From 09fcc6dcb83a3165bf46cbb679693dc9729b07b6 Mon Sep 17 00:00:00 2001
From: Drew Weymouth <dweymouth@gmail.com>
Date: Fri, 28 Jul 2023 17:10:40 -0700
Subject: [PATCH] clear in-memory image cache on server logout

---
 backend/imagecache.go   |  7 +++++++
 backend/imagemanager.go | 16 ++++++++++++----
 2 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/backend/imagecache.go b/backend/imagecache.go
index 10257fd..8de7a68 100644
--- a/backend/imagecache.go
+++ b/backend/imagecache.go
@@ -128,6 +128,13 @@ func (i *ImageCache) GetWithNewTTL(key string, newTtl time.Duration) (image.Imag
 	return nil, ErrNotFound
 }
 
+func (i *ImageCache) Clear() {
+	i.mu.Lock()
+	defer i.mu.Unlock()
+
+	i.cache = make(map[string]CacheItem)
+}
+
 // must be called when rwmutex is already acquired for writing
 func (i *ImageCache) evictOne() {
 	now := time.Now().Unix()
diff --git a/backend/imagemanager.go b/backend/imagemanager.go
index d65c07e..24268ba 100644
--- a/backend/imagemanager.go
+++ b/backend/imagemanager.go
@@ -49,7 +49,11 @@ func NewImageManager(ctx context.Context, s *ServerManager, baseCacheDir string)
 			DefaultTTL: 1 * time.Minute,
 		},
 	}
-	i.thumbnailCache.OnEvictTaskRan = i.clearExpiredFullSizeCover
+	s.OnLogout(func() {
+		i.thumbnailCache.Clear()
+		i.clearFullSizeCover()
+	})
+	i.thumbnailCache.OnEvictTaskRan = i.clearFullSizeCoverIfExpired
 	i.thumbnailCache.Init(ctx, 2*time.Minute)
 	return i
 }
@@ -223,10 +227,14 @@ func (i *ImageManager) loadLocalImage(path string) (image.Image, bool) {
 	return nil, false
 }
 
-func (i *ImageManager) clearExpiredFullSizeCover() {
+func (i *ImageManager) clearFullSizeCoverIfExpired() {
 	now := time.Now().UnixMilli()
 	if now-i.cachedFullSizeCoverAccessedAt > fullSizeCoverExpires.Milliseconds() {
-		i.cachedFullSizeCoverID = ""
-		i.cachedFullSizeCover = nil
+		i.clearFullSizeCover()
 	}
 }
+
+func (i *ImageManager) clearFullSizeCover() {
+	i.cachedFullSizeCoverID = ""
+	i.cachedFullSizeCover = nil
+}