executor,server: re-implement the kill statement by checking the `N…

…ext()` function (10841) (#10879)

executor/adapter.go

@@ -98,7 +98,7 @@ func schema2ResultFields(schema *expression.Schema, defaultDB string) (rfs []*as
 // next query.
 // If stmt is not nil and chunk with some rows inside, we simply update last query found rows by the number of row in chunk.
 func (a *recordSet) Next(ctx context.Context, chk *chunk.Chunk) error {
-	err := a.executor.Next(ctx, chk)
+	err := Next(ctx, a.executor, chk)
 	if err != nil {
 		a.lastErr = err
 		return errors.Trace(err)
@@ -286,7 +286,7 @@ func (a *ExecStmt) handleNoDelayExecutor(ctx context.Context, sctx sessionctx.Co
 		a.logAudit()
 	}()
 
-	err = e.Next(ctx, e.newFirstChunk())
+	err = Next(ctx, e, e.newFirstChunk())
 	if err != nil {
 		return nil, errors.Trace(err)
 	}

executor/aggregate.go

@@ -549,7 +549,7 @@ func (e *HashAggExec) fetchChildData(ctx context.Context) {
 			}
 			chk = input.chk
 		}
-		err = e.children[0].Next(ctx, chk)
+		err = Next(ctx, e.children[0], chk)
 		if err != nil {
 			e.finalOutputCh <- &AfFinalResult{err: errors.Trace(err)}
 			return
@@ -669,7 +669,7 @@ func (e *HashAggExec) unparallelExec(ctx context.Context, chk *chunk.Chunk) erro
 func (e *HashAggExec) execute(ctx context.Context) (err error) {
 	inputIter := chunk.NewIterator4Chunk(e.childResult)
 	for {
-		err := e.children[0].Next(ctx, e.childResult)
+		err := Next(ctx, e.children[0], e.childResult)
 		if err != nil {
 			return errors.Trace(err)
 		}
@@ -856,7 +856,7 @@ func (e *StreamAggExec) fetchChildIfNecessary(ctx context.Context, chk *chunk.Ch
 		return errors.Trace(err)
 	}
 
-	err = e.children[0].Next(ctx, e.childResult)
+	err = Next(ctx, e.children[0], e.childResult)
 	if err != nil {
 		return errors.Trace(err)
 	}

executor/delete.go

@@ -100,7 +100,7 @@ func (e *DeleteExec) deleteSingleTableByChunk(ctx context.Context) error {
 	for {
 		iter := chunk.NewIterator4Chunk(chk)
 
-		err := e.children[0].Next(ctx, chk)
+		err := Next(ctx, e.children[0], chk)
 		if err != nil {
 			return errors.Trace(err)
 		}
@@ -177,7 +177,7 @@ func (e *DeleteExec) deleteMultiTablesByChunk(ctx context.Context) error {
 	chk := e.children[0].newFirstChunk()
 	for {
 		iter := chunk.NewIterator4Chunk(chk)
-		err := e.children[0].Next(ctx, chk)
+		err := Next(ctx, e.children[0], chk)
 		if err != nil {
 			return errors.Trace(err)
 		}

executor/distsql.go

@@ -754,7 +754,7 @@ func (w *tableWorker) executeTask(ctx context.Context, task *lookupTableTask) er
 	task.rows = make([]chunk.Row, 0, handleCnt)
 	for {
 		chk := tableReader.newFirstChunk()
-		err = tableReader.Next(ctx, chk)
+		err = Next(ctx, tableReader, chk)
 		if err != nil {
 			logutil.Logger(ctx).Error("table reader fetch next chunk failed", zap.Error(err))
 			return errors.Trace(err)

executor/errors.go

@@ -45,6 +45,7 @@ var (
 	ErrCantChangeTxCharacteristics = terror.ClassExecutor.New(mysql.ErrCantChangeTxCharacteristics, mysql.MySQLErrName[mysql.ErrCantChangeTxCharacteristics])
 	ErrPsManyParam                 = terror.ClassExecutor.New(mysql.ErrPsManyParam, mysql.MySQLErrName[mysql.ErrPsManyParam])
 	ErrAdminCheckTable             = terror.ClassExecutor.New(mysql.ErrAdminCheckTable, mysql.MySQLErrName[mysql.ErrAdminCheckTable])
+	ErrQueryInterrupted            = terror.ClassExecutor.New(mysql.ErrQueryInterrupted, mysql.MySQLErrName[mysql.ErrQueryInterrupted])
 )
 
 func init() {
@@ -57,6 +58,7 @@ func init() {
 		mysql.ErrCantChangeTxCharacteristics: mysql.ErrCantChangeTxCharacteristics,
 		mysql.ErrPsManyParam:                 mysql.ErrPsManyParam,
 		mysql.ErrAdminCheckTable:             mysql.ErrAdminCheckTable,
+		mysql.ErrQueryInterrupted:            mysql.ErrQueryInterrupted,
 	}
 	terror.ErrClassToMySQLCodes[terror.ClassExecutor] = tableMySQLErrCodes
 }

executor/executor.go

@@ -83,6 +83,10 @@ type baseExecutor struct {
 	runtimeStats  *execdetails.RuntimeStats
 }
 
