *Thumbnailer) Height() int {
+	return this.height
 }
 
 func (this *Thumbnailer) RenderFile(absPath string) ([]byte, error) {
 
+	if this.thumbCache != nil {
 		thumb, ok := this.thumbCache.Get(absPath)
 		if ok {
 			return thumb.([]byte), nil
 		}
+	}
 
 	// Add to cache
 	thumb, err := this.RenderFile_NoCache(absPath)
@@ -78,8 +96,11 @@ func (this *Thumbnailer) RenderFile(absPath string) ([]byte, error) {
 		return nil, err
 	}
 
+	if this.thumbCache != nil {
 		this.thumbCache.Add(absPath, thumb)
-	return thumb.([]byte), nil
+	}
+
+	return thumb, nil
 }
 
 func FiletypeSupported(ext string) bool {
@@ -92,18 +113,18 @@ func FiletypeSupported(ext string) bool {
 }
 
 func (this *Thumbnailer) RenderFile_NoCache(absPath string) ([]byte, error) {
+	return this.RenderFile_NoCache_MimeType(absPath, mime.TypeByExtension(filepath.Ext(absPath)))
+}
+
+func (this *Thumbnailer) RenderFile_NoCache_MimeType(absPath, mimeType string) ([]byte, error) {
 
 	fh, err := os.OpenFile(absPath, os.O_RDONLY, 0400)
 	if err != nil {
 		return nil, err
 	}
-
 	defer fh.Close()
 
-	extension := strings.ToLower(filepath.Ext(absPath))
-
-	switch extension {
-	case ".jpg", ".jpeg":
+	if mimeType == `image/jpeg` {
 		src, err := jpeg.Decode(fh)
 		if err != nil {
 			return nil, err
@@ -111,7 +132,7 @@ func (this *Thumbnailer) RenderFile_NoCache(absPath string) ([]byte, error) {
 
 		return this.RenderScaledImage(src)
 
-	case ".png":
+	} else if mimeType == `image/png` {
 		src, err := png.Decode(fh)
 		if err != nil {
 			return nil, err
@@ -119,7 +140,7 @@ func (this *Thumbnailer) RenderFile_NoCache(absPath string) ([]byte, error) {
 
 		return this.RenderScaledImage(src)
 
-	case ".gif":
+	} else if mimeType == `image/gif` {
 		src, err := gif.Decode(fh)
 		if err != nil {
 			return nil, err
@@ -127,10 +148,10 @@ func (this *Thumbnailer) RenderFile_NoCache(absPath string) ([]byte, error) {
 
 		return this.RenderScaledImage(src)
 
-	case ".avi", ".mkv", ".mp4", ".ogm", ".wmv", ".flv", ".rm", ".rmvb":
+	} else if strings.HasPrefix(mimeType, `video/`) {
 		return this.RenderScaledFfmpeg(absPath)
 
-	default:
+	} else {
 		return nil, ErrUnsupportedFiletype
 
 	}

_dist/README.txt

@@ -0,0 +1,23 @@
+A thumbnailing library for Go.
+
+Written in Go
+
+Earlier versions of this project were vendored into `webdir`.
+
+- Supports jpeg / png / gif files (internally) and video files (requires `ffmpeg` in `$PATH`)
+- LRU cache of recent thumbnails for performance
+- Scaling algorithms: Nearest-neighbour or bilinear
+- Aspect ratio preserving (fit outside with image crop; fit inside with transparent background; fit inside with dimension reduction)
+- Output formats: JPG (internal) or transparent PNG (via `go-imagequant`)
+
+A standalone binary `mkthumb` is provided as a sample utility.
+
+=CHANGELOG=
+
+2017-11-18 0.2.0
+- Initial standalone release
+- Feature: Decode input with specified mime type
+- Feature: Allow passing zero as thumbnail cache size
+
+2017-01-03 webdir-1.0
+- Version of `thumbnail` vendored with `webdir` 1.0

cmd/mkthumb/mkthumb.go

@@ -5,7 +5,7 @@ import (
 	"fmt"
 	"os"
 
-	"code.ivysaur.me/webdir/thumbnail"
+	"code.ivysaur.me/thumbnail"
 )
 
 func main() {