void write_vtk_file(const Domain<lattice_model>& domain, const std::string& output_dir,
const std::string& output_filename, uint64_t t)
{
const auto xl = domain.xlength();
const auto yl = domain.ylength();
const auto zl = domain.zlength();
// Compute point coordinates
auto points = vtkSmartPointer<vtkPoints>::New();
compute_coordinates(domain, points);
// Compute velocity and density vectors
auto velocities = vtkSmartPointer<vtkDoubleArray>::New();
auto densities = vtkSmartPointer<vtkDoubleArray>::New();
velocities->SetNumberOfComponents(lattice_model::D);
densities->SetNumberOfComponents(1);
velocities->SetName("Velocity");
densities->SetName("Density");
for (auto z = 1u; z < zl + 1; ++z) {
for (auto y = 1u; y < yl + 1; ++y) {
for (auto x = 1u; x < xl + 1; ++x) {
auto current_cell = domain.cell(x, y, z);
auto density = current_cell.density();
auto vel = current_cell.velocity(density);
densities->InsertNextTuple1(density);
velocities->InsertNextTuple3(vel[0], vel[1], vel[2]);
}
}
}
// Create a grid and write coordinates and velocity/density
auto structuredGrid = vtkSmartPointer<vtkStructuredGrid>::New();
structuredGrid->SetDimensions(xl, yl, zl);
structuredGrid->SetPoints(points);
structuredGrid->GetPointData()->SetVectors(velocities);
structuredGrid->GetPointData()->SetScalars(densities);
// Save filename as a combination of passed filename and timestep
std::stringstream sstr;
sstr << output_dir << "/" << output_filename << "." << t << ".vts";
// Write file
auto writer = vtkSmartPointer<vtkXMLStructuredGridWriter>::New();
writer->SetFileName(sstr.str().c_str());
writer->SetInput(structuredGrid);
writer->Write();
}
/* To determine the coordinates of the local node initially
* Ping a subset of nodes and determine coordinates */
void init_coordinates(I3ServerList *list)
{
int n = MIN(NUM_LANDMARKS_COORDINATE, list->num_newservers + list->num_ping_list);
I3ServerListNode *node = list->list, *temp_node;
uint64_t start_time = wall_time();
Coordinates_RTT coord_rtt[NUM_LANDMARKS_COORDINATE];
int num_landmarks = 0; int started_full_list = 0;
struct in_addr ia;
nw_skt_t tmp_ping_sock;
#ifdef ICMP_PING
if (init_icmp_socket(&tmp_ping_sock) == -1)
abort();
#else
if (init_udp_socket(&tmp_ping_sock) == -1)
abort();
#endif
// wait for responses and accumulate
// cut and pasted from below
while ((wall_time() - start_time < COORD_INIT_PING_WAIT_TIME) &&
(num_landmarks < n)) {
fd_set rset;
struct timeval to;
int ret;
FD_ZERO(&rset);
if (!node && !started_full_list) {
node = list-> full_list;
started_full_list = 1;
}
if (node) {
ia.s_addr = htonl(node->addr);
I3_PRINT_DEBUG1(I3_DEBUG_LEVEL_VERBOSE,
"Sending ICMP echo request to %s\n", inet_ntoa(ia));
#ifdef ICMP_PING
send_echo_request(tmp_ping_sock, node->addr, 0);
#else
i3_echo_request(tmp_ping_sock, node->addr, node->port, 0);
#endif
node = node->next_list;
}
FD_SET(tmp_ping_sock, &rset);
to.tv_sec = 0; to.tv_usec = 200000ULL;
if ((ret = select(tmp_ping_sock+1, &rset, NULL, NULL, &to)) < 0) {
int err = nw_error();
if (err == EINTR)
continue;
else {
perror("select");
abort();
}
}
// message received on icmp socket
if (FD_ISSET(tmp_ping_sock, &rset)) {
uint32_t addr; uint16_t port, seq; uint64_t rtt;
#ifdef ICMP_PING
if (recv_echo_reply(tmp_ping_sock, &addr, &seq, &rtt)) {
#else
if (recv_i3_echo_reply(tmp_ping_sock, &addr, &port, &seq, &rtt)) {
#endif
temp_node = lookup_i3server(list, addr);
assert(NULL != temp_node);
coord_rtt[num_landmarks].coord = temp_node->coord;
coord_rtt[num_landmarks].rtt = rtt;
num_landmarks++;
ia.s_addr = htonl(addr);
I3_PRINT_DEBUG4(I3_DEBUG_LEVEL_VERBOSE,
"Node: %s Coordinate: %.1f:%.1f RTT: %Ld\n",
inet_ntoa(ia), temp_node->coord.latitude,
temp_node->coord.longitude, rtt);
}
}
}
nw_close(tmp_ping_sock);
// compute own coordinate
compute_coordinates(num_landmarks, coord_rtt);
}
/* Update the coordinates of a node using ping information */
void update_coordinate(I3ServerList *list, I3ServerListNode *next_to_ping)
{
Coordinates_RTT coord_rtt[NUM_LANDMARKS_COORDINATE];
int count, num_landmarks = 0;
I3ServerListNode *node;
// n1 and n2: number of landmarks from ping_list and rest in
// proportion to the number of nodes in those lists
int i, n = MIN(NUM_LANDMARKS_COORDINATE,
list->num_newservers + list->num_ping_list);
int n1 = ((float)list->num_ping_list/
(list->num_newservers + list->num_ping_list)) * n;
int n2 = n-n1;
// add from ping list
count = 0;
for (i = 0, node = list->list;
i < list->num_ping_list, count < n1;
node = node->next_list, ++i) {
if (node->n > 0) {
coord_rtt[count].rtt = get_rtt_node(node);
coord_rtt[count].coord = node->coord;
count++;
}
}
num_landmarks = count;
// add from rest
count = 0;
for (i = 0, node = list->full_list;
i < list->num_newservers, count < n2;
node = node->next_list, ++i) {
if (node->n > 0) {
coord_rtt[num_landmarks + count].rtt = get_rtt_node(node);
coord_rtt[num_landmarks + count].coord = node->coord;
count++;
}
}
num_landmarks += count;
// recompute coordinates
compute_coordinates(num_landmarks, coord_rtt);
// repopulate ping list afresh
change_ping_list(list, &next_to_ping, 1);
}
