/**
* routing using A* algorithm http://en.wikipedia.org/wiki/A*_search_algorithm
*
* @param startNode
* @param endNode
* @param startTime
* @param dayIndex
* @param pathNodeList return path
* @return
*/
public static double routingAStar(
long startNode, long endNode, int startTime, int dayIndex, ArrayList<Long> pathNodeList) {
// System.out.println("start finding the path...");
int debug = 0;
double totalCost = -1;
try {
// test store transversal nodes
// HashSet<Long> transversalSet = new HashSet<Long>();
if (!OSMData.nodeHashMap.containsKey(startNode)
|| !OSMData.nodeHashMap.containsKey(endNode)) {
System.err.println("cannot find start or end node!");
return -1;
}
if (startNode == endNode) {
System.out.println("start node is the same as end node.");
return 0;
}
HashSet<Long> closedSet = new HashSet<Long>();
HashMap<Long, NodeInfoHelper> nodeHelperCache = new HashMap<Long, NodeInfoHelper>();
PriorityQueue<NodeInfoHelper> openSet =
initialStartSet(startNode, endNode, startTime, dayIndex, nodeHelperCache);
HashSet<Long> endSet = initialEndSet(endNode);
NodeInfoHelper current = null;
while (!openSet.isEmpty()) {
// remove current from openset
current = openSet.poll();
// if(!transversalSet.contains(current.getNodeId()))
// transversalSet.add(current.getNodeId());
long nodeId = current.getNodeId();
// add current to closedset
closedSet.add(nodeId);
if (endSet.contains(nodeId)) { // find the destination
current = current.getEndNodeHelper(endNode);
totalCost = current.getCost();
break;
}
// for time dependent routing
int timeIndex =
startTime
+ (int)
(current.getCost() / OSMParam.SECOND_PER_MINUTE / OSMRouteParam.TIME_INTERVAL);
if (timeIndex
> OSMRouteParam.TIME_RANGE
- 1) // time [6am - 9 pm], we regard times after 9pm as constant edge weights
timeIndex = OSMRouteParam.TIME_RANGE - 1;
LinkedList<ToNodeInfo> adjNodeList = OSMData.adjListHashMap.get(nodeId);
if (adjNodeList == null) continue; // this node cannot go anywhere
double arriveTime = current.getCost();
// for each neighbor in neighbor_nodes(current)
for (ToNodeInfo toNode : adjNodeList) {
debug++;
long toNodeId = toNode.getNodeId();
int travelTime;
if (toNode.isFix()) // fix time
travelTime = toNode.getTravelTime();
else // fetch from time array
travelTime = toNode.getSpecificTravelTime(dayIndex, timeIndex);
// tentative_g_score := g_score[current] + dist_between(current,neighbor)
double costTime = arriveTime + (double) travelTime / OSMParam.MILLI_PER_SECOND;
// tentative_f_score := tentative_g_score + heuristic_cost_estimate(neighbor, goal)
double heuristicTime = estimateHeuristic(toNodeId, endNode);
double totalCostTime = costTime + heuristicTime;
// if neighbor in closedset and tentative_f_score >= f_score[neighbor]
if (closedSet.contains(toNodeId)
&& nodeHelperCache.get(toNodeId).getTotalCost() <= totalCostTime) {
continue;
}
NodeInfoHelper node = null;
// if neighbor not in openset or tentative_f_score < f_score[neighbor]
if (!nodeHelperCache.containsKey(toNodeId)) { // neighbor not in openset
node = new NodeInfoHelper(toNodeId);
nodeHelperCache.put(node.getNodeId(), node);
} else if (nodeHelperCache.get(toNodeId).getTotalCost()
> totalCostTime) { // neighbor in openset
node = nodeHelperCache.get(toNodeId);
if (closedSet.contains(toNodeId)) { // neighbor in closeset
closedSet.remove(toNodeId); // remove neighbor form colseset
} else {
openSet.remove(node);
}
}
// neighbor need update
if (node != null) {
node.setCost(costTime);
node.setHeuristic(heuristicTime);
