config: add user cache async/sync timeout options

previously were constants in usercache.go, now app.userCache is
instantiated in main.go with NewUserCache(time.Duration, time.Duration).

config.go

@@ -188,6 +188,10 @@ func (app *appContext) loadConfig() error {
 	app.config.Section("jellyfin").Key("device").SetValue("jfa-go")
 	app.config.Section("jellyfin").Key("device_id").SetValue(fmt.Sprintf("jfa-go-%s-%s", version, commit))
 
+	app.MustSetValue("jellyfin", "cache_timeout", "30")
+	app.MustSetValue("jellyfin", "web_cache_async_timeout", "1")
+	app.MustSetValue("jellyfin", "web_cache_sync_timeout", "10")
+
 	LOGIP = app.config.Section("advanced").Key("log_ips").MustBool(false)
 	LOGIPU = app.config.Section("advanced").Key("log_ips_users").MustBool(false)
 

main.go

@@ -134,7 +134,7 @@ type appContext struct {
 	pwrCaptchas                 map[string]Captcha
 	ConfirmationKeys            map[string]map[string]ConfirmationKey // Map of invite code to jwt to request
 	confirmationKeysLock        sync.Mutex
-	userCache                   UserCache
+	userCache                   *UserCache
 }
 
 func generateSecret(length int) (string, error) {
@@ -406,7 +406,7 @@ func start(asDaemon, firstCall bool) {
 
 		// Initialize jellyfin/emby connection
 		server := app.config.Section("jellyfin").Key("server").String()
-		cacheTimeout := int(app.config.Section("jellyfin").Key("cache_timeout").MustUint(30))
+		cacheTimeout := app.config.Section("jellyfin").Key("cache_timeout").MustInt()
 		stringServerType := app.config.Section("jellyfin").Key("type").String()
 		timeoutHandler := mediabrowser.NewNamedTimeoutHandler("Jellyfin", "\""+server+"\"", true)
 		if stringServerType == "emby" {
@@ -469,6 +469,11 @@ func start(asDaemon, firstCall bool) {
 			}
 		}
 
+		app.userCache = NewUserCache(
+			time.Minute*time.Duration(app.config.Section("jellyfin").Key("web_cache_async_timeout").MustInt()),
+			time.Minute*time.Duration(app.config.Section("jellyfin").Key("web_cache_sync_timeout").MustInt()),
+		)
+
 		// Since email depends on language, the email reload in loadConfig won't work first time.
 		// Email also handles its own proxying, as (SMTP atleast) doesn't use a HTTP transport.
 		app.email = NewEmailer(app)

usercache.go

@@ -10,12 +10,8 @@ import (
 )
 
 const (
-	// After cache is this old, re-sync, but do it in the background and return the old cache.
-	WEB_USER_CACHE_SYNC = 30 * time.Second
-	// After cache is this old, re-sync and wait for it and return the new cache.
-	WEB_USER_CACHE_WAIT_FOR_SYNC = 5 * time.Minute
-	USER_DEFAULT_SORT_FIELD      = "name"
-	USER_DEFAULT_SORT_ASCENDING  = true
+	USER_DEFAULT_SORT_FIELD     = "name"
+	USER_DEFAULT_SORT_ASCENDING = true
 )
 
 // UserCache caches the transport representation of users,
@@ -28,19 +24,30 @@ type UserCache struct {
 	Ref      []*respUser
 	Sorted   bool
 	LastSync time.Time
-	SyncLock sync.Mutex
-	Syncing  bool
-	SortLock sync.Mutex
-	Sorting  bool
+	// After cache is this old, re-sync, but do it in the background and return the old cache.
+	SyncTimeout time.Duration
+	// After cache is this old, re-sync and wait for it and return the new cache.
+	WaitForSyncTimeout time.Duration
+	SyncLock           sync.Mutex
+	Syncing            bool
+	SortLock           sync.Mutex
+	Sorting            bool
+}
+
+func NewUserCache(syncTimeout, waitForSyncTimeout time.Duration) *UserCache {
+	return &UserCache{
+		SyncTimeout:        syncTimeout,
+		WaitForSyncTimeout: waitForSyncTimeout,
+	}
 }
 
 // MaybeSync (maybe) syncs the cache, resulting in updated UserCache.Cache/.Ref/.Sorted.
-// Only syncs if WEB_USER_CACHE_SYNC duration has passed since last one.
-// If WEB_USER_CACHE_WAIT_FOR_SYNC duration has passed, this will block until a sync is complete, otherwise it will sync in the background
+// Only syncs if c.SyncTimeout duration has passed since last one.
+// If c.WaitForSyncTimeout duration has passed, this will block until a sync is complete, otherwise it will sync in the background
 // (expecting you to use the old cache data). Only one sync will run at a time.
 func (c *UserCache) MaybeSync(app *appContext) error {
-	shouldWaitForSync := time.Now().After(c.LastSync.Add(WEB_USER_CACHE_WAIT_FOR_SYNC)) || c.Ref == nil || len(c.Ref) == 0
-	shouldSync := time.Now().After(c.LastSync.Add(WEB_USER_CACHE_SYNC))
+	shouldWaitForSync := time.Now().After(c.LastSync.Add(c.WaitForSyncTimeout)) || c.Ref == nil || len(c.Ref) == 0
+	shouldSync := time.Now().After(c.LastSync.Add(c.SyncTimeout))
 
 	if !shouldSync {
 		return nil