82 lines
1.4 KiB
Go
82 lines
1.4 KiB
Go
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package thumbnail
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import (
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"fmt"
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"image"
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"image/jpeg"
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"image/png"
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"os"
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"strings"
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"sync"
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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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MaxCacheSize int
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cacheMtx sync.RWMutex
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thumbCache map[string][]byte
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}
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func NewThumbnailer() *Thumbnailer {
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return &Thumbnailer{
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Width: 100,
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Height: 100,
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MaxCacheSize: 10,
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thumbCache: make(map[string][]byte, 0),
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}
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}
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func (this *Thumbnailer) RenderFile(absPath string) ([]byte, error) {
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this.cacheMtx.RLock()
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tcache, ok := this.thumbCache[absPath]
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this.cacheMtx.RUnlock()
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if ok {
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return tcache, nil
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}
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// Add to cache
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tcache, 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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this.cacheMtx.Lock()
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// FIXME prune old cached thumbnails
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this.thumbCache[absPath] = tcache
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this.cacheMtx.Unlock()
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return tcache, nil
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}
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func (this *Thumbnailer) RenderFile_NoCache(absPath 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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var src image.Image
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err = fmt.Errorf("No thumbnailer for file type")
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comparePath := strings.ToLower(absPath)
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if strings.HasSuffix(comparePath, "jpg") {
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src, err = jpeg.Decode(fh)
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} else if strings.HasSuffix(comparePath, "png") {
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src, err = png.Decode(fh)
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}
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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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}
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