Add default cache configuration and pass down to memstore and Entry.

Wrap global variables into one default struct.
Update test steps so that tests run every time so we  don't get
the cached results.

1 files changed, 28 insertions, 6 deletions

diff --git a/internal/source/gitlab/cache/cache.go b/internal/source/gitlab/cache/cache.go
index 9a4ab753..bb3567b4 100644
--- a/internal/source/gitlab/cache/cache.go
+++ b/internal/source/gitlab/cache/cache.go
@@ -2,22 +2,44 @@ package cache
 
 import (
 	"context"
+	"time"
 
 	"gitlab.com/gitlab-org/gitlab-pages/internal/source/gitlab/api"
 	"gitlab.com/gitlab-org/gitlab-pages/metrics"
 )
 
+var defaultCacheConfig = cacheConfig{
+	cacheExpiry:          10 * time.Minute,
+	entryRefreshTimeout:  30 * time.Second,
+	retrievalTimeout:     5 * time.Second,
+	maxRetrievalInterval: time.Second,
+	maxRetrievalRetries:  3,
+}
+
 // Cache is a short and long caching mechanism for GitLab source
 type Cache struct {
-	client api.Client
-	store  Store
+	client      api.Client
+	store       Store
+	cacheConfig *cacheConfig
+}
+
+type cacheConfig struct {
+	cacheExpiry          time.Duration
+	entryRefreshTimeout  time.Duration
+	retrievalTimeout     time.Duration
+	maxRetrievalInterval time.Duration
+	maxRetrievalRetries  int
 }
 
 // NewCache creates a new instance of Cache.
-func NewCache(client api.Client) *Cache {
+func NewCache(client api.Client, cc *cacheConfig) *Cache {
+	if cc == nil {
+		cc = &defaultCacheConfig
+	}
+
 	return &Cache{
 		client: client,
-		store:  newMemStore(),
+		store:  newMemStore(client, cc),
 	}
 }
 
@@ -25,8 +47,8 @@ func NewCache(client api.Client) *Cache {
 // algorithm works as follows:
 // - We first check if the cache entry exists, and if it is up-to-date. If it
 //   is fresh we return the lookup entry from cache and it is a cache hit.
-// - If entry is not up-to-date, what means that it has been created in a cache
-//   more than `shortCacheExpiry` duration ago,  we schedule an asynchronous
+// - If entry is not up-to-date, that means it has been created in a cache
+//   more than `entryRefreshTimeout` duration ago,  we schedule an asynchronous
 //   retrieval of the latest configuration we are going to obtain through the
 //   API, and we immediately return an old value, to avoid blocking clients. In
 //   this case it is also a cache hit.