node.setParentId(nodeId);
openSet.offer(node); // add neighbor to openset again
}
}
}
if (totalCost != -1) {
long traceNodeId = current.getNodeId();
pathNodeList.add(traceNodeId); // add end node
traceNodeId = current.getParentId();
while (traceNodeId != 0) {
pathNodeList.add(traceNodeId); // add node
current = nodeHelperCache.get(traceNodeId);
traceNodeId = current.getParentId();
}
Collections.reverse(pathNodeList); // reverse the path list
// System.out.println("find the path successful!");
} else {
System.out.println("can not find the path!");
}
// OSMOutput.generateTransversalNodeKML(transversalSet, nodeHashMap);
} catch (Exception e) {
e.printStackTrace();
System.err.println(
"tdsp: debug code " + debug + ", start node " + startNode + ", end node " + endNode);
}
return totalCost;
}
@Override
public void run() {
// TODO Auto-generated method stub
PriorityQueue<NodeInfoHelper> openSet =
new PriorityQueue<NodeInfoHelper>(
10000,
new Comparator<NodeInfoHelper>() {
public int compare(NodeInfoHelper n1, NodeInfoHelper n2) {
return (int) (n1.getTotalCost() - n2.getTotalCost());
}
});
HashSet<Long> closedSet = new HashSet<Long>();
initialEndSet(startNode, endNode, openSet, nodeHelperCache);
NodeInfoHelper current = null;
// HashSet<Long> transversalSet = new HashSet<Long>();
while (!openSet.isEmpty()) {
// remove current from openset
current = openSet.poll();
long nodeId = current.getNodeId();
// transversalSet.add(nodeId);
// add current to closedset
closedSet.add(nodeId);
// check if forward searching finish
if (sharingData.isSearchingFinish()) break;
// add to reverse cover nodes, only add the nodes on the highway
if (current.getCurrentLevel() == 1) sharingData.addReverseNode(nodeId);
NodeInfo fromNodeInfo = OSMData.nodeHashMap.get(nodeId);
LinkedList<ToNodeInfo> adjNodeList = adjListHashMap.get(nodeId);
if (adjNodeList == null) continue; // this node cannot go anywhere
double arriveTime = current.getCost();
// for each neighbor in neighbor_nodes(current)
for (ToNodeInfo toNode : adjNodeList) {
long toNodeId = toNode.getNodeId();
NodeInfo toNodeInfo = OSMData.nodeHashMap.get(toNodeId);
EdgeInfo edgeInfo = fromNodeInfo.getEdgeFromNodes(toNodeInfo);
// check if "highway" not found in param, add it
// String highway = edgeInfo.getHighway();
int level = 10;
if (OSMData.hierarchyHashMap.containsKey(edgeInfo.getHighway()))
level = OSMData.hierarchyHashMap.get(edgeInfo.getHighway());
// 1) always level up, e.g. currently in primary, never go secondary
// if(level > current.getCurrentLevel()) { // do not level down
// continue;
// }
// 2) keep on highway
if (current.getCurrentLevel() == 1 && level > 1) {
continue;
}
int travelTime = toNode.getMinTravelTime();
// tentative_g_score := g_score[current] + dist_between(current,neighbor)
double costTime = arriveTime + (double) travelTime / OSMParam.MILLI_PER_SECOND;
// tentative_f_score := tentative_g_score + heuristic_cost_estimate(neighbor, goal)
double heuristicTime = OSMRouting.estimateHeuristic(toNodeId, endNode);
double totalCostTime = costTime + heuristicTime;
// if neighbor in closedset and tentative_f_score >= f_score[neighbor]
if (closedSet.contains(toNodeId)
&& nodeHelperCache.get(toNodeId).getTotalCost() <= totalCostTime) {
continue;
}
NodeInfoHelper node = null;
// if neighbor not in openset or tentative_f_score < f_score[neighbor]
if (!nodeHelperCache.containsKey(toNodeId)) { // neighbor not in openset
node = new NodeInfoHelper(toNodeId);
