feature/remove-peer (#24)

* started working on remove

* added test

dht/dht.go

@@ -127,6 +127,18 @@ func (d *DHT) AddPeer(id state.Peer) {
 	d.LeafSet.Insert(id)
 }
 
+// RemovePeer removes a peer from the dht.
+func (d *DHT) RemovePeer(id state.Peer) {
+	d.Lock()
+	defer d.Unlock()
+
+	ns, _ := d.NeighborhoodSet.Remove(id)
+	d.NeighborhoodSet = ns
+
+	d.RoutingTable = d.RoutingTable.Remove(d.ID, id)
+	d.LeafSet.Remove(id)
+}
+
 // deliver sends the message to all connected applications.
 func (d *DHT) deliver(msg *pb.Message) {
 	d.RLock()

dht/dht_test.go

@@ -1,6 +1,7 @@
 package dht_test
 
 import (
+	"bytes"
 	"context"
 	"testing"
 
@@ -12,6 +13,40 @@ import (
 	"github.com/decanus/bureka/pb"
 )
 
+func TestNode_AddPeer_And_RemovePeer(t *testing.T) {
+	id := []byte{5, 5, 5, 5}
+	insert := []byte{0, 1, 3, 3}
+	n := dht.New(id, nil)
+
+	n.AddPeer(insert)
+
+	if !bytes.Equal(n.LeafSet.Closest(insert), insert) {
+		t.Error("failed to insert in LeafSet")
+	}
+
+	if !bytes.Equal(n.NeighborhoodSet.Closest(insert), insert) {
+		t.Error("failed to insert in NeighborhoodSet")
+	}
+
+	if !bytes.Equal(n.RoutingTable.Route(id, insert), insert) {
+		t.Error("failed to insert in NeighborhoodSet")
+	}
+
+	n.RemovePeer(insert)
+
+	if n.RoutingTable.Route(id, insert) != nil {
+		t.Error("failed to remove peer from RoutingTable")
+	}
+
+	if n.NeighborhoodSet.Closest(insert) != nil {
+		t.Error("failed to remove peer from NeighborhoodSet")
+	}
+
+	if n.LeafSet.Closest(insert) != nil {
+		t.Error("failed to remove peer from LeafSet")
+	}
+}
+
 func TestNode_Send_ToSelf(t *testing.T) {
 	ctrl := gomock.NewController(t)
 	defer ctrl.Finish()

dht/state/routingtable.go

@@ -33,6 +33,18 @@ func (r RoutingTable) grow(n int) RoutingTable {
 	return nr
 }
 
+func (r RoutingTable) Remove(self, id Peer) RoutingTable {
+	nr := r
+	p := row(self, id)
+
+	newrow, ok := nr[p].Remove(id)
+	if ok {
+		nr[p] = newrow
+	}
+
+	return nr
+}
+
 func row(self, target Peer) int {
 	for i, v := range self {
 		if v == target[i] {

dht/state/routingtable_test.go

@@ -20,6 +20,23 @@ func TestRoutingTable_Insert(t *testing.T) {
 	}
 }
 
+func TestRoutingTable_Remove(t *testing.T) {
+	id := []byte{1, 2, 3, 4}
+	insert := []byte{1, 2, 2, 3}
+
+	r := make(state.RoutingTable, 0)
+
+	r = r.Insert(id, insert)
+	if !bytes.Equal(r[2][0], insert) {
+		t.Error("not inserted")
+	}
+
+	r = r.Remove(id, insert)
+	if len(r[2]) != 0 {
+		t.Error("not removed")
+	}
+}
+
 func TestRoutingTable_Route(t *testing.T) {
 	id := []byte{1, 2, 3, 4}
 	insert := []byte{1, 2, 2, 3}