From 4d0c38623d505529d9b3796a9d275c837a8ad8bc Mon Sep 17 00:00:00 2001
From: Azhng <archer.xn@gmail.com>
Date: Wed, 15 Sep 2021 16:55:38 -0400
Subject: [PATCH] sql: fix JSON deserialization for sql stats lastExecAt field

Previsouly, lastExecAt field for roachpb.CollectedStatementStatistics
was not properly updated. This caused the status API to return
empty data for that field.
This commit fixes the deserialization and extended the randomize
testing framework to also test time.Time type.

Partially Resolves #69675

Release Justification: Bug fixes and low-risk updates to new
functionality

Release note (bug fix): Last Execution Timestamp is now properly
updating.
---
 .../sqlstatsutil/BUILD.bazel                  |  1 +
 .../sqlstatsutil/json_encoding_test.go        |  2 +-
 .../sqlstatsutil/json_impl.go                 |  2 +-
 .../sqlstatsutil/testutils.go                 | 36 +++++++++++++------
 4 files changed, 29 insertions(+), 12 deletions(-)

diff --git a/pkg/sql/sqlstats/persistedsqlstats/sqlstatsutil/BUILD.bazel b/pkg/sql/sqlstats/persistedsqlstats/sqlstatsutil/BUILD.bazel
index 168347bf8e74..ebcd42563330 100644
--- a/pkg/sql/sqlstats/persistedsqlstats/sqlstatsutil/BUILD.bazel
+++ b/pkg/sql/sqlstats/persistedsqlstats/sqlstatsutil/BUILD.bazel
@@ -16,6 +16,7 @@ go_library(
         "//pkg/sql/sem/tree",
         "//pkg/util/encoding",
         "//pkg/util/json",
+        "//pkg/util/timeutil",
         "@com_github_cockroachdb_apd_v2//:apd",
         "@com_github_cockroachdb_errors//:errors",
         "@com_github_stretchr_testify//require",
diff --git a/pkg/sql/sqlstats/persistedsqlstats/sqlstatsutil/json_encoding_test.go b/pkg/sql/sqlstats/persistedsqlstats/sqlstatsutil/json_encoding_test.go
index cc8918c0be59..1284fb3729be 100644
--- a/pkg/sql/sqlstats/persistedsqlstats/sqlstatsutil/json_encoding_test.go
+++ b/pkg/sql/sqlstats/persistedsqlstats/sqlstatsutil/json_encoding_test.go
@@ -59,7 +59,7 @@ func TestSQLStatsJsonEncoding(t *testing.T) {
          "cnt": {{.Int64}},
          "firstAttemptCnt": {{.Int64}},
          "maxRetries":      {{.Int64}},
-         "lastExecAt":      "0001-01-01T00:00:00Z",
+         "lastExecAt":      "{{stringifyTime .Time}}",
          "numRows": {
            "mean": {{.Float}},
            "sqDiff": {{.Float}}
diff --git a/pkg/sql/sqlstats/persistedsqlstats/sqlstatsutil/json_impl.go b/pkg/sql/sqlstats/persistedsqlstats/sqlstatsutil/json_impl.go
index ddee5e7b103f..cc040f3c97a0 100644
--- a/pkg/sql/sqlstats/persistedsqlstats/sqlstatsutil/json_impl.go
+++ b/pkg/sql/sqlstats/persistedsqlstats/sqlstatsutil/json_impl.go
@@ -334,7 +334,7 @@ func (t *jsonTime) decodeJSON(js json.JSON) error {
 		return err
 	}
 
-	tm := (time.Time)(*t)
+	tm := (*time.Time)(t)
 	if err := tm.UnmarshalText([]byte(s)); err != nil {
 		return err
 	}
diff --git a/pkg/sql/sqlstats/persistedsqlstats/sqlstatsutil/testutils.go b/pkg/sql/sqlstats/persistedsqlstats/sqlstatsutil/testutils.go
index 59d4094dcf4c..cc4364d878e1 100644
--- a/pkg/sql/sqlstats/persistedsqlstats/sqlstatsutil/testutils.go
+++ b/pkg/sql/sqlstats/persistedsqlstats/sqlstatsutil/testutils.go
@@ -17,8 +17,10 @@ import (
 	"strconv"
 	"strings"
 	"testing"
+	"time"
 
 	"github.com/cockroachdb/cockroach/pkg/roachpb"
+	"github.com/cockroachdb/cockroach/pkg/util/timeutil"
 	"github.com/stretchr/testify/require"
 )
 
@@ -42,6 +44,7 @@ type randomData struct {
 	Int64    int64
 	Float    float64
 	IntArray []int64
+	Time     time.Time
 }
 
 var alphabet = []rune("abcdefghijklmkopqrstuvwxyz")
@@ -67,6 +70,7 @@ func genRandomData() randomData {
 		r.IntArray[i] = rand.Int63()
 	}
 
+	r.Time = timeutil.Now()
 	return r
 }
 
@@ -78,10 +82,16 @@ func fillTemplate(t *testing.T, tmplStr string, data randomData) string {
 		}
 		return strings.Join(strArr, ",")
 	}
+	stringifyTime := func(tm time.Time) string {
+		s, err := tm.MarshalText()
+		require.NoError(t, err)
+		return string(s)
+	}
 	tmpl, err := template.
 		New("").
 		Funcs(template.FuncMap{
-			"joinInts": joinInts,
+			"joinInts":      joinInts,
+			"stringifyTime": stringifyTime,
 		}).
 		Parse(tmplStr)
 	require.NoError(t, err)
@@ -101,7 +111,6 @@ var fieldBlacklist = map[string]struct{}{
 	"SensitiveInfo":           {},
 	"LegacyLastErr":           {},
 	"LegacyLastErrRedacted":   {},
-	"LastExecTimestamp":       {},
 	"StatementFingerprintIDs": {},
 	"AggregatedTs":            {},
 }
@@ -130,15 +139,22 @@ func fillObject(t *testing.T, val reflect.Value, data *randomData) {
 			val.Set(reflect.Append(val, reflect.ValueOf(randInt)))
 		}
 	case reflect.Struct:
-		numFields := val.NumField()
-		for i := 0; i < numFields; i++ {
-			fieldName := val.Type().Field(i).Name
-			fieldAddr := val.Field(i).Addr()
-			if _, ok := fieldBlacklist[fieldName]; ok {
-				continue
+		switch val.Type().Name() {
+		// Special handling time.Time.
+		case "Time":
+			val.Set(reflect.ValueOf(data.Time))
+			return
+		default:
+			numFields := val.NumField()
+			for i := 0; i < numFields; i++ {
+				fieldName := val.Type().Field(i).Name
+				fieldAddr := val.Field(i).Addr()
+				if _, ok := fieldBlacklist[fieldName]; ok {
+					continue
+				}
+
+				fillObject(t, fieldAddr, data)
 			}
-
-			fillObject(t, fieldAddr, data)
 		}
 	default:
 		t.Fatalf("unsupported type: %s", val.Kind().String())