stats: fix converting duration to timestamp (#8174) (#8182)

statistics/gc.go

@@ -19,7 +19,6 @@ import (
 
 	"github.com/cznic/mathutil"
 	"github.com/pingcap/tidb/infoschema"
-	"github.com/pingcap/tidb/store/tikv/oracle"
 	"github.com/pingcap/tidb/util/sqlexec"
 	"github.com/pkg/errors"
 	"golang.org/x/net/context"
@@ -31,7 +30,7 @@ func (h *Handle) GCStats(is infoschema.InfoSchema, ddlLease time.Duration) error
 	// To make sure that all the deleted tables' schema and stats info have been acknowledged to all tidb,
 	// we only garbage collect version before 10 lease.
 	lease := mathutil.MaxInt64(int64(h.Lease), int64(ddlLease))
-	offset := oracle.ComposeTS(10*lease, 0)
+	offset := DurationToTS(10 * time.Duration(lease))
 	if h.LastUpdateVersion() < offset {
 		return nil
 	}

statistics/handle.go

@@ -109,6 +109,11 @@ func (h *Handle) GetQueryFeedback() []*QueryFeedback {
 	return h.feedback
 }
 
+// DurationToTS converts duration to timestamp.
+func DurationToTS(d time.Duration) uint64 {
+	return oracle.ComposeTS(d.Nanoseconds()/int64(time.Millisecond), 0)
+}
+
 // Update reads stats meta from store and updates the stats map.
 func (h *Handle) Update(is infoschema.InfoSchema) error {
 	lastVersion := h.LastUpdateVersion()
@@ -117,7 +122,7 @@ func (h *Handle) Update(is infoschema.InfoSchema) error {
 	// and A0 < B0 < B1 < A1. We will first read the stats of B, and update the lastVersion to B0, but we cannot read
 	// the table stats of A0 if we read stats that greater than lastVersion which is B0.
 	// We can read the stats if the diff between commit time and version is less than three lease.
-	offset := oracle.ComposeTS(3*int64(h.Lease), 0)
+	offset := DurationToTS(3 * h.Lease)
 	if lastVersion >= offset {
 		lastVersion = lastVersion - offset
 	} else {

statistics/handle_test.go

@@ -238,6 +238,14 @@ func (s *testStatsCacheSuite) TestAvgColLen(c *C) {
 	c.Assert(statsTbl.Columns[tableInfo.Columns[3].ID].AvgColSize(statsTbl.Count), Equals, 16.0)
 }
 
+func (s *testStatsCacheSuite) TestDurationToTS(c *C) {
+	tests := []time.Duration{time.Millisecond, time.Second, time.Minute, time.Hour}
+	for _, t := range tests {
+		ts := statistics.DurationToTS(t)
+		c.Assert(oracle.ExtractPhysical(ts)*int64(time.Millisecond), Equals, int64(t))
+	}
+}
+
 func (s *testStatsCacheSuite) TestVersion(c *C) {
 	defer cleanEnv(c, s.store, s.do)
 	testKit := testkit.NewTestKit(c, s.store)
@@ -249,11 +257,12 @@ func (s *testStatsCacheSuite) TestVersion(c *C) {
 	tbl1, err := is.TableByName(model.NewCIStr("test"), model.NewCIStr("t1"))
 	c.Assert(err, IsNil)
 	tableInfo1 := tbl1.Meta()
-	h := statistics.NewHandle(testKit.Se, 1)
-	testKit.MustExec("update mysql.stats_meta set version = 2 where table_id = ?", tableInfo1.ID)
+	h := statistics.NewHandle(testKit.Se, time.Millisecond)
+	unit := oracle.ComposeTS(1, 0)
+	testKit.MustExec("update mysql.stats_meta set version = ? where table_id = ?", 2*unit, tableInfo1.ID)
 
 	h.Update(is)
-	c.Assert(h.LastUpdateVersion(), Equals, uint64(2))
+	c.Assert(h.LastUpdateVersion(), Equals, 2*unit)
 	statsTbl1 := h.GetTableStats(tableInfo1)
 	c.Assert(statsTbl1.Pseudo, IsFalse)
 
@@ -264,15 +273,15 @@ func (s *testStatsCacheSuite) TestVersion(c *C) {
 	c.Assert(err, IsNil)
 	tableInfo2 := tbl2.Meta()
 	// A smaller version write, and we can still read it.
-	testKit.MustExec("update mysql.stats_meta set version = 1 where table_id = ?", tableInfo2.ID)
+	testKit.MustExec("update mysql.stats_meta set version = ? where table_id = ?", unit, tableInfo2.ID)
 	h.Update(is)
-	c.Assert(h.LastUpdateVersion(), Equals, uint64(2))
+	c.Assert(h.LastUpdateVersion(), Equals, 2*unit)
 	statsTbl2 := h.GetTableStats(tableInfo2)
 	c.Assert(statsTbl2.Pseudo, IsFalse)
 
 	testKit.MustExec("insert t1 values(1,2)")
 	testKit.MustExec("analyze table t1")
-	offset := oracle.ComposeTS(3*int64(h.Lease), 0)
+	offset := 3 * unit
 	testKit.MustExec("update mysql.stats_meta set version = ? where table_id = ?", offset+4, tableInfo1.ID)
 	h.Update(is)
 	c.Assert(h.LastUpdateVersion(), Equals, offset+uint64(4))