Switch snapshot format to use unix timestamp

file_snapshot.go

@@ -13,6 +13,7 @@ import (
 	"os"
 	"path/filepath"
 	"sort"
+	"strconv"
 	"strings"
 	"time"
 )
@@ -116,7 +117,9 @@ func (f *FileSnapshotStore) testPermissions() error {
 
 // snapshotName generate s name for the snapshot
 func snapshotName(term, index uint64) string {
-	return fmt.Sprintf("%d-%d-%s", term, index, time.Now().Format(time.RFC3339Nano))
+	now := time.Now()
+	msec := now.UnixNano() / int64(time.Millisecond)
+	return fmt.Sprintf("%d-%d-%d", term, index, msec)
 }
 
 // parseName parse the components of a name
@@ -126,6 +129,17 @@ func parseName(name string) (uint64, uint64, time.Time, error) {
 	if _, err := fmt.Sscanf(name, "%d-%d-%s", &term, &index, &timeString); err != nil {
 		return 0, 0, time.Time{}, err
 	}
+
+	// Due to a format change, the timeString can either be unix time in
+	// milliseconds, OR it could be RFC3339Nano format
+	unixMsec, err := strconv.ParseInt(timeString, 10, 64)
+	if err == nil {
+		unixNano := unixMsec * int64(time.Millisecond)
+		when := time.Unix(0, unixNano)
+		return term, index, when, nil
+	}
+
+	// Try for the RFC3339Nano format
 	when, err := time.Parse(time.RFC3339Nano, timeString)
 	if err != nil {
 		return 0, 0, time.Time{}, err

file_snapshot_test.go

@@ -241,6 +241,23 @@ func TestFileSS_Names(t *testing.T) {
 	if time.Now().Sub(when) > time.Millisecond {
 		t.Fatalf("bad: %v", when)
 	}
+
+	// Ensure old-style name works
+	name = "50-100-2006-01-02T15:04:05.999999999Z"
+	term, index, when, err = parseName(name)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+	if term != 50 {
+		t.Fatalf("bad: %v", index)
+	}
+	if index != 100 {
+		t.Fatalf("bad: %v", index)
+	}
+	expect := time.Date(2006, 01, 02, 15, 04, 05, 0, time.UTC)
+	if diff := when.Sub(expect); diff > time.Second {
+		t.Fatalf("bad: %v %v", when, diff)
+	}
 }
 
 func TestFileSS_Ordering(t *testing.T) {