package arrange import ( "crypto/md5" "fmt" "image/gif" "image/jpeg" "image/png" "io" "log" "os" "path/filepath" "strings" "sync" "time" ) var exts map[string]bool func init() { exts = map[string]bool{ // images ".jpg": true, ".jpeg": true, ".png": true, ".gif": true, // videos ".mov": true, ".mp4": true, ".m4v": true, ".avi": true, } } func mtime(path string) (time.Time, error) { ti := time.Time{} s, err := os.Stat(path) if err != nil { return ti, fmt.Errorf("failure to collect times from stat: %v", err) } return s.ModTime(), nil } // PrepOutput creates all possible content-address prefix directories. func PrepOutput(root string) error { for i := 0; i <= 0xff; i++ { dirname := filepath.Join(root, "content", fmt.Sprintf("%02x", i)) if err := os.MkdirAll(dirname, 0755); err != nil { return err } } if err := os.MkdirAll(filepath.Join(root, "date"), 0755); err != nil { return err } return nil } // Source returns sends all files that match known extensions. func Source(root string) <-chan string { out := make(chan string) go func() { err := filepath.Walk( root, func(path string, info os.FileInfo, err error) error { if err != nil { return err } if info.IsDir() { return nil } ext := strings.ToLower(filepath.Ext(path)) if _, ok := exts[ext]; ok { out <- path } return nil }, ) if err != nil { log.Printf("problem during crawl: %+v", err) } close(out) }() return out } // Parse runs the file parser for each file on input chan, and sends results // down output chan. // // Exists so that it can be called many times concurrently. func Parse(in <-chan string) <-chan Media { out := make(chan Media) go func() { for path := range in { f, err := _parse(path) if err != nil { switch err.(type) { case NotMedia: log.Printf("%+v", err) default: log.Printf("parse error: %+v", err) } continue } else { out <- f } } close(out) }() return out } // Move calls Move on each Media on input chan. It is the first step in the // pipeline after fan-in. func Move(in <-chan Media, root string) <-chan error { out := make(chan error) go func() { for i := range in { out <- i.Move(root) } close(out) }() return out } func _parse(path string) (Media, error) { ext := strings.ToLower(filepath.Ext(path)) var r Media hash := md5.New() var t time.Time f, err := os.Open(path) if err != nil { return r, fmt.Errorf("problem opening file: %v", err) } defer f.Close() switch ext { default: return r, NotMedia{path} case ".jpg", ".jpeg": if _, err := jpeg.DecodeConfig(f); err != nil { return r, NotMedia{path} } if _, err := f.Seek(0, 0); err != nil { return r, fmt.Errorf("couldn't seek back in file: %v", err) } // try a few things for a time value { success := false if t, err = parseExif(f); err == nil { success = true } if !success { t, err = mtime(path) } if err != nil { return r, fmt.Errorf("unable to calculate reasonble time for jpg %q: %v", path, err) } } case ".png": if _, err := png.DecodeConfig(f); err != nil { return r, NotMedia{path} } if _, err := f.Seek(0, 0); err != nil { return r, fmt.Errorf("couldn't seek back in file: %v", err) } t, err = mtime(path) if err != nil { return r, fmt.Errorf("unable to calculate reasonble time for media %q: %v", path, err) } case ".gif": if _, err := gif.DecodeConfig(f); err != nil { return r, NotMedia{path} } if _, err := f.Seek(0, 0); err != nil { return r, fmt.Errorf("couldn't seek back in file: %v", err) } t, err = mtime(path) if err != nil { return r, fmt.Errorf("unable to calculate reasonble time for media %q: %v", path, err) } case ".mov", ".mp4", ".m4v", ".avi": t, err = mtime(path) if err != nil { return r, fmt.Errorf("unable to calculate reasonble time for media %q: %v", path, err) } } if _, err := f.Seek(0, 0); err != nil { return r, fmt.Errorf("couldn't seek back in file: %v", err) } if _, err := io.Copy(hash, f); err != nil { return r, fmt.Errorf("problem calculating checksum on %q: %v", path, err) } r = Media{ Path: path, Hash: fmt.Sprintf("%x", hash.Sum(nil)), Extension: ext, Time: t, } return r, nil } // Merge implements fan-in. func Merge(cs []<-chan Media) <-chan Media { out := make(chan Media) var wg sync.WaitGroup output := func(c <-chan Media) { for n := range c { out <- n } wg.Done() } for _, c := range cs { go output(c) } wg.Add(len(cs)) go func() { wg.Wait() close(out) }() return out }