behavioursroleselectorimpl.java

p2p仿真器。开发者可以工作在覆盖层中进行创造和测试逻辑算法或者创建和测试新的服务。PlanetSim还可以将仿真代码平稳转换为在Internet上的实验代码

package planet.generic.commonapi.behaviours;

import java.util.*;
import planet.util.Properties;
import planet.commonapi.Id;
import planet.commonapi.behaviours.BehavioursRoleSelector;

/**
 * BehaviourRoleSelectorImpl provides a default implementation for BehaviourRoleSelector
 * interface. The node's role can only be determined on  behaviour's context. It uses the 
 * following behaviour properties file:
 * <ol>
 * <li> BEHAVIOURS_PROPERTIES_FAULTY_NODES: percentatge of faulty nodes within the network.
 * <li> BEHAVIOURS_PROPERTIES_MALICIOUS_DISTRIBUTION: type of distribution of the faulty nodes: 
 *      <ol> 
 * 			<li> BehaviourPropertiesImpl.BEHAVIOUR_UNIFORM_MALICIOUS_DISTRIBUTION_MASK: 
 *               faulty nodes distributed uniformly along the network.
 * 			<li> BehaviourPropertiesImpl.BEHAVIOUR_CHAIN_MALICIOUS_DISTRIBUTION_MASK: 
 *               faulty  nodes  forming a continous chain of faulty nodes.
 * 		</ol>
 * </ol> 
 * @author Marc S醤chez <[e-mail]> *
 */
public class BehavioursRoleSelectorImpl implements BehavioursRoleSelector {
	/**
	 * This methods selects malicious nodes from the overlay according to a percentage and
	 * distribution of them along the network.
	 * @param network Iterator of all ids. 
	 * @param percentage Percentage of faulty nodes.
	 * @param distribution Distribution's type of faulty nodes: chain or uniform.
	 * @throws ClassCastException if <b>network</b> is not a collection of id's objects. 
	 * @return Returns a set with Ids of malicious nodes.
	 */
	public Set select(Iterator network, double percentage, int distribution) {
			int howMany = (int)Math.round(percentage*(double)Properties.factoriesNetworkSize);
			boolean uniformDT = distribution == BehavioursPropertiesImpl.BEHAVIOUR_UNIFORM_MALICIOUS_DISTRIBUTION_MASK; 
			int interleaving = 0;
			if (howMany > 0) interleaving = uniformDT? Properties.factoriesNetworkSize / howMany: 1;
			else return null;
			Set badSet = new HashSet();
			for (int step = 0; network.hasNext();) {
				Id node = (Id) network.next(); 
				if (++step == interleaving) {
					badSet.add(node);
					step = 0;
					if (--howMany <= 0) break;
				}
			}
			return badSet;
	}
}