Interface Graph

core/src/main/java/com/graphhopper/storage/Graph.java:33–126

An interface to represent a (geo) graph - suited for efficient storage as it can be requested via indices called node IDs. To get the lat,lon point you need to set up a LocationIndex instance. @author Peter Karich

 * @author Peter Karich
 */
public interface Graph {
    /**
     * @return a graph which behaves like an unprepared graph and e.g. the normal unidirectional
     * Dijkstra or any graph traversal algorithm can be executed.
     */
    BaseGraph getBaseGraph();

    /**
     * @return the number of created locations - via setNode() or edge()
     */
    int getNodes();

    /**
     * @return the number of edges in this graph. Equivalent to getAllEdges().length().
     */
    int getEdges();

    /**
     * Creates an object to access node properties.
     */
    NodeAccess getNodeAccess();

    /**
     * Returns the implicit bounds of this graph calculated from the lat,lon input of setNode
     */
    BBox getBounds();

    /**
     * Creates an edge between the nodes a and b. To set distance or access use the returned edge
     * and e.g. edgeState.setDistance
     *
     * @param a the index of the starting (tower) node of the edge
     * @param b the index of the ending (tower) node of the edge
     * @return the newly created edge
     */
    EdgeIteratorState edge(int a, int b);

    /**
     * Returns a wrapper over the specified edgeId.
     *
     * @param adjNode is the node that will be returned via getAdjNode(). If adjNode is
     *                Integer.MIN_VALUE then the edge will be returned in the direction of how it is stored
     * @return a new EdgeIteratorState object or potentially null if adjNode does not match
     * @throws IllegalStateException if edgeId is not valid
     */
    EdgeIteratorState getEdgeIteratorState(int edgeId, int adjNode);

    /**
     * Returns the edge state for the given edge key
     *
     * @see EdgeIteratorState#getEdgeKey()
     */
    EdgeIteratorState getEdgeIteratorStateForKey(int edgeKey);

    /**
     * @return the 'opposite' node of a given edge, so if there is an edge 3-2 and node =2 this returns 3
     */
    int getOtherNode(int edge, int node);