nodeHelperCache.put(node.getNodeId(), node);
} else if (nodeHelperCache.get(toNodeId).getTotalCost()
> totalCostTime) { // neighbor in openset
node = nodeHelperCache.get(toNodeId);
if (closedSet.contains(toNodeId)) { // neighbor in closeset
closedSet.remove(toNodeId); // remove neighbor form colseset
} else {
openSet.remove(node);
}
}
// neighbor need update
if (node != null) {
node.setCost(costTime);
node.setHeuristic(heuristicTime);
node.setCurrentLevel(level);
node.setParentId(nodeId);
openSet.offer(node); // add neighbor to openset again
}
}
}
// OSMOutput.generateTransversalNodeKML(transversalSet, nodeHashMap, "reverse_transversal");
}
// TODO : if start or end is already in the highway, will occur the problem, need to fix
public static double routingHierarchy(
long startNode, long endNode, int startTime, int dayIndex, ArrayList<Long> pathNodeList) {
// System.out.println("start finding the path...");
int debug = 0;
try {
if (!OSMData.nodeHashMap.containsKey(startNode)
|| !OSMData.nodeHashMap.containsKey(endNode)) {
System.err.println("cannot find start or end node!");
return -1;
}
if (startNode == endNode) {
System.out.println("start node is the same as end node.");
return 0;
}
NodeInfo start = OSMData.nodeHashMap.get(startNode);
NodeInfo end = OSMData.nodeHashMap.get(endNode);
double minDistance = Geometry.calculateDistance(start.getLocation(), end.getLocation());
if (minDistance < 5) { // use normal A* algorithm to calculate small distance
return routingAStar(
start.getNodeId(),
end.getNodeId(),
OSMRouteParam.START_TIME,
OSMRouteParam.DAY_INDEX,
pathNodeList);
}
SearchingSharing sharingData = new SearchingSharing();
HashMap<Long, NodeInfoHelper> nodeForwardCache = new HashMap<Long, NodeInfoHelper>();
HashMap<Long, NodeInfoHelper> nodeReverseCache = new HashMap<Long, NodeInfoHelper>();
ForwardSearching forwardSearching =
new ForwardSearching(
startNode, endNode, startTime, dayIndex, sharingData, nodeForwardCache);
ReverseSearching reverseSearching =
new ReverseSearching(endNode, startNode, sharingData, nodeReverseCache);
// two thread run simultaneously
Thread forwardThread = new Thread(forwardSearching);
Thread reverseThread = new Thread(reverseSearching);
// search forward
forwardThread.start();
// let forward searching for a while
// Thread.sleep(100);
// search reverse
reverseThread.start();
// waiting for thread finish
forwardThread.join();
reverseThread.join();
// get the searching intersects
ArrayList<Long> intersectList = sharingData.getIntersectList();
// pick the least cost one according to time-dependent
double minCost = Double.MAX_VALUE;
ArrayList<Long> minCostPath = new ArrayList<Long>();
for (long intersect : intersectList) {
NodeInfoHelper current = nodeForwardCache.get(intersect);
// cost from source to intersect
double cost = current.getCost();
current = nodeReverseCache.get(intersect);
// update the reverse cost as forward cost
current.setCost(cost);
ArrayList<Long> reversePath = new ArrayList<Long>();
double totalCost = Double.MAX_VALUE;
// recalculate from intersect to destination
while (true) {
long nodeId = current.getNodeId();
int timeIndex =
startTime
+ (int)
(current.getCost()
/ OSMParam.SECOND_PER_MINUTE
/ OSMRouteParam.TIME_INTERVAL);
if (timeIndex
> OSMRouteParam.TIME_RANGE
- 1) // time [6am - 9 pm], we regard times after 9pm as constant edge weights
timeIndex = OSMRouteParam.TIME_RANGE - 1;
long nextNodeId = current.getParentId();
double arriveTime = current.getCost();
// arrive end
