write method Null safety

Future<TransactionModel> write(
  1. Uint8List contents
)

Creates a TransactionModel with the contents and save to local database.

When a TransactionModel is created it is not added to the next block immediately. It needs to wait until the _blockTimer runs again to check if the oldest transaction was created more than _blockInterval duration or if there are more than _maxTransactions waiting to be added to a BlockModel.

Implementation

Future<TransactionModel> write(Uint8List contents) async {
  TransactionModel transaction =
      _transactionService.create(contents, _primaryKey);
  List<TransactionModel> transactions = _transactionService.getPending();
  if (transactions.length >= _maxTransactions) {
    await _createBlock(transactions);
  }
  return transaction;
}