public AHAddress NextHop(AHAddress from, SimPacket p, bool debug, out bool deliverlocally) {
Debug.WriteLineIf(debug, "src:" + p.Source + ", dest:" + p.Destination);
Debug.WriteLineIf(debug, "Dumping local connections for:" + this.LocalAddress.ToString());
foreach(AHAddress cons in _con_table.GetAllConnections()) {
Debug.WriteLineIf(debug, cons.ToString());
}
AHAddress next_node = null;
deliverlocally = false;
AHAddress dest = (AHAddress)p.Destination;
if( p.Hops > SimPacket.MAX_TTL) {
Debug.WriteLineIf(debug, "TTL exceeded.");
next_node = null;
}
else if ( LocalAddress.Equals(dest) ) {
Debug.WriteLineIf(debug, "Destination reached.");
deliverlocally = true;
next_node = null;
}
else {
/*
* else we know hops < ttl, we can route:
* We now need to check the ConnectionTable
*/
int dest_idx = _con_table.IndexOf(dest);
if( dest_idx >= 0 ) {
//We actually have a connection to this node:
next_node = _con_table.GetByIndex(dest_idx);
Debug.WriteLineIf(debug, "We actually have a connection to that node.");
} else if( _con_table.GetTotalCount() == 0) {
//We don't have any structured connections. I guess we are the closest:
Debug.WriteLineIf(debug, "No structured connections");
deliverlocally = true;
next_node = null;
}
else {
dest_idx = ~dest_idx;
/*
* Here are the right and left neighbors of the destination
* left is increasing, right is decreasing.
* Remember the ConnectionTable wraps around, so no need to worry
* about the size of index
*/
int left_idx = dest_idx;
AHAddress left_n = _con_table.GetByIndex(left_idx);
int right_idx = dest_idx - 1;
AHAddress right_n = _con_table.GetByIndex(right_idx);
//We check the a couple of connections:
BigInteger l_dist = dest.DistanceTo((AHAddress)left_n).abs();
BigInteger r_dist = dest.DistanceTo((AHAddress)right_n).abs();
AHAddress closest_node;
AHAddress other_node;
BigInteger closest_dist;
BigInteger other_dist;
if( l_dist < r_dist ) {
closest_node = left_n;
other_node = right_n;
closest_dist = l_dist;
other_dist = r_dist;
Debug.WriteLineIf(debug, "Left seems closest:" + left_n.ToString());
}
else {
closest_node = right_n;
other_node = left_n;
closest_dist = r_dist;
other_dist = l_dist;
Debug.WriteLineIf(debug, "Right seems closest:" + right_n.ToString());
}
if (p.Mode == RoutingMode.Greedy) {
Debug.WriteLineIf(debug, "Executing greedy routing mode. ");
BigInteger our_dist = dest.DistanceTo(this.LocalAddress).abs();
if( closest_dist < our_dist ) {
if( closest_node != from ) {
next_node = closest_node;
Debug.WriteLineIf(debug, "Closest distance less that our distance (valid next node).");
} else {
next_node = null;
Debug.WriteLineIf(debug, "Closest distance less that our distance. (but still setting to null)");
}
deliverlocally = false;
} else {
next_node = null;
deliverlocally = true;
Debug.WriteLineIf(debug, "Looks like we are the closest.");
}
}
else //other routing modes
{
Debug.WriteLineIf(debug, "Executing other routing modes. ");
int our_idx = _con_table.IndexOf(this.LocalAddress);
Debug.Assert(our_idx < 0,"I cannot be in my own routing table:" + our_idx);
//Compute our left neighbor.
if( our_idx < 0 ) {
our_idx = ~our_idx;
}
AHAddress our_left_n = _con_table.GetByIndex(our_idx);
if( left_n == our_left_n ) {
Debug.WriteLineIf(debug, "Common neighbor case: " + our_left_n);
/*
* We share a common left neighbor, so we should deliver locally
* This is the only case where we should deliver locally,
* otherwise there is at least one node on either side of the
* target, so one of them should probably get the packet.
*/
deliverlocally = true;
//The next step should be the node on the "other side"
if(this.LocalAddress.IsLeftOf( dest ) ) {
Debug.WriteLineIf(debug, "We are to the left. ");
next_node = right_n;
}
else {
Debug.WriteLineIf(debug, "We are to the right. ");
next_node = left_n;
}
if(from == next_node) {
//Console.WriteLine("setting next node to null");
next_node = null;
}
}
else if ( p.Hops == 0 ) {
/*
* This is the case that we sent the packet, and we are not
* a neighbor of the packet (the previous case)
* So, the closest_con must be good since we are the source
*/
Debug.WriteLineIf(debug, "0 hops, still good to go.");
next_node = closest_node;
}
else if (p.Hops <= SimPacket.MAX_UPHILL_HOPS ) {
/*
* We will allow the packet to go uphill (get further from the source)
* at first, but this has to stop in order to prevent loops
*
* This may help the network form in the massive join case, or under
* heavy churn. @todo analyze approaches for improving stabilization
* in massively disordered cases.
