importsdk, importer: fix sampled source size in import estimate

pkg/executor/importer/sampler.go

@@ -39,7 +39,6 @@ import (
 	plannercore "github.com/pingcap/tidb/pkg/planner/core"
 	"github.com/pingcap/tidb/pkg/table"
 	"github.com/pingcap/tidb/pkg/table/tables"
-	"github.com/pingcap/tidb/pkg/types"
 	contextutil "github.com/pingcap/tidb/pkg/util/context"
 	"github.com/pingcap/tidb/pkg/util/dbterror/exeerrors"
 	"go.uber.org/zap"
@@ -352,27 +351,30 @@ func (s *kvSizeSampler) sampleOneFile(
 	}()
 
 	var (
-		count        int
-		readRowCache []types.Datum
-		readFn       = parserEncodeReader(parser, chunk.Chunk.EndOffset, chunk.GetKey())
-		kvBatch      = newEncodedKVGroupBatch(ksCodec, maxRowCount)
+		count   int
+		kvBatch = newEncodedKVGroupBatch(ksCodec, maxRowCount)
 	)
 	for count < maxRowCount {
-		row, closed, readErr := readFn(ctx, readRowCache)
-		if readErr != nil {
-			return 0, 0, 0, readErr
-		}
-		if closed {
+		startPos, _ := parser.Pos()
+		if s.cfg.Format != DataFormatParquet && startPos >= chunk.Chunk.EndOffset {
 			break
 		}
-		readRowCache = row.row
-		if rowDelta := row.endOffset - row.startPos; rowDelta > 0 {
-			sourceSize += rowDelta
+
+		readErr := parser.ReadRow()
+		if readErr != nil {
+			if errors.Cause(readErr) == io.EOF {
+				break
+			}
+			return 0, 0, 0, common.ErrEncodeKV.Wrap(readErr).GenWithStackByArgs(chunk.GetKey(), startPos)
 		}
-		kvs, encodeErr := encoder.Encode(row.row, row.rowID)
-		row.resetFn()
+
+		lastRow := parser.LastRow()
+		sourceSize += s.sampledRowSourceSize(parser, startPos, lastRow)
+
+		kvs, encodeErr := encoder.Encode(lastRow.Row, lastRow.RowID)
+		parser.RecycleRow(lastRow)
 		if encodeErr != nil {
-			return 0, 0, 0, common.ErrEncodeKV.Wrap(encodeErr).GenWithStackByArgs(chunk.GetKey(), row.startPos)
+			return 0, 0, 0, common.ErrEncodeKV.Wrap(encodeErr).GenWithStackByArgs(chunk.GetKey(), startPos)
 		}
 		if _, err = kvBatch.add(kvs); err != nil {
 			return 0, 0, 0, err
@@ -382,3 +384,19 @@ func (s *kvSizeSampler) sampleOneFile(
 	dataKVSize, indexKVSize = kvBatch.groupChecksum.DataAndIndexSumSize()
 	return sourceSize, dataKVSize, indexKVSize, nil
 }
+
+func (s *kvSizeSampler) sampledRowSourceSize(parser mydump.Parser, startPos int64, row mydump.Row) int64 {
+	// Sampling needs per-row source bytes, not buffered reader progress.
+	// SQL/CSV parsers expose byte offsets through Pos(), including compressed
+	// input where Pos() tracks uncompressed bytes and stays aligned with the
+	// RealSize-based source totals. Parquet Pos() is row-count based and must
+	// fall back to the row-size estimate.
+	if s.cfg.Format == DataFormatParquet {
+		return int64(row.Length)
+	}
+	endPos, _ := parser.Pos()
+	if rowDelta := endPos - startPos; rowDelta > 0 {
+		return rowDelta
+	}
+	return int64(row.Length)
+}

pkg/executor/importer/sampler_test.go

@@ -238,6 +238,57 @@ func TestSampleIndexSizeRatio(t *testing.T) {
 		require.Error(t, err)
 		require.True(t, reader.closed)
 	})
+
+	t.Run("sql_source_size_uses_consumed_bytes_not_buffered_progress", func(t *testing.T) {
+		dir := t.TempDir()
+		var fileSB strings.Builder
+		fileSB.WriteString("INSERT INTO t VALUES\n")
+		for i := 0; i < 20; i++ {
+			_, err := fmt.Fprintf(&fileSB, "(%d,'v%d','w%d','x%d')", i, i, i, i)
+			require.NoError(t, err)
+			if i < 19 {
+				fileSB.WriteString(",\n")
+				continue
+			}
+			fileSB.WriteString(";\n")
+		}
+		content := fileSB.String()
+		require.NoError(t, os.WriteFile(filepath.Join(dir, "001.sql"), []byte(content), 0o644))
+
+		p := parser.New()
+		node, err := p.ParseOneStmt(`create table t (a int, b text, c text, d text, index idx(a));`, "", "")
+		require.NoError(t, err)
+		sctx := utilmock.NewContext()
+		tblInfo, err := ddl.MockTableInfo(sctx, node.(*ast.CreateTableStmt), 1)
+		require.NoError(t, err)
+		tblInfo.State = model.StatePublic
+		table := tables.MockTableFromMeta(tblInfo)
+
+		ctrl, err := NewLoadDataController(&Plan{
+			Path:         filepath.Join(dir, "*.sql"),
+			Format:       DataFormatSQL,
+			InImportInto: true,
+		}, table, &ASTArgs{})
+		require.NoError(t, err)
+		ctrl.logger = zap.Must(zap.NewDevelopment())
+		ctx := context.Background()
+		require.NoError(t, ctrl.InitDataFiles(ctx))
+
+		sampled, err := SampleFileImportKVSize(
+			ctx,
+			ctrl.buildKVSizeSampleConfig(),
+			table,
+			ctrl.dataStore,
+			ctrl.dataFiles,
+			nil,
+			ctrl.logger,
+		)
+		require.NoError(t, err)
+		require.Positive(t, sampled.SourceSize)
+		require.Positive(t, sampled.TotalKVSize())
+		require.Greater(t, sampled.SourceSize, int64(len(content)/2))
+		require.Less(t, sampled.SourceSize, int64(len(content)*2))
+	})
 }
 func TestSampleIndexSizeRatioVeryLongRows(t *testing.T) {
 	simpleTbl := `create table t (a int, b text, c text, d text, index idx(a));`