Method open

nodedb-wal/src/segmented.rs:101–134

Open or create a segmented WAL in the given directory. On first startup, creates the directory and the first segment. On subsequent startups, discovers existing segments and opens the last one for continued appending.

(config: SegmentedWalConfig)

    /// On subsequent startups, discovers existing segments and opens the
    /// last one for continued appending.
    pub fn open(config: SegmentedWalConfig) -> Result<Self> {
        fs::create_dir_all(&config.wal_dir).map_err(WalError::Io)?;

        let segments = discover_segments(&config.wal_dir)?;

        let (writer, active_first_lsn) = if segments.is_empty() {
            // Fresh WAL — create the first segment starting at LSN 1.
            let path = segment_path(&config.wal_dir, 1);
            let writer = WalWriter::open(&path, config.writer_config.clone())?;
            (writer, 1u64)
        } else {
            // Resume from the last segment.
            let last = &segments[segments.len() - 1];
            let writer = WalWriter::open(&last.path, config.writer_config.clone())?;
            (writer, last.first_lsn)
        };

        info!(
            wal_dir = %config.wal_dir.display(),
            segments = segments.len().max(1),
            active_first_lsn,
            next_lsn = writer.next_lsn(),
            "segmented WAL opened"
        );

        Ok(Self {
            wal_dir: config.wal_dir,
            writer,
            active_first_lsn,
            segment_target_size: config.segment_target_size,
            writer_config: config.writer_config,
            encryption_ring: None,
        })
    }

    /// Set the encryption key ring. All subsequent records will be encrypted.
    ///