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src/huskymaps: Location -> Spatial4J Point
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@kevinlin1
kevinlin1 committed Oct 17, 2022
1 parent b5d4881 commit e5ee258
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Showing 3 changed files with 74 additions and 215 deletions.
160 changes: 0 additions & 160 deletions src/huskymaps/Location.java
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90 changes: 44 additions & 46 deletions src/huskymaps/MapGraph.java
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Original file line number Diff line number Diff line change
Expand Up @@ -4,6 +4,8 @@
import autocomplete.TreeSetAutocomplete;
import graphs.AStarGraph;
import graphs.Edge;
import org.locationtech.spatial4j.context.SpatialContext;
import org.locationtech.spatial4j.shape.Point;
import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;
Expand All @@ -19,18 +21,17 @@
import java.util.zip.GZIPInputStream;

/**
* {@link AStarGraph} of places as {@link Location} vertices and streets edges weighted by physical distance. Estimated
* distance is defined by {@link Location#distance(Location)}.
* {@link AStarGraph} of places as {@link Point} vertices and streets edges weighted by physical distance.
*
* @see AStarGraph
* @see Location
* @see MapServer
*/
public class MapGraph implements AStarGraph<Location> {
public class MapGraph implements AStarGraph<Point> {
private final String osmPath;
private final String placesPath;
private final Map<Location, Set<Edge<Location>>> neighbors;
private final Map<String, List<Location>> locations;
private final SpatialContext context;
private final Map<Point, Set<Edge<Point>>> neighbors;
private final Map<String, List<Point>> locations;
private final Autocomplete autocomplete;
private final Map<CharSequence, Integer> importance;

Expand All @@ -43,10 +44,11 @@ public class MapGraph implements AStarGraph<Location> {
* @throws SAXException for SAX errors.
* @throws IOException if a file is not found or if the file is not gzipped.
*/
public MapGraph(String osmPath, Collection<String> allowedHighwayTypes, String placesPath)
public MapGraph(String osmPath, Collection<String> allowedHighwayTypes, String placesPath, SpatialContext context)
throws ParserConfigurationException, SAXException, IOException {
this.osmPath = osmPath;
this.placesPath = placesPath;
this.context = context;

// Parse the OpenStreetMap (OSM) data using the SAXParser XML tree walker.
neighbors = new HashMap<>();
Expand All @@ -55,7 +57,7 @@ public MapGraph(String osmPath, Collection<String> allowedHighwayTypes, String p
saxParser.parse(new GZIPInputStream(fileStream(osmPath)), handler);

// Add reachable locations to the Autocomplete engine.
locations = handler.locations();
locations = handler.byName;
autocomplete = new TreeSetAutocomplete();
autocomplete.addAll(locations.keySet());

Expand Down Expand Up @@ -89,8 +91,10 @@ private static InputStream fileStream(String path) throws FileNotFoundException
* @param target the target location.
* @return the id of the location closest to the target.
*/
public Location closest(Location target) {
return Collections.min(neighbors.keySet(), Comparator.comparingDouble(target::distance));
public Point closest(Point target) {
return Collections.min(neighbors.keySet(), Comparator.comparingDouble(
location -> context.calcDistance(target, location)
));
}

/**
Expand All @@ -111,23 +115,23 @@ public List<CharSequence> getLocationsByPrefix(String prefix) {
* @param locationName a full name of a valid location.
* @return a list of locations whose name matches the location name.
*/
public List<Location> getLocations(String locationName, Location center) {
public List<Point> getLocations(String locationName, Point center) {
if (locationName == null || !locations.containsKey(locationName)) {
return List.of();
}
List<Location> result = new ArrayList<>(locations.get(locationName));
result.sort(Comparator.comparingDouble(center::distance));
List<Point> result = new ArrayList<>(locations.get(locationName));
result.sort(Comparator.comparingDouble(location -> context.calcDistance(center, location)));
return result;
}

@Override
public List<Edge<Location>> neighbors(Location v) {
public List<Edge<Point>> neighbors(Point v) {
return new ArrayList<>(neighbors.getOrDefault(v, Set.of()));
}

