From dc77bbcfa40dea8b8fc7713a2ecacbc6a9d08a25 Mon Sep 17 00:00:00 2001
From: Blake Mizerany <blake.mizerany@gmail.com>
Date: Wed, 31 Jul 2024 16:01:24 -0700
Subject: [PATCH] server: fix json marshalling of downloadBlobPart (#6108)

---
 server/download.go | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/server/download.go b/server/download.go
index 45483ba6..10074554 100644
--- a/server/download.go
+++ b/server/download.go
@@ -61,6 +61,36 @@ type blobDownloadPart struct {
 	*blobDownload `json:"-"`
 }
 
+type jsonBlobDownloadPart struct {
+	N         int
+	Offset    int64
+	Size      int64
+	Completed int64
+}
+
+func (p *blobDownloadPart) MarshalJSON() ([]byte, error) {
+	return json.Marshal(jsonBlobDownloadPart{
+		N:         p.N,
+		Offset:    p.Offset,
+		Size:      p.Size,
+		Completed: p.Completed.Load(),
+	})
+}
+
+func (p *blobDownloadPart) UnmarshalJSON(b []byte) error {
+	var j jsonBlobDownloadPart
+	if err := json.Unmarshal(b, &j); err != nil {
+		return err
+	}
+	*p = blobDownloadPart{
+		N:      j.N,
+		Offset: j.Offset,
+		Size:   j.Size,
+	}
+	p.Completed.Store(j.Completed)
+	return nil
+}
+
 const (
 	numDownloadParts          = 64
 	minDownloadPartSize int64 = 100 * format.MegaByte