From 70b7513c7e513b77cad8cf5048437ee11b13167f Mon Sep 17 00:00:00 2001 From: wojtekt Date: Wed, 30 Jan 2019 16:39:38 +0100 Subject: [PATCH] Optimize Index() method to avoid unnecessary copies --- .../tools/cache/thread_safe_store.go | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) diff --git a/staging/src/k8s.io/client-go/tools/cache/thread_safe_store.go b/staging/src/k8s.io/client-go/tools/cache/thread_safe_store.go index 1c201efb629..5cbdd17ed45 100644 --- a/staging/src/k8s.io/client-go/tools/cache/thread_safe_store.go +++ b/staging/src/k8s.io/client-go/tools/cache/thread_safe_store.go @@ -148,12 +148,19 @@ func (c *threadSafeMap) Index(indexName string, obj interface{}) ([]interface{}, } index := c.indices[indexName] - // need to de-dupe the return list. Since multiple keys are allowed, this can happen. - returnKeySet := sets.String{} - for _, indexKey := range indexKeys { - set := index[indexKey] - for _, key := range set.UnsortedList() { - returnKeySet.Insert(key) + var returnKeySet sets.String + if len(indexKeys) == 1 { + // In majority of cases, there is exactly one value matching. + // Optimize the most common path - deduping is not needed here. + returnKeySet = index[indexKeys[0]] + } else { + // Need to de-dupe the return list. + // Since multiple keys are allowed, this can happen. + returnKeySet = sets.String{} + for _, indexKey := range indexKeys { + for key := range index[indexKey] { + returnKeySet.Insert(key) + } } }