watchtower/wtdb: add Encode/Decode methods to wtclient structs

watchtower/wtdb/tower.go

@@ -2,8 +2,8 @@ package wtdb
 
 import (
 	"errors"
+	"io"
 	"net"
-	"sync"
 
 	"github.com/btcsuite/btcd/btcec"
 	"github.com/lightningnetwork/lnd/lnwire"
@@ -47,18 +47,15 @@ type Tower struct {
 
 	// Addresses is a list of possible addresses to reach the tower.
 	Addresses []net.Addr
-
-	mu sync.RWMutex
 }
 
 // AddAddress adds the given address to the tower's in-memory list of addresses.
 // If the address's string is already present, the Tower will be left
 // unmodified. Otherwise, the adddress is prepended to the beginning of the
 // Tower's addresses, on the assumption that it is fresher than the others.
+//
+// NOTE: This method is NOT safe for concurrent use.
 func (t *Tower) AddAddress(addr net.Addr) {
-	t.mu.Lock()
-	defer t.mu.Unlock()
-
 	// Ensure we don't add a duplicate address.
 	addrStr := addr.String()
 	for _, existingAddr := range t.Addresses {
@@ -75,10 +72,9 @@ func (t *Tower) AddAddress(addr net.Addr) {
 // LNAddrs generates a list of lnwire.NetAddress from a Tower instance's
 // addresses. This can be used to have a client try multiple addresses for the
 // same Tower.
+//
+// NOTE: This method is NOT safe for concurrent use.
 func (t *Tower) LNAddrs() []*lnwire.NetAddress {
-	t.mu.RLock()
-	defer t.mu.RUnlock()
-
 	addrs := make([]*lnwire.NetAddress, 0, len(t.Addresses))
 	for _, addr := range t.Addresses {
 		addrs = append(addrs, &lnwire.NetAddress{
@@ -89,3 +85,21 @@ func (t *Tower) LNAddrs() []*lnwire.NetAddress {
 
 	return addrs
 }
+
+// Encode writes the Tower to the passed io.Writer. The TowerID is not
+// serialized, since it acts as the key.
+func (t *Tower) Encode(w io.Writer) error {
+	return WriteElements(w,
+		t.IdentityKey,
+		t.Addresses,
+	)
+}
+
+// Decode reads a Tower from the passed io.Reader. The TowerID is meant to be
+// decoded from the key.
+func (t *Tower) Decode(r io.Reader) error {
+	return ReadElements(r,
+		&t.IdentityKey,
+		&t.Addresses,
+	)
+}