Merge pull request #735 from mauserzjeh/master

colLimit function

file.go

@@ -27,10 +27,12 @@ type File struct {
 	DefinedNames         []*xlsxDefinedName
 	cellStoreConstructor CellStoreConstructor
 	rowLimit             int
+	colLimit             int
 	valueOnly            bool
 }
 
 const NoRowLimit int = -1
+const NoColLimit int = -1
 
 type FileOption func(f *File)
 
@@ -42,6 +44,14 @@ func RowLimit(n int) FileOption {
 	}
 }
 
+// ColLimit will limit the columns handled in any given sheet to the
+// first n, where n is the number of columns
+func ColLimit(n int) FileOption {
+	return func(f *File) {
+		f.colLimit = n
+	}
+}
+
 // ValueOnly treats all NULL values as meaningless and it will delete all NULL value cells,
 // before decode worksheet.xml. this option can save memory and time when parsing files
 // with a large number of NULL values. But it may also cause accidental injury,
@@ -60,6 +70,7 @@ func NewFile(options ...FileOption) *File {
 		Sheets:               make([]*Sheet, 0),
 		DefinedNames:         make([]*xlsxDefinedName, 0),
 		rowLimit:             NoRowLimit,
+		colLimit:             NoColLimit,
 		cellStoreConstructor: NewMemoryCellStore,
 	}
 	for _, opt := range options {

go.mod

@@ -3,13 +3,13 @@ module github.com/tealeg/xlsx/v3
 go 1.15
 
 require (
-	golang.org/x/text v0.3.3
 	github.com/frankban/quicktest v1.11.2
 	github.com/google/btree v1.0.0 // indirect
 	github.com/niemeyer/pretty v0.0.0-20200227124842-a10e7caefd8e // indirect
 	github.com/peterbourgon/diskv v2.0.1+incompatible
 	github.com/pkg/profile v1.5.0
 	github.com/rogpeppe/fastuuid v1.2.0
 	github.com/shabbyrobe/xmlwriter v0.0.0-20200208144257-9fca06d00ffa
+	golang.org/x/text v0.3.3 // indirect
 	gopkg.in/check.v1 v1.0.0-20200902074654-038fdea0a05b
 )

go.sum

@@ -11,7 +11,6 @@ github.com/kr/text v0.1.0 h1:45sCR5RtlFHMR4UwH9sdQ5TC8v0qDQCHnXt+kaKSTVE=
 github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
 github.com/niemeyer/pretty v0.0.0-20200227124842-a10e7caefd8e h1:fD57ERR4JtEqsWbfPhv4DMiApHyliiK5xCTNVSPiaAs=
 github.com/niemeyer/pretty v0.0.0-20200227124842-a10e7caefd8e/go.mod h1:zD1mROLANZcx1PVRCS0qkT7pwLkGfwJo4zjcN/Tysno=
-github.com/peterbourgon/diskv v1.0.0 h1:bRU92KzrX3TQ6IYobfie/PnZkFC+1opBfHpf/PHPDoo=
 github.com/peterbourgon/diskv v2.0.1+incompatible h1:UBdAOUP5p4RWqPBg048CAvpKN+vxiaj6gdUUzhl4XmI=
 github.com/peterbourgon/diskv v2.0.1+incompatible/go.mod h1:uqqh8zWWbv1HBMNONnaR/tNboyR3/BZd58JJSHlUSCU=
 github.com/pkg/profile v1.5.0 h1:042Buzk+NhDI+DeSAA62RwJL8VAuZUMQZUjCsRz1Mug=

