/**
* Requires vn to point to a relation element. From there it iterates over all matches of the ap.
* Puts an empty list for each referenced way.
*/
private List<Tuple2<WayRole, Long>> extractWayRefs(VTDNav vn, Hashtable<Long, List<Long>> ways)
throws NavException, XPathEvalException {
vn.push();
List<Tuple2<WayRole, Long>> refs = new ArrayList<>();
for (int j = MEMBER_WAY_PATH.evalXPath(); j != -1; j = MEMBER_WAY_PATH.evalXPath()) {
long ref = Long.parseLong(vn.toString(vn.getAttrVal("ref")));
String roleAsString = vn.toString(vn.getAttrVal("role")).toLowerCase();
WayRole role;
switch (roleAsString) {
case "inner":
role = WayRole.INNER;
break;
case "outer":
role = WayRole.OUTER;
break;
default:
continue;
}
refs.add(Tuple.tuple(role, ref));
ways.put(ref, Collections.emptyList());
}
MEMBER_WAY_PATH.resetXPath();
vn.pop();
return refs;
}
private void extractReferencedWays(
VTDNav vn, Hashtable<Long, List<Long>> ways, Hashtable<Long, Point2D> nodes)
throws XPathEvalException, NavException {
vn.push();
for (int i = WAY_PATH.evalXPath(); i != -1; i = WAY_PATH.evalXPath()) {
long id = Long.parseLong(vn.toString(vn.getAttrVal("id")));
// By checking that we already referenced the id we can reduce memory pressure
if (ways.containsKey(id)) {
ways.put(id, extractNodeRefs(vn, nodes));
}
}
vn.pop();
}
/**
* Requires vn to point to a way element. From there it iterates over all matches of the ap. Puts
* a dummy point into nodes for every node it finds.
*/
private List<Long> extractNodeRefs(VTDNav vn, Hashtable<Long, Point2D> nodes)
throws NavException, XPathEvalException {
vn.push();
List<Long> refs = new ArrayList<>();
for (int j = NODE_REF_PATH.evalXPath(); j != -1; j = NODE_REF_PATH.evalXPath()) {
long ref = Long.parseLong(vn.toString(j + 1));
refs.add(ref);
nodes.put(ref, new Point2D(0, 0));
}
NODE_REF_PATH.resetXPath();
vn.pop();
return refs;
}
private List<List<Long>> extractWaysOfBuildings(VTDNav vn, Hashtable<Long, Point2D> nodes)
throws XPathEvalException, NavException {
vn.push();
List<List<Long>> ways = new ArrayList<>();
for (int i = BUILDING_WAY_PATH.evalXPath(); i != -1; i = BUILDING_WAY_PATH.evalXPath()) {
// The lambda will put in a dummy value for each encountered node,
// so that we know later which nodes we need to parse.
ways.add(extractNodeRefs(vn, nodes));
}
vn.pop();
BUILDING_WAY_PATH.resetXPath();
return ways;
}
private List<List<Tuple2<WayRole, Long>>> extractWayRefsOfMultipolygons(
VTDNav vn, Hashtable<Long, List<Long>> ways) throws NavException, XPathEvalException {
vn.push();
List<List<Tuple2<WayRole, Long>>> multipolygons = new ArrayList<>();
for (int i = BUILDING_MULTIPOLYGON_PATH.evalXPath();
i != -1;
i = BUILDING_MULTIPOLYGON_PATH.evalXPath()) {
// For an explanation for the lambda see extractWaysOfBuildings
multipolygons.add(extractWayRefs(vn, ways));
}
vn.pop();
BUILDING_WAY_PATH.resetXPath();
return multipolygons;
}
private void extractReferencedNodes(VTDNav vn, Hashtable<Long, Point2D> nodes)
throws XPathEvalException, NavException {
vn.push();
for (int i = NODE_PATH.evalXPath(); i != -1; i = NODE_PATH.evalXPath()) {
long id = Long.parseLong(vn.toString(vn.getAttrVal("id")));
// By checking that we already referenced the id we can reduce memory pressure
if (nodes.containsKey(id)) {
nodes.put(
id,
new Point2D(
Double.parseDouble(vn.toString(vn.getAttrVal("lon"))) * (1 << 10),
Double.parseDouble(vn.toString(vn.getAttrVal("lat"))) * (1 << 10)));
}
}
// Make sure we have all referenced nodes extracted
// assert !nodes.containsValue(DUMMY_POINT);
vn.pop();
}