Added random test for trie

diff --git a/src/trie_rand_test.go b/src/trie_rand_test.go
new file mode 100644 (file)
index 0000000..f8b860c
--- /dev/null
+++ b/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)
+               }
+       }
+}