Add RowsColumnScanner support (Go 1.27+)

rows.go

@@ -9,217 +9,218 @@
 package mysql
 
 import (
-	"database/sql/driver"
-	"io"
-	"math"
-	"reflect"
+"database/sql/driver"
+"io"
+"math"
+"reflect"
 )
 
 type resultSet struct {
-	columns     []mysqlField
-	columnNames []string
-	done        bool
+columns     []mysqlField
+columnNames []string
+done        bool
 }
 
 type mysqlRows struct {
-	mc     *mysqlConn
-	rs     resultSet
-	finish func()
+mc      *mysqlConn
+rs      resultSet
+finish  func()
+rawCols [][]byte // buffered per-column raw bytes for RowsColumnScanner (Go 1.27+)
 }
 
 type binaryRows struct {
-	mysqlRows
+mysqlRows
 }
 
 type textRows struct {
-	mysqlRows
+mysqlRows
 }
 
 func (rows *mysqlRows) Columns() []string {
-	if rows.rs.columnNames != nil {
-		return rows.rs.columnNames
-	}
-
-	columns := make([]string, len(rows.rs.columns))
-	if rows.mc != nil && rows.mc.cfg.ColumnsWithAlias {
-		for i := range columns {
-			if tableName := rows.rs.columns[i].tableName; len(tableName) > 0 {
-				columns[i] = tableName + "." + rows.rs.columns[i].name
-			} else {
-				columns[i] = rows.rs.columns[i].name
-			}
-		}
-	} else {
-		for i := range columns {
-			columns[i] = rows.rs.columns[i].name
-		}
-	}
-
-	rows.rs.columnNames = columns
-	return columns
+if rows.rs.columnNames != nil {
+return rows.rs.columnNames
+}
+
+columns := make([]string, len(rows.rs.columns))
+if rows.mc != nil && rows.mc.cfg.ColumnsWithAlias {
+for i := range columns {
+if tableName := rows.rs.columns[i].tableName; len(tableName) > 0 {
+columns[i] = tableName + "." + rows.rs.columns[i].name
+} else {
+columns[i] = rows.rs.columns[i].name
+}
+}
+} else {
+for i := range columns {
+columns[i] = rows.rs.columns[i].name
+}
+}
+
+rows.rs.columnNames = columns
+return columns
 }
 
 func (rows *mysqlRows) ColumnTypeDatabaseTypeName(i int) string {
-	return rows.rs.columns[i].typeDatabaseName()
+return rows.rs.columns[i].typeDatabaseName()
 }
 
 // func (rows *mysqlRows) ColumnTypeLength(i int) (length int64, ok bool) {
-// 	return int64(rows.rs.columns[i].length), true
+// return int64(rows.rs.columns[i].length), true
 // }
 
 func (rows *mysqlRows) ColumnTypeNullable(i int) (nullable, ok bool) {
-	return rows.rs.columns[i].flags&flagNotNULL == 0, true
+return rows.rs.columns[i].flags&flagNotNULL == 0, true
 }
 
 func (rows *mysqlRows) ColumnTypePrecisionScale(i int) (int64, int64, bool) {
-	column := rows.rs.columns[i]
-	decimals := int64(column.decimals)
-
-	switch column.fieldType {
-	case fieldTypeDecimal, fieldTypeNewDecimal:
-		if decimals > 0 {
-			return int64(column.length) - 2, decimals, true
-		}
-		return int64(column.length) - 1, decimals, true
-	case fieldTypeTimestamp, fieldTypeDateTime, fieldTypeTime:
-		return decimals, decimals, true
-	case fieldTypeFloat, fieldTypeDouble:
-		if decimals == 0x1f {
-			return math.MaxInt64, math.MaxInt64, true
-		}
-		return math.MaxInt64, decimals, true
-	}
-
-	return 0, 0, false
+column := rows.rs.columns[i]
+decimals := int64(column.decimals)
+
+switch column.fieldType {
+case fieldTypeDecimal, fieldTypeNewDecimal:
+if decimals > 0 {
+return int64(column.length) - 2, decimals, true
+}
+return int64(column.length) - 1, decimals, true
+case fieldTypeTimestamp, fieldTypeDateTime, fieldTypeTime:
+return decimals, decimals, true
+case fieldTypeFloat, fieldTypeDouble:
+if decimals == 0x1f {
+return math.MaxInt64, math.MaxInt64, true
+}
+return math.MaxInt64, decimals, true
+}
+
+return 0, 0, false
 }
 
 func (rows *mysqlRows) ColumnTypeScanType(i int) reflect.Type {
-	return rows.rs.columns[i].scanType()
+return rows.rs.columns[i].scanType()
 }
 