*/
Debug.WriteLineIf(debug, "Uphill hops. ");
if( closest_node != from ) {
//Awesome. This is an easy case...
Debug.WriteLineIf(debug, "Still good to go. ");
next_node = closest_node;
}
else {
Debug.WriteLineIf(debug, "The second closest case. ");
/*
* Look at the two next closest and choose the minimum distance of
* the three
*/
int sc_idx = -1;
if( closest_node == right_n ) {
//move one over
sc_idx = right_idx - 1;
}
else {
//Must be the left:
sc_idx = left_idx + 1;
}
AHAddress second_closest = _con_table.GetByIndex(sc_idx);
BigInteger second_dist =
dest.DistanceTo( (AHAddress)second_closest).abs();
if( second_dist < other_dist ) {
other_node = second_closest;
}
if( other_node != from ) {
//If we only have one neighbor,
//other and closest might be the same
next_node = other_node;
}
else {
//We just can't win...
//Console.WriteLine("setting next node to null (cannot win)");
next_node = null;
}
}
}
else {
Debug.WriteLineIf(debug, "Not a neighbor case, and beyond 2-hops. ");
/*
* This is the case where we are not a neighbor of the destination
* according to our table, and the packet has taken at least 2 hops.
*/
deliverlocally = false;
if( ( closest_node == from )
&& ( other_node != from ) ) {
closest_dist = other_dist;
closest_node = other_node;
}
AHAddress prev = from;
if( prev != null ) {
BigInteger prev_dist = dest.DistanceTo( (AHAddress)prev ).abs();
if( closest_dist >= prev_dist ) {
//Don't send it if you can't get it closer than it was before
next_node = null;
Debug.WriteLineIf(debug, "Prev distance smaller than closest. Stop.");
//Console.WriteLine("setting next node to null (cannot get any closer than before)");
}
else {
Debug.WriteLineIf(debug, "Prev distance larger than closest. Keep going.");
next_node = closest_node;
}
}
else {
//This is the case that we don't have a connection
//on the Edge the packet came from, this shouldn't happen,
//but it is not a disaster.
Debug.WriteLineIf(debug, "Prev distance smalled than closest. ");
next_node = closest_node;
}
}//End of non-neareast neighbor case
}//End of Annealing case
} //End of the case where we had to find a near route
}
if(p.Mode == RoutingMode.Exact) {
if(this.LocalAddress.Equals(dest) ) {
deliverlocally = true;
next_node = null;
}
else {
deliverlocally = false;
}
}
return next_node;
}
public static void DoInexactRouting() {
//
// Analyse routing for keys. (large number of keys).
//
int network_size = sorted_node_list.Count;
double greedy_inconsistent = 0;
double annealing_inconsistent = 0;
int max_destinations = 0;
Hashtable annealing_destinations = new Hashtable();
double greedy_success_hop_count = 0.0;
double greedy_fail_hop_count = 0.0;
double greedy_all_hop_count = 0.0;
double annealing_success_hop_count = 0.0;
double annealing_fail_hop_count = 0.0;
double annealing_all_hop_count = 0.0;
for (int i = 0; i < key_list.Length; i++) {
if (i%1000 == 0) {
Console.WriteLine("current greedy inconsistent: {0}", greedy_inconsistent);
Console.WriteLine("current annealing inconsistent: {0}", annealing_inconsistent);
}
AHAddress key = key_list[i];
//first determine the left and right
int left_idx = sorted_node_list.BinarySearch(key);
if (left_idx > 0) {
Console.WriteLine("astronomically improbable.");
continue;
}
left_idx = ~left_idx;
left_idx = left_idx%network_size;
int right_idx = left_idx - 1;
if (right_idx < 0) {
right_idx += network_size;
}
SimNode left = (SimNode) address_to_node[(AHAddress) sorted_node_list[left_idx]];
SimNode right = (SimNode) address_to_node[(AHAddress) sorted_node_list[right_idx]];
// source the key at different nodes in the network.
