Avoid Allocating RowDimension Unneccesarily

This PR builds on PR PHPOffice#3527, introduced but subsequently closed by @goetas. The observation was that AutoFilter did not need to allocate a new RowDimension when the row was not to be filtered. While vetting the PR, it became apparent that Xlsx Writer also allocates RowDimension unnecessarily, with some minor adjustments possible for Ods and Mpdf as well. My tests confirm the initial observation that there can be a considerable memory savings when RowDimension is allocated only when needed. So, even though the original PR is withdrawn, there seems to be value in proceeding with it anyhow.

Author: oleibman

src/PhpSpreadsheet/Worksheet/AutoFilter.php

@@ -1049,7 +1049,11 @@ public function showHideRows()
                 }
             }
             //    Set show/hide for the row based on the result of the autoFilter result
-            $this->workSheet->getRowDimension((int) $row)->setVisible($result);
+            //    If the RowDimension object has not been allocated yet and the row should be visible,
+            //    then we can avoid any operation since the rows are visible by default (saves a lot of memory)
+            if ($result === false || $this->workSheet->rowDimensionExists((int) $row)) {
+                $this->workSheet->getRowDimension((int) $row)->setVisible($result);
+            }
         }
         $this->evaluated = true;
 

src/PhpSpreadsheet/Worksheet/Worksheet.php

@@ -3874,4 +3874,9 @@ public static function nameRequiresQuotes(string $sheetName): bool
     {
         return preg_match(self::SHEET_NAME_REQUIRES_NO_QUOTES, $sheetName) !== 1;
     }
+
+    public function isRowVisible(int $row): bool
+    {
+        return !$this->rowDimensionExists($row) || $this->getRowDimension($row)->getVisible();
+    }
 }

src/PhpSpreadsheet/Writer/Html.php

@@ -504,7 +504,7 @@ public function generateSheetData()
                 $html .= $startTag;
 
                 // Write row if there are HTML table cells in it
-                $mpdfInvisible = $this->isMPdf && $sheet->getRowDimension($row)->getVisible() === false;
+                $mpdfInvisible = $this->isMPdf && !$sheet->isRowVisible($row);
                 if (!$mpdfInvisible && !isset($this->isSpannedRow[$sheet->getParent()->getIndex($sheet)][$row])) {
                     // Start a new rowData
                     $rowData = [];

src/PhpSpreadsheet/Writer/Ods/Content.php

@@ -171,7 +171,7 @@ private function writeRows(XMLWriter $objWriter, Worksheet $sheet, int $sheetInd
                     $objWriter->endElement();
                     $span_row = 0;
                 } else {
-                    if ($sheet->getRowDimension($row->getRowIndex())->getRowHeight() > 0) {
+                    if ($sheet->rowDimensionExists($row->getRowIndex()) && $sheet->getRowDimension($row->getRowIndex())->getRowHeight() > 0) {
                         $objWriter->writeAttribute(
                             'table:style-name',
                             sprintf('%s_%d_%d', Style::ROW_STYLE_PREFIX, $sheetIndex, $row->getRowIndex())

src/PhpSpreadsheet/Writer/Xlsx/Worksheet.php

@@ -13,6 +13,7 @@
 use PhpOffice\PhpSpreadsheet\Style\Conditional;
 use PhpOffice\PhpSpreadsheet\Style\ConditionalFormatting\ConditionalDataBar;
 use PhpOffice\PhpSpreadsheet\Style\ConditionalFormatting\ConditionalFormattingRuleExtension;
+use PhpOffice\PhpSpreadsheet\Worksheet\RowDimension;
 use PhpOffice\PhpSpreadsheet\Worksheet\SheetView;
 use PhpOffice\PhpSpreadsheet\Worksheet\Worksheet as PhpspreadsheetWorksheet;
 
@@ -1143,11 +1144,12 @@ private function writeSheetData(XMLWriter $objWriter, PhpspreadsheetWorksheet $w
         }
 
         $currentRow = 0;
+        $emptyDimension = new RowDimension();
         while ($currentRow++ < $highestRow) {
             $isRowSet = isset($cellsByRow[$currentRow]);
             if ($isRowSet || $worksheet->rowDimensionExists($currentRow)) {
                 // Get row dimension
-                $rowDimension = $worksheet->getRowDimension($currentRow);
+                $rowDimension = $worksheet->rowDimensionExists($currentRow) ? $worksheet->getRowDimension($currentRow) : $emptyDimension;
 
                 // Write current row?
                 $writeCurrentRow = $isRowSet || $rowDimension->getRowHeight() >= 0 || $rowDimension->getVisible() === false || $rowDimension->getCollapsed() === true || $rowDimension->getOutlineLevel() > 0 || $rowDimension->getXfIndex() !== null;

tests/PhpSpreadsheetTests/Worksheet/AutoFilter/AutoFilterCustomNumericTest.php

@@ -95,6 +95,7 @@ public function testEqualsListSimple(): void
     public function testEqualsList(): void
     {
         $sheet = $this->initSheet();
+        $sheet->getRowDimension(4)->setRowHeight(25);
         $maxRow = $this->maxRow;
         $autoFilter = $sheet->getAutoFilter();
         $autoFilter->setRange("A1:A$maxRow");
@@ -115,6 +116,17 @@ public function testEqualsList(): void
             ->setRuleType(Rule::AUTOFILTER_RULETYPE_CUSTOMFILTER);
 
         self::assertEquals([3, 4, 9, 10], $this->getVisible());
+        self::assertTrue($sheet->rowDimensionExists(2));
+        self::assertFalse($sheet->rowDimensionExists(3), 'row visible by default');
+        self::assertTrue($sheet->rowDimensionExists(4), 'row is visible but height has been set');
+        self::assertTrue($sheet->rowDimensionExists(5));
+        self::assertTrue($sheet->rowDimensionExists(6));
+        self::assertTrue($sheet->rowDimensionExists(7));
+        self::assertTrue($sheet->rowDimensionExists(8));
+        self::assertFalse($sheet->rowDimensionExists(9), 'row visible by default');
+        self::assertFalse($sheet->rowDimensionExists(10), 'row visible by default');
+        self::assertTrue($sheet->rowDimensionExists(11));
+        self::assertTrue($sheet->rowDimensionExists(12));
     }
 
     public function testNotEqualsList(): void

tests/PhpSpreadsheetTests/Worksheet/AutoFilter/SetupTeardown.php

@@ -62,7 +62,7 @@ public function getVisibleSheet(Worksheet $sheet): array
         $sheet->getAutoFilter()->showHideRows();
         $actualVisible = [];
         for ($row = 2; $row <= $this->maxRow; ++$row) {
-            if ($sheet->getRowDimension($row)->getVisible()) {
+            if ($sheet->isRowVisible($row)) {
                 $actualVisible[] = $row;
             }
         }