executor: tiny clean up by removing unnecessary string creation (ping…

…cap#10213)

* executor: clean up by remove unnecessary string creation
* check if id is nil

executor/benchmark_test.go

@@ -30,7 +30,6 @@ import (
 	"github.com/pingcap/tidb/types"
 	"github.com/pingcap/tidb/util/chunk"
 	"github.com/pingcap/tidb/util/mock"
-	"github.com/pingcap/tidb/util/stringutil"
 )
 
 var (
@@ -128,7 +127,7 @@ func (mds *mockDataSource) Next(ctx context.Context, req *chunk.RecordBatch) err
 }
 
 func buildMockDataSource(opt mockDataSourceParameters) *mockDataSource {
-	baseExec := newBaseExecutor(opt.ctx, opt.schema, stringutil.StringerStr(""))
+	baseExec := newBaseExecutor(opt.ctx, opt.schema, nil)
 	m := &mockDataSource{baseExec, opt, nil, nil, 0}
 	types := m.retTypes()
 	colData := make([][]interface{}, len(types))

executor/executor.go

@@ -141,7 +141,9 @@ func newBaseExecutor(ctx sessionctx.Context, schema *expression.Schema, id fmt.S
 		maxChunkSize: ctx.GetSessionVars().MaxChunkSize,
 	}
 	if ctx.GetSessionVars().StmtCtx.RuntimeStatsColl != nil {
-		e.runtimeStats = e.ctx.GetSessionVars().StmtCtx.RuntimeStatsColl.GetRootStats(e.id.String())
+		if e.id != nil {
+			e.runtimeStats = e.ctx.GetSessionVars().StmtCtx.RuntimeStatsColl.GetRootStats(e.id.String())
+		}
 	}
 	if schema != nil {
 		cols := schema.Columns

executor/executor_pkg_test.go

@@ -29,7 +29,6 @@ import (
 	"github.com/pingcap/tidb/util/chunk"
 	"github.com/pingcap/tidb/util/mock"
 	"github.com/pingcap/tidb/util/ranger"
-	"github.com/pingcap/tidb/util/stringutil"
 )
 
 var _ = Suite(&testExecSuite{})
@@ -93,7 +92,7 @@ func (s *testExecSuite) TestShowProcessList(c *C) {
 
 	// Compose executor.
 	e := &ShowExec{
-		baseExecutor: newBaseExecutor(sctx, schema, stringutil.StringerStr("")),
+		baseExecutor: newBaseExecutor(sctx, schema, nil),
 		Tp:           ast.ShowProcessList,
 	}
 

executor/executor_required_rows_test.go

@@ -33,7 +33,6 @@ import (
 	"github.com/pingcap/tidb/util/chunk"
 	"github.com/pingcap/tidb/util/memory"
 	"github.com/pingcap/tidb/util/mock"
-	"github.com/pingcap/tidb/util/stringutil"
 )
 
 type requiredRowsDataSource struct {
@@ -63,7 +62,7 @@ func newRequiredRowsDataSource(ctx sessionctx.Context, totalRows int, expectedRo
 		cols[i] = &expression.Column{Index: i, RetType: retTypes[i]}
 	}
 	schema := expression.NewSchema(cols...)
-	baseExec := newBaseExecutor(ctx, schema, stringutil.StringerStr(""))
+	baseExec := newBaseExecutor(ctx, schema, nil)
 	return &requiredRowsDataSource{baseExec, totalRows, 0, ctx, expectedRowsRet, 0, defaultGenerator}
 }
 
@@ -191,7 +190,7 @@ func (s *testExecSuite) TestLimitRequiredRows(c *C) {
 
 func buildLimitExec(ctx sessionctx.Context, src Executor, offset, count int) Executor {
 	n := mathutil.Min(count, ctx.GetSessionVars().MaxChunkSize)
-	base := newBaseExecutor(ctx, src.Schema(), stringutil.StringerStr(""), src)
+	base := newBaseExecutor(ctx, src.Schema(), nil, src)
 	base.initCap = n
 	limitExec := &LimitExec{
 		baseExecutor: base,
@@ -206,7 +205,7 @@ func defaultCtx() sessionctx.Context {
 	ctx.GetSessionVars().InitChunkSize = variable.DefInitChunkSize
 	ctx.GetSessionVars().MaxChunkSize = variable.DefMaxChunkSize
 	ctx.GetSessionVars().MemQuotaSort = variable.DefTiDBMemQuotaSort
-	ctx.GetSessionVars().StmtCtx.MemTracker = memory.NewTracker(stringutil.StringerStr(""), ctx.GetSessionVars().MemQuotaQuery)
+	ctx.GetSessionVars().StmtCtx.MemTracker = memory.NewTracker(nil, ctx.GetSessionVars().MemQuotaQuery)
 	ctx.GetSessionVars().SnapshotTS = uint64(1)
 	return ctx
 }
@@ -274,7 +273,7 @@ func (s *testExecSuite) TestSortRequiredRows(c *C) {
 
 func buildSortExec(sctx sessionctx.Context, byItems []*plannercore.ByItems, src Executor) Executor {
 	sortExec := SortExec{
-		baseExecutor: newBaseExecutor(sctx, src.Schema(), stringutil.StringerStr(""), src),
+		baseExecutor: newBaseExecutor(sctx, src.Schema(), nil, src),
 		ByItems:      byItems,
 		schema:       src.Schema(),
 	}
@@ -381,7 +380,7 @@ func (s *testExecSuite) TestTopNRequiredRows(c *C) {
 
