org.jgroups.raft.util.Utils Maven / Gradle / Ivy
package org.jgroups.raft.util;
import org.jgroups.Address;
import org.jgroups.View;
import org.jgroups.protocols.raft.RAFT;
import org.jgroups.raft.testfwk.RaftTestUtils;
import java.util.Objects;
/**
* @author Bela Ban
* @since 1.0.6
*/
public class Utils {
public enum Majority {
reached, lost, leader_lost, no_change
}
public static boolean majorityReached(View old, View new_view, int majority) {
return (old == null || old.size() < majority) && new_view.size() >= majority;
}
public static boolean majorityLost(View old, View new_view, int majority) {
return (old != null && old.size() >= majority) && new_view.size() < majority;
}
public static Majority computeMajority(View old, View new_view, int majority, Address leader) {
if(majorityReached(old, new_view, majority))
return Majority.reached;
if(majorityLost(old, new_view, majority))
return Majority.lost;
if(leader != null && !new_view.containsMember(leader))
return Majority.leader_lost;
return Majority.no_change;
}
/**
* Verify if the coordinator change between two views.
*
* @param prev: The old {@link View}, it can be null.
* @param curr: The recent {@link View}.
* @return true if the coordinator changed, false, otherwise.
*/
public static boolean viewCoordinatorChanged(View prev, View curr) {
if (prev == null) return true;
return !Objects.equals(prev.getCoord(), curr.getCoord());
}
/**
* Deletes the log data for the given {@link RAFT} instance.
*
* Warning: This should be used in tests only.
*
*
* @param r: RAFT instance to delete the log contents.
* @throws Exception: If an exception happens while deleting the log.
* @deprecated Use {@link RaftTestUtils#deleteRaftLog(RAFT)} instead.
*/
@Deprecated(since = "1.0.13", forRemoval = true)
public static void deleteLog(RAFT r) throws Exception {
RaftTestUtils.deleteRaftLog(r);
}
}