Added random test for trie

src/trie_rand_test.go

@@ -0,0 +1,120 @@
+package main
+
+import (
+	"math/rand"
+	"sort"
+	"testing"
+)
+
+const (
+	NumberOfPeers     = 100
+	NumberOfAddresses = 250
+	NumberOfTests     = 10000
+)
+
+type SlowRouter []*Trie
+
+func (r SlowRouter) Len() int {
+	return len(r)
+}
+
+func (r SlowRouter) Less(i, j int) bool {
+	return r[i].cidr > r[j].cidr
+}
+
+func (r SlowRouter) Swap(i, j int) {
+	r[i], r[j] = r[j], r[i]
+}
+
+func (r SlowRouter) Insert(addr []byte, cidr uint, peer *Peer) SlowRouter {
+	for _, t := range r {
+		if t.cidr == cidr && commonBits(t.bits, addr) >= cidr {
+			t.peer = peer
+			t.bits = addr
+			return r
+		}
+	}
+	r = append(r, &Trie{
+		cidr: cidr,
+		bits: addr,
+		peer: peer,
+	})
+	sort.Sort(r)
+	return r
+}
+
+func (r SlowRouter) Lookup(addr []byte) *Peer {
+	for _, t := range r {
+		common := commonBits(t.bits, addr)
+		if common >= t.cidr {
+			return t.peer
+		}
+	}
+	return nil
+}
+
+func TestTrieRandomIPv4(t *testing.T) {
+	var trie *Trie
+	var slow SlowRouter
+	var peers []*Peer
+
+	rand.Seed(1)
+
+	const AddressLength = 4
+
+	for n := 0; n < NumberOfPeers; n += 1 {
+		peers = append(peers, &Peer{})
+	}
+
+	for n := 0; n < NumberOfAddresses; n += 1 {
+		var addr [AddressLength]byte
+		rand.Read(addr[:])
+		cidr := uint(rand.Uint32() % (AddressLength * 8))
+		index := rand.Int() % NumberOfPeers
+		trie = trie.Insert(addr[:], cidr, peers[index])
+		slow = slow.Insert(addr[:], cidr, peers[index])
+	}
+
+	for n := 0; n < NumberOfTests; n += 1 {
+		var addr [AddressLength]byte
+		rand.Read(addr[:])
+		peer1 := slow.Lookup(addr[:])
+		peer2 := trie.Lookup(addr[:])
+		if peer1 != peer2 {
+			t.Error("Trie did not match niave implementation, for:", addr)
+		}
+	}
+}
+
+func TestTrieRandomIPv6(t *testing.T) {
+	var trie *Trie
+	var slow SlowRouter
+	var peers []*Peer
+
+	rand.Seed(1)
+
+	const AddressLength = 16
+
+	for n := 0; n < NumberOfPeers; n += 1 {
+		peers = append(peers, &Peer{})
+	}
+
+	for n := 0; n < NumberOfAddresses; n += 1 {
+		var addr [AddressLength]byte
+		rand.Read(addr[:])
+		cidr := uint(rand.Uint32() % (AddressLength * 8))
+		index := rand.Int() % NumberOfPeers
+		trie = trie.Insert(addr[:], cidr, peers[index])
+		slow = slow.Insert(addr[:], cidr, peers[index])
+	}
+
+	for n := 0; n < NumberOfTests; n += 1 {
+		var addr [AddressLength]byte
+		rand.Read(addr[:])
+		peer1 := slow.Lookup(addr[:])
+		peer2 := trie.Lookup(addr[:])
+		if peer1 != peer2 {
+			t.Error("Trie did not match niave implementation, for:", addr)
+		}
+	}
+}