add sql value support to timed version

utils/timed_version.go

@@ -15,6 +15,9 @@
 package utils
 
 import (
+	"database/sql/driver"
+	"encoding/binary"
+	"errors"
 	"fmt"
 	"sync"
 	"time"
@@ -110,10 +113,22 @@ func TimedVersionFromTime(t time.Time) TimedVersion {
 }
 
 func (t *TimedVersion) Update(other *TimedVersion) bool {
+	return t.Upgrade(other)
+}
+
+func (t *TimedVersion) Upgrade(other *TimedVersion) bool {
+	return t.update(other, func(ov, prev uint64) bool { return ov > prev })
+}
+
+func (t *TimedVersion) Downgrade(other *TimedVersion) bool {
+	return t.update(other, func(ov, prev uint64) bool { return ov < prev })
+}
+
+func (t *TimedVersion) update(other *TimedVersion, cmp func(ov, prev uint64) bool) bool {
 	ov := other.v.Load()
 	for {
 		prev := t.v.Load()
-		if ov <= prev {
+		if !cmp(ov, prev) {
 			return false
 		}
 		if t.v.CompareAndSwap(prev, ov) {
@@ -167,3 +182,36 @@ func (t *TimedVersion) String() string {
 	ts, ticks := timedVersionComponents(t.v.Load())
 	return fmt.Sprintf("%d.%d", ts, ticks)
 }
+
+func (t TimedVersion) Value() (driver.Value, error) {
+	if t.IsZero() {
+		return nil, nil
+	}
+
+	ts, ticks := timedVersionComponents(t.v.Load())
+	b := make([]byte, 0, 12)
+	b = binary.BigEndian.AppendUint64(b, uint64(ts))
+	b = binary.BigEndian.AppendUint32(b, uint32(ticks))
+	return b, nil
+}
+
+func (t *TimedVersion) Scan(src interface{}) (err error) {
+	switch b := src.(type) {
+	case []byte:
+		switch len(b) {
+		case 0:
+			t.v.Store(0)
+		case 12:
+			ts := int64(binary.BigEndian.Uint64(b))
+			ticks := int32(binary.BigEndian.Uint32(b[8:]))
+			*t = timedVersionFromComponents(ts, ticks)
+		default:
+			return errors.New("(*TimedVersion).Scan: unsupported format")
+		}
+	case nil:
+		t.v.Store(0)
+	default:
+		return errors.New("(*TimedVersion).Scan: unsupported data type")
+	}
+	return nil
+}

utils/timed_version_test.go

@@ -64,4 +64,8 @@ func TestTimedVersion(t *testing.T) {
 		require.Equal(t, ts1, ts2)
 		require.Equal(t, tv1.v.Load(), tv2.v.Load())
 	})
+
+	t.Run("timed version from nil is zero", func(t *testing.T) {
+		require.True(t, NewTimedVersionFromProto(nil).IsZero())
+	})
 }