Fix downloadChunked for larger files

closes #298

Author: corny

client.go

@@ -338,7 +338,6 @@ func (c *Client) GetStreamContext(ctx context.Context, video *Video, format *For
 	} else {
 		// we have length information, let's download by chunks!
 		c.downloadChunked(ctx, req, w, format)
-
 	}
 
 	return r, contentLength, nil
@@ -402,19 +401,21 @@ func (c *Client) downloadChunked(ctx context.Context, req *http.Request, w *io.P
 	currentChunk := atomic.Uint32{}
 	for i := 0; i < maxRoutines; i++ {
 		go func() {
-			i := int(currentChunk.Add(1)) - 1
-			if i > len(chunks) {
-				// no more chunks
-				return
-			}
+			for {
+				chunkIndex := int(currentChunk.Add(1)) - 1
+				if chunkIndex >= len(chunks) {
+					// no more chunks
+					return
+				}
 
-			chunk := &chunks[i]
-			err := c.downloadChunk(req.Clone(cancelCtx), chunk)
-			close(chunk.data)
+				chunk := &chunks[chunkIndex]
+				err := c.downloadChunk(req.Clone(cancelCtx), chunk)
+				close(chunk.data)
 
-			if err != nil {
-				abort(err)
-				return
+				if err != nil {
+					abort(err)
+					return
+				}
 			}
 		}()
 	}
@@ -424,6 +425,7 @@ func (c *Client) downloadChunked(ctx context.Context, req *http.Request, w *io.P
 		for i := 0; i < len(chunks); i++ {
 			select {
 			case <-cancelCtx.Done():
+				abort(context.Canceled)
 				return
 			case data := <-chunks[i].data:
 				_, err := io.Copy(w, bytes.NewBuffer(data))

client_test.go

@@ -129,6 +129,15 @@ func TestGetVideoWithManifestURL(t *testing.T) {
 func TestGetStream(t *testing.T) {
 	assert, require := assert.New(t), require.New(t)
 
+	expectedSize := 988479
+
+	// Create testclient to enforce re-using of routines
+	testClient := Client{
+		Debug:       true,
+		MaxRoutines: 10,
+		ChunkSize:   int64(expectedSize) / 11,
+	}
+
 	// Download should not last longer than a minute.
 	// Otherwise we assume Youtube is throtteling us.
 	ctx, cancel := context.WithTimeout(context.Background(), time.Minute)
@@ -141,7 +150,7 @@ func TestGetStream(t *testing.T) {
 
 	reader, size, err := testClient.GetStreamContext(ctx, video, &video.Formats[0])
 	require.NoError(err)
-	assert.EqualValues(988479, size)
+	assert.EqualValues(expectedSize, size)
 
 	data, err := io.ReadAll(reader)
 	require.NoError(err)