// makeThumbnails6 makes thumbnails for each file received from the channel.
// It returns the number of bytes occupied by the files it creates.
func makeThumbnails6(filenames <-chan string) int64 {
sizes := make(chan int64)
var wg sync.WaitGroup // number of working goroutines
for f := range filenames {
wg.Add(1)
// worker
go func(f string) {
defer wg.Done()
thumb, err := thumbnail.ImageFile(f)
if err != nil {
log.Println(err)
return
}
info, _ := os.Stat(thumb) // OK to ignore error
sizes <- info.Size()
}(f)
}
// closer
go func() {
wg.Wait()
close(sizes)
}()
var total int64
for size := range sizes {
total += size
}
return total
}
func makeThumbnail(filenames []string) (thumbfiles []string, err error) {
type item struct {
thumbnail string
err error
}
ch := make(chan item, len(filenames))
for _, f := range filenames {
go func(f string) {
var it item
it.thumbnail, it.err = thumbnail.ImageFile(f)
}(f)
}
for range filenames {
it := <-ch
if it.err != nil {
return nil, it.err
}
thumbfiles = append(thumbfiles, it.thumbnail)
}
return thumbfiles, nil
}
func main() {
//fmt.Println(time.Unix(1389058332, 0).Format("2006-01-02 15:04:05"))
//fmt.Println(time.Now().Format("2006-01-02 15:04:05"))
go spinner(100 * time.Millisecond)
_, err := thumbnail.ImageFile("")
if err != nil {
fmt.Println(err)
}
const n = 45
fibN := fib(45)
fmt.Println("\rFibonacci(%d) = %d\n", n, fibN)
}