Function findSessionDir

apps/vis/server/src/lib/session-store.ts:303–331

(home: string, sessionId: string)

}

async function findSessionDir(home: string, sessionId: string): Promise<string | null> {
  if (!SESSION_ID_RE.test(sessionId)) return null;
  const sessionsRoot = resolve(join(home, 'sessions'));
  const sessionsRootPrefix = sessionsRoot + sep;
  // Try index first — but only trust entries that point *under*
  // `<home>/sessions/` AND whose basename matches the requested id.
  // This blocks stale/poisoned index lines from redirecting reads to
  // unrelated directories.
  try {
    const indexLines = (await readFile(join(home, 'session_index.jsonl'), 'utf8')).split(/\r?\n/);
    for (const line of indexLines) {
      if (!line.trim()) continue;
      const entry = JSON.parse(line) as { sessionId?: string; sessionDir?: string };
      if (entry.sessionId !== sessionId || typeof entry.sessionDir !== 'string') continue;
      const candidate = resolve(entry.sessionDir);
      if (!candidate.startsWith(sessionsRootPrefix)) continue;
      if (candidate.split(sep).pop() !== sessionId) continue;
      if (await pathExists(candidate)) return candidate;
    }
  } catch { /* no index */ }
  // Fall back to scanning buckets
  const buckets = await readdir(sessionsRoot, { withFileTypes: true }).catch(() => []);
  for (const bucket of buckets) {
    if (!bucket.isDirectory()) continue;
    const candidate = join(sessionsRoot, bucket.name, sessionId);
    if (await pathExists(candidate)) return candidate;
  }
  return null;
}

async function scanWire(path: string): Promise<{ count: number; protocolVersion: string }> {
  const stream = createReadStream(path, { encoding: 'utf8' });