lib.go

@@ -182,7 +182,7 @@ func getMaxMinFromDimensionRef(ref string) (minx, miny, maxx, maxy int, err erro
 // calculateMaxMinFromWorkSheet works out the dimensions of a spreadsheet
 // that doesn't have a DimensionRef set.  The only case currently
 // known where this is true is with XLSX exported from Google Docs.
-func calculateMaxMinFromWorksheet(worksheet *xlsxWorksheet) (minx, miny, maxx, maxy int, err error) {
+func calculateMaxMinFromWorksheet(worksheet *xlsxWorksheet, colLimit int) (minx, miny, maxx, maxy int, err error) {
 	// Note, this method could be very slow for large spreadsheets.
 	var x, y int
 	var maxVal int
@@ -202,6 +202,12 @@ func calculateMaxMinFromWorksheet(worksheet *xlsxWorksheet) (minx, miny, maxx, m
 			if err != nil {
 				return wrap(err)
 			}
+
+			// break out of the loop if a column limit is set
+			if colLimit != NoColLimit && x+1 > colLimit {
+				break
+			}
+
 			if x < minx {
 				minx = x
 			}
@@ -457,7 +463,7 @@ func fillCellDataFromInlineString(rawcell xlsxC, cell *Cell) {
 // rows from a XSLXWorksheet, populates them with Cells and resolves
 // the value references from the reference table and stores them in
 // the rows and columns.
-func readRowsFromSheet(Worksheet *xlsxWorksheet, file *File, sheet *Sheet, rowLimit int, linkTable hyperlinkTable) error {
+func readRowsFromSheet(Worksheet *xlsxWorksheet, file *File, sheet *Sheet, rowLimit, colLimit int, linkTable hyperlinkTable) error {
 	var row *Row
 	var maxCol, maxRow, colCount, rowCount int
 	var reftable *RefTable
@@ -474,10 +480,10 @@ func readRowsFromSheet(Worksheet *xlsxWorksheet, file *File, sheet *Sheet, rowLi
 		return nil
 	}
 	reftable = file.referenceTable
-	if len(Worksheet.Dimension.Ref) > 0 && len(strings.Split(Worksheet.Dimension.Ref, cellRangeChar)) == 2 && rowLimit == NoRowLimit {
+	if len(Worksheet.Dimension.Ref) > 0 && len(strings.Split(Worksheet.Dimension.Ref, cellRangeChar)) == 2 && rowLimit == NoRowLimit && colLimit == NoColLimit {
 		_, _, maxCol, maxRow, err = getMaxMinFromDimensionRef(Worksheet.Dimension.Ref)
 	} else {
-		_, _, maxCol, maxRow, err = calculateMaxMinFromWorksheet(Worksheet)
+		_, _, maxCol, maxRow, err = calculateMaxMinFromWorksheet(Worksheet, colLimit)
 	}
 	if err != nil {
 		return wrap(err)
@@ -545,6 +551,11 @@ func readRowsFromSheet(Worksheet *xlsxWorksheet, file *File, sheet *Sheet, rowLi
 				return wrap(err)
 			}
 
+			// break out of the loop if column limit is set
+			if colLimit != NoColLimit && colLimit < x+1 {
+				break
+			}
+
 			cellX := x
 
 			cell := newCell(row, cellX)
@@ -687,7 +698,7 @@ func makeHyperlinkTable(worksheet *xlsxWorksheet, fi *File, rsheet *xlsxSheet) (
 // into a Sheet struct.  This work can be done in parallel and so
 // readSheetsFromZipFile will spawn an instance of this function per
 // sheet and get the results back on the provided channel.
-func readSheetFromFile(rsheet xlsxSheet, fi *File, sheetXMLMap map[string]string, rowLimit int, valueOnly bool) (sheet *Sheet, errRes error) {
+func readSheetFromFile(rsheet xlsxSheet, fi *File, sheetXMLMap map[string]string, rowLimit, colLimit int, valueOnly bool) (sheet *Sheet, errRes error) {
 	defer func() {
 		if x := recover(); x != nil {
 			errRes = errors.New(fmt.Sprintf("%v\n%s\n", x, debug.Stack()))
@@ -714,7 +725,7 @@ func readSheetFromFile(rsheet xlsxSheet, fi *File, sheetXMLMap map[string]string
 	}
 