if (nextNodeId == 0) {
totalCost = arriveTime;
break;
}
// add node
reversePath.add(nextNodeId);
// calculate cost according adjlist
LinkedList<ToNodeInfo> adjNodeList = OSMData.adjListHashMap.get(nodeId);
double costTime = 0;
for (ToNodeInfo toNode : adjNodeList) {
if (toNode.getNodeId() == nextNodeId) {
int travelTime;
// forward searching is time dependent
if (toNode.isFix()) // fix time
travelTime = toNode.getTravelTime();
else // fetch from time array
travelTime = toNode.getSpecificTravelTime(dayIndex, timeIndex);
costTime = arriveTime + (double) travelTime / OSMParam.MILLI_PER_SECOND;
break;
}
}
current = nodeReverseCache.get(nextNodeId);
if (costTime == 0) System.err.println("cost time cannot be zero!");
else current.setCost(costTime);
}
// process the left nodes to real destination
long lastNode = reversePath.get(reversePath.size() - 1);
if (lastNode != endNode) {
NodeInfo last = OSMData.nodeHashMap.get(lastNode);
NodeInfo dest = OSMData.nodeHashMap.get(endNode);
EdgeInfo onEdge = last.getEdgeFromNodes(dest);
current = nodeReverseCache.get(lastNode);
int totalDistance = onEdge.getDistance();
int distance;
long toNodeId;
if (onEdge.getStartNode() == lastNode) { // from start to middle
distance = onEdge.getStartDistance(endNode);
toNodeId = onEdge.getEndNode();
} else { // from end to middle
distance = onEdge.getEndDistance(endNode);
toNodeId = onEdge.getStartNode();
}
LinkedList<ToNodeInfo> adjNodeList = OSMData.adjListHashMap.get(lastNode);
double costTime = 0;
int timeIndex =
startTime
+ (int) (totalCost / OSMParam.SECOND_PER_MINUTE / OSMRouteParam.TIME_INTERVAL);
if (timeIndex
> OSMRouteParam.TIME_RANGE
- 1) // time [6am - 9 pm], we regard times after 9pm as constant edge weights
timeIndex = OSMRouteParam.TIME_RANGE - 1;
for (ToNodeInfo toNode : adjNodeList) {
if (toNode.getNodeId() == toNodeId) {
int travelTime;
// forward searching is time dependent
if (toNode.isFix()) // fix time
travelTime = toNode.getTravelTime();
else // fetch from time array
travelTime = toNode.getSpecificTravelTime(dayIndex, timeIndex);
costTime = (double) travelTime / OSMParam.MILLI_PER_SECOND;
break;
}
}
if (costTime != 0) {
costTime *= (double) distance / totalDistance;
}
totalCost += costTime; // add cost
reversePath.add(endNode); // add dest
}
// if found less cost path, build forward path
if (totalCost < minCost) {
ArrayList<Long> forwardPath = new ArrayList<Long>();
minCost = totalCost;
current = nodeForwardCache.get(intersect);
long traceNodeId = current.getParentId();
while (traceNodeId != 0) {
forwardPath.add(traceNodeId); // add node
current = nodeForwardCache.get(traceNodeId);
traceNodeId = current.getParentId();
}
Collections.reverse(forwardPath); // reverse the path list
// record min-cost path, combine forward path and reverse path
minCostPath = new ArrayList<Long>();
minCostPath.addAll(forwardPath);
minCostPath.add(intersect);
minCostPath.addAll(reversePath);
// output kml
// OSMOutput.generatePathKML(nodeHashMap, pathNodeList, "path_" + intersect);
// ArrayList<Long> intersectNode = new ArrayList<Long>();
// intersectNode.add(intersect);
// OSMOutput.generatePathNodeKML(nodeHashMap, intersectNode, "intersect_" + intersect);
}
}
pathNodeList.addAll(minCostPath);
return minCost;
} catch (Exception e) {
e.printStackTrace();
System.err.println("routingHierarchy: debug code " + debug);
}
return 0;
}
@Override
public void run() {
HashSet<Long> closedSet = new HashSet<Long>();
PriorityQueue<NodeInfoHelper> openSet =
