cache: review feedback

Signed-off-by: Vicent Marti <[email protected]>

go/cache/cache.go

@@ -42,10 +42,9 @@ type cachedObject interface {
 	CachedSize(alloc bool) int64
 }
 
-// NewDefaultCacheImpl returns the default cache implementation for Vitess. If the given capacity
-// is given in bytes, the implementation will be LFU-based and keep track of the total memory usage
-// for the cache. If the implementation is given in entries, the legacy LRU implementation will be used,
-// keeping track
+// NewDefaultCacheImpl returns the default cache implementation for Vitess. The options in the
+// Config struct control the memory and entry limits for the cache, and the underlying cache
+// implementation.
 func NewDefaultCacheImpl(cfg *Config) Cache {
 	switch {
 	case cfg == nil || (cfg.MaxEntries == 0 && cfg.MaxMemoryUsage == 0):

go/vt/vtgate/planbuilder/plan_test.go

@@ -630,9 +630,7 @@ func BenchmarkSelectVsDML(b *testing.B) {
 	var selectCases []testCase
 
 	for tc := range iterateExecFile("dml_cases.txt") {
-		if tc.output2ndPlanner != "" {
-			dmlCases = append(dmlCases, tc)
-		}
+		dmlCases = append(dmlCases, tc)
 	}
 
 	for tc := range iterateExecFile("select_cases.txt") {

go/vt/vttablet/endtoend/config_test.go

@@ -177,7 +177,7 @@ func TestConsolidatorReplicasOnly(t *testing.T) {
 }
 
 func TestQueryPlanCache(t *testing.T) {
-	if cache.DefaultCacheSize.Bytes() != 0 {
+	if cache.DefaultConfig.LFU {
 		const cacheItemSize = 40
 		const cachedPlanSize = 2275 + cacheItemSize
 		const cachePlanSize2 = 2254 + cacheItemSize