// This is the standard DeltaBlue benchmark. A long chain of
// equality constraints is constructed with a stay constraint on
// one end. An edit constraint is then added to the opposite end
// and the time is measured for adding and removing this
// constraint, and extracting and executing a constraint
// satisfaction plan. There are two cases. In case 1, the added
// constraint is stronger than the stay constraint and values must
// propagate down the entire length of the chain. In case 2, the
// added constraint is weaker than the stay constraint so it cannot
// be accomodated. The cost in this case is, of course, very
// low. Typical situations lie somewhere between these two
// extremes.
//
private void chainTest(int n)
{
planner = new Planner();
Variable prev = null, first = null, last = null;
// Build chain of n equality constraints
for (int i = 0; i <= n; i++)
{
String name = "v" + i;
Variable v = new Variable(name);
if (prev != null)
new EqualityConstraint(prev, v, Strength.required);
if (i == 0) first = v;
if (i == n) last = v;
prev = v;
}
new StayConstraint(last, Strength.strongDefault);
Constraint editC = new EditConstraint(first, Strength.preferred);
ArrayList editV = new ArrayList();
editV.Add(editC);
Plan plan = planner.extractPlanFromConstraints(editV);
for (int i = 0; i < 100; i++)
{
first.value = i;
plan.execute();
if (last.value != i)
error("Chain test failed!");
}
editC.destroyConstraint();
deltablue.chains++;
}
// This test constructs a two sets of variables related to each
// other by a simple linear transformation (scale and offset). The
// time is measured to change a variable on either side of the
// mapping and to change the scale and offset factors.
//
private void projectionTest(int n)
{
planner = new Planner();
Variable scale = new Variable("scale", 10);
Variable offset = new Variable("offset", 1000);
Variable src = null, dst = null;
ArrayList dests = new ArrayList();
for (int i = 0; i < n; ++i)
{
src = new Variable("src" + i, i);
dst = new Variable("dst" + i, i);
dests.Add(dst);
new StayConstraint(src, Strength.normal);
new ScaleConstraint(src, scale, offset, dst, Strength.required);
}
change(src, 17);
if (dst.value != 1170) error("Projection test 1 failed!");
change(dst, 1050);
if (src.value != 5) error("Projection test 2 failed!");
change(scale, 5);
for (int i = 0; i < n - 1; ++i)
{
if (((Variable)dests[i]).value != i * 5 + 1000)
error("Projection test 3 failed!");
}
change(offset, 2000);
for (int i = 0; i < n - 1; ++i)
{
if (((Variable)dests[i]).value != i * 5 + 2000)
error("Projection test 4 failed!");
}
deltablue.projections++;
}