planner: use code-gen to generate CloneForPlanCache method for some o…

…perators (#54601)

ref #54057

build/nogo_config.json

@@ -522,6 +522,7 @@
       "pkg/parser/goyacc/": "ignore goyacc code",
       "pkg/parser/ast/": "ignore parser/ast code",
       "pkg/parser/test_driver/": "ignore parser/test_driver code",
+      "pkg/planner/core/plan_clone_generated.go": "ignore plan_clone_generated code",
       ".*_test\\.go$": "ignore generated code",
       ".*_generated\\.go$": "ignore generated code",
       ".*mock.go$": "ignore generated code",

pkg/expression/schema.go

@@ -67,6 +67,9 @@ func (s *Schema) String() string {
 
 // Clone copies the total schema.
 func (s *Schema) Clone() *Schema {
+	if s == nil {
+		return nil
+	}
 	cols := make([]*Column, 0, s.Len())
 	keys := make([]KeyInfo, 0, len(s.Keys))
 	for _, col := range s.Columns {

pkg/planner/core/BUILD.bazel

@@ -64,6 +64,8 @@ go_library(
         "plan_cache_rebuild.go",
         "plan_cache_utils.go",
         "plan_cacheable_checker.go",
+        "plan_clone_generated.go",
+        "plan_clone_generator.go",
         "plan_cost_detail.go",
         "plan_cost_ver1.go",
         "plan_cost_ver2.go",
@@ -256,6 +258,7 @@ go_test(
         "plan_cache_rebuild_test.go",
         "plan_cache_test.go",
         "plan_cacheable_checker_test.go",
+        "plan_clone_test.go",
         "plan_cost_detail_test.go",
         "plan_cost_ver1_test.go",
         "plan_cost_ver2_test.go",
@@ -271,7 +274,10 @@ go_test(
         "stringer_test.go",
         "util_test.go",
     ],
-    data = glob(["testdata/**"]),
+    data = glob([
+        "testdata/**",
+        "*.go",
+    ]),
     embed = [":core"],
     flaky = True,
     shard_count = 50,

pkg/planner/core/physical_plans.go

@@ -680,26 +680,26 @@ type PhysicalIndexScan struct {
 	// AccessCondition is used to calculate range.
 	AccessCondition []expression.Expression
 
-	Table      *model.TableInfo
-	Index      *model.IndexInfo
+	Table      *model.TableInfo `plan-cache-clone:"shallow"` // please see comment on genPlanCloneForPlanCacheCode.
+	Index      *model.IndexInfo `plan-cache-clone:"shallow"`
 	IdxCols    []*expression.Column
 	IdxColLens []int
 	Ranges     []*ranger.Range
-	Columns    []*model.ColumnInfo
-	DBName     model.CIStr
+	Columns    []*model.ColumnInfo `plan-cache-clone:"shallow"`
+	DBName     model.CIStr         `plan-cache-clone:"shallow"`
 
-	TableAsName *model.CIStr
+	TableAsName *model.CIStr `plan-cache-clone:"shallow"`
 
 	// dataSourceSchema is the original schema of DataSource. The schema of index scan in KV and index reader in TiDB
 	// will be different. The schema of index scan will decode all columns of index but the TiDB only need some of them.
-	dataSourceSchema *expression.Schema
+	dataSourceSchema *expression.Schema `plan-cache-clone:"shallow"`
 
 	rangeInfo string
 
 	// The index scan may be on a partition.
 	physicalTableID int64
 
-	GenExprs map[model.TableItemID]expression.Expression `json:"-"`
+	GenExprs map[model.TableItemID]expression.Expression `plan-cache-clone:"must-nil"`
 
 	isPartition bool
 	Desc        bool
@@ -715,18 +715,18 @@ type PhysicalIndexScan struct {
 
 	// required by cost model
 	// tblColHists contains all columns before pruning, which are used to calculate row-size
-	tblColHists   *statistics.HistColl
+	tblColHists   *statistics.HistColl `plan-cache-clone:"shallow"`
 	pkIsHandleCol *expression.Column
 
 	// constColsByCond records the constant part of the index columns caused by the access conds.
 	// e.g. the index is (a, b, c) and there's filter a = 1 and b = 2, then the column a and b are const part.
 	constColsByCond []bool
 
-	prop *property.PhysicalProperty
+	prop *property.PhysicalProperty `plan-cache-clone:"shallow"`
 
 	// usedStatsInfo records stats status of this physical table.
 	// It's for printing stats related information when display execution plan.
-	usedStatsInfo *stmtctx.UsedStatsInfoForTable
+	usedStatsInfo *stmtctx.UsedStatsInfoForTable `plan-cache-clone:"shallow"`
 }
 
 // Clone implements op.PhysicalPlan interface.
@@ -857,12 +857,12 @@ type PhysicalTableScan struct {
 	// TODO: remove this field after we support pushing down selection to coprocessor.
 	LateMaterializationFilterCondition []expression.Expression
 
-	Table   *model.TableInfo
-	Columns []*model.ColumnInfo
-	DBName  model.CIStr
+	Table   *model.TableInfo    `plan-cache-clone:"shallow"`
+	Columns []*model.ColumnInfo `plan-cache-clone:"shallow"`
+	DBName  model.CIStr         `plan-cache-clone:"shallow"`
 	Ranges  []*ranger.Range
 