+func (e *baseExecutor) base() *baseExecutor {
+	return e
+}
+
 // Open initializes children recursively and "childrenResults" according to children's schemas.
 func (e *baseExecutor) Open(ctx context.Context) error {
 	for _, child := range e.children {
@@ -161,6 +165,7 @@ func newBaseExecutor(ctx sessionctx.Context, schema *expression.Schema, id strin
 // return a batch of rows, other than a single row in Volcano.
 // NOTE: Executors must call "chk.Reset()" before appending their results to it.
 type Executor interface {
+	base() *baseExecutor
 	Open(context.Context) error
 	Next(ctx context.Context, chk *chunk.Chunk) error
 	Close() error
@@ -170,6 +175,16 @@ type Executor interface {
 	newFirstChunk() *chunk.Chunk
 }
 
+// Next is a wrapper function on e.Next(), it handles some common codes.
+func Next(ctx context.Context, e Executor, chk *chunk.Chunk) error {
+	sessVars := e.base().ctx.GetSessionVars()
+	if atomic.CompareAndSwapUint32(&sessVars.Killed, 1, 0) {
+		return ErrQueryInterrupted
+	}
+
+	return e.Next(ctx, chk)
+}
+
 // CancelDDLJobsExec represents a cancel DDL jobs executor.
 type CancelDDLJobsExec struct {
 	baseExecutor
@@ -533,7 +548,7 @@ func (e *CheckIndexExec) Next(ctx context.Context, chk *chunk.Chunk) error {
 	}
 	chk = e.src.newFirstChunk()
 	for {
-		err := e.src.Next(ctx, chk)
+		err := Next(ctx, e.src, chk)
 		if err != nil {
 			return errors.Trace(err)
 		}
@@ -636,7 +651,7 @@ func (e *SelectLockExec) Open(ctx context.Context) error {
 // Next implements the Executor Next interface.
 func (e *SelectLockExec) Next(ctx context.Context, chk *chunk.Chunk) error {
 	chk.GrowAndReset(e.maxChunkSize)
-	err := e.children[0].Next(ctx, chk)
+	err := Next(ctx, e.children[0], chk)
 	if err != nil {
 		return errors.Trace(err)
 	}
@@ -693,7 +708,7 @@ func (e *LimitExec) Next(ctx context.Context, chk *chunk.Chunk) error {
 	for !e.meetFirstBatch {
 		// transfer req's requiredRows to childResult and then adjust it in childResult
 		e.childResult = e.childResult.SetRequiredRows(chk.RequiredRows(), e.maxChunkSize)
-		err := e.children[0].Next(ctx, e.adjustRequiredRows(e.childResult))
+		err := Next(ctx, e.children[0], e.adjustRequiredRows(e.childResult))
 		if err != nil {
 			return errors.Trace(err)
 		}
@@ -718,7 +733,7 @@ func (e *LimitExec) Next(ctx context.Context, chk *chunk.Chunk) error {
 		e.cursor += batchSize
 	}
 	e.adjustRequiredRows(chk)
-	err := e.children[0].Next(ctx, chk)
+	err := Next(ctx, e.children[0], chk)
 	if err != nil {
 		return errors.Trace(err)
 	}
@@ -788,7 +803,7 @@ func init() {
 		}
 		chk := exec.newFirstChunk()
 		for {
-			err = exec.Next(ctx, chk)
+			err = Next(ctx, exec, chk)
 			if err != nil {
 				return rows, errors.Trace(err)
 			}
@@ -897,7 +912,7 @@ func (e *SelectionExec) Next(ctx context.Context, chk *chunk.Chunk) error {
 			}
 			chk.AppendRow(e.inputRow)
 		}
-		err := e.children[0].Next(ctx, e.childResult)
+		err := Next(ctx, e.children[0], e.childResult)
 		if err != nil {
 			return errors.Trace(err)
 		}
@@ -929,7 +944,7 @@ func (e *SelectionExec) unBatchedNext(ctx context.Context, chk *chunk.Chunk) err
 				return nil
 			}
 		}
-		err := e.children[0].Next(ctx, e.childResult)
+		err := Next(ctx, e.children[0], e.childResult)
 		if err != nil {
 			return errors.Trace(err)
 		}
@@ -1069,7 +1084,7 @@ func (e *MaxOneRowExec) Next(ctx context.Context, chk *chunk.Chunk) error {
 		return nil
 	}
 	e.evaluated = true
-	err := e.children[0].Next(ctx, chk)
+	err := Next(ctx, e.children[0], chk)
 	if err != nil {
 		return errors.Trace(err)
 	}

