fix ut

br/pkg/lightning/mydump/csv_parser.go

@@ -34,8 +34,13 @@ var (
 	errUnterminatedQuotedField = errors.NewNoStackError("syntax error: unterminated quoted field")
 	errDanglingBackslash       = errors.NewNoStackError("syntax error: no character after backslash")
 	errUnexpectedQuoteField    = errors.NewNoStackError("syntax error: cannot have consecutive fields without separator")
+	LargestEntryLimit          int
 )
 
+func init() {
+	LargestEntryLimit = tidbconfig.MaxTxnEntrySizeLimit
+}
+
 // CSVParser is basically a copy of encoding/csv, but special-cased for MySQL-like input.
 type CSVParser struct {
 	blockParser
@@ -337,7 +342,7 @@ func (parser *CSVParser) readUntil(chars *byteSet) ([]byte, byte, error) {
 	var buf []byte
 	for {
 		buf = append(buf, parser.buf...)
-		if len(buf) > tidbconfig.MaxTxnEntrySizeLimit {
+		if len(buf) > LargestEntryLimit {
 			return buf, 0, errors.New("size of row cannot exceed the max value of txn-entry-size-limit")
 		}
 		parser.buf = nil

br/pkg/lightning/mydump/csv_parser_test.go

@@ -17,7 +17,6 @@ import (
 	"github.com/pingcap/tidb/br/pkg/lightning/log"
 	"github.com/pingcap/tidb/br/pkg/lightning/mydump"
 	"github.com/pingcap/tidb/br/pkg/lightning/worker"
-	tidbconfig "github.com/pingcap/tidb/config"
 	"github.com/pingcap/tidb/types"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
@@ -26,12 +25,6 @@ import (
 
 var ioWorkers = worker.NewPool(context.Background(), 5, "test_csv")
 
-var largestEntryLimit int
-
-func init() {
-	largestEntryLimit = tidbconfig.MaxTxnEntrySizeLimit
-}
-
 func assertPosEqual(t *testing.T, parser mydump.Parser, expectPos, expectRowID int64) {
 	pos, rowID := parser.Pos()
 	require.Equal(t, expectPos, pos)
@@ -697,8 +690,9 @@ func TestTooLargeRow(t *testing.T) {
 	}
 	var testCase bytes.Buffer
 	testCase.WriteString("a,b,c,d")
-	// WARN: will take up 120MB memory here.
-	for i := 0; i < largestEntryLimit; i++ {
+	// WARN: will take up 10KB memory here.
+	mydump.LargestEntryLimit = 10 * 1024
+	for i := 0; i < mydump.LargestEntryLimit; i++ {
 		testCase.WriteByte('d')
 	}
 	charsetConvertor, err := mydump.NewCharsetConvertor(cfg.DataCharacterSet, cfg.DataInvalidCharReplace)