-	TableAsName *model.CIStr
+	TableAsName *model.CIStr `plan-cache-clone:"shallow"`
 
 	physicalTableID int64
 
@@ -890,13 +890,13 @@ type PhysicalTableScan struct {
 
 	PlanPartInfo *PhysPlanPartInfo
 
-	SampleInfo *tablesampler.TableSampleInfo
+	SampleInfo *tablesampler.TableSampleInfo `plan-cache-clone:"must-nil"`
 
 	// required by cost model
 	// tblCols and tblColHists contains all columns before pruning, which are used to calculate row-size
-	tblCols     []*expression.Column
-	tblColHists *statistics.HistColl
-	prop        *property.PhysicalProperty
+	tblCols     []*expression.Column       `plan-cache-clone:"shallow"`
+	tblColHists *statistics.HistColl       `plan-cache-clone:"shallow"`
+	prop        *property.PhysicalProperty `plan-cache-clone:"shallow"`
 
 	// constColsByCond records the constant part of the index columns caused by the access conds.
 	// e.g. the index is (a, b, c) and there's filter a = 1 and b = 2, then the column a and b are const part.
@@ -905,10 +905,10 @@ type PhysicalTableScan struct {
 
 	// usedStatsInfo records stats status of this physical table.
 	// It's for printing stats related information when display execution plan.
-	usedStatsInfo *stmtctx.UsedStatsInfoForTable
+	usedStatsInfo *stmtctx.UsedStatsInfoForTable `plan-cache-clone:"shallow"`
 
 	// for runtime filter
-	runtimeFilterList []*RuntimeFilter
+	runtimeFilterList []*RuntimeFilter `plan-cache-clone:"must-nil"` // plan with runtime filter is not cached
 	maxWaitTimeMs     int
 }
 

pkg/planner/core/plan.go

@@ -249,14 +249,14 @@ func getActualProbeCntFromProbeParents(pps []base.PhysicalPlan, statsColl *execd
 type basePhysicalPlan struct {
 	baseimpl.Plan
 
-	childrenReqProps []*property.PhysicalProperty
+	childrenReqProps []*property.PhysicalProperty `plan-cache-clone:"shallow"`
 	self             base.PhysicalPlan
 	children         []base.PhysicalPlan
 
 	// used by the new cost interface
 	planCostInit bool
 	planCost     float64
-	planCostVer2 costusage.CostVer2
+	planCostVer2 costusage.CostVer2 `plan-cache-clone:"shallow"`
 
 	// probeParents records the IndexJoins and Applys with this operator in their inner children.
 	// Please see comments in op.PhysicalPlan for details.
@@ -268,6 +268,37 @@ type basePhysicalPlan struct {
 	TiFlashFineGrainedShuffleStreamCount uint64
 }
 
+func (p *basePhysicalPlan) cloneForPlanCacheWithSelf(newCtx base.PlanContext, newSelf base.PhysicalPlan) (*basePhysicalPlan, bool) {
+	cloned := new(basePhysicalPlan)
+	*cloned = *p
+	cloned.SetSCtx(newCtx)
+	cloned.self = newSelf
+	cloned.children = make([]base.PhysicalPlan, 0, len(p.children))
+	for _, child := range p.children {
+		clonedChild, ok := child.CloneForPlanCache(newCtx)
+		if !ok {
+			return nil, false
+		}
+		clonedPP, ok := clonedChild.(base.PhysicalPlan)
+		if !ok {
+			return nil, false
+		}
+		cloned.children = append(cloned.children, clonedPP)
+	}
+	for _, probe := range p.probeParents {
+		clonedProbe, ok := probe.CloneForPlanCache(newCtx)
+		if !ok {
+			return nil, false
+		}
+		clonedPP, ok := clonedProbe.(base.PhysicalPlan)
+		if !ok {
+			return nil, false
+		}
+		cloned.probeParents = append(cloned.probeParents, clonedPP)
+	}
+	return cloned, true
+}
+
 func (p *basePhysicalPlan) cloneWithSelf(newCtx base.PlanContext, newSelf base.PhysicalPlan) (*basePhysicalPlan, error) {
 	base := &basePhysicalPlan{
 		Plan:                                 p.Plan,

pkg/planner/core/plan_cache_rebuild_test.go

@@ -153,7 +153,7 @@ func TestCheckPlanClone(t *testing.T) {
 
 	// test tag
 	type S struct {
-		p1 *int `plan-cache-shallow-clone:"true"`
+		p1 *int `plan-cache-clone:"shallow"`
 		p2 *int
 	}
 	s1 := new(S)
@@ -255,8 +255,8 @@ func planCacheUnclearCloneCheck(v1, v2 reflect.Value, path string, visited map[v
 		return planCacheUnclearCloneCheck(v1.Elem(), v2.Elem(), path, visited)
 	case reflect.Struct:
 		for i, n := 0, v1.NumField(); i < n; i++ {
-			tag := v1.Type().Field(i).Tag.Get("plan-cache-shallow-clone")
-			if tag == "true" {
+			tag := v1.Type().Field(i).Tag.Get("plan-cache-clone")
+			if tag == "shallow" {
 				continue
 			}
 			fieldName := v1.Type().Field(i).Name