Function loadExistingRecordStates

packages/core/src/sync/simple-sync.ts:496–557

(
  db: Awaited<ReturnType<typeof getDB>>,
  tableName: string,
  pk: string,
  timestampCol: string,
  ids: unknown[],
)

}

async function loadExistingRecordStates(
  db: Awaited<ReturnType<typeof getDB>>,
  tableName: string,
  pk: string,
  timestampCol: string,
  ids: unknown[],
): Promise<Map<string, ExistingRecordState>> {
  const states = new Map<string, ExistingRecordState>();
  if (ids.length === 0) return states;

  const columns = await getTableColumns(db, tableName);
  const deletedAtSelect = columns.has("deleted_at") ? ", deleted_at AS deleted_at" : "";

  const chunkSize = 200;
  for (let offset = 0; offset < ids.length; offset += chunkSize) {
    const chunk = ids.slice(offset, offset + chunkSize);
    const placeholders = chunk.map(() => "?").join(", ");
    const rows = await db.select<{
      id: string;
      timestamp: number | null;
      deleted_at?: number | null;
    }>(
      `SELECT ${pk} AS id, ${timestampCol} AS timestamp${deletedAtSelect} FROM ${tableName} WHERE ${pk} IN (${placeholders})`,
      chunk,
    );

    for (const row of rows) {
      states.set(String(row.id), {
        timestamp: row.timestamp ?? 0,
        deletedAt: normalizeDeletedAt(row.deleted_at),
      });
    }
  }

  try {
    for (let offset = 0; offset < ids.length; offset += chunkSize) {
      const chunk = ids.slice(offset, offset + chunkSize);
      const placeholders = chunk.map(() => "?").join(", ");
      const tombstones = await db.select<{ id: string; deleted_at: number }>(
        `SELECT id, deleted_at
         FROM sync_tombstones
         WHERE table_name = ?
           AND id IN (${placeholders})`,
        [tableName, ...chunk],
      );
      for (const tombstone of tombstones) {
        const id = String(tombstone.id);
        const deletedAt = tombstone.deleted_at ?? 0;
        const existing = states.get(id);
        if (!existing || deletedAt > existing.timestamp) {
          states.set(id, {
            timestamp: deletedAt,
          });
        }
      }
    }
  } catch {
    // sync_tombstones may not exist on older schema variants.