public boolean equals(Object o) {
if (o instanceof JoinPolicy) {
JoinPolicy that = (JoinPolicy) o;
return this == that || this.joinComponents().equals(that.joinComponents());
}
return false;
}
public boolean relabelsTo(Policy pol, Set s) {
if (this == pol || this.equals(pol)) return true;
Set temp = new HashSet();
// this == c1 join ... join cn
// this <= pol if for all Ci, Ci <= pol
boolean sat = true;
for (Iterator i = components.iterator(); i.hasNext(); ) {
Policy Ci = (Policy) i.next();
if (!labelUtil.relabelsTo(Ci, pol, temp)) {
sat = false;
break;
}
}
if (sat) {
s.addAll(temp);
return true;
}
temp.clear();
// failed so far, try taking advantage of structure on the RHS
if (pol instanceof MeetPolicy) {
// this <= d1 meet ... meet dn if for all di
// we have this <= di
MeetPolicy mp = (MeetPolicy) pol;
sat = true;
for (Iterator i = mp.meetComponents().iterator(); i.hasNext(); ) {
Policy Di = (Policy) i.next();
if (!labelUtil.relabelsTo(this, Di, temp)) {
sat = false;
break;
}
}
if (sat) {
s.addAll(temp);
return true;
}
}
if (pol instanceof JoinPolicy) {
// this <= d1 join ... join dn if there is some di
// such that this <= di
JoinPolicy jp = (JoinPolicy) pol;
for (Iterator i = jp.joinComponents().iterator(); i.hasNext(); ) {
temp.clear();
Policy Di = (Policy) i.next();
if (labelUtil.relabelsTo(this, Di, temp)) {
s.addAll(temp);
return true;
}
}
}
return false;
}
