reduce heap allocations #12

Summary:
* Make `corrToDuration` as a method of `Correction`
* Migrate usages
* Implement tests

This should help to avoid allocations in logging, but definitely improve code readability

Reviewed By: deathowl

Differential Revision: D58468150

fbshipit-source-id: 76d91cbc317435729595a81e2ee0dd2193e4fb54

ptp/protocol/types.go

@@ -163,6 +163,15 @@ func (t Correction) Nanoseconds() float64 {
 	return IntFloat(t).Value()
 }
 
+// Duration converts PTP CorrectionField to time.Duration, ignoring
+// case where correction is too big, and dropping fractions of nanoseconds
+func (t Correction) Duration() time.Duration {
+	if !t.TooBig() {
+		return time.Duration(t.Nanoseconds())
+	}
+	return 0
+}
+
 func (t Correction) String() string {
 	if t.TooBig() {
 		return "Correction(Too big)"

ptp/protocol/types_test.go

@@ -249,7 +249,7 @@ func TestTimestamp(t *testing.T) {
 	}
 }
 
-func TestCorrection(t *testing.T) {
+func TestCorrectionFromDuration(t *testing.T) {
 	tests := []struct {
 		in         time.Duration
 		want       Correction
@@ -285,6 +285,28 @@ func TestCorrection(t *testing.T) {
 	}
 }
 
+func TestDurationFromCorrection(t *testing.T) {
+	tests := []struct {
+		in   Correction
+		want time.Duration
+	}{
+		{
+			in:   Correction(65536000000),
+			want: time.Millisecond,
+		},
+		{
+			in:   Correction(0x7fffffffffffffff),
+			want: 0,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(fmt.Sprintf("Duration of %v", tt.in), func(t *testing.T) {
+			got := tt.in.Duration()
+			require.Equal(t, tt.want, got)
+		})
+	}
+}
+
 func TestLogInterval(t *testing.T) {
 	tests := []struct {
 		in   LogInterval

ptp/simpleclient/client.go

@@ -89,15 +89,6 @@ func (c *udpConnTS) WriteToWithTS(b []byte, addr net.Addr) (int, time.Time, erro
 	return n, hwts, nil
 }
 
-// corrToDuration converts PTP CorrectionField to time.Duration, ignoring
-// case where correction is too big, and dropping fractions of nanoseconds
-func corrToDuration(correction ptp.Correction) (corr time.Duration) {
-	if !correction.TooBig() {
-		corr = time.Duration(correction.Nanoseconds())
-	}
-	return
-}
-
 // Config specifies Client run options
 type Config struct {
 	// address of a server to talk to
@@ -361,16 +352,16 @@ func (c *Client) handleAnnounce(b *ptp.Announce) error {
 
 // handleSync handles SYNC packet and adds send timestamp to measurements
 func (c *Client) handleSync(b *ptp.SyncDelayReq, ts time.Time) error {
-	c.logReceive(ptp.MessageSync, "seq=%d, our ReceiveTimestamp(T2)=%v, correctionField(C1)=%v", b.SequenceID, ts, corrToDuration(b.CorrectionField))
-	c.m.addSync(b.SequenceID, ts, corrToDuration(b.CorrectionField))
+	c.logReceive(ptp.MessageSync, "seq=%d, our ReceiveTimestamp(T2)=%v, correctionField(C1)=%v", b.SequenceID, ts, b.CorrectionField.Duration())
+	c.m.addSync(b.SequenceID, ts, b.CorrectionField.Duration())
 	return nil
 }
 
 // handleDelay handles DELAY packet and adds ReceiveTimestamp to measurements
 func (c *Client) handleDelay(b *ptp.DelayResp) error {
-	c.logReceive(ptp.MessageDelayResp, "seq=%d, server ReceiveTimestamp(T4)=%v, correctionField(C3)=%v", b.SequenceID, b.ReceiveTimestamp.Time(), corrToDuration(b.CorrectionField))
+	c.logReceive(ptp.MessageDelayResp, "seq=%d, server ReceiveTimestamp(T4)=%v, correctionField(C3)=%v", b.SequenceID, b.ReceiveTimestamp.Time(), b.CorrectionField.Duration())
 	// store data in measurements
-	c.m.addDelayResp(b.SequenceID, b.ReceiveTimestamp.Time(), corrToDuration(b.CorrectionField))
+	c.m.addDelayResp(b.SequenceID, b.ReceiveTimestamp.Time(), b.CorrectionField.Duration())
 
