Function read_turn

atomic-agent/src/transcript/opencode.rs:113–159

Read the current turn's data for `session_id` from OpenCode's store. Returns `None` when the database is missing or unreadable, the session is unknown, or the session belongs to a different directory than `expected_dir` (a guard against reading an unrelated project's session with a colliding ID).

(session_id: &str, expected_dir: &Path)

/// `expected_dir` (a guard against reading an unrelated project's session
/// with a colliding ID).
pub(crate) fn read_turn(session_id: &str, expected_dir: &Path) -> Option<TurnData> {
    let db_path = locate_db()?;

    let conn = match Connection::open_with_flags(
        &db_path,
        OpenFlags::SQLITE_OPEN_READ_ONLY | OpenFlags::SQLITE_OPEN_NO_MUTEX,
    ) {
        Ok(c) => c,
        Err(e) => {
            log::debug!("opencode store: cannot open {}: {}", db_path.display(), e);
            return None;
        }
    };
    let _ = conn.busy_timeout(std::time::Duration::from_millis(DB_BUSY_TIMEOUT_MS));

    // The session row carries the project directory; refuse to read a
    // session that belongs to a different checkout.
    let directory: String = match conn.query_row(
        "SELECT directory FROM session WHERE id = ?1",
        [session_id],
        |row| row.get(0),
    ) {
        Ok(d) => d,
        Err(e) => {
            log::debug!(
                "opencode store: session {} not found in {}: {}",
                session_id,
                db_path.display(),
                e
            );
            return None;
        }
    };
    if !same_dir(Path::new(&directory), expected_dir) {
        log::warn!(
            "opencode store: session {} belongs to '{}', not '{}' — skipping",
            session_id,
            directory,
            expected_dir.display()
        );
        return None;
    }

    let messages = read_messages(&conn, session_id)?;
    let parts = read_parts(&conn, session_id)?;
    Some(assemble(&messages, &parts))
}

/// Compare two directories, canonicalizing when possible.
fn same_dir(a: &Path, b: &Path) -> bool {