add io.Closer interface and implementation to Peerstore.

peerstore.go

@@ -2,6 +2,7 @@ package peerstore
 
 import (
 	"fmt"
+	"io"
 	"sync"
 
 	peer "github.com/libp2p/go-libp2p-peer"
@@ -31,6 +32,19 @@ func NewPeerstore(kb KeyBook, ab AddrBook, md PeerMetadata) Peerstore {
 	}
 }
 
+func (ps *peerstore) Close() (err error) {
+	if cl, ok := ps.KeyBook.(io.Closer); ok {
+		cl.Close()
+	}
+	if cl, ok := ps.AddrBook.(io.Closer); ok {
+		cl.Close()
+	}
+	if cl, ok := ps.PeerMetadata.(io.Closer); ok {
+		cl.Close()
+	}
+	return nil
+}
+
 func (ps *peerstore) Peers() peer.IDSlice {
 	set := map[peer.ID]struct{}{}
 	for _, p := range ps.PeersWithKeys() {