swarm/swap: addressed PR comments

swarm/network/stream/stream.go

@@ -734,6 +734,9 @@ func (c *clientParams) clientCreated() {
 	close(c.clientCreatedC)
 }
 
+//Return the streamer spec to callers
+//This used to be a global variable but for simulations with
+//multiple nodes its fields (notably the Hook) would be overwritten
 func (r *Registry) GetSpec() *protocols.Spec {
 	return r.spec
 }

swarm/swap/swap.go

@@ -38,6 +38,15 @@ type Swap struct {
 	balances   map[enode.ID]int64 //map of balances for each peer
 }
 
+// New - swap constructor
+func New(stateStore state.Store) (swap *Swap) {
+	swap = &Swap{
+		stateStore: stateStore,
+		balances:   make(map[enode.ID]int64),
+	}
+	return
+}
+
 //Swap implements the protocols.Balance interface
 //Add is the (sole) accounting function
 func (s *Swap) Add(amount int64, peer *protocols.Peer) (err error) {
@@ -51,7 +60,7 @@ func (s *Swap) Add(amount int64, peer *protocols.Peer) (err error) {
 	s.balances[peer.ID()] += amount
 	//save the new balance to the state store
 	peerBalance := s.balances[peer.ID()]
-	s.stateStore.Put(peer.ID().String(), &peerBalance)
+	err = s.stateStore.Put(peer.ID().String(), &peerBalance)
 
 	log.Debug(fmt.Sprintf("balance for peer %s: %s", peer.ID().String(), strconv.FormatInt(peerBalance, 10)))
 	return err
@@ -77,14 +86,5 @@ func (s *Swap) loadState(peer *protocols.Peer) {
 		s.stateStore.Get(peerID.String(), &peerBalance)
 		s.balances[peerID] = peerBalance
 	}
-}
-
-// New - swap constructor
-func New(stateStore state.Store) (swap *Swap) {
-
-	swap = &Swap{
-		stateStore: stateStore,
-		balances:   make(map[enode.ID]int64),
-	}
 	return
 }

swarm/swap/swap_test.go

@@ -23,6 +23,7 @@ import (
 	mrand "math/rand"
 	"os"
 	"testing"
+	"time"
 
 	"github.com/ethereum/go-ethereum/log"
 	"github.com/ethereum/go-ethereum/p2p"
@@ -38,6 +39,7 @@ var (
 
 func init() {
 	flag.Parse()
+	mrand.Seed(time.Now().UnixNano())
 
 	log.PrintOrigins(true)
 	log.Root().SetHandler(log.LvlFilterHandler(log.Lvl(*loglevel), log.StreamHandler(colorable.NewColorableStderr(), log.TerminalFormat(true))))
@@ -92,9 +94,9 @@ func TestRepeatedBookings(t *testing.T) {
 //try restoring a balance from state store
 //this is simulated by creating a node,
 //assigning it an arbitrary balance,
-//send a message (triggers to save to store),
-//then create a different SwapPeer instance with same peerID,
-//which will try to load a balance from the stateStore
+//then closing the state store.
+//Then we re-open the state store and check that
+//the balance is still the same
 func TestRestoreBalanceFromStateStore(t *testing.T) {
 	//create a test swap account
 	swap, testDir := createTestSwap(t)

swarm/swarm.go

@@ -174,7 +174,11 @@ func NewSwarm(config *api.Config, mockStore *mock.NodeStore) (self *Swarm, err e
 	self.netStore.NewNetFetcherFunc = network.NewFetcherFactory(delivery.RequestFromPeers, config.DeliverySkipCheck).New
 
 	if config.SwapEnabled {
-		self.swap = swap.New(stateStore)
+		balancesStore, err := state.NewDBStore(filepath.Join(config.Path, "balances.db"))
+		if err != nil {
+			return
+		}
+		self.swap = swap.New(balancesStore)
 	}
 
 	var nodeID enode.ID