 func buildTopNExec(ctx sessionctx.Context, offset, count int, byItems []*plannercore.ByItems, src Executor) Executor {
 	sortExec := SortExec{
-		baseExecutor: newBaseExecutor(ctx, src.Schema(), stringutil.StringerStr(""), src),
+		baseExecutor: newBaseExecutor(ctx, src.Schema(), nil, src),
 		ByItems:      byItems,
 		schema:       src.Schema(),
 	}
@@ -474,7 +473,7 @@ func (s *testExecSuite) TestSelectionRequiredRows(c *C) {
 
 func buildSelectionExec(ctx sessionctx.Context, filters []expression.Expression, src Executor) Executor {
 	return &SelectionExec{
-		baseExecutor: newBaseExecutor(ctx, src.Schema(), stringutil.StringerStr(""), src),
+		baseExecutor: newBaseExecutor(ctx, src.Schema(), nil, src),
 		filters:      filters,
 	}
 }
@@ -592,7 +591,7 @@ func (s *testExecSuite) TestProjectionParallelRequiredRows(c *C) {
 
 func buildProjectionExec(ctx sessionctx.Context, exprs []expression.Expression, src Executor, numWorkers int) Executor {
 	return &ProjectionExec{
-		baseExecutor:  newBaseExecutor(ctx, src.Schema(), stringutil.StringerStr(""), src),
+		baseExecutor:  newBaseExecutor(ctx, src.Schema(), nil, src),
 		numWorkers:    int64(numWorkers),
 		evaluatorSuit: expression.NewEvaluatorSuite(exprs, false),
 	}

executor/pkg_test.go

@@ -64,7 +64,7 @@ func (s *pkgTestSuite) TestNestedLoopApply(c *C) {
 	con := &expression.Constant{Value: types.NewDatum(6), RetType: types.NewFieldType(mysql.TypeLong)}
 	outerSchema := expression.NewSchema(col0)
 	outerExec := &MockExec{
-		baseExecutor: newBaseExecutor(sctx, outerSchema, stringutil.StringerStr("")),
+		baseExecutor: newBaseExecutor(sctx, outerSchema, nil),
 		Rows: []chunk.MutRow{
 			chunk.MutRowFromDatums(types.MakeDatums(1)),
 			chunk.MutRowFromDatums(types.MakeDatums(2)),
@@ -75,7 +75,7 @@ func (s *pkgTestSuite) TestNestedLoopApply(c *C) {
 		}}
 	innerSchema := expression.NewSchema(col1)
 	innerExec := &MockExec{
-		baseExecutor: newBaseExecutor(sctx, innerSchema, stringutil.StringerStr("")),
+		baseExecutor: newBaseExecutor(sctx, innerSchema, nil),
 		Rows: []chunk.MutRow{
 			chunk.MutRowFromDatums(types.MakeDatums(1)),
 			chunk.MutRowFromDatums(types.MakeDatums(2)),
@@ -91,7 +91,7 @@ func (s *pkgTestSuite) TestNestedLoopApply(c *C) {
 		make([]types.Datum, innerExec.Schema().Len()), []expression.Expression{otherFilter}, outerExec.retTypes(), innerExec.retTypes())
 	joinSchema := expression.NewSchema(col0, col1)
 	join := &NestedLoopApplyExec{
-		baseExecutor: newBaseExecutor(sctx, joinSchema, stringutil.StringerStr("")),
+		baseExecutor: newBaseExecutor(sctx, joinSchema, nil),
 		outerExec:    outerExec,
 		innerExec:    innerExec,
 		outerFilter:  []expression.Expression{outerFilter},
@@ -122,7 +122,7 @@ func prepareOneColChildExec(sctx sessionctx.Context, rowCount int) Executor {
 	col0 := &expression.Column{Index: 0, RetType: types.NewFieldType(mysql.TypeLong)}
 	schema := expression.NewSchema(col0)
 	exec := &MockExec{
-		baseExecutor: newBaseExecutor(sctx, schema, stringutil.StringerStr("")),
+		baseExecutor: newBaseExecutor(sctx, schema, nil),
 		Rows:         make([]chunk.MutRow, rowCount)}
 	for i := 0; i < len(exec.Rows); i++ {
 		exec.Rows[i] = chunk.MutRowFromDatums(types.MakeDatums(i % 10))

executor/table_readers_required_rows_test.go

@@ -30,7 +30,6 @@ import (
 	"github.com/pingcap/tidb/table/tables"
 	"github.com/pingcap/tidb/types"
 	"github.com/pingcap/tidb/util/chunk"
-	"github.com/pingcap/tidb/util/stringutil"
 	"github.com/pingcap/tipb/go-tipb"
 )
 
@@ -143,7 +142,7 @@ func buildMockBaseExec(sctx sessionctx.Context) baseExecutor {
 		cols[i] = &expression.Column{Index: i, RetType: retTypes[i]}
 	}
 	schema := expression.NewSchema(cols...)
-	baseExec := newBaseExecutor(sctx, schema, stringutil.StringerStr(""))
+	baseExec := newBaseExecutor(sctx, schema, nil)
 	return baseExec
 }