OSMRouting.initialStartSet(startNode, endNode, startTime, dayIndex, nodeHelperCache);
NodeInfoHelper current = null;
// test
// HashSet<Long> transversalSet = new HashSet<Long>();
while (!openSet.isEmpty()) {
// remove current from openset
current = openSet.poll();
long nodeId = current.getNodeId();
// transversalSet.add(nodeId);
// add current to closedset
closedSet.add(nodeId);
// check reverse searching covering nodes
if (sharingData.isNodeInReverseSet(nodeId)) {
// we found a path, stop here
sharingData.addIntersect(nodeId);
if (sharingData.isSearchingFinish()) break;
else continue;
}
NodeInfo fromNodeInfo = OSMData.nodeHashMap.get(nodeId);
// for time dependent routing in forwarding search
int timeIndex =
startTime
+ (int)
(current.getCost() / OSMParam.SECOND_PER_MINUTE / OSMRouteParam.TIME_INTERVAL);
if (timeIndex
> OSMRouteParam.TIME_RANGE
- 1) // time [6am - 9 pm], we regard times after 9pm as constant edge weights
timeIndex = OSMRouteParam.TIME_RANGE - 1;
LinkedList<ToNodeInfo> adjNodeList = adjListHashMap.get(nodeId);
if (adjNodeList == null) continue; // this node cannot go anywhere
double arriveTime = current.getCost();
// for each neighbor in neighbor_nodes(current)
for (ToNodeInfo toNode : adjNodeList) {
long toNodeId = toNode.getNodeId();
NodeInfo toNodeInfo = OSMData.nodeHashMap.get(toNodeId);
EdgeInfo edgeInfo = fromNodeInfo.getEdgeFromNodes(toNodeInfo);
// check if "highway" not found in param, add it
// String highway = edgeInfo.getHighway();
int level = 10;
if (OSMData.hierarchyHashMap.containsKey(edgeInfo.getHighway()))
level = OSMData.hierarchyHashMap.get(edgeInfo.getHighway());
// 1) always level up, e.g. currently in primary, never go secondary
// if(level > current.getCurrentLevel()) { // do not level down
// continue;
// }
// 2) keep on highway
if (current.getCurrentLevel() == 1 && level > 1) {
continue;
}
int travelTime;
// forward searching is time dependent
if (toNode.isFix()) // fix time
travelTime = toNode.getTravelTime();
else // fetch from time array
travelTime = toNode.getSpecificTravelTime(dayIndex, timeIndex);
// tentative_g_score := g_score[current] + dist_between(current,neighbor)
double costTime = arriveTime + (double) travelTime / OSMParam.MILLI_PER_SECOND;
// tentative_f_score := tentative_g_score + heuristic_cost_estimate(neighbor, goal)
double heuristicTime = OSMRouting.estimateHeuristic(toNodeId, endNode);
double totalCostTime = costTime + heuristicTime;
// if neighbor in closedset and tentative_f_score >= f_score[neighbor]
if (closedSet.contains(toNodeId)
&& nodeHelperCache.get(toNodeId).getTotalCost() <= totalCostTime) {
continue;
}
NodeInfoHelper node = null;
// if neighbor not in openset or tentative_f_score < f_score[neighbor]
if (!nodeHelperCache.containsKey(toNodeId)) { // neighbor not in openset
node = new NodeInfoHelper(toNodeId);
nodeHelperCache.put(node.getNodeId(), node);
} else if (nodeHelperCache.get(toNodeId).getTotalCost()
> totalCostTime) { // neighbor in openset
node = nodeHelperCache.get(toNodeId);
if (closedSet.contains(toNodeId)) { // neighbor in closeset
closedSet.remove(toNodeId); // remove neighbor form colseset
} else {
openSet.remove(node);
}
}
// neighbor need update
if (node != null) {
node.setCost(costTime);
node.setHeuristic(heuristicTime);
node.setCurrentLevel(level);
node.setParentId(nodeId);
openSet.offer(node); // add neighbor to openset again
}
}
}
// test
// OSMOutput.generateTransversalNodeKML(transversalSet, "forward_transversal");
}