 	// do whatever needs to be done with current measurements
 	res, err := c.m.latest()
@@ -384,8 +375,8 @@ func (c *Client) handleDelay(b *ptp.DelayResp) error {
 
 // handleFollowUp handles FOLLOW_UP packet and sends DELAY_REQ packet
 func (c *Client) handleFollowUp(b *ptp.FollowUp) error {
-	c.logReceive(ptp.MessageFollowUp, "seq=%d, server PreciseOriginTimestamp(T1)=%v, correctionField(C2)=%v", b.SequenceID, b.PreciseOriginTimestamp.Time(), corrToDuration(b.CorrectionField))
-	c.m.addFollowUp(b.SequenceID, b.PreciseOriginTimestamp.Time(), corrToDuration(b.CorrectionField))
+	c.logReceive(ptp.MessageFollowUp, "seq=%d, server PreciseOriginTimestamp(T1)=%v, correctionField(C2)=%v", b.SequenceID, b.PreciseOriginTimestamp.Time(), b.CorrectionField.Duration())
+	c.m.addFollowUp(b.SequenceID, b.PreciseOriginTimestamp.Time(), b.CorrectionField.Duration())
 	// ask for delay
 	seq, hwts, err := c.sendEventMsg(reqDelay(c.clockID))
 	if err != nil {

ptp/sptp/client/client.go

@@ -31,15 +31,6 @@ import (
 	ptp "github.com/facebook/time/ptp/protocol"
 )
 
-// corrToDuration converts PTP CorrectionField to time.Duration, ignoring
-// case where correction is too big, and dropping fractions of nanoseconds
-func corrToDuration(correction ptp.Correction) (corr time.Duration) {
-	if !correction.TooBig() {
-		corr = time.Duration(correction.Nanoseconds())
-	}
-	return
-}
-
 // ReqDelay is a helper to build ptp.SyncDelayReq
 func ReqDelay(clockID ptp.ClockIdentity, portID uint16) *ptp.SyncDelayReq {
 	return &ptp.SyncDelayReq{
@@ -194,14 +185,14 @@ func (c *Client) handleAnnounce(b *ptp.Announce) {
 		ptp.MessageAnnounce,
 		b.SequenceID,
 		b.OriginTimestamp.Time(),
-		corrToDuration(b.CorrectionField),
+		b.CorrectionField.Duration(),
 		b.GrandmasterIdentity,
 		b.TimeSource,
 		b.StepsRemoved)
 	c.m.currentUTCoffset = time.Duration(b.CurrentUTCOffset) * time.Second
 	// announce carries T1 and CF2
 	c.m.addT1(b.SequenceID, b.OriginTimestamp.Time())
-	c.m.addCF2(b.SequenceID, corrToDuration(b.CorrectionField))
+	c.m.addCF2(b.SequenceID, b.CorrectionField.Duration())
 	c.m.addAnnounce(*b)
 }
 
@@ -213,9 +204,9 @@ func (c *Client) handleSync(b *ptp.SyncDelayReq, ts time.Time) {
 		b.SequenceID,
 		ts,
 		b.OriginTimestamp.Time(),
-		corrToDuration(b.CorrectionField))
+		b.CorrectionField.Duration())
 	// T2 and CF1
-	c.m.addT2andCF1(b.SequenceID, ts, corrToDuration(b.CorrectionField))
+	c.m.addT2andCF1(b.SequenceID, ts, b.CorrectionField.Duration())
 	// sync carries T4 as well
 	c.m.addT4(b.SequenceID, b.OriginTimestamp.Time())
 }