@Override
public double estimatedDistance(Location start, Location end) {
return start.distance(end);
public double estimatedDistance(Point start, Point end) {
return context.calcDistance(start, end);
}

@Override
Expand All @@ -141,53 +145,43 @@ public String toString() {
/**
* Adds an edge to this graph if it doesn't already exist, using distance as the weight.
*/
private void addEdge(Location from, Location to) {
private void addEdge(Point from, Point to) {
if (!neighbors.containsKey(from)) {
neighbors.put(from, new HashSet<>());
}
neighbors.get(from).add(new Edge<>(from, to, from.distance(to)));
neighbors.get(from).add(new Edge<>(from, to, estimatedDistance(from, to)));
}

/**
* Parses OSM XML files to construct a StreetMapGraph.
*/
private class Handler extends DefaultHandler {
private final Collection<String> allowedHighwayTypes;
private final Map<Long, Location> nodes;
private final Map<Long, Point> byId;
private final Map<String, List<Point>> byName;
private String state;
private long id;
private String name;
private boolean validWay;
private Location.Builder builder;
private Queue<Location> path;
private Point location;
private Queue<Point> path;

Handler(Collection<String> allowedHighwayTypes) {
this.allowedHighwayTypes = allowedHighwayTypes;
this.nodes = new HashMap<>();
this.byId = new HashMap<>();
this.byName = new HashMap<>();
reset();
}

Map<String, List<Location>> locations() {
Map<String, List<Location>> result = new HashMap<>();
for (Location location : nodes.values()) {
String name = location.getName();
if (name != null) {
if (!result.containsKey(name)) {
result.put(name, new ArrayList<>());
}
result.get(name).add(location);
}
}
return result;
}

/**
* Reset the handler state before processing a new way or node.
*/
private void reset() {
state = "";
id = Long.MIN_VALUE;
name = "";
validWay = false;
builder = new Location.Builder();
location = null;
path = new ArrayDeque<>();
}

Expand All @@ -209,27 +203,27 @@ public void startElement(String uri, String localName, String qName, Attributes
if (qName.equals("node")) {
state = "node";
id = Long.parseLong(attributes.getValue("id"));
double lat = Double.parseDouble(attributes.getValue("lat"));
double lon = Double.parseDouble(attributes.getValue("lon"));
builder.setLat(lat).setLon(lon);
location = context.getShapeFactory().pointLatLon(
Double.parseDouble(attributes.getValue("lat")),
Double.parseDouble(attributes.getValue("lon"))
);
} else if (qName.equals("way")) {
state = "way";
} else if (state.equals("way") && qName.equals("nd")) {
long ref = Long.parseLong(attributes.getValue("ref"));
path.add(nodes.get(ref));
path.add(byId.get(ref));
} else if (state.equals("way") && qName.equals("tag")) {
String k = attributes.getValue("k");
String v = attributes.getValue("v");
if (k.equals("highway")) {
validWay = allowedHighwayTypes.contains(v);
}
} else if (state.equals("node") && qName.equals("tag") && attributes.getValue("k").equals("name")) {
String name = attributes.getValue("v").strip()
name = attributes.getValue("v").strip()
.replace('“', '"')
.replace('”', '"')
.replace('‘', '\'')
.replace('’', '\'');
builder.setName(name);
}
}

Expand All @@ -247,17 +241,21 @@ public void startElement(String uri, String localName, String qName, Attributes
public void endElement(String uri, String localName, String qName) {
if (qName.equals("way")) {
if (validWay && !path.isEmpty()) {
Location from = path.remove();
Point from = path.remove();
while (!path.isEmpty()) {
Location to = path.remove();
Point to = path.remove();
addEdge(from, to);
addEdge(to, from);
from = to;
}
}
reset();
} else if (qName.equals("node")) {
nodes.put(id, builder.build());
byId.put(id, location);
if (!name.isBlank()) {
byName.putIfAbsent(name, new ArrayList<>());
byName.get(name).add(location);
}
reset();
}
}
Expand Down
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