Merge pull request #38 from jbenet/feat/bitswap-import-cleanup

chore(bitswap) tidy up bitswap, ledger

bitswap/bitswap.go

 package bitswap
 
 import (
-	"github.com/jbenet/go-ipfs/Godeps/_workspace/src/code.google.com/p/goprotobuf/proto"
+	"time"
+
+	proto "github.com/jbenet/go-ipfs/Godeps/_workspace/src/code.google.com/p/goprotobuf/proto"
+	ds "github.com/jbenet/go-ipfs/Godeps/_workspace/src/github.com/jbenet/datastore.go"
+
 	blocks "github.com/jbenet/go-ipfs/blocks"
 	peer "github.com/jbenet/go-ipfs/peer"
 	routing "github.com/jbenet/go-ipfs/routing"
 	dht "github.com/jbenet/go-ipfs/routing/dht"
 	swarm "github.com/jbenet/go-ipfs/swarm"
 	u "github.com/jbenet/go-ipfs/util"
-
-	ds "github.com/jbenet/go-ipfs/Godeps/_workspace/src/github.com/jbenet/datastore.go"
-
-	"time"
 )
 
 // PartnerWantListMax is the bound for the number of keys we'll store per
@@ -44,7 +44,7 @@ type BitSwap struct {
 	// The Ledger has the peer.ID, and the peer connection works through net.
 	// Ledgers of known relationships (active or inactive) stored in datastore.
 	// Changes to the Ledger should be committed to the datastore.
-	partners map[u.Key]*Ledger
+	partners LedgerMap
 
 	// haveList is the set of keys we have values for. a map for fast lookups.
 	// haveList KeySet -- not needed. all values in datastore?
@@ -136,7 +136,7 @@ func (bs *BitSwap) getBlock(k u.Key, p *peer.Peer, timeout time.Duration) ([]byt
 func (bs *BitSwap) HaveBlock(blk *blocks.Block) error {
 	go func() {
 		for _, ledger := range bs.partners {
-			if _, ok := ledger.WantList[blk.Key()]; ok {
+			if ledger.WantListContains(blk.Key()) {
 				//send block to node
 				if ledger.ShouldSend() {
 					bs.SendBlock(ledger.Partner, blk)
@@ -189,14 +189,13 @@ func (bs *BitSwap) handleMessages() {
 // and then if we do, check the ledger for whether or not we should send it.
 func (bs *BitSwap) peerWantsBlock(p *peer.Peer, want string) {
 	u.DOut("peer [%s] wants block [%s]\n", p.ID.Pretty(), u.Key(want).Pretty())
-	ledg := bs.GetLedger(p)
+	ledger := bs.getLedger(p)
 
 	dsk := ds.NewKey(want)
 	blk_i, err := bs.datastore.Get(dsk)
 	if err != nil {
 		if err == ds.ErrNotFound {
-			// TODO: this needs to be different. We need timeouts.
-			ledg.WantList[u.Key(want)] = struct{}{}
+			ledger.Wants(u.Key(want))
 		}
 		u.PErr("datastore get error: %v\n", err)
 		return
@@ -208,7 +207,7 @@ func (bs *BitSwap) peerWantsBlock(p *peer.Peer, want string) {
 		return
 	}
 
-	if ledg.ShouldSend() {
+	if ledger.ShouldSend() {
 		u.DOut("Sending block to peer.\n")
 		bblk, err := blocks.NewBlock(blk)
 		if err != nil {
@@ -216,7 +215,7 @@ func (bs *BitSwap) peerWantsBlock(p *peer.Peer, want string) {
 			return
 		}
 		bs.SendBlock(p, bblk)
-		ledg.SentBytes(len(blk))
+		ledger.SentBytes(len(blk))
 	} else {
 		u.DOut("Decided not to send block.")
 	}
@@ -236,11 +235,11 @@ func (bs *BitSwap) blockReceive(p *peer.Peer, blk *blocks.Block) {
 	}
 	bs.listener.Respond(string(blk.Key()), mes)
 
-	ledger := bs.GetLedger(p)
+	ledger := bs.getLedger(p)
 	ledger.ReceivedBytes(len(blk.Data))
 }
 
