lnd/routing/heap_test.go
Juan Pablo Civile df70095ad0 routing: optimize path finding structures
distance map now holds the edge the current path is coming from,
removing the need for next map.

Both distance map and distanceHeap now hold pointers instead of the full
struct to reduce allocations and copies.

Both these changes reduced path finding time by ~5% and memory usage by
~2mb.
2019-10-24 21:38:07 -03:00

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(0)
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)
}
}