From 38654a3bd7a740fb363eff68223f10072af035c6 Mon Sep 17 00:00:00 2001
From: Michael Eischer <michael.eischer@fau.de>
Date: Thu, 30 May 2024 18:48:52 +0200
Subject: [PATCH] backend/retry: do not log final error if context was canceled

Calls to `List(ctx, ...)` are usually stopped by canceling the context
once no further entries are required by the caller. Thus, don't log the
final error if the used context was canceled.
---
 internal/backend/retry/backend_retry.go      |  6 ++---
 internal/backend/retry/backend_retry_test.go | 25 +++++++++++++++++---
 2 files changed, 25 insertions(+), 6 deletions(-)

diff --git a/internal/backend/retry/backend_retry.go b/internal/backend/retry/backend_retry.go
index d5134d433..8d0f42bfd 100644
--- a/internal/backend/retry/backend_retry.go
+++ b/internal/backend/retry/backend_retry.go
@@ -43,7 +43,7 @@ func New(be backend.Backend, maxElapsedTime time.Duration, report func(string, e
 
 // retryNotifyErrorWithSuccess is an extension of backoff.RetryNotify with notification of success after an error.
 // success is NOT notified on the first run of operation (only after an error).
-func retryNotifyErrorWithSuccess(operation backoff.Operation, b backoff.BackOff, notify backoff.Notify, success func(retries int)) error {
+func retryNotifyErrorWithSuccess(operation backoff.Operation, b backoff.BackOffContext, notify backoff.Notify, success func(retries int)) error {
 	var operationWrapper backoff.Operation
 	if success == nil {
 		operationWrapper = operation
@@ -61,8 +61,8 @@ func retryNotifyErrorWithSuccess(operation backoff.Operation, b backoff.BackOff,
 	}
 	err := backoff.RetryNotify(operationWrapper, b, notify)
 
-	if err != nil && notify != nil {
-		// log final error
+	if err != nil && notify != nil && b.Context().Err() == nil {
+		// log final error, unless the context was canceled
 		notify(err, -1)
 	}
 	return err
diff --git a/internal/backend/retry/backend_retry_test.go b/internal/backend/retry/backend_retry_test.go
index cd0c4d48b..fd76200d4 100644
--- a/internal/backend/retry/backend_retry_test.go
+++ b/internal/backend/retry/backend_retry_test.go
@@ -460,7 +460,7 @@ func TestNotifyWithSuccessIsNotCalled(t *testing.T) {
 		t.Fatal("Success should not have been called")
 	}
 
-	err := retryNotifyErrorWithSuccess(operation, &backoff.ZeroBackOff{}, notify, success)
+	err := retryNotifyErrorWithSuccess(operation, backoff.WithContext(&backoff.ZeroBackOff{}, context.Background()), notify, success)
 	if err != nil {
 		t.Fatal("retry should not have returned an error")
 	}
@@ -486,7 +486,7 @@ func TestNotifyWithSuccessIsCalled(t *testing.T) {
 		successCalled++
 	}
 
-	err := retryNotifyErrorWithSuccess(operation, &backoff.ZeroBackOff{}, notify, success)
+	err := retryNotifyErrorWithSuccess(operation, backoff.WithContext(&backoff.ZeroBackOff{}, context.Background()), notify, success)
 	if err != nil {
 		t.Fatal("retry should not have returned an error")
 	}
@@ -515,12 +515,31 @@ func TestNotifyWithSuccessFinalError(t *testing.T) {
 		successCalled++
 	}
 
-	err := retryNotifyErrorWithSuccess(operation, backoff.WithMaxRetries(&backoff.ZeroBackOff{}, 5), notify, success)
+	err := retryNotifyErrorWithSuccess(operation, backoff.WithContext(backoff.WithMaxRetries(&backoff.ZeroBackOff{}, 5), context.Background()), notify, success)
 	test.Assert(t, err.Error() == "expected error in test", "wrong error message %v", err)
 	test.Equals(t, 6, notifyCalled, "notify should have been called 6 times")
 	test.Equals(t, 0, successCalled, "success should not have been called")
 }
 
+func TestNotifyWithCancelError(t *testing.T) {
+	operation := func() error {
+		return errors.New("expected error in test")
+	}
+
+	notify := func(error, time.Duration) {
+		t.Error("unexpected call to notify")
+	}
+
+	success := func(retries int) {
+		t.Error("unexpected call to success")
+	}
+	ctx, cancel := context.WithCancel(context.Background())
+	cancel()
+
+	err := retryNotifyErrorWithSuccess(operation, backoff.WithContext(&backoff.ZeroBackOff{}, ctx), notify, success)
+	test.Assert(t, err == context.Canceled, "wrong error message %v", err)
+}
+
 type testClock struct {
 	Time time.Time
 }