executor/explain.go

@@ -73,7 +73,7 @@ func (e *ExplainExec) generateExplainInfo(ctx context.Context) ([][]string, erro
 	if e.analyzeExec != nil {
 		chk := e.analyzeExec.newFirstChunk()
 		for {
-			err := e.analyzeExec.Next(ctx, chk)
+			err := Next(ctx, e.analyzeExec, chk)
 			if err != nil {
 				return nil, err
 			}

executor/index_lookup_join.go

@@ -363,7 +363,7 @@ func (ow *outerWorker) buildTask(ctx context.Context) (*lookUpJoinTask, error) {
 
 	task.memTracker.Consume(task.outerResult.MemoryUsage())
 	for task.outerResult.NumRows() < ow.batchSize {
-		err := ow.executor.Next(ctx, ow.executorChk)
+		err := Next(ctx, ow.executor, ow.executorChk)
 		if err != nil {
 			return task, errors.Trace(err)
 		}
@@ -555,7 +555,7 @@ func (iw *innerWorker) fetchInnerResults(ctx context.Context, task *lookUpJoinTa
 	innerResult.GetMemTracker().SetLabel("inner result")
 	innerResult.GetMemTracker().AttachTo(task.memTracker)
 	for {
-		err := innerExec.Next(ctx, iw.executorChk)
+		err := Next(ctx, innerExec, iw.executorChk)
 		if err != nil {
 			return errors.Trace(err)
 		}

executor/insert_common.go

@@ -309,7 +309,7 @@ func (e *InsertValues) insertRowsFromSelect(ctx context.Context, exec func(rows
 	batchInsert := (sessVars.BatchInsert && !sessVars.InTxn()) || config.GetGlobalConfig().EnableBatchDML
 
 	for {
-		err := selectExec.Next(ctx, chk)
+		err := Next(ctx, selectExec, chk)
 		if err != nil {
 			return errors.Trace(err)
 		}

executor/join.go

@@ -203,7 +203,7 @@ func (e *HashJoinExec) fetchOuterChunks(ctx context.Context) {
 			}
 		}
 		outerResult := outerResource.chk
-		err := e.outerExec.Next(ctx, outerResult)
+		err := Next(ctx, e.outerExec, outerResult)
 		if err != nil {
 			e.joinResultCh <- &hashjoinWorkerResult{
 				err: errors.Trace(err),
@@ -268,7 +268,7 @@ func (e *HashJoinExec) fetchInnerRows(ctx context.Context, chkCh chan<- *chunk.C
 				return
 			}
 			chk := e.children[e.innerIdx].newFirstChunk()
-			err = e.innerExec.Next(ctx, chk)
+			err = Next(ctx, e.innerExec, chk)
 			if err != nil {
 				e.innerFinished <- errors.Trace(err)
 				return
@@ -648,7 +648,7 @@ func (e *NestedLoopApplyExec) fetchSelectedOuterRow(ctx context.Context, chk *ch
 	outerIter := chunk.NewIterator4Chunk(e.outerChunk)
 	for {
 		if e.outerChunkCursor >= e.outerChunk.NumRows() {
-			err := e.outerExec.Next(ctx, e.outerChunk)
+			err := Next(ctx, e.outerExec, e.outerChunk)
 			if err != nil {
 				return nil, errors.Trace(err)
 			}
@@ -685,7 +685,7 @@ func (e *NestedLoopApplyExec) fetchAllInners(ctx context.Context) error {
 	e.innerList.Reset()
 	innerIter := chunk.NewIterator4Chunk(e.innerChunk)
 	for {
-		err := e.innerExec.Next(ctx, e.innerChunk)
+		err := Next(ctx, e.innerExec, e.innerChunk)
 		if err != nil {
 			return errors.Trace(err)
 		}

