From e1542300aead4bb60806e8decc655321f5b02057 Mon Sep 17 00:00:00 2001
From: gmarek <gmarek@google.com>
Date: Fri, 18 Nov 2016 13:54:10 +0100
Subject: [PATCH] Add fast-path for Listing with ResourceVersion=0

---
 pkg/storage/watch_cache.go | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/pkg/storage/watch_cache.go b/pkg/storage/watch_cache.go
index 54c1ccd8fd1..767899a2f9e 100644
--- a/pkg/storage/watch_cache.go
+++ b/pkg/storage/watch_cache.go
@@ -283,10 +283,13 @@ func (w *watchCache) waitUntilFreshAndBlock(resourceVersion uint64, trace *util.
 
 // WaitUntilFreshAndList returns list of pointers to <storeElement> objects.
 func (w *watchCache) WaitUntilFreshAndList(resourceVersion uint64, trace *util.Trace) ([]interface{}, uint64, error) {
-	err := w.waitUntilFreshAndBlock(resourceVersion, trace)
-	defer w.RUnlock()
-	if err != nil {
-		return nil, 0, err
+	// If resourceVersion == 0 we'll return the data that we currently have in cache.
+	if resourceVersion != 0 {
+		err := w.waitUntilFreshAndBlock(resourceVersion, trace)
+		defer w.RUnlock()
+		if err != nil {
+			return nil, 0, err
+		}
 	}
 	return w.store.List(), w.resourceVersion, nil
 }