refactor: remove open function

src/main.rs

@@ -66,6 +66,7 @@ fn commands_backup(cli: &Cli, _args: &BackupArgs) -> io::Result<()> {
         cli.chain_len,
         cli.chains,
     );
+    manager.load()?;
 
     manager.create_backup()?;
     manager.remove_old_backups()

src/server/backups.rs

@@ -250,19 +250,7 @@ impl BackupManager {
         }
     }
 
-    pub fn open(
-        backup_dir: PathBuf,
-        config_dir: PathBuf,
-        world_dir: PathBuf,
-        chain_len: u64,
-        chains_to_keep: u64,
-    ) -> std::io::Result<Self> {
-        let mut manager = Self::new(backup_dir, config_dir, world_dir, chain_len, chains_to_keep);
-        manager.load_json()?;
-
-        Ok(manager)
-    }
-
+    /// Create a new backup with the expected type.
     pub fn create_backup(&mut self) -> io::Result<()> {
         let dirs = vec![
             (PathBuf::from("config"), self.config_dir.clone()),
@@ -296,12 +284,12 @@ impl BackupManager {
         // The above statement always creates this element, so this unwrap is safe
         self.chains.last_mut().unwrap().push(backup);
 
-        self.write_json()?;
+        self.save()?;
 
         Ok(())
     }
 
-    /// Remove the oldest backups
+    /// Delete all backups associated with outdated chains, and forget those chains.
     pub fn remove_old_backups(&mut self) -> std::io::Result<()> {
         let chains_to_store: usize = self.chains_to_keep.try_into().unwrap();
 
@@ -322,24 +310,28 @@ impl BackupManager {
             }
         }
 
-        self.write_json()?;
+        self.save()?;
 
         Ok(())
     }
 
-    pub fn write_json(&self) -> std::io::Result<()> {
+    /// Write the in-memory state to disk.
+    pub fn save(&self) -> std::io::Result<()> {
         let json_file = File::create(self.backup_dir.join(Self::METADATA_FILE))?;
         serde_json::to_writer(json_file, &self.chains)?;
 
         Ok(())
     }
 
-    pub fn load_json(&mut self) -> std::io::Result<()> {
+    /// Overwrite the in-memory state with the on-disk state.
+    pub fn load(&mut self) -> std::io::Result<()> {
         let json_file = match File::open(self.backup_dir.join(Self::METADATA_FILE)) {
             Ok(f) => f,
             Err(e) => {
                 // Don't error out if the file isn't there, it will be created when necessary
                 if e.kind() == io::ErrorKind::NotFound {
+                    self.chains = Vec::new();
+
                     return Ok(());
                 } else {
                     return Err(e);

src/server/command.rs

@@ -186,13 +186,15 @@ impl ServerCommand {
     }
 
     pub fn spawn(&mut self) -> std::io::Result<ServerProcess> {
-        let manager = BackupManager::open(
+        let mut manager = BackupManager::new(
             self.backup_dir.clone(),
             self.config_dir.clone(),
             self.world_dir.clone(),
             self.chain_len,
             self.chains_to_keep,
-        )?;
+        );
+        manager.load()?;
+
         let mut cmd = self.create_cmd();
         self.accept_eula()?;
         let child = cmd.spawn()?;