WorksheetStartXml iterator

Directory.Packages.props

@@ -5,12 +5,12 @@
   </PropertyGroup>
   <ItemGroup>
     <GlobalPackageReference Include="ErrorProne.NET.CoreAnalyzers" Version="0.4.0-beta.1" />
-    <GlobalPackageReference Include="Meziantou.Analyzer" Version="2.0.159" />
+    <GlobalPackageReference Include="Meziantou.Analyzer" Version="2.0.160" />
     <GlobalPackageReference Include="Microsoft.CodeAnalysis.BannedApiAnalyzers" Version="3.3.4" />
     <GlobalPackageReference Include="Microsoft.VisualStudio.Threading.Analyzers" Version="17.10.48" />
     <GlobalPackageReference Include="PrimaryConstructorAnalyzer" Version="1.0.6" />
     <GlobalPackageReference Include="Roslynator.Analyzers" Version="4.12.4" />
-    <GlobalPackageReference Include="SonarAnalyzer.CSharp" Version="9.28.0.94264" />
+    <GlobalPackageReference Include="SonarAnalyzer.CSharp" Version="9.29.0.95321" />
   </ItemGroup>
   <ItemGroup>
     <PackageVersion Include="BenchmarkDotNet" Version="0.13.12" />
@@ -26,17 +26,17 @@
     <PackageVersion Include="Microsoft.CodeAnalysis.CSharp" Version="4.7.0" />
     <PackageVersion Include="Microsoft.CodeAnalysis.CSharp.Workspaces" Version="4.7.0" />
     <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="17.10.0" />
-    <PackageVersion Include="Polyfill" Version="5.5.3" />
+    <PackageVersion Include="Polyfill" Version="5.6.0" />
     <PackageVersion Include="PolySharp" Version="1.14.1" />
     <PackageVersion Include="PublicApiGenerator" Version="11.1.0" />
     <PackageVersion Include="System.Collections.Immutable" Version="8.0.0" />
     <PackageVersion Include="System.IO.Compression" Version="4.3.0" />
     <PackageVersion Include="System.Memory" Version="4.5.5" />
     <PackageVersion Include="TngTech.ArchUnitNET.xUnit" Version="0.10.6" />
     <PackageVersion Include="Verify.SourceGenerators" Version="2.2.0" />
-    <PackageVersion Include="Verify.Xunit" Version="25.0.4" />
-    <PackageVersion Include="xunit" Version="2.8.1" />
-    <PackageVersion Include="xunit.assert" Version="2.8.1" />
-    <PackageVersion Include="xunit.runner.visualstudio" Version="2.8.1" />
+    <PackageVersion Include="Verify.Xunit" Version="25.3.1" />
+    <PackageVersion Include="xunit" Version="2.9.0" />
+    <PackageVersion Include="xunit.assert" Version="2.9.0" />
+    <PackageVersion Include="xunit.runner.visualstudio" Version="2.8.2" />
   </ItemGroup>
 </Project>

SpreadCheetah.Benchmark/Benchmarks/MultipleWorksheets.cs

@@ -0,0 +1,39 @@
+using BenchmarkDotNet.Attributes;
+using BenchmarkDotNet.Jobs;
+using SpreadCheetah.Worksheets;
+
+namespace SpreadCheetah.Benchmark.Benchmarks;
+
+[SimpleJob(RuntimeMoniker.Net80)]
+[MemoryDiagnoser]
+public class MultipleWorksheets
+{
+    private static readonly SpreadCheetahOptions Options = new() { DefaultDateTimeFormat = null };
+
+    [Benchmark]
+    public async Task SpreadCheetah()
+    {
+        await using var spreadsheet = await Spreadsheet.CreateNewAsync(Stream.Null, Options);
+        var worksheetOptions = new WorksheetOptions();
+        worksheetOptions.Column(1).Width = 100;
+        worksheetOptions.Column(2).Hidden = false;
+
+        for (var i = 0; i < 1000; ++i)
+        {
+            if (i % 2 == 0)
+            {
+                await spreadsheet.StartWorksheetAsync(i.ToString());
+                continue;
+            }
+
+            worksheetOptions.FrozenColumns = i % 4 == 0 ? 1 : null;
+            worksheetOptions.FrozenRows = i % 8 == 0 ? 1 : null;
+            worksheetOptions.Visibility = i % 16 == 0 ? WorksheetVisibility.Hidden : WorksheetVisibility.Visible;
+            worksheetOptions.Column(2).Hidden = i % 32 == 0;
+
+            await spreadsheet.StartWorksheetAsync(i.ToString(), worksheetOptions);
+        }
+
+        await spreadsheet.FinishAsync();
+    }
+}

