Persist only cache entries that are in use

1 files changed, 8 insertions, 1 deletions

diff --git a/later b/later
index 12a6aa4..2f13872 100755
--- a/later
+++ b/later
@@ -64,6 +64,7 @@ class TitleMap:
         self.update = update
         self.commit_to_disk = update
         self.ytdl = None
+        self.seen = set()
 
         try:
             with open(path) as handle:
@@ -77,6 +78,8 @@ class TitleMap:
             sys.exit(f"later: cannot read title cache: {err}")
 
     def get(self, key):
+        self.seen.add(key)
+
         if key in self.map:
             return self.map[key]
 
@@ -119,9 +122,13 @@ class TitleMap:
 
         os.makedirs(later_cache_dir, exist_ok=True)
 
+        seen_entries = {
+            key: value for key, value in self.map.items() if key in self.seen
+        }
+
         try:
             with open(self.path, "w") as handle:
-                json.dump(self.map, handle)
+                json.dump(seen_entries, handle)
         except OSError as err:
             sys.exit(f"later: cannot write title cache: {err}")