dex: redesign p2p network topology

- Let p2p server support direct connection and group connection.
- Introduce node meta table to maintain IP of all nodes in node set,
  in memory and let nodes in the network can sync this table.
- Let peerSet able to manage direct connections to notary set and dkg set.

The mechanism to refresh the network topology when configuration round
change is not done yet.

1 files changed, 93 insertions, 0 deletions

diff --git a/dex/nodetable_test.go b/dex/nodetable_test.go
new file mode 100644
index 000000000..5b3f7de57
--- /dev/null
+++ b/dex/nodetable_test.go
@@ -0,0 +1,93 @@
+package dex
+
+import (
+	"math/rand"
+	"testing"
+	"time"
+
+	"github.com/dexon-foundation/dexon/common"
+	"github.com/dexon-foundation/dexon/p2p/enode"
+)
+
+func TestNodeTable(t *testing.T) {
+	table := newNodeTable()
+	ch := make(chan newMetasEvent)
+	table.SubscribeNewMetasEvent(ch)
+
+	metas1 := []*NodeMeta{
+		&NodeMeta{ID: randomID()},
+		&NodeMeta{ID: randomID()},
+	}
+
+	metas2 := []*NodeMeta{
+		&NodeMeta{ID: randomID()},
+		&NodeMeta{ID: randomID()},
+	}
+
+	go table.Add(metas1)
+
+	select {
+	case newMetas := <-ch:
+		m := map[common.Hash]struct{}{}
+		for _, meta := range newMetas.Metas {
+			m[meta.Hash()] = struct{}{}
+		}
+
+		if len(m) != len(metas1) {
+			t.Errorf("len mismatch: got %d, want: %d",
+				len(m), len(metas1))
+		}
+
+		for _, meta := range metas1 {
+			if _, ok := m[meta.Hash()]; !ok {
+				t.Errorf("expected meta (%s) not exists", meta.Hash())
+			}
+		}
+	case <-time.After(1 * time.Second):
+		t.Error("did not receive new metas event within one second")
+	}
+
+	go table.Add(metas2)
+	select {
+	case newMetas := <-ch:
+		m := map[common.Hash]struct{}{}
+		for _, meta := range newMetas.Metas {
+			m[meta.Hash()] = struct{}{}
+		}
+
+		if len(m) != len(metas1) {
+			t.Errorf("len mismatch: got %d, want: %d",
+				len(m), len(metas2))
+		}
+
+		for _, meta := range metas2 {
+			if _, ok := m[meta.Hash()]; !ok {
+				t.Errorf("expected meta (%s) not exists", meta.Hash())
+			}
+		}
+	case <-time.After(1 * time.Second):
+		t.Error("did not receive new metas event within one second")
+	}
+
+	var metas []*NodeMeta
+	metas = append(metas, metas1...)
+	metas = append(metas, metas2...)
+	allMetas := table.Metas()
+	if len(allMetas) != len(metas) {
+		t.Errorf("all metas num mismatch: got %d, want %d",
+			len(metas), len(allMetas))
+	}
+
+	for _, m := range metas {
+		if m.Hash() != table.Get(m.ID).Hash() {
+			t.Errorf("meta (%s) mismatch", m.ID.String())
+		}
+	}
+}
+
+func randomID() (id enode.ID) {
+	for i := range id {
+		id[i] = byte(rand.Intn(255))
+	}
+	return id
+}