152 lines
3.1 KiB
Go
152 lines
3.1 KiB
Go
package thumbnail
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import (
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"errors"
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"image/gif"
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"image/jpeg"
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"image/png"
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"mime"
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"os"
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"path/filepath"
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"strings"
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lru "github.com/hashicorp/golang-lru"
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)
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type OutputFormat uint8
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type AspectFormat uint8
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type ScaleFormat uint8
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const (
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OUTPUT_PNG_CRUSH OutputFormat = 2
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OUTPUT_JPG OutputFormat = 3
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OUTPUT__DEFAULT = OUTPUT_PNG_CRUSH
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ASPECT_PAD_TO_DIMENSIONS AspectFormat = 80
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ASPECT_RESPECT_MAX_DIMENSION_ONLY AspectFormat = 81
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ASPECT_CROP_TO_DIMENSIONS AspectFormat = 82
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ASPECT__DEFAULT = ASPECT_PAD_TO_DIMENSIONS
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SCALEFMT_NN ScaleFormat = 120
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SCALEFMT_BILINEAR ScaleFormat = 121
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SCALEFMT__DEFAULT = SCALEFMT_BILINEAR
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)
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var (
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ErrInvalidOption error = errors.New("Invalid format parameter")
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ErrUnsupportedFiletype error = errors.New("Unsupported filetype")
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)
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type Thumbnailer struct {
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width int
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height int
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ofmt OutputFormat
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afmt AspectFormat
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sfmt ScaleFormat
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thumbCache *lru.Cache // threadsafe, might be nil
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}
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func NewThumbnailer(Width, Height int, MaxCacheSize uint) *Thumbnailer {
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return NewThumbnailerEx(Width, Height, MaxCacheSize, OUTPUT__DEFAULT, ASPECT__DEFAULT, SCALEFMT__DEFAULT)
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}
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func NewThumbnailerEx(Width, Height int, MaxCacheSize uint, of OutputFormat, af AspectFormat, sf ScaleFormat) *Thumbnailer {
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ret := &Thumbnailer{
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width: Width,
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height: Height,
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ofmt: of,
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afmt: af,
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sfmt: sf,
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thumbCache: nil,
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}
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if MaxCacheSize > 0 {
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thumbCache, err := lru.New(int(MaxCacheSize))
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if err != nil {
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panic(err)
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}
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ret.thumbCache = thumbCache
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}
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return ret
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}
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func (this *Thumbnailer) RenderFile(absPath string) ([]byte, error) {
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if this.thumbCache != nil {
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thumb, ok := this.thumbCache.Get(absPath)
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if ok {
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return thumb.([]byte), nil
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}
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}
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// Add to cache
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thumb, err := this.RenderFile_NoCache(absPath)
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if err != nil {
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return nil, err
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}
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if this.thumbCache != nil {
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this.thumbCache.Add(absPath, thumb)
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}
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return thumb, nil
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}
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func FiletypeSupported(ext string) bool {
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switch strings.ToLower(ext) {
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case ".jpg", ".jpeg", ".png", ".gif", ".avi", ".mkv", ".mp4", ".ogm", ".wmv", ".flv", ".rm", ".rmvb":
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return true
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default:
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return false
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}
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}
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func (this *Thumbnailer) RenderFile_NoCache(absPath string) ([]byte, error) {
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return this.RenderFile_NoCache_MimeType(absPath, mime.TypeByExtension(filepath.Ext(absPath)))
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}
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func (this *Thumbnailer) RenderFile_NoCache_MimeType(absPath, mimeType string) ([]byte, error) {
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fh, err := os.OpenFile(absPath, os.O_RDONLY, 0400)
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if err != nil {
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return nil, err
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}
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defer fh.Close()
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if mimeType == `image/jpeg` {
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src, err := jpeg.Decode(fh)
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if err != nil {
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return nil, err
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}
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return this.RenderScaledImage(src)
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} else if mimeType == `image/png` {
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src, err := png.Decode(fh)
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if err != nil {
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return nil, err
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}
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return this.RenderScaledImage(src)
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} else if mimeType == `image/gif` {
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src, err := gif.Decode(fh)
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if err != nil {
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return nil, err
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}
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return this.RenderScaledImage(src)
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} else if strings.HasPrefix(mimeType, `video/`) {
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return this.RenderScaledFfmpeg(absPath)
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} else {
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return nil, ErrUnsupportedFiletype
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}
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}
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