Implement multiple concurrent downloads

cmd/WiiUDownloader/progressWindow.go

@@ -2,6 +2,8 @@ package main
 
 import (
 	"fmt"
+	"sync"
+	"time"
 
 	"github.com/dustin/go-humanize"
 	"github.com/gotk3/gotk3/glib"
@@ -33,6 +35,14 @@ func (sa *SpeedAverager) AddSpeed(speed int64) {
 	sa.speeds = append(sa.speeds, speed)
 }
 
+func calculateDownloadSpeed(downloaded int64, startTime, endTime time.Time) int64 {
+	duration := endTime.Sub(startTime).Seconds()
+	if duration > 0 {
+		return int64(float64(downloaded) / duration)
+	}
+	return 0
+}
+
 func (sa *SpeedAverager) calculateAverageOfSpeeds() {
 	var total int64
 	for _, speed := range sa.speeds {
@@ -55,7 +65,9 @@ type ProgressWindow struct {
 	cancelled       bool
 	totalToDownload int64
 	totalDownloaded int64
+	progressMutex   sync.Mutex
 	speedAverager   *SpeedAverager
+	startTime       time.Time
 }
 
 func (pw *ProgressWindow) SetGameTitle(title string) {
@@ -67,13 +79,13 @@ func (pw *ProgressWindow) SetGameTitle(title string) {
 	}
 }
 
-func (pw *ProgressWindow) UpdateDownloadProgress(downloaded, speed int64, filePath string) {
+func (pw *ProgressWindow) UpdateDownloadProgress(downloaded int64) {
 	glib.IdleAdd(func() {
 		pw.cancelButton.SetSensitive(true)
-		currentDownload := downloaded + pw.totalDownloaded
+		pw.AddToTotalDownloaded(downloaded)
-		pw.bar.SetFraction(float64(currentDownload) / float64(pw.totalToDownload))
+		pw.bar.SetFraction(float64(pw.totalDownloaded) / float64(pw.totalToDownload))
-		pw.speedAverager.AddSpeed(speed)
+		pw.speedAverager.AddSpeed(calculateDownloadSpeed(pw.totalDownloaded, pw.startTime, time.Now()))
-		pw.bar.SetText(fmt.Sprintf("Downloading %s (%s/%s) (%s/s)", filePath, humanize.Bytes(uint64(currentDownload)), humanize.Bytes(uint64(pw.totalToDownload)), humanize.Bytes(uint64(int64(pw.speedAverager.GetAverageSpeed())))))
+		pw.bar.SetText(fmt.Sprintf("Downloading... (%s/%s) (%s/s)", humanize.Bytes(uint64(pw.totalDownloaded)), humanize.Bytes(uint64(pw.totalToDownload)), humanize.Bytes(uint64(int64(pw.speedAverager.GetAverageSpeed())))))
 	})
 	for gtk.EventsPending() {
 		gtk.MainIteration()
@@ -110,11 +122,19 @@ func (pw *ProgressWindow) SetDownloadSize(size int64) {
 }
 
 func (pw *ProgressWindow) SetTotalDownloaded(total int64) {
+	pw.progressMutex.Lock()
 	pw.totalDownloaded = total
+	pw.progressMutex.Unlock()
 }
 
 func (pw *ProgressWindow) AddToTotalDownloaded(toAdd int64) {
+	pw.progressMutex.Lock()
 	pw.totalDownloaded += toAdd
+	pw.progressMutex.Unlock()
+}
+
+func (pw *ProgressWindow) SetStartTime(startTime time.Time) {
+	pw.startTime = startTime
 }
 
 func createProgressWindow(parent *gtk.ApplicationWindow) (*ProgressWindow, error) {

downloader.go

@@ -2,6 +2,7 @@ package wiiudownloader
 
 import (
 	"bytes"
+	"context"
 	"encoding/binary"
 	"fmt"
 	"io"
@@ -10,27 +11,92 @@ import (
 	"path/filepath"
 	"strings"
 	"time"
+
+	"golang.org/x/sync/errgroup"
+	"golang.org/x/sync/semaphore"
 )
 
 const (
 	maxRetries             = 5
 	retryDelay             = 5 * time.Second
+	maxConcurrentDownloads = 4
+)
+
+var (
+	errCancel = fmt.Errorf("cancelled download")
 )
 
