Add length hints for resources (#692)

Signed-off-by: Joe Andaverde <joe@temporal.io>
envoyproxy · May 15, 2023 · f040a1a · f040a1a
1 parent 8f62900
commit f040a1a
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Showing 2 changed files with 4 additions and 4 deletions.
diff --git a/pkg/cache/v3/resources.go b/pkg/cache/v3/resources.go
@@ -13,7 +13,7 @@ type Resources struct {
 
 // IndexResourcesByName creates a map from the resource name to the resource.
 func IndexResourcesByName(items []types.ResourceWithTTL) map[string]types.ResourceWithTTL {
-	indexed := make(map[string]types.ResourceWithTTL)
+	indexed := make(map[string]types.ResourceWithTTL, len(items))
 	for _, item := range items {
 		indexed[GetResourceName(item.Resource)] = item
 	}
@@ -22,7 +22,7 @@ func IndexResourcesByName(items []types.ResourceWithTTL) map[string]types.Resour
 
 // IndexRawResourcesByName creates a map from the resource name to the resource.
 func IndexRawResourcesByName(items []types.Resource) map[string]types.Resource {
-	indexed := make(map[string]types.Resource)
+	indexed := make(map[string]types.Resource, len(items))
 	for _, item := range items {
 		indexed[GetResourceName(item)] = item
 	}
@@ -31,7 +31,7 @@ func IndexRawResourcesByName(items []types.Resource) map[string]types.Resource {
 
 // NewResources creates a new resource group.
 func NewResources(version string, items []types.Resource) Resources {
-	itemsWithTTL := []types.ResourceWithTTL{}
+	itemsWithTTL := make([]types.ResourceWithTTL, 0, len(items))
 	for _, item := range items {
 		itemsWithTTL = append(itemsWithTTL, types.ResourceWithTTL{Resource: item})
 	}

diff --git a/pkg/cache/v3/snapshot.go b/pkg/cache/v3/snapshot.go
@@ -185,7 +185,7 @@ func (s *Snapshot) ConstructVersionMap() error {
 			return err
 		}
 		if _, ok := s.VersionMap[typeURL]; !ok {
-			s.VersionMap[typeURL] = make(map[string]string)
+			s.VersionMap[typeURL] = make(map[string]string, len(resources.Items))
 		}
 
 		for _, r := range resources.Items {