-func (bs *BitSwap) GetLedger(p *peer.Peer) *Ledger {
+func (bs *BitSwap) getLedger(p *peer.Peer) *Ledger {
 	l, ok := bs.partners[p.Key()]
 	if ok {
 		return l
@@ -273,7 +272,7 @@ func (bs *BitSwap) Halt() {
 
 func (bs *BitSwap) SetStrategy(sf StrategyFunc) {
 	bs.strategy = sf
-	for _, ledg := range bs.partners {
-		ledg.Strategy = sf
+	for _, ledger := range bs.partners {
+		ledger.Strategy = sf
 	}
 }

bitswap/ledger.go

 package bitswap
 
 import (
+	"sync"
+	"time"
+
 	peer "github.com/jbenet/go-ipfs/peer"
 	u "github.com/jbenet/go-ipfs/util"
-
-	"time"
 )
 
 // Ledger stores the data exchange relationship between two peers.
 type Ledger struct {
+	lock sync.RWMutex
 
 	// Partner is the remote Peer.
 	Partner *peer.Peer
@@ -16,17 +18,17 @@ type Ledger struct {
 	// Accounting tracks bytes sent and recieved.
 	Accounting debtRatio
 
-	// FirstExchnage is the time of the first data exchange.
-	FirstExchange time.Time
+	// firstExchnage is the time of the first data exchange.
+	firstExchange time.Time
 
-	// LastExchange is the time of the last data exchange.
-	LastExchange time.Time
+	// lastExchange is the time of the last data exchange.
+	lastExchange time.Time
 
-	// Number of exchanges with this peer
-	ExchangeCount uint64
+	// exchangeCount is the number of exchanges with this peer
+	exchangeCount uint64
 
-	// WantList is a (bounded, small) set of keys that Partner desires.
-	WantList KeySet
+	// wantList is a (bounded, small) set of keys that Partner desires.
+	wantList KeySet
 
 	Strategy StrategyFunc
 }
@@ -35,17 +37,48 @@ type Ledger struct {
 type LedgerMap map[u.Key]*Ledger
 
 func (l *Ledger) ShouldSend() bool {
+	l.lock.Lock()
+	defer l.lock.Unlock()
+
 	return l.Strategy(l)
 }
 
 func (l *Ledger) SentBytes(n int) {
-	l.ExchangeCount++
-	l.LastExchange = time.Now()
+	l.lock.Lock()
+	defer l.lock.Unlock()
+
+	l.exchangeCount++
+	l.lastExchange = time.Now()
 	l.Accounting.BytesSent += uint64(n)
 }
 
 func (l *Ledger) ReceivedBytes(n int) {
-	l.ExchangeCount++
-	l.LastExchange = time.Now()
+	l.lock.Lock()
+	defer l.lock.Unlock()
+
+	l.exchangeCount++
+	l.lastExchange = time.Now()
 	l.Accounting.BytesRecv += uint64(n)
 }
+
+// TODO: this needs to be different. We need timeouts.
+func (l *Ledger) Wants(k u.Key) {
+	l.lock.Lock()
+	defer l.lock.Unlock()
+
+	l.wantList[k] = struct{}{}
+}
+
+func (l *Ledger) WantListContains(k u.Key) bool {
+	l.lock.RLock()
+	defer l.lock.RUnlock()
+
+	_, ok := l.wantList[k]
+	return ok
+}
+
+func (l *Ledger) ExchangeCount() uint64 {
+	l.lock.RLock()
+	defer l.lock.RUnlock()
+	return l.exchangeCount
+}

bitswap/ledger_test.go

+package bitswap
+
+import (
+	"sync"
+	"testing"
+)
+
+func TestRaceConditions(t *testing.T) {
+	const numberOfExpectedExchanges = 10000
+	l := new(Ledger)
+	var wg sync.WaitGroup
+	for i := 0; i < numberOfExpectedExchanges; i++ {
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			l.ReceivedBytes(1)
+		}()
+	}
+	wg.Wait()
+	if l.ExchangeCount() != numberOfExpectedExchanges {
+		t.Fail()
+	}
+}