 type ProgressReporter interface {
 	SetGameTitle(title string)
-	UpdateDownloadProgress(downloaded, speed int64, filePath string)
+	UpdateDownloadProgress(downloaded int64)
 	UpdateDecryptionProgress(progress float64)
 	Cancelled() bool
 	SetCancelled()
 	SetDownloadSize(size int64)
 	SetTotalDownloaded(total int64)
 	AddToTotalDownloaded(toAdd int64)
+	SetStartTime(startTime time.Time)
+}
+
+func downloadFileWithSemaphore(ctx context.Context, progressReporter ProgressReporter, client *http.Client, downloadURL, dstPath string, doRetries bool, sem *semaphore.Weighted) error {
+	if err := sem.Acquire(ctx, 1); err != nil {
+		return nil
+	}
+	defer sem.Release(1)
+
+	for attempt := 1; attempt <= maxRetries; attempt++ {
+		req, err := http.NewRequestWithContext(ctx, "GET", downloadURL, nil)
+		if err != nil {
+			return err
+		}
+
+		req.Header.Set("User-Agent", "WiiUDownloader")
+
+		resp, err := client.Do(req)
+		if err != nil {
+			if doRetries && attempt < maxRetries && !progressReporter.Cancelled() {
+				time.Sleep(retryDelay)
+				continue
+			}
+			return err
+		}
+
+		if resp.StatusCode != http.StatusOK {
+			resp.Body.Close()
+			if doRetries && attempt < maxRetries && !progressReporter.Cancelled() {
+				time.Sleep(retryDelay)
+				continue
+			}
+			fmt.Printf("download error after %d attempts, status code: %d, url: %s\n", attempt, resp.StatusCode, downloadURL)
+			return fmt.Errorf("download error after %d attempts, status code: %d", attempt, resp.StatusCode)
+		}
+
+		file, err := os.Create(dstPath)
+		if err != nil {
+			resp.Body.Close()
+			return err
+		}
+
+		writerProgress := newWriterProgress(file, progressReporter)
+		_, err = io.Copy(writerProgress, resp.Body)
+		if err != nil {
+			file.Close()
+			resp.Body.Close()
+			if doRetries && attempt < maxRetries && !progressReporter.Cancelled() {
+				time.Sleep(retryDelay)
+				continue
+			}
+			return err
+		}
+		file.Close()
+		resp.Body.Close()
+		break
+	}
+
+	return nil
 }
 
 func downloadFile(progressReporter ProgressReporter, client *http.Client, downloadURL, dstPath string, doRetries bool) error {
-	filePath := filepath.Base(dstPath)
-
 	for attempt := 1; attempt <= maxRetries; attempt++ {
 		req, err := http.NewRequest("GET", downloadURL, nil)
 		if err != nil {
@@ -63,7 +129,7 @@ func downloadFile(progressReporter ProgressReporter, client *http.Client, downlo
 			return err
 		}
 
-		writerProgress := newWriterProgress(file, progressReporter, time.Now(), filePath)
+		writerProgress := newWriterProgress(file, progressReporter)
 		_, err = io.Copy(writerProgress, resp.Body)
 		if err != nil {
 			file.Close()
@@ -133,17 +199,28 @@ func DownloadTitle(titleID, outputDirectory string, doDecryption bool, progressR
 	}
 
 	var titleSize uint64
-	var contentSizes []uint64
+	contents := make([]Content, contentCount)
-	for i := 0; i < int(contentCount); i++ {
+	tmdDataReader := bytes.NewReader(tmdData)
-		contentDataLoc := 0xB04 + (0x30 * i)
 
-		var contentSizeInt uint64
+	for i := 0; i < int(contentCount); i++ {
-		if err := binary.Read(bytes.NewReader(tmdData[contentDataLoc+8:contentDataLoc+8+8]), binary.BigEndian, &contentSizeInt); err != nil {
+		offset := 0xB04 + (0x30 * i)
+
+		tmdDataReader.Seek(int64(offset), io.SeekStart)
+		if err := binary.Read(tmdDataReader, binary.BigEndian, &contents[i].ID); err != nil {
 			return err
 		}
 
-		titleSize += contentSizeInt
+		tmdDataReader.Seek(8, io.SeekCurrent)
-		contentSizes = append(contentSizes, contentSizeInt)
+
+		if err := binary.Read(tmdDataReader, binary.BigEndian, &contents[i].Type); err != nil {
+			return err
+		}
+
+		if err := binary.Read(tmdDataReader, binary.BigEndian, &contents[i].Size); err != nil {
+			return err
+		}
+
+		titleSize += contents[i].Size
 	}
 
 	progressReporter.SetDownloadSize(int64(titleSize))
@@ -164,39 +241,47 @@ func DownloadTitle(titleID, outputDirectory string, doDecryption bool, progressR
 	if err := binary.Write(certFile, binary.BigEndian, cert.Bytes()); err != nil {
 		return err
 	}
-	defer certFile.Close()
+	certFile.Close()
 	logger.Info("Certificate saved to %v \n", certPath)
 
