142 lines
3.0 KiB
Go
142 lines
3.0 KiB
Go
package concurrent
|
|
|
|
import (
|
|
"fmt"
|
|
"io/ioutil"
|
|
"path"
|
|
"strconv"
|
|
"time"
|
|
|
|
"github.com/dustin/go-humanize"
|
|
"github.com/logrusorgru/aurora"
|
|
"github.com/tjhorner/e6dl/e621"
|
|
)
|
|
|
|
// workState stores the state of all the jobs and
|
|
// is shared across workers
|
|
type workState struct {
|
|
Total int
|
|
Completed int
|
|
Successes int
|
|
Failures int
|
|
SaveDirectory string
|
|
}
|
|
|
|
// BeginDownload takes a slice of posts, a directory to save them in, and a
|
|
// number of concurrent workers to make. It blocks until all the post have
|
|
// been processed. It returns the number of successes, failures, and the total
|
|
// amount of posts.
|
|
func BeginDownload(posts *[]e621.Post, saveDirectory *string, maxConcurrents *int) (*int, *int, *int) {
|
|
// Channel for main goroutine to give workers a post when they are done downloading one
|
|
wc := make(chan *e621.Post)
|
|
|
|
var current int
|
|
|
|
total := len(*posts)
|
|
|
|
state := workState{
|
|
Total: total,
|
|
SaveDirectory: *saveDirectory,
|
|
}
|
|
|
|
// If we have more workers than posts, then we don't need all of them
|
|
if *maxConcurrents > total {
|
|
*maxConcurrents = total
|
|
}
|
|
|
|
for i := 0; i < *maxConcurrents; i++ {
|
|
// Create our workers
|
|
go work(i+1, &state, wc)
|
|
|
|
// Give them their initial posts
|
|
wc <- &(*posts)[current]
|
|
current++
|
|
|
|
time.Sleep(time.Millisecond * 50)
|
|
}
|
|
|
|
for {
|
|
// Wait for a worker to be done (they send nil to wc)
|
|
<-wc
|
|
|
|
// If we finished downloading all posts, break out of the loop
|
|
if state.Successes+state.Failures == total {
|
|
break
|
|
}
|
|
|
|
// If there's no more posts to give, stop the worker
|
|
if current >= total {
|
|
wc <- nil
|
|
continue
|
|
}
|
|
|
|
// Give the worker the next post in the array
|
|
wc <- &(*posts)[current]
|
|
current++
|
|
}
|
|
|
|
return &state.Successes, &state.Failures, &total
|
|
}
|
|
|
|
func work(wn int, state *workState, wc chan *e621.Post) {
|
|
for {
|
|
state.Completed++
|
|
|
|
// Wait for a post from main
|
|
post := <-wc
|
|
if post == nil { // nil means there aren't any more posts, so we're OK to break
|
|
return
|
|
}
|
|
|
|
progress := aurora.Sprintf(aurora.Green("[%d/%d]"), state.Completed, state.Total)
|
|
workerText := aurora.Sprintf(aurora.Cyan("[w%d]"), wn)
|
|
|
|
fmt.Println(aurora.Sprintf(
|
|
"%s %s Downloading post %d (%s) -> %s...",
|
|
progress,
|
|
workerText,
|
|
post.ID,
|
|
humanize.Bytes(uint64(post.FileSize)),
|
|
getSavePath(post, &state.SaveDirectory),
|
|
))
|
|
|
|
err := downloadPost(post, state.SaveDirectory)
|
|
if err != nil {
|
|
fmt.Printf("[w%d] Failed to download post %d: %v\n", wn, post.ID, err)
|
|
state.Failures++
|
|
} else {
|
|
state.Successes++
|
|
}
|
|
|
|
wc <- nil
|
|
}
|
|
}
|
|
|
|
func getSavePath(post *e621.Post, directory *string) string {
|
|
savePath := path.Join(*directory, strconv.Itoa(post.ID)+"."+post.FileExt)
|
|
return savePath
|
|
}
|
|
|
|
func downloadPost(post *e621.Post, directory string) error {
|
|
savePath := getSavePath(post, &directory)
|
|
|
|
resp, err := e621.HTTPGet(post.FileURL)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
defer resp.Body.Close()
|
|
|
|
body, err := ioutil.ReadAll(resp.Body)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
err = ioutil.WriteFile(savePath, body, 0755)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
return nil
|
|
}
|