SpreadCheetah.Test/Helpers/DoubleEqualityComparer.cs

@@ -0,0 +1,7 @@
+namespace SpreadCheetah.Test.Helpers;
+
+internal sealed class DoubleEqualityComparer(double tolerance) : IEqualityComparer<double>
+{
+    public bool Equals(double x, double y) => Math.Abs(x - y) <= tolerance;
+    public int GetHashCode(double obj) => obj.GetHashCode();
+}

SpreadCheetah.Test/Tests/SpreadsheetTests.cs

@@ -324,27 +324,53 @@ public async Task Spreadsheet_StartWorksheet_MultipleWorksheets(int count)
         // Arrange
         var sheetNames = Enumerable.Range(1, count).Select(x => "Sheet " + x).ToList();
         using var stream = new MemoryStream();
-        await using (var spreadsheet = await Spreadsheet.CreateNewAsync(stream, new SpreadCheetahOptions { BufferSize = SpreadCheetahOptions.MinimumBufferSize }))
-        {
-            // Act
-            foreach (var name in sheetNames)
-            {
-                await spreadsheet.StartWorksheetAsync(name);
-                await spreadsheet.AddRowAsync(new DataCell(name));
-            }
+        var spreadsheetOptions = new SpreadCheetahOptions { BufferSize = SpreadCheetahOptions.MinimumBufferSize };
+        await using var spreadsheet = await Spreadsheet.CreateNewAsync(stream, spreadsheetOptions);
 
-            await spreadsheet.FinishAsync();
+        // Act
+        foreach (var name in sheetNames)
+        {
+            await spreadsheet.StartWorksheetAsync(name);
+            await spreadsheet.AddRowAsync(new DataCell(name));
         }
 
+        await spreadsheet.FinishAsync();
+
         // Assert
-        SpreadsheetAssert.Valid(stream);
-        using var actual = SpreadsheetDocument.Open(stream, true);
-        var sheets = actual.WorkbookPart!.Workbook.Sheets!.Cast<Sheet>().ToList();
-        var worksheets = actual.WorkbookPart.WorksheetParts.Select(x => x.Worksheet);
-        var cells = worksheets.Select(x => x.Descendants<DocumentFormat.OpenXml.Spreadsheet.Cell>().Single());
+        using var sheets = SpreadsheetAssert.Sheets(stream);
         Assert.Equal(count, sheets.Count);
-        Assert.Equal(sheetNames, sheets.Select(x => x.Name?.Value));
-        Assert.Equal(sheetNames, cells.Select(x => x.InnerText));
+        Assert.Equal(sheetNames, sheets.Select(x => x.Name));
+        Assert.Equal(sheetNames, sheets.Select(x => x["A1"].StringValue));
+    }
+
+    [Theory]
+    [InlineData(2)]
+    [InlineData(10)]
+    [InlineData(100)]
+    [InlineData(2000)]
+    [InlineData(16383)]
+    public async Task Spreadsheet_StartWorksheet_WorksheetWithMultipleColumnOptions(int count)
+    {
+        // Arrange
+        var columnWidths = Enumerable.Range(1, count).Select(x => 20d + (x % 100)).ToList();
+        using var stream = new MemoryStream();
+        var spreadsheetOptions = new SpreadCheetahOptions { BufferSize = SpreadCheetahOptions.MinimumBufferSize };
+        await using var spreadsheet = await Spreadsheet.CreateNewAsync(stream, spreadsheetOptions);
+        var options = new WorksheetOptions();
+
+        // Act
+        foreach (var (i, columnWidth) in columnWidths.Index())
+        {
+            options.Column(i + 1).Width = columnWidth;
+        }
+
+        await spreadsheet.StartWorksheetAsync("Sheet", options);
+        await spreadsheet.FinishAsync();
+
+        // Assert
+        using var sheet = SpreadsheetAssert.SingleSheet(stream);
+        Assert.Equal(columnWidths.Count, sheet.Columns.Count);
+        Assert.Equal(columnWidths, sheet.Columns.Select(x => x.Width), new DoubleEqualityComparer(0.01d));
     }
 
