narrow lock time to not include network request

cache.go

@@ -147,7 +147,6 @@ func (c *Cache) getOrFetch(ctx context.Context, u string, forceRefresh bool) (in
 	// has this entry been fetched? (but ignore and do a fetch
 	// if forceRefresh is true)
 	if forceRefresh || !e.hasBeenFetched() {
-
 		// Only one goroutine may enter this section.
 		// redundant checks allow cached gets avoid the semaphore,
 		// which allows them to return cached data immediately

queue.go

@@ -318,12 +318,12 @@ func (q *queue) refreshLoop(ctx context.Context, errSink ErrSink) {
 }
 
 func (q *queue) fetchAndStore(ctx context.Context, e *entry) error {
-	e.mu.Lock()
-	defer e.mu.Unlock()
-
+	now := time.Now()
 	// synchronously go fetch
-	e.lastFetch = time.Now()
 	res, err := q.fetch.fetch(ctx, e.request)
+	e.mu.Lock()
+	defer e.mu.Unlock()
+	e.lastFetch = now
 	if err != nil {
 		// Even if the request failed, we need to queue the next fetch
 		q.enqueueNextFetch(nil, e)