getDocument function

Implementation

Future<Map<String, Object?>?> getDocument(String path) {
  final completer = Completer<Map<String, Object?>?>();
  final receive = RawReceivePort();
  receive.handler = (Object? message) {
    receive.close();
    final bytes = message! as Uint8List;
    final header = ByteData.sublistView(bytes);
    final seq = header.getInt64(8, Endian.host);
    if (seq < 0) {
      completer.completeError(
        FirestoreException(
          seq.toInt(),
          seq == -2
              ? 'the document exists but could not be encoded'
              : 'read failed',
          'get $path',
        ),
      );
      return;
    }
    completer.complete(decodeDocument(bytes));
  };
  final p = path.toNativeUtf8();
  final rc = fdbFsGet(p.cast(), receive.sendPort.nativePort);
  calloc.free(p);
  if (rc != 0) {
    receive.close();
    return Future.error(StateError('get $path failed to start ($rc)'));
  }
  return completer.future;
}