rinde.sim.core.graph.MultiAttributeData Maven / Gradle / Ivy
package rinde.sim.core.graph;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import javax.annotation.Nullable;
/**
* {@link ConnectionData} implementation which allows to associate multiple
* attributes to a connection (through a {@link HashMap}). There are two
* "default" supported properties defined: connection length, and maximum speed
* on a connection.
* @author Bartosz Michalik
* @author Rinde van Lon
* @since 2.0
*/
public class MultiAttributeData implements ConnectionData {
/**
* Represents an empty value for usage in {@link TableGraph}.
*/
public static final MultiAttributeData EMPTY = new MultiAttributeData(0);
static {
EMPTY.attributes.clear();
}
/**
* Key for length of a connection.
*/
public static final String KEY_LENGTH = "data.length";
/**
* Key for maximum speed of a connection.
*/
public static final String KEY_MAX_SPEED = "data.max.speed";
private final Map attributes;
/**
* New instance only using a single attribute: length.
* @param length The length to set.
*/
public MultiAttributeData(double length) {
attributes = new HashMap();
attributes.put(KEY_LENGTH, length);
}
/**
* New instance using both length and maximum speed attributes.
* @param length The length of the connection.
* @param maxSpeed The maximum speed for the connection.
*/
public MultiAttributeData(double length, double maxSpeed) {
attributes = new HashMap();
attributes.put(KEY_LENGTH, length);
attributes.put(KEY_MAX_SPEED, maxSpeed);
}
/**
*
* @return Length of the connection. If the length is not specified the
* {@link Double#NaN} value is returned
* @see rinde.sim.core.graph.ConnectionData#getLength()
*/
@Override
public double getLength() {
final Object l = attributes.get(KEY_LENGTH);
if (l instanceof Double) {
return (Double) l;
}
return Double.NaN;
}
/**
* Returns max speed defined for a connection. If the max speed is not
* specified the {@link Double#NaN} value is returned
* @return The max speed.
* @see rinde.sim.core.graph.ConnectionData#getLength()
*/
public double getMaxSpeed() {
final Object l = attributes.get(KEY_MAX_SPEED);
if (l instanceof Double) {
return (Double) l;
}
return Double.NaN;
}
/**
* Set max speed.
* @param maxSpeed The new speed.
* @return old max speed or {@link Double#NaN}.
*/
public double setMaxSpeed(double maxSpeed) {
final Object l = attributes.put(KEY_MAX_SPEED, maxSpeed);
if (l instanceof Double) {
return (Double) l;
}
return Double.NaN;
}
/**
* Add an attribute. Note: this can override existing attributes.
* @param key A string used as key.
* @param value The value associated with key.
* @param The type of value.
*/
public void put(String key, E value) {
attributes.put(key, value);
}
/**
* Retrieve an attribute.
* @param key The key to use.
* @param type The type of object that needs to be retrieved.
* @param The type.
* @return An object associated to the key or null if it does not
* exist.
*/
@SuppressWarnings("unchecked")
@Nullable
public E get(String key, Class type) {
final Object r = attributes.get(key);
if (r != null && type.isAssignableFrom(r.getClass())) {
return (E) r;
}
return null;
}
/**
* @return Unmodifiable view on the attributes.
*/
public Map getAttributes() {
return Collections.unmodifiableMap(attributes);
}
@Override
public int hashCode() {
return attributes.hashCode();
}
@Override
public boolean equals(@Nullable Object obj) {
if (this == obj) {
return true;
}
if (obj == null) {
return false;
}
if (!(obj instanceof MultiAttributeData)) {
return false;
}
final MultiAttributeData other = (MultiAttributeData) obj;
return attributes.equals(other.getAttributes());
}
}