     [Theory]

SpreadCheetah.TestHelpers/Assertions/ClosedXmlAssertSheet.cs

@@ -5,6 +5,8 @@ namespace SpreadCheetah.TestHelpers.Assertions;
 internal sealed class ClosedXmlAssertSheet(XLWorkbook workbook, IXLWorksheet sheet)
     : ISpreadsheetAssertSheet
 {
+    public string Name => sheet.Name;
+
     public ISpreadsheetAssertCell this[string reference]
     {
         get
@@ -36,6 +38,9 @@ public ISpreadsheetAssertColumn Column(string columnName)
         return new ClosedXmlAssertColumn(sheet.Column(columnName));
     }
 
+    private IReadOnlyList<ISpreadsheetAssertColumn>? _columns;
+    public IReadOnlyList<ISpreadsheetAssertColumn> Columns => _columns ??= [.. sheet.Columns().Select(x => new ClosedXmlAssertColumn(x))];
+
     public IEnumerable<ISpreadsheetAssertCell> Row(int rowNumber)
     {
         var row = sheet.Row(rowNumber);

SpreadCheetah.TestHelpers/Assertions/ISpreadsheetAssertSheet.cs

@@ -2,11 +2,14 @@ namespace SpreadCheetah.TestHelpers.Assertions;
 
 public interface ISpreadsheetAssertSheet : IDisposable
 {
+    string Name { get; }
+
     ISpreadsheetAssertCell this[string reference] { get; }
     ISpreadsheetAssertCell this[string columnName, int rowNumber] { get; }
     int CellCount { get; }
     int RowCount { get; }
 
     ISpreadsheetAssertColumn Column(string columnName);
+    IReadOnlyList<ISpreadsheetAssertColumn> Columns { get; }
     IEnumerable<ISpreadsheetAssertCell> Row(int rowNumber);
 }

SpreadCheetah.TestHelpers/Assertions/SpreadsheetAssert.cs

@@ -1,6 +1,7 @@
 using ClosedXML.Excel;
 using DocumentFormat.OpenXml.Packaging;
 using DocumentFormat.OpenXml.Validation;
+using SpreadCheetah.TestHelpers.Collections;
 using Xunit;
 
 namespace SpreadCheetah.TestHelpers.Assertions;
@@ -21,6 +22,19 @@ public static ISpreadsheetAssertSheet SingleSheet(Stream stream)
         return new ClosedXmlAssertSheet(workbook, sheet);
     }
 
+    public static IWorksheetList Sheets(Stream stream)
+    {
+        if (stream is null)
+            throw new ArgumentNullException(nameof(stream));
+
+        Valid(stream);
+
+#pragma warning disable CA2000 // Dispose objects before losing scope
+        var workbook = new XLWorkbook(stream);
+#pragma warning restore CA2000 // Dispose objects before losing scope
+        return new ClosedXmlWorksheetList(workbook);
+    }
+
     public static void Valid(Stream stream)
     {
         if (stream is null)

SpreadCheetah.TestHelpers/Collections/ClosedXmlWorksheetList.cs

@@ -0,0 +1,20 @@
+using ClosedXML.Excel;
+using SpreadCheetah.TestHelpers.Assertions;
+using System.Collections;
+
+namespace SpreadCheetah.TestHelpers.Collections;
+
+internal sealed class ClosedXmlWorksheetList(XLWorkbook workbook) : IWorksheetList
+{
+    private readonly List<ISpreadsheetAssertSheet> _list =
+    [
+        .. workbook.Worksheets.Select(x => new ClosedXmlAssertSheet(workbook, x))
+    ];
+
+    public ISpreadsheetAssertSheet this[int index] => _list[index];
+    public int Count => _list.Count;
+    public IEnumerator<ISpreadsheetAssertSheet> GetEnumerator() => _list.GetEnumerator();
+    IEnumerator IEnumerable.GetEnumerator() => _list.GetEnumerator();
+
+    public void Dispose() => workbook