From bdf9298496c721916aaec6064a17fad2f5d9da69 Mon Sep 17 00:00:00 2001
From: Milas Bowman <devnull@milas.dev>
Date: Mon, 10 Mar 2025 22:54:48 -0400
Subject: [PATCH] chore(poll): return NotModifiedTimeoutErr on 304

---
 client.go           |  3 +++
 poll_batch.go       |  7 ++++++-
 poll_batch_test.go  | 35 +++++++++++++++++++++++++++++++++++
 poll_single_test.go | 21 +++++++++++++++++++++
 4 files changed, 65 insertions(+), 1 deletion(-)

diff --git a/client.go b/client.go
index 4bc6a1c..36a074b 100644
--- a/client.go
+++ b/client.go
@@ -22,6 +22,7 @@ const CausalityTokenHeader = "X-Garage-Causality-Token"
 var TombstoneItemErr = errors.New("item is a tombstone")
 var NoSuchItemErr = errors.New("item does not exist")
 var ConcurrentItemsErr = errors.New("item has multiple concurrent values")
+var NotModifiedTimeoutErr = errors.New("not modified within timeout")
 
 var awsSigner = v4.NewSigner()
 
@@ -300,6 +301,8 @@ func (c *Client) readItemSingle(ctx context.Context, b Bucket, pk string, sk str
 		return nil, "", NoSuchItemErr
 	case http.StatusConflict:
 		return nil, ct, ConcurrentItemsErr
+	case http.StatusNotModified:
+		return nil, "", NotModifiedTimeoutErr
 	default:
 		return nil, "", fmt.Errorf("http status code %d", resp.StatusCode)
 	}
diff --git a/poll_batch.go b/poll_batch.go
index c3ed20f..83df65b 100644
--- a/poll_batch.go
+++ b/poll_batch.go
@@ -67,7 +67,12 @@ func (c *Client) PollRange(ctx context.Context, b Bucket, pk string, q PollRange
 		return nil, err
 	}
 
-	if resp.StatusCode != http.StatusOK {
+	switch resp.StatusCode {
+	case http.StatusOK:
+		break
+	case http.StatusNotModified:
+		return nil, NotModifiedTimeoutErr
+	default:
 		return nil, fmt.Errorf("http status code %d: %s", resp.StatusCode, body)
 	}
 
diff --git a/poll_batch_test.go b/poll_batch_test.go
index 546bede..384aafa 100644
--- a/poll_batch_test.go
+++ b/poll_batch_test.go
@@ -80,3 +80,38 @@ func TestClient_PollRange(t *testing.T) {
 		require.Equal(t, "hello3", string(result.Items[0].Values[0]))
 	}
 }
+
+func TestClient_PollRange_Timeout(t *testing.T) {
+	if testing.Short() {
+		t.Skip("Skipping in short mode: 1 sec minimum to trigger timeout")
+		return
+	}
+	t.Parallel()
+
+	f, ctx := newFixture(t)
+
+	pk := randomPk()
+	sk := randomSk()
+
+	for i := range 5 {
+		err := f.cli.InsertItem(ctx, f.bucket, pk, sk+"-"+strconv.Itoa(i), "", []byte("hello1"))
+		require.NoError(t, err)
+	}
+
+	// first read should complete immediately
+	q := k2v.PollRangeQuery{
+		Start: sk,
+	}
+	result, err := f.cli.PollRange(ctx, f.bucket, pk, q, 5*time.Second)
+	require.NoError(t, err)
+	require.NotEmpty(t, result.SeenMarker)
+	require.Len(t, result.Items, 5)
+	for i := range result.Items {
+		require.Len(t, result.Items[i].Values, 1)
+		require.Equal(t, "hello1", string(result.Items[i].Values[0]))
+	}
+
+	q.SeenMarker = result.SeenMarker
+	result, err = f.cli.PollRange(ctx, f.bucket, pk, q, 1*time.Second)
+	require.ErrorIs(t, err, k2v.NotModifiedTimeoutErr)
+}
diff --git a/poll_single_test.go b/poll_single_test.go
index 21f3276..dcca3de 100644
--- a/poll_single_test.go
+++ b/poll_single_test.go
@@ -46,3 +46,24 @@ func TestClient_PollItem(t *testing.T) {
 	require.NotEmpty(t, ct)
 	require.NoError(t, <-updateErrCh)
 }
+
+func TestClient_PollItem_Timeout(t *testing.T) {
+	if testing.Short() {
+		t.Skip("Skipping in short mode: 1 sec minimum to trigger timeout")
+		return
+	}
+	t.Parallel()
+
+	f, ctx := newFixture(t)
+
+	pk := randomPk()
+	sk := randomSk()
+
+	err := f.cli.InsertItem(ctx, f.bucket, pk, sk, "", []byte("hello1"))
+	require.NoError(t, err)
+
+	_, ct, err := f.cli.ReadItemSingle(ctx, f.bucket, pk, sk)
+	item, ct, err := f.cli.PollItem(ctx, f.bucket, pk, sk, ct, 1*time.Second)
+	require.ErrorIs(t, err, k2v.NotModifiedTimeoutErr)
+	require.Empty(t, item)
+}