 	sheet.File = fi
-	err = readRowsFromSheet(worksheet, fi, sheet, rowLimit, linkTable)
+	err = readRowsFromSheet(worksheet, fi, sheet, rowLimit, colLimit, linkTable)
 	if err != nil {
 		return wrap(err)
 	}
@@ -743,7 +754,7 @@ func readSheetFromFile(rsheet xlsxSheet, fi *File, sheetXMLMap map[string]string
 // readSheetsFromZipFile is an internal helper function that loops
 // over the Worksheets defined in the XSLXWorkbook and loads them into
 // Sheet objects stored in the Sheets slice of a xlsx.File struct.
-func readSheetsFromZipFile(f *zip.File, file *File, sheetXMLMap map[string]string, rowLimit int, valueOnly bool) (map[string]*Sheet, []*Sheet, error) {
+func readSheetsFromZipFile(f *zip.File, file *File, sheetXMLMap map[string]string, rowLimit, colLimit int, valueOnly bool) (map[string]*Sheet, []*Sheet, error) {
 	var workbook *xlsxWorkbook
 	var err error
 	var rc io.ReadCloser
@@ -787,7 +798,7 @@ func readSheetsFromZipFile(f *zip.File, file *File, sheetXMLMap map[string]strin
 		i, rawsheet := i, rawsheet
 		go func() {
 			sheet, err := readSheetFromFile(rawsheet, file,
-				sheetXMLMap, rowLimit, valueOnly)
+				sheetXMLMap, rowLimit, colLimit, valueOnly)
 			sheetChan <- &indexedSheet{
 				Index: i,
 				Sheet: sheet,
@@ -1073,7 +1084,7 @@ func ReadZipReader(r *zip.Reader, options ...FileOption) (*File, error) {
 
 		file.styles = style
 	}
-	sheetsByName, sheets, err = readSheetsFromZipFile(workbook, file, sheetXMLMap, file.rowLimit, file.valueOnly)
+	sheetsByName, sheets, err = readSheetsFromZipFile(workbook, file, sheetXMLMap, file.rowLimit, file.colLimit, file.valueOnly)
 	if err != nil {
 		return wrap(err)
 	}

lib_test.go

@@ -237,7 +237,7 @@ func TestLib(t *testing.T) {
 		worksheet := new(xlsxWorksheet)
 		err := xml.NewDecoder(sheetxml).Decode(worksheet)
 		c.Assert(err, qt.IsNil)
-		minx, miny, maxx, maxy, err := calculateMaxMinFromWorksheet(worksheet)
+		minx, miny, maxx, maxy, err := calculateMaxMinFromWorksheet(worksheet, NoColLimit)
 		c.Assert(err, qt.IsNil)
 		c.Assert(minx, qt.Equals, 0)
 		c.Assert(miny, qt.Equals, 0)
@@ -346,7 +346,7 @@ func TestLib(t *testing.T) {
 		sheet, err := NewSheet("test")
 		c.Assert(err, qt.IsNil)
 		lt := make(hyperlinkTable)
-		err = readRowsFromSheet(worksheet, file, sheet, NoRowLimit, lt)
+		err = readRowsFromSheet(worksheet, file, sheet, NoRowLimit, NoColLimit, lt)
 		c.Assert(err, qt.IsNil)
 		c.Assert(sheet.MaxRow, qt.Equals, 2)
 		c.Assert(sheet.MaxCol, qt.Equals, 2)
@@ -445,7 +445,7 @@ func TestLib(t *testing.T) {
 
 		// Discarding all return values; this test is a regression for
 		// a panic due to an "index out of range."
-		readRowsFromSheet(worksheet, file, sheet, NoRowLimit, lt)
+		readRowsFromSheet(worksheet, file, sheet, NoRowLimit, NoColLimit, lt)
 	})
 
 	csRunC(c, "ReadRowsFromSheetWithLeadingEmptyRows", func(c *qt.C, constructor CellStoreConstructor) {
@@ -495,7 +495,7 @@ func TestLib(t *testing.T) {
 		c.Assert(err, qt.IsNil)
 		lt := make(hyperlinkTable)
 
-		err = readRowsFromSheet(worksheet, file, sheet, NoRowLimit, lt)
+		err = readRowsFromSheet(worksheet, file, sheet, NoRowLimit, NoColLimit, lt)
 		c.Assert(err, qt.IsNil)
 		c.Assert(sheet.MaxRow, qt.Equals, 5)
 		c.Assert(sheet.MaxCol, qt.Equals, 1)
@@ -577,7 +577,7 @@ func TestLib(t *testing.T) {
 		c.Assert(err, qt.IsNil)
 		lt := make(hyperlinkTable)
 
-		err = readRowsFromSheet(worksheet, file, sheet, NoRowLimit, lt)
+		err = readRowsFromSheet(worksheet, file, sheet, NoRowLimit, NoColLimit, lt)
 		c.Assert(err, qt.IsNil)
 		c.Assert(sheet.MaxRow, qt.Equals, 2)
 		c.Assert(sheet.MaxCol, qt.Equals, 4)
@@ -725,7 +725,7 @@ func TestLib(t *testing.T) {
 		c.Assert(err, qt.IsNil)
 		lt := make(hyperlinkTable)
 
