Struct DbBackupManager 

pub struct DbBackupManager {
    db_dir: PathBuf,
    current_version: GitVersion,
}

Manages versioned SQLite database backups.

Fields

db_dir: PathBuf

current_version: GitVersion

Implementations

impl DbBackupManager

pub fn new(db_dir: PathBuf, current_version: GitVersion) -> Self

Creates a backup manager for the database directory.

db_dir is the directory containing cadmus.sqlite. Backups are stored in db_dir/backups/.

fn backup_dir(&self) -> PathBuf

Returns the path to the backup directory.

fn manifest_path(&self) -> PathBuf

Returns the path to the backup manifest.

pub async fn create_backup( &self, pool: &SqlitePool, retention: usize, ) -> Result<PathBuf, Error>

Creates a backup of the current database using the SQLite online backup API.

The backup is stored as backups/cadmus-v<version>.sqlite. The manifest is updated and old backups exceeding the retention limit are removed.

pub async fn restore_best_backup( &self, active_path: &Path, newer_version: &GitVersion, ) -> Result<PathBuf, RestoreError>

Restores the best available backup for the target version.

The restore is performed in three steps to avoid losing the active database if an error occurs mid-way:

1. Copy the backup to a staging path (cadmus-v<version>-restore-staged.sqlite).
2. Rename the active database to cadmus-v<newer_version>-demoted.sqlite.
3. Rename the staged copy to the active path.

If step 3 fails the demoted database is renamed back to active_path as a best-effort rollback. Demoted files are not tracked in the manifest and are never automatically deleted — they remain as a safety net for manual recovery.

Returns the path of the restored backup file on success.

Errors

• RestoreError::NoBackupFound — no manifest entry exists for the target version.
• RestoreError::BackupFileMissing — the manifest references a file that is absent on disk.
• RestoreError::Io — an I/O or filesystem error occurred during the restore.

pub fn find_best_backup( &self, target_version: &GitVersion, ) -> Result<Option<BackupEntry>, Error>

Finds the best backup for the target version.

Prefers an exact version match. Otherwise, returns the newest backup whose version is less than or equal to the target version.

fn read_manifest(&self) -> Result<BackupManifest, Error>

Reads the backup manifest from disk.

fn write_manifest(&self, manifest: &BackupManifest) -> Result<(), Error>

Writes the backup manifest to disk.

async fn update_manifest_and_cleanup( &self, filename: &str, created_at: DateTime<Utc>, migration_hash: MigrationHash, retention: usize, ) -> Result<(), Error>

Updates the manifest with a new backup entry and removes old backups.

The current version’s entry is always retained. Old backups from other versions are removed until the total count is within retention.

Trait Implementations

impl Clone for DbBackupManager

fn clone(&self) -> DbBackupManager

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.