 func (rows *mysqlRows) Close() (err error) {
-	if f := rows.finish; f != nil {
-		f()
-		rows.finish = nil
-	}
-
-	mc := rows.mc
-	if mc == nil {
-		return nil
-	}
-	if err := mc.error(); err != nil {
-		return err
-	}
-
-	// Remove unread packets from stream
-	if !rows.rs.done {
-		err = mc.skipRows()
-	}
-	if err == nil {
-		handleOk := mc.clearResult()
-		if err = handleOk.discardResults(); err != nil {
-			return err
-		}
-	}
-
-	rows.mc = nil
-	return err
+if f := rows.finish; f != nil {
+f()
+rows.finish = nil
+}
+
+mc := rows.mc
+if mc == nil {
+return nil
+}
+if err := mc.error(); err != nil {
+return err
+}
+
+// Remove unread packets from stream
+if !rows.rs.done {
+err = mc.skipRows()
+}
+if err == nil {
+handleOk := mc.clearResult()
+if err = handleOk.discardResults(); err != nil {
+return err
+}
+}
+
+rows.mc = nil
+return err
 }
 
 func (rows *mysqlRows) HasNextResultSet() (b bool) {
-	if rows.mc == nil {
-		return false
-	}
-	return rows.mc.status&statusMoreResultsExists != 0
+if rows.mc == nil {
+return false
+}
+return rows.mc.status&statusMoreResultsExists != 0
 }
 
 func (rows *mysqlRows) nextResultSet() (int, error) {
-	if rows.mc == nil {
-		return 0, io.EOF
-	}
-	if err := rows.mc.error(); err != nil {
-		return 0, err
-	}
-
-	// Remove unread packets from stream
-	if !rows.rs.done {
-		if err := rows.mc.skipRows(); err != nil {
-			return 0, err
-		}
-		rows.rs.done = true
-	}
-
-	if !rows.HasNextResultSet() {
-		rows.mc = nil
-		return 0, io.EOF
-	}
-	rows.rs = resultSet{}
-	// rows.mc.affectedRows and rows.mc.insertIds accumulate on each call to
-	// nextResultSet.
-	resLen, _, err := rows.mc.resultUnchanged().readResultSetHeaderPacket()
-	if err != nil {
-		// Clean up about multi-results flag
-		rows.rs.done = true
-		rows.mc.status = rows.mc.status & (^statusMoreResultsExists)
-	}
-	return resLen, err
+if rows.mc == nil {
+return 0, io.EOF
+}
+if err := rows.mc.error(); err != nil {
+return 0, err
+}
+
+// Remove unread packets from stream
+if !rows.rs.done {
+if err := rows.mc.skipRows(); err != nil {
+return 0, err
+}
+rows.rs.done = true
+}
+
+if !rows.HasNextResultSet() {
+rows.mc = nil
+return 0, io.EOF
+}
+rows.rs = resultSet{}
+// rows.mc.affectedRows and rows.mc.insertIds accumulate on each call to
+// nextResultSet.
+resLen, _, err := rows.mc.resultUnchanged().readResultSetHeaderPacket()
+if err != nil {
+// Clean up about multi-results flag
+rows.rs.done = true
+rows.mc.status = rows.mc.status & (^statusMoreResultsExists)
+}
+return resLen, err
 }
 
 func (rows *mysqlRows) nextNotEmptyResultSet() (int, error) {
-	for {
-		resLen, err := rows.nextResultSet()
-		if err != nil {
-			return 0, err
-		}
+for {
+resLen, err := rows.nextResultSet()
+if err != nil {
+return 0, err
+}
 
-		if resLen > 0 {
-			return resLen, nil
-		}
+if resLen > 0 {
+return resLen, nil
+}
 
-		rows.rs.done = true
-	}
+rows.rs.done = true
+}
 }
 
 func (rows *binaryRows) NextResultSet() error {
-	resLen, err := rows.nextNotEmptyResultSet()
-	if err != nil {
-		return err
-	}
+resLen, err := rows.nextNotEmptyResultSet()
+if err != nil {
+return err
+}
 
-	rows.rs.columns, err = rows.mc.readColumns(resLen, nil)
-	return err
+rows.rs.columns, err = rows.mc.readColumns(resLen, nil)
+return err
 }
 
 func (rows *binaryRows) Next(dest []driver.Value) error {
-	if mc := rows.mc; mc != nil {
-		if err := mc.error(); err != nil {
-			return err
-		}
+if mc := rows.mc; mc != nil {
+if err := mc.error(); err != nil {
+return err
+}
 
-		// Fetch next row from stream
-		return rows.readRow(dest)
-	}
-	return io.EOF
+// Fetch next row from stream
+return rows.readRow(dest)
+}
+return io.EOF
 }
 
 func (rows *textRows) NextResultSet() (err error) {
-	resLen, err := rows.nextNotEmptyResultSet()
-	if err != nil {
-		return err
-	}
+resLen, err := rows.nextNotEmptyResultSet()
+if err != nil {
+return err
+}
 
-	rows.rs.columns, err = rows.mc.readColumns(resLen, nil)
-	return err
+rows.rs.columns, err = rows.mc.readColumns(resLen, nil)
+return err
 }
 
 func (rows *textRows) Next(dest []driver.Value) error {
-	if mc := rows.mc; mc != nil {
-		if err := mc.error(); err != nil {
-			return err
-		}
-
-		// Fetch next row from stream
-		return rows.readRow(dest)
-	}
-	return io.EOF
+if mc := rows.mc; mc != nil {
+if err := mc.error(); err != nil {
+return err
+}
+
+// Fetch next row from stream
+return rows.readRow(dest)
+}
+return io.EOF
 }