Add check if connected and remove block list and removing of old data.

app/src/DnaStore.cpp

@@ -161,6 +161,20 @@ void DnaStore::sync()
   t.detach();
 }
 
+bool DnaStore::ping(){
+  int sock = TcpSocket::connectt(HOST_NAME, keyPort);
+  if (sock < 0)
+  {
+    return false;
+  }
+
+  int64_t header = 0;
+  TcpSocket::recvt(sock, &header, sizeof(header));
+  TcpSocket::closet(sock);
+
+  return header == StartHeader;
+}
+
 void client(std::string_view prefix)
 {
   constexpr int extra_buff = 22; // len of 2**31 -> 2147483648 plus the pattern size