foreach (SimNode n in address_to_node.Values) {
ArrayList destinations = new ArrayList();
SimPacket p = new SimPacket(n.LocalAddress, key, RoutingMode.Greedy);
SimNode curr = n;
AHAddress prev_addr = null;
while (true) {
bool deliverlocally;
AHAddress next = curr.NextHop(prev_addr, p, out deliverlocally);
if (deliverlocally) {
destinations.Add(curr);
}
if (next == null) {
break;
}
prev_addr = curr.LocalAddress;
curr = (SimNode) address_to_node[next];
p.Hops += 1;
}
//lets see how well we did
if (destinations.Contains(left) || destinations.Contains(right)) {
//we are good.
greedy_success_hop_count += p.Hops;
} else {
greedy_inconsistent += 1;
greedy_fail_hop_count += p.Hops;
}
greedy_all_hop_count += p.Hops;
//now do annealing routing for the keys
destinations = new ArrayList();
p = new SimPacket(n.LocalAddress, key, RoutingMode.Annealing);
curr = n;
prev_addr = null;
while (true) {
bool deliverlocally;
AHAddress next = curr.NextHop(prev_addr, p, out deliverlocally);
if (deliverlocally) {
destinations.Add(curr);
}
if (next == null) {
break;
}
prev_addr = curr.LocalAddress;
curr = (SimNode) address_to_node[next];
p.Hops += 1;
}
//lets see how well we did
if (destinations.Contains(left) || destinations.Contains(right)) {
//we are good.
annealing_success_hop_count += p.Hops ;
} else {
annealing_inconsistent += 1;
annealing_fail_hop_count += p.Hops;
}
annealing_all_hop_count += p.Hops;
if (destinations.Contains(left)) {
destinations.Remove(left);
}
if (destinations.Contains(right)) {
destinations.Remove(right);
}
int x = destinations.Count;
if (annealing_destinations.Contains(x)) {
int y = (int) annealing_destinations[x];
annealing_destinations[x] = y + 1;
} else {
annealing_destinations[x] = 1;
}
if (x > max_destinations) {
max_destinations = x;
}
//Console.WriteLine("destinations.count: {0}", destinations.Count);
}
}
Console.WriteLine("total greedy inconsistent: {0}", greedy_inconsistent);
Console.WriteLine("Average (greedy) inconsistency per key: {0}", greedy_inconsistent/(1.0*key_list.Length));
Console.WriteLine("hop count (greedy, fail): {0}", greedy_fail_hop_count/greedy_inconsistent);
Console.WriteLine("hop count (greedy, success): {0}",
greedy_success_hop_count/(network_size*key_list.Length - greedy_inconsistent));
Console.WriteLine("average hop count (greedy): {0}",
greedy_all_hop_count/(network_size*key_list.Length));
Console.WriteLine("total annealing inconsistent: {0}", annealing_inconsistent);
Console.WriteLine("Average (annealing) inconsistency per key: {0}", annealing_inconsistent/(1.0*key_list.Length));
Console.WriteLine("distribution of annealing destinations");
for (int i = 0; i <= max_destinations; i++) {
Console.WriteLine("dist annealing {0} {1}", i, (int) annealing_destinations[i]);
}
Console.WriteLine("hop count (annealing, fail): {0}", annealing_fail_hop_count/annealing_inconsistent);
Console.WriteLine("hop count (annealing, success): {0}",
annealing_success_hop_count/(network_size*key_list.Length - annealing_inconsistent));
Console.WriteLine("average hop count (annealing): {0}",
annealing_all_hop_count/(network_size*key_list.Length));
}
public AHAddress NextHop(AHAddress from, SimPacket p, out bool deliverlocally) {
return NextHop(from, p, false, out deliverlocally);
}
public static void DoExactRouting() {
//
// Analyse exact (greedy, annealing) routing.
//
int network_size = sorted_node_list.Count;
Console.WriteLine("Analysing exact (greedy, annealing) routing");
int greedy_broken_routes = 0;
double greedy_success_hop_count = 0.0;
double greedy_fail_hop_count = 0.0;
double greedy_all_hop_count = 0.0;
double greedy_destinations = 0.0;
//double greedy_tunnel_hops_fail = 0.0;
//double greedy_tunnel_hops_success = 0.0;
//double greedy_tunnel_hops_all = 0.0;
double greedy_real_fail = 0.0;
double greedy_real_success = 0.0;
double greedy_real_all = 0.0;
int annealing_broken_routes = 0;
double annealing_success_hop_count = 0.0;
double annealing_fail_hop_count = 0.0;
double annealing_all_hop_count = 0.0;
double annealing_destinations = 0.0;
int annealing_sucks = 0;
foreach (SimNode n1 in address_to_node.Values) {
foreach (SimNode n2 in address_to_node.Values) {
bool greedy_success = false;
bool annealing_success = false;
ArrayList destinations = new ArrayList();
SimPacket p = new SimPacket(n1.LocalAddress, n2.LocalAddress, RoutingMode.Greedy);
SimNode curr = n1;
AHAddress prev_addr = null;
int real_hops = 0;
while (true) {
bool deliverlocally;
AHAddress next = curr.NextHop(prev_addr, p, out deliverlocally);
if (deliverlocally) {
destinations.Add(curr);
}
if (next == null) {
break;
}
if (curr.ConnectionTable.IndexOf(next) < 0) {
Console.WriteLine("Taking a wrong hop.");
}
SimNode next_node = (SimNode) address_to_node[next];
bool tunnel_hop = false;
//if this hop was over a tunnel edge.
