Filter out stale metadata entries.

src/lib.rs

@@ -438,7 +438,6 @@ impl MovieLibrary {
         let f = File::open(&path).context(format!("open {}", path.display()))?;
         let r = BufReader::new(f);
 
-        // Read the JSON contents of the file as an instance of `User`.
         let mdf: MetadataFile = serde_json::from_reader(r)
             .context(format!("serde_json::from_reader {}", path.display()))?;
 
@@ -548,7 +547,7 @@ impl MovieLibrary {
     pub fn update_metadata(&self) -> Result<Vec<String>, Error> {
         let path = Path::new(&self.root).join(FULL_METADATA_FILENAME);
 
-        let old_metadata: HashMap<String, Value> = match File::open(&path) {
+        let mut old_metadata: HashMap<String, Value> = match File::open(&path) {
             Ok(f) => {
                 let r = BufReader::new(f);
                 serde_json::from_reader(r)?
@@ -560,6 +559,29 @@ impl MovieLibrary {
         };
 
         info!("Read metadata, {} videos found", old_metadata.len());
+        // Filter out stale metadata (where the file no longer exists).
+        let old_metadata: HashMap<String, Value> = self
+            .iter_video_files()
+            .filter(|r| r.is_ok())
+            .filter_map(|r| {
+                let path = r
+                    .as_ref()
+                    .unwrap()
+                    .strip_prefix(&self.root)
+                    .unwrap()
+                    .to_str()
+                    .unwrap()
+                    .to_owned();
+                match old_metadata.remove(&path) {
+                    Some(v) => Some((path, v)),
+                    None => None,
+                }
+            })
+            .collect();
+        info!(
+            "After removing stale metadata, {} videos found",
+            old_metadata.len()
+        );
 
         let mut metadata: HashMap<_, _> = self
             .iter_video_files()

src/main.rs

@@ -245,14 +245,8 @@ fn main() -> Result<(), Box<dyn Error>> {
         }
         Command::UpdateAndCompactMetadata => {
             let lib = MovieLibrary::new(MOVIE_DIR);
-            let new_videos = lib.update_metadata()?;
+            lib.update_metadata()?;
-            if !new_videos.is_empty() {
+            lib.compact_metadata()?;
-                info!(
-                    "{} new videos added, recompacting metadata",
-                    new_videos.len()
-                );
-                lib.compact_metadata()?;
-            }
         }
     }
     Ok(())