func BenchmarkSparseBitVector(b *testing.B) {
prng := rand.New(rand.NewSource(0))
for tries := 0; tries < b.N; tries++ {
var x, y, z intsets.Sparse
for i := 0; i < 1000; i++ {
n := int(prng.Int()) % 100000
if i%2 == 0 {
x.Insert(n)
} else {
y.Insert(n)
}
}
z.Union(&x, &y)
z.Difference(&x, &y)
}
}
func computeChainFrom(from, to canvas.Node) (chain []canvas.NodeIfc) {
// For each link, there is a chain of modules to be invoked: the
// ingress policy modules, the egress policy modules, and the final
// forwarding nexthop.
//
// To compute the chain in each direction, the following algorithm is
// followed:
// Let T and F represent the set of groups for the 'to' and 'from'
// nodes, respectively.
// The leaving set L is the set difference between F and T.
// L := F - T
// The entering set E is the set difference between T and F
// E := T - F
//
// For the directed edge from:to, the chain is built as follows:
// For each module e in E, invoke the ingress policy (e.ifc[1])
// For each module l in L, invoke the egress policy (l.ifc[2])
//
// The directed edge to:from is calculated by calling this function
// with to/from reversed.
var e, l, x intsets.Sparse
l.Difference(from.Groups(), to.Groups())
e.Difference(to.Groups(), from.Groups())
var id int
x.Copy(&e)
for x.TakeMin(&id) {
chain = append(chain, canvas.NodeIfc{id, 1})
}
x.Copy(&l)
for x.TakeMin(&id) {
chain = append(chain, canvas.NodeIfc{id, 2})
}
return chain
}