-	var content Content
+	g, ctx := errgroup.WithContext(context.Background())
-	tmdDataReader := bytes.NewReader(tmdData)
+	g.SetLimit(maxConcurrentDownloads)
+	sem := semaphore.NewWeighted(maxConcurrentDownloads)
+	progressReporter.SetStartTime(time.Now())
 
 	for i := 0; i < int(contentCount); i++ {
-		offset := 2820 + (48 * i)
+		i := i
-		tmdDataReader.Seek(int64(offset), 0)
+		g.Go(func() error {
-		if err := binary.Read(tmdDataReader, binary.BigEndian, &content.ID); err != nil {
-			return err
-		}
-		filePath := filepath.Join(outputDir, fmt.Sprintf("%08X.app", content.ID))
-		if err := downloadFile(progressReporter, client, fmt.Sprintf("%s/%08X", baseURL, content.ID), filePath, true); err != nil {
-			if progressReporter.Cancelled() {
-				break
-			}
-			return err
-		}
-		progressReporter.AddToTotalDownloaded(int64(contentSizes[i]))
 
-		if tmdData[offset+7]&0x2 == 2 {
+			filePath := filepath.Join(outputDir, fmt.Sprintf("%08X.app", contents[i].ID))
-			filePath = filepath.Join(outputDir, fmt.Sprintf("%08X.h3", content.ID))
+			if err := downloadFileWithSemaphore(ctx, progressReporter, client, fmt.Sprintf("%s/%08X", baseURL, contents[i].ID), filePath, true, sem); err != nil {
-			if err := downloadFile(progressReporter, client, fmt.Sprintf("%s/%08X.h3", baseURL, content.ID), filePath, true); err != nil {
 				if progressReporter.Cancelled() {
-					break
+					return errCancel
+				}
+				return err
+			}
+
+			if contents[i].Type&0x2 == 2 { // has a hash
+				filePath = filepath.Join(outputDir, fmt.Sprintf("%08X.h3", contents[i].ID))
+				if err := downloadFileWithSemaphore(ctx, progressReporter, client, fmt.Sprintf("%s/%08X.h3", baseURL, contents[i].ID), filePath, true, sem); err != nil {
+					if progressReporter.Cancelled() {
+						return errCancel
 					}
 					return err
 				}
 			}
 			if progressReporter.Cancelled() {
-			break
+				return errCancel
 			}
+			return nil
+		})
+	}
+
+	if err := g.Wait(); err != nil {
+		if err == errCancel {
+			return nil
+		}
+		return err
 	}
 
 	if doDecryption && !progressReporter.Cancelled() {

writerProgress.go

@@ -5,35 +5,31 @@ import (
 	"time"
 )
 
-func calculateDownloadSpeed(downloaded int64, startTime, endTime time.Time) int64 {
-	duration := endTime.Sub(startTime).Seconds()
-	if duration > 0 {
-		return int64(float64(downloaded) / duration)
-	}
-	return 0
-}
-
 type WriterProgress struct {
 	writer               io.Writer
 	progressReporter     ProgressReporter
-	startTime        time.Time
+	updateProgressTicker *time.Ticker
-	filePath         string
+	downloadToReport     int64 // Number of bytes to report to the progressReporter since the last update
-	totalDownloaded  int64
 }
 
-func newWriterProgress(writer io.Writer, progressReporter ProgressReporter, startTime time.Time, filePath string) *WriterProgress {
+func newWriterProgress(writer io.Writer, progressReporter ProgressReporter) *WriterProgress {
-	return &WriterProgress{writer: writer, totalDownloaded: 0, progressReporter: progressReporter, startTime: startTime, filePath: filePath}
+	return &WriterProgress{writer: writer, progressReporter: progressReporter, updateProgressTicker: time.NewTicker(25 * time.Millisecond), downloadToReport: 0}
 }
 
 func (r *WriterProgress) Write(p []byte) (n int, err error) {
+	select {
+	case <-r.updateProgressTicker.C:
+		r.progressReporter.UpdateDownloadProgress(r.downloadToReport)
+		r.downloadToReport = 0
+	default:
+	}
 	if r.progressReporter.Cancelled() {
-		return len(p), nil
+		return 0, nil
 	}
 	n, err = r.writer.Write(p)
 	if err != nil && err != io.EOF {
 		return n, err
 	}
-	r.totalDownloaded += int64(n)
+	r.downloadToReport += int64(n)
-	r.progressReporter.UpdateDownloadProgress(r.totalDownloaded, calculateDownloadSpeed(r.totalDownloaded, r.startTime, time.Now()), r.filePath)
 	return n, err
 }