From 39e98537fd342dac1bcb1f6f118c97d70711e85e Mon Sep 17 00:00:00 2001
From: Vincent Boutour <bob@vibioh.fr>
Date: Fri, 11 Aug 2023 23:49:16 +0200
Subject: [PATCH] feat(cache): Setting optional extend on hit

Signed-off-by: Vincent Boutour <bob@vibioh.fr>
---
 pkg/cache/cache.go      | 13 +++++++++++--
 pkg/cache/cache_test.go |  5 +++++
 pkg/cache/list.go       | 10 ++++++++--
 3 files changed, 24 insertions(+), 4 deletions(-)

diff --git a/pkg/cache/cache.go b/pkg/cache/cache.go
index dd2ddcbd..1135a0e6 100644
--- a/pkg/cache/cache.go
+++ b/pkg/cache/cache.go
@@ -43,6 +43,7 @@ type App[K comparable, V any] struct {
 	onMissMany  fetchMany[K, V]
 	ttl         time.Duration
 	concurrency int
+	extendOnHit bool
 }
 
 func New[K comparable, V any](client RedisClient, toKey func(K) string, onMiss fetch[K, V], ttl time.Duration, concurrency int, tracer trace.Tracer) *App[K, V] {
@@ -78,6 +79,12 @@ func (a *App[K, V]) WithRead(client RedisClient) *App[K, V] {
 	return a
 }
 
+func (a *App[K, V]) WithExtendOnHit() *App[K, V] {
+	a.extendOnHit = true
+
+	return a
+}
+
 func getClient(client RedisClient) RedisClient {
 	if !model.IsNil(client) && client.Enabled() {
 		return client
@@ -110,7 +117,9 @@ func (a *App[K, V]) Get(ctx context.Context, id K) (V, error) {
 	} else if value, ok, err := a.decode([]byte(content)); err != nil {
 		logUnmarshallError(ctx, key, err)
 	} else if ok {
-		a.extendTTL(ctx, key)
+		if a.extendOnHit {
+			a.extendTTL(ctx, key)
+		}
 
 		return value, nil
 	}
@@ -166,7 +175,7 @@ func (a *App[K, V]) decode(content []byte) (value V, ok bool, err error) {
 }
 
 func (a *App[K, V]) extendTTL(ctx context.Context, keys ...string) {
-	if a.write == nil {
+	if a.write == nil || len(keys) == 0 {
 		return
 	}
 
diff --git a/pkg/cache/cache_test.go b/pkg/cache/cache_test.go
index 96288af0..f04e3530 100644
--- a/pkg/cache/cache_test.go
+++ b/pkg/cache/cache_test.go
@@ -131,6 +131,8 @@ func TestGet(t *testing.T) {
 			case "cached":
 				mockRedisClient.EXPECT().Load(gomock.Any(), gomock.Any()).Return([]byte(`{"id":8000}`), nil)
 				mockRedisClient.EXPECT().Expire(gomock.Any(), testCase.args.duration, gomock.Any()).Return(nil)
+			case "cached no extend":
+				mockRedisClient.EXPECT().Load(gomock.Any(), gomock.Any()).Return([]byte(`{"id":8000}`), nil)
 			case "store error":
 				mockRedisClient.EXPECT().Load(gomock.Any(), gomock.Any()).Return(nil, nil)
 				mockRedisClient.EXPECT().Store(gomock.Any(), gomock.Any(), gomock.Any(), gomock.Any()).Return(errors.New("store error"))
@@ -147,6 +149,9 @@ func TestGet(t *testing.T) {
 			}
 
 			instance := New(mockRedisClient, strconv.Itoa, testCase.args.onMiss, testCase.args.duration, -1, nil)
+			if intention == "cached" {
+				instance = instance.WithExtendOnHit()
+			}
 
 			got, gotErr := instance.Get(context.Background(), testCase.args.key)
 
diff --git a/pkg/cache/list.go b/pkg/cache/list.go
index 4cc8d3eb..165591ea 100644
--- a/pkg/cache/list.go
+++ b/pkg/cache/list.go
@@ -95,7 +95,10 @@ func (a App[K, V]) handleListSingle(ctx context.Context, onMissError func(K, err
 			value, ok, err := a.decode([]byte(values[index]))
 			if ok {
 				output[index] = value
-				extendKeys = append(extendKeys, keys[index])
+
+				if a.extendOnHit {
+					extendKeys = append(extendKeys, keys[index])
+				}
 
 				return nil
 			}
@@ -127,7 +130,10 @@ func (a App[K, V]) handleListMany(ctx context.Context, items []K, keys, values [
 	for index, item := range items {
 		if value, ok, err := a.decode([]byte(values[index])); ok {
 			output[index] = value
-			extendKeys = append(extendKeys, keys[index])
+
+			if a.extendOnHit {
+				extendKeys = append(extendKeys, keys[index])
+			}
 
 			continue
 		} else if err != nil {