revert removable of mockable time

bitswap/client/internal/messagequeue/donthavetimeoutmgr.go

@@ -5,6 +5,7 @@ import (
 	"sync"
 	"time"
 
+	"github.com/benbjohnson/clock"
 	"github.com/gammazero/deque"
 	cid "github.com/ipfs/go-cid"
 	"github.com/libp2p/go-libp2p/p2p/protocol/ping"
@@ -32,9 +33,12 @@ type DontHaveTimeoutConfig struct {
 	// MessageLatencyMultiplier gives a margin for error. The timeout is calculated as
 	// MessageLatencyMultiplier * message latency
 	MessageLatencyMultiplier int
+
 	// timeoutsSignal used for testing -- caller-provided channel to signals
 	// when a dont have timeout was triggered.
 	timeoutsSignal chan<- struct{}
+	// clock is a mockable time api used for testing.
+	clock clock.Clock
 }
 
 func (c *DontHaveTimeoutConfig) Enabled() bool {
@@ -95,7 +99,7 @@ type dontHaveTimeoutMgr struct {
 	// ewma of message latency (time from message sent to response received)
 	messageLatency *latencyEwma
 	// timer used to wait until want at front of queue expires
-	checkForTimeoutsTimer *time.Timer
+	checkForTimeoutsTimer *clock.Timer
 }
 
 // newDontHaveTimeoutMgr creates a new dontHaveTimeoutMgr
@@ -110,6 +114,9 @@ func newDontHaveTimeoutMgr(pc PeerConnection, onDontHaveTimeout func([]cid.Cid,
 	if cfg == nil {
 		cfg = DefaultDontHaveTimeoutConfig()
 	}
+	if cfg.clock == nil {
+		cfg.clock = clock.New()
+	}
 	ctx, shutdown := context.WithCancel(context.Background())
 	return &dontHaveTimeoutMgr{
 		ctx:               ctx,
@@ -221,6 +228,7 @@ func (dhtm *dontHaveTimeoutMgr) checkForTimeouts() {
 
 	// Figure out which of the blocks that were wanted were not received
 	// within the timeout
+	now := dhtm.config.clock.Now()
 	expired := make([]cid.Cid, 0, len(dhtm.activeWants))
 	for dhtm.wantQueue.Len() > 0 {
 		pw := dhtm.wantQueue.Front()
@@ -229,7 +237,7 @@ func (dhtm *dontHaveTimeoutMgr) checkForTimeouts() {
 		if pw.active {
 			// The queue is in order from earliest to latest, so if we
 			// didn't find an expired entry we can stop iterating
-			if time.Since(pw.sent) < dhtm.timeout {
+			if now.Sub(pw.sent) < dhtm.timeout {
 				break
 			}
 
@@ -260,9 +268,9 @@ func (dhtm *dontHaveTimeoutMgr) checkForTimeouts() {
 	// Schedule the next check for the moment when the oldest pending want will
 	// timeout
 	oldestStart := dhtm.wantQueue.Front().sent
-	until := time.Until(oldestStart.Add(dhtm.timeout))
+	until := oldestStart.Add(dhtm.timeout).Sub(now)
 	if dhtm.checkForTimeoutsTimer == nil {
-		dhtm.checkForTimeoutsTimer = time.NewTimer(until)
+		dhtm.checkForTimeoutsTimer = dhtm.config.clock.Timer(until)
 		go func() {
 			for {
 				select {
@@ -288,7 +296,7 @@ func (dhtm *dontHaveTimeoutMgr) AddPending(ks []cid.Cid) {
 		return
 	}
 
-	start := time.Now()
+	start := dhtm.config.clock.Now()
 
 	dhtm.lk.Lock()
 	defer dhtm.lk.Unlock()