//we can infer this from the authorizer.
if (!authorizer.Allow(curr, next_node)) {
tunnel_hop = true;
}
prev_addr = curr.LocalAddress;
curr = next_node;
p.Hops += 1;
//add another hop if it is a tunnel hop
if (tunnel_hop) {
real_hops += 2;
} else {
real_hops += 1;
}
}
greedy_destinations += destinations.Count;
if (!destinations.Contains(n2)) {
greedy_broken_routes += 1;
greedy_fail_hop_count += p.Hops;
greedy_real_fail += real_hops;
} else {
greedy_success_hop_count += p.Hops;
greedy_success = true;
greedy_real_success += real_hops;
}
greedy_all_hop_count += p.Hops;
greedy_real_all += real_hops;
//also check annealing in the same loop
destinations = new ArrayList();
p = new SimPacket(n1.LocalAddress, n2.LocalAddress, RoutingMode.Exact);
real_hops = 0;
curr = n1;
prev_addr = null;
while (true) {
bool deliverlocally;
AHAddress next = curr.NextHop(prev_addr, p, out deliverlocally);
if (deliverlocally) {
destinations.Add(curr);
}
if (next == null) {
break;
}
if (curr.ConnectionTable.IndexOf(next) < 0) {
Console.WriteLine("Taking a wrong hop.");
}
SimNode next_node = (SimNode) address_to_node[next];
bool tunnel_hop = false;
//if this hop was over a tunnel edge.
//we can infer this from the authorizer.
if (!authorizer.Allow(curr, next_node)) {
tunnel_hop = true;
}
prev_addr = curr.LocalAddress;
curr = next_node;
p.Hops += 1;
if (tunnel_hop) {
real_hops += 2;
} else {
real_hops += 1;
}
}
annealing_destinations += destinations.Count;
if (!destinations.Contains(n2)) {
annealing_broken_routes += 1;
annealing_fail_hop_count += p.Hops;
if (p.Hops >= 99) {
Console.WriteLine("ttl expired for annealing");
}
} else {
annealing_success_hop_count += p.Hops;
annealing_success = true;
//Console.WriteLine("success: {0}", p.Hops);
}
annealing_all_hop_count += p.Hops;
if (greedy_success && !annealing_success) {
Console.WriteLine("annealing sucks");
annealing_sucks += 1;
}
}
}
Console.WriteLine("broken pairs (greedy): {0}", greedy_broken_routes);
Console.WriteLine("hop count (greedy, fail): {0}", greedy_fail_hop_count/greedy_broken_routes);
Console.WriteLine("hop count (greedy, success): {0}",
greedy_success_hop_count/(network_size*network_size - greedy_broken_routes));
Console.WriteLine("average hop count (greedy): {0}",
greedy_all_hop_count/(network_size*network_size));
Console.WriteLine("real hop count (greedy, fail): {0}", greedy_real_fail/greedy_broken_routes);
Console.WriteLine("real hop count (greedy, success): {0}",
greedy_real_success/(network_size*network_size - greedy_broken_routes));
Console.WriteLine("real average hop count (greedy): {0}",
greedy_real_all/(network_size*network_size));
Console.WriteLine("destinations (greedy): {0}", greedy_destinations/(network_size*network_size));
Console.WriteLine("broken pairs (annealing): {0}", annealing_broken_routes);
Console.WriteLine("hop count (annealing, fail): {0}", annealing_fail_hop_count/annealing_broken_routes);
Console.WriteLine("hop count (annealing, success): {0}",
annealing_success_hop_count/(network_size*network_size - annealing_broken_routes));
Console.WriteLine("average hop count (annealing): {0}",
annealing_all_hop_count/(network_size*network_size));
Console.WriteLine("destinations (annealing): {0}", annealing_destinations/(network_size*network_size));
Console.WriteLine("sucks (annealing): {0}", annealing_sucks);
}