lnd/routing/heap_test.go
nsa 7e6a34532e routing: add index map to distanceHeap
This commit adds the pubkeyIndices map to the distanceHeap to avoid
duplicate entries on the heap. This happened in the earlier iteration
of the findPath algorithm and would cause the driving loop to
evaluate already evaluated entries when there was no need.
2019-07-12 06:08:01 -04:00

78 lines
2.1 KiB
Go

package routing
import (
"container/heap"
prand "math/rand"
"reflect"
"sort"
"testing"
"github.com/lightningnetwork/lnd/routing/route"
)
// TestHeapOrdering ensures that the items inserted into the heap are properly
// retrieved in minimum order of distance.
func TestHeapOrdering(t *testing.T) {
t.Parallel()
// First, create a blank heap, we'll use this to push on randomly
// generated items.
nodeHeap := newDistanceHeap()
prand.Seed(1)
// Create 100 random entries adding them to the heap created above, but
// also a list that we'll sort with the entries.
const numEntries = 100
sortedEntries := make([]nodeWithDist, 0, numEntries)
for i := 0; i < numEntries; i++ {
var pubKey [33]byte
prand.Read(pubKey[:])
entry := nodeWithDist{
node: route.Vertex(pubKey),
dist: prand.Int63(),
}
// Use the PushOrFix method for the initial push to test the scenario
// where entry doesn't exist on the heap.
nodeHeap.PushOrFix(entry)
// Re-generate this entry's dist field
entry.dist = prand.Int63()
// Reorder the heap with a PushOrFix call.
nodeHeap.PushOrFix(entry)
sortedEntries = append(sortedEntries, entry)
}
// Sort the regular slice, we'll compare this against all the entries
// popped from the heap.
sort.Slice(sortedEntries, func(i, j int) bool {
return sortedEntries[i].dist < sortedEntries[j].dist
})
// One by one, pop of all the entries from the heap, they should come
// out in sorted order.
var poppedEntries []nodeWithDist
for nodeHeap.Len() != 0 {
e := heap.Pop(&nodeHeap).(nodeWithDist)
poppedEntries = append(poppedEntries, e)
}
// Assert that the pubkeyIndices map is empty after popping all of the
// items off of it.
if len(nodeHeap.pubkeyIndices) != 0 {
t.Fatalf("there are still %d pubkeys in the pubkeyIndices map",
len(nodeHeap.pubkeyIndices))
}
// Finally, ensure that the items popped from the heap and the items we
// sorted are identical at this rate.
if !reflect.DeepEqual(poppedEntries, sortedEntries) {
t.Fatalf("items don't match: expected %v, got %v", sortedEntries,
poppedEntries)
}
}