From ac3f7a87c3315751a5fd07d15697c84905f33fef Mon Sep 17 00:00:00 2001
From: Nick Craig-Wood <nick@craig-wood.com>
Date: Mon, 16 Dec 2024 17:04:16 +0000
Subject: [PATCH] azureblob: speed up server side copies for small files #8249

This speeds up server side copies for small files which need the check
the copy status by using an exponential ramp up of time to check the
copy status endpoint.
---
 backend/azureblob/azureblob.go | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/backend/azureblob/azureblob.go b/backend/azureblob/azureblob.go
index d5733c910..441473e13 100644
--- a/backend/azureblob/azureblob.go
+++ b/backend/azureblob/azureblob.go
@@ -1649,13 +1649,15 @@ func (f *Fs) Copy(ctx context.Context, src fs.Object, remote string) (fs.Object,
 
 	copyStatus := startCopy.CopyStatus
 	getOptions := blob.GetPropertiesOptions{}
+	pollTime := 100 * time.Millisecond
 	for copyStatus != nil && string(*copyStatus) == string(container.CopyStatusTypePending) {
-		time.Sleep(1 * time.Second)
+		time.Sleep(pollTime)
 		getMetadata, err := dstBlobSVC.GetProperties(ctx, &getOptions)
 		if err != nil {
 			return nil, err
 		}
 		copyStatus = getMetadata.CopyStatus
+		pollTime = min(2*pollTime, time.Second)
 	}
 
 	return f.NewObject(ctx, remote)