Alexman-Clemford/src/main/org/insa/graph/io/BinaryPathReader.java
2018-01-29 12:35:24 +01:00

70 lines
1.6 KiB
Java

package org.insa.graph.io;
import java.io.DataInputStream;
import java.io.IOException;
import java.util.ArrayList;
import org.insa.graph.Graph;
import org.insa.graph.Node;
import org.insa.graph.Path;
public class BinaryPathReader extends BinaryReader implements AbstractPathReader {
// Map version and magic number targeted for this reader.
private static final int VERSION = 1;
private static final int MAGIC_NUMBER = 0xdecafe;
public BinaryPathReader(DataInputStream dis) {
super(MAGIC_NUMBER, VERSION, dis);
}
@Override
public Path readPath(Graph graph) throws Exception {
// Read and check magic number and version.
checkMagicNumberOrThrow(dis.readInt());
checkVersionOrThrow(dis.readInt());
// Read map ID and check against graph.
int mapId = dis.readInt();
if (mapId != graph.getMapId()) {
throw new MapMismatchException(mapId, graph.getMapId());
}
// Number of nodes in the path (without first and last).
int nbNodes = dis.readInt();
ArrayList<Node> nodes = new ArrayList<Node>(nbNodes + 2);
// Read first node
nodes.add(readNode(graph));
// Read last node
Node lastNode = readNode(graph);
// Read intermediate nodes:
for (int node = 0; node < nbNodes; ++node) {
nodes.add(readNode(graph));
}
// Add last node
nodes.add(lastNode);
return new Path(graph, nodes);
}
/**
* Read a node from the stream and returns id.
*
* @return
* @throws IOException
*/
protected Node readNode(Graph graph) throws IOException {
// Discard zone.
dis.readUnsignedByte();
return graph.getNodes().get(read24bits());
}
}