-		err = readRowsFromSheet(worksheet, file, sheet, NoRowLimit, lt)
+		err = readRowsFromSheet(worksheet, file, sheet, NoRowLimit, NoColLimit, lt)
 		c.Assert(err, qt.IsNil)
 		c.Assert(sheet.MaxRow, qt.Equals, 3)
 		c.Assert(sheet.MaxCol, qt.Equals, 3)
@@ -773,7 +773,7 @@ func TestLib(t *testing.T) {
 		c.Assert(err, qt.IsNil)
 		lt := make(hyperlinkTable)
 
-		err = readRowsFromSheet(worksheet, file, sheet, NoRowLimit, lt)
+		err = readRowsFromSheet(worksheet, file, sheet, NoRowLimit, NoColLimit, lt)
 		c.Assert(err, qt.IsNil)
 		c.Assert(sheet.MaxCol, qt.Equals, 4)
 		c.Assert(sheet.MaxRow, qt.Equals, 8)
@@ -891,7 +891,7 @@ func TestLib(t *testing.T) {
 
 		lt := make(hyperlinkTable)
 
-		err = readRowsFromSheet(worksheet, file, sheet, NoRowLimit, lt)
+		err = readRowsFromSheet(worksheet, file, sheet, NoRowLimit, NoColLimit, lt)
 		c.Assert(err, qt.IsNil)
 		c.Assert(sheet.MaxRow, qt.Equals, 2)
 		c.Assert(sheet.MaxCol, qt.Equals, 4)
@@ -972,7 +972,7 @@ func TestLib(t *testing.T) {
 		c.Assert(err, qt.IsNil)
 		lt := make(hyperlinkTable)
 
-		err = readRowsFromSheet(worksheet, file, sheet, NoRowLimit, lt)
+		err = readRowsFromSheet(worksheet, file, sheet, NoRowLimit, NoColLimit, lt)
 		c.Assert(err, qt.IsNil)
 		c.Assert(sheet.MaxRow, qt.Equals, 1)
 		c.Assert(sheet.MaxCol, qt.Equals, 6)
@@ -1051,7 +1051,7 @@ func TestLib(t *testing.T) {
 		c.Assert(err, qt.IsNil)
 		lt := make(hyperlinkTable)
 
-		err = readRowsFromSheet(worksheet, file, sheet, NoRowLimit, lt)
+		err = readRowsFromSheet(worksheet, file, sheet, NoRowLimit, NoColLimit, lt)
 		c.Assert(err, qt.IsNil)
 		c.Assert(sheet.MaxRow, qt.Equals, 1)
 		c.Assert(sheet.MaxCol, qt.Equals, 2)
@@ -1197,7 +1197,7 @@ func TestLib(t *testing.T) {
 
 		lt := make(hyperlinkTable)
 
-		err = readRowsFromSheet(worksheet, file, sheet, NoRowLimit, lt)
+		err = readRowsFromSheet(worksheet, file, sheet, NoRowLimit, NoColLimit, lt)
 		c.Assert(err, qt.IsNil)
 		c.Assert(sheet.MaxCol, qt.Equals, 3)
 		c.Assert(sheet.MaxRow, qt.Equals, 2)
@@ -1345,7 +1345,7 @@ func TestLib(t *testing.T) {
 
 		lt := make(hyperlinkTable)
 
-		err = readRowsFromSheet(worksheet, file, sheet, NoRowLimit, lt)
+		err = readRowsFromSheet(worksheet, file, sheet, NoRowLimit, NoColLimit, lt)
 		c.Assert(err, qt.IsNil)
 		row, err := sheet.Row(3)
 		c.Assert(err, qt.Equals, nil)
@@ -1440,7 +1440,7 @@ func TestReadRowsFromSheet(t *testing.T) {
 		sheet, err := NewSheetWithCellStore("test", constructor)
 		c.Assert(err, qt.IsNil)
 		lt := make(hyperlinkTable)
-		err = readRowsFromSheet(worksheet, file, sheet, NoRowLimit, lt)
+		err = readRowsFromSheet(worksheet, file, sheet, NoRowLimit, NoColLimit, lt)
 		c.Assert(err, qt.IsNil)
 		row, err := sheet.Row(0)
 		c.Assert(err, qt.Equals, nil)