Order relay queue select to return oldest entries first

relayapi/storage/postgres/relay_queue_table.go

@@ -52,6 +52,7 @@ const deleteQueueEntriesSQL = "" +
 const selectQueueEntriesSQL = "" +
 	"SELECT json_nid FROM relayapi_queue" +
 	" WHERE server_name = $1" +
+	" ORDER BY json_nid" +
 	" LIMIT $2"
 
 const selectQueueEntryCountSQL = "" +

relayapi/storage/shared/storage.go

@@ -109,7 +109,8 @@ func (d *Database) GetTransaction(
 	ctx context.Context,
 	userID gomatrixserverlib.UserID,
 ) (*gomatrixserverlib.Transaction, *receipt.Receipt, error) {
-	nids, err := d.RelayQueue.SelectQueueEntries(ctx, nil, userID.Domain(), 1)
+	entriesRequested := 1
+	nids, err := d.RelayQueue.SelectQueueEntries(ctx, nil, userID.Domain(), entriesRequested)
 	if err != nil {
 		return nil, nil, fmt.Errorf("d.SelectQueueEntries: %w", err)
 	}

relayapi/storage/sqlite3/relay_queue_table.go

@@ -53,6 +53,7 @@ const deleteQueueEntriesSQL = "" +
 const selectQueueEntriesSQL = "" +
 	"SELECT json_nid FROM relayapi_queue" +
 	" WHERE server_name = $1" +
+	" ORDER BY json_nid" +
 	" LIMIT $2"
 
 const selectQueueEntryCountSQL = "" +

relayapi/storage/tables/relay_queue_table_test.go

@@ -107,6 +107,47 @@ func TestShouldRetrieveInsertedQueueTransaction(t *testing.T) {
 	})
 }
 
+func TestShouldRetrieveOldestInsertedQueueTransaction(t *testing.T) {
+	ctx := context.Background()
+	test.WithAllDatabases(t, func(t *testing.T, dbType test.DBType) {
+		db, close := mustCreateQueueTable(t, dbType)
+		defer close()
+
+		transactionID := gomatrixserverlib.TransactionID(fmt.Sprintf("%d", time.Now().UnixNano()))
+		serverName := gomatrixserverlib.ServerName("domain")
+		nid := int64(2)
+		err := db.Table.InsertQueueEntry(ctx, nil, transactionID, serverName, nid)
+		if err != nil {
+			t.Fatalf("Failed inserting transaction: %s", err.Error())
+		}
+
+		transactionID = gomatrixserverlib.TransactionID(fmt.Sprintf("%d", time.Now().UnixNano()))
+		serverName = gomatrixserverlib.ServerName("domain")
+		oldestNID := int64(1)
+		err = db.Table.InsertQueueEntry(ctx, nil, transactionID, serverName, oldestNID)
+		if err != nil {
+			t.Fatalf("Failed inserting transaction: %s", err.Error())
+		}
+
+		retrievedNids, err := db.Table.SelectQueueEntries(ctx, nil, serverName, 1)
+		if err != nil {
+			t.Fatalf("Failed retrieving transaction: %s", err.Error())
+		}
+
+		assert.Equal(t, oldestNID, retrievedNids[0])
+		assert.Equal(t, 1, len(retrievedNids))
+
+		retrievedNids, err = db.Table.SelectQueueEntries(ctx, nil, serverName, 10)
+		if err != nil {
+			t.Fatalf("Failed retrieving transaction: %s", err.Error())
+		}
+
+		assert.Equal(t, oldestNID, retrievedNids[0])
+		assert.Equal(t, nid, retrievedNids[1])
+		assert.Equal(t, 2, len(retrievedNids))
+	})
+}
+
 func TestShouldDeleteQueueTransaction(t *testing.T) {
 	ctx := context.Background()
 	test.WithAllDatabases(t, func(t *testing.T, dbType test.DBType) {