executor/merge_join.go

@@ -139,7 +139,7 @@ func (t *mergeJoinInnerTable) nextRow() (chunk.Row, error) {
 		if t.curRow == t.curIter.End() {
 			t.reallocReaderResult()
 			oldMemUsage := t.curResult.MemoryUsage()
-			err := t.reader.Next(t.ctx, t.curResult)
+			err := Next(t.ctx, t.reader, t.curResult)
 			// error happens or no more data.
 			if err != nil || t.curResult.NumRows() == 0 {
 				t.curRow = t.curIter.End()
@@ -378,7 +378,7 @@ func (e *MergeJoinExec) fetchNextInnerRows() (err error) {
 // may not all belong to the same join key, but are guaranteed to be sorted
 // according to the join key.
 func (e *MergeJoinExec) fetchNextOuterRows(ctx context.Context) (err error) {
-	err = e.outerTable.reader.Next(ctx, e.outerTable.chk)
+	err = Next(ctx, e.outerTable.reader, e.outerTable.chk)
 	if err != nil {
 		return errors.Trace(err)
 	}

executor/point_get.go

@@ -18,10 +18,8 @@ import (
 	"github.com/pingcap/failpoint"
 	"github.com/pingcap/parser/model"
 	"github.com/pingcap/parser/mysql"
-	"github.com/pingcap/tidb/expression"
 	"github.com/pingcap/tidb/kv"
 	plannercore "github.com/pingcap/tidb/planner/core"
-	"github.com/pingcap/tidb/sessionctx"
 	"github.com/pingcap/tidb/table"
 	"github.com/pingcap/tidb/table/tables"
 	"github.com/pingcap/tidb/tablecodec"
@@ -38,22 +36,23 @@ func (b *executorBuilder) buildPointGet(p *plannercore.PointGetPlan) Executor {
 		b.err = errors.Trace(err)
 		return nil
 	}
-	return &PointGetExecutor{
-		ctx:     b.ctx,
-		schema:  p.Schema(),
-		tblInfo: p.TblInfo,
-		idxInfo: p.IndexInfo,
-		idxVals: p.IndexValues,
-		handle:  p.Handle,
-		startTS: startTS,
-	}
+	e := &PointGetExecutor{
+		baseExecutor: newBaseExecutor(b.ctx, p.Schema(), p.ExplainID()),
+		tblInfo:      p.TblInfo,
+		idxInfo:      p.IndexInfo,
+		idxVals:      p.IndexValues,
+		handle:       p.Handle,
+		startTS:      startTS,
+	}
+	e.base().initCap = 1
+	e.base().maxChunkSize = 1
+	return e
 }
 
 // PointGetExecutor executes point select query.
 type PointGetExecutor struct {
-	ctx      sessionctx.Context
-	schema   *expression.Schema
-	tps      []*types.FieldType
+	baseExecutor
+
 	tblInfo  *model.TableInfo
 	handle   int64
 	idxInfo  *model.IndexInfo
@@ -232,22 +231,3 @@ func getColInfoByID(tbl *model.TableInfo, colID int64) *model.ColumnInfo {
 	}
 	return nil
 }
-
-// Schema implements the Executor interface.
-func (e *PointGetExecutor) Schema() *expression.Schema {
-	return e.schema
-}
-
-func (e *PointGetExecutor) retTypes() []*types.FieldType {
-	if e.tps == nil {
-		e.tps = make([]*types.FieldType, e.schema.Len())
-		for i := range e.schema.Columns {
-			e.tps[i] = e.schema.Columns[i].RetType
-		}
-	}
-	return e.tps
-}
-
-func (e *PointGetExecutor) newFirstChunk() *chunk.Chunk {
-	return chunk.New(e.retTypes(), 1, 1)
-}

executor/projection.go

@@ -173,7 +173,7 @@ func (e *ProjectionExec) isUnparallelExec() bool {
 func (e *ProjectionExec) unParallelExecute(ctx context.Context, chk *chunk.Chunk) error {
 	// push requiredRows down
 	e.childResult.SetRequiredRows(chk.RequiredRows(), e.maxChunkSize)
-	err := e.children[0].Next(ctx, e.childResult)
+	err := Next(ctx, e.children[0], e.childResult)
 	if err != nil {
 		return errors.Trace(err)
 	}
@@ -306,7 +306,7 @@ func (f *projectionInputFetcher) run(ctx context.Context) {
 
 		requiredRows := atomic.LoadInt64(&f.proj.parentReqRows)
 		input.chk.SetRequiredRows(int(requiredRows), f.proj.maxChunkSize)
-		err := f.child.Next(ctx, input.chk)
+		err := Next(ctx, f.child, input.chk)
 		if err != nil || input.chk.NumRows() == 0 {
 			output.done <- errors.Trace(err)
 			return