From 5a23230fa90715c99389c585be807d8c437d4daf 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 a6929cc4f..ffb8dc084 100644
--- a/backend/azureblob/azureblob.go
+++ b/backend/azureblob/azureblob.go
@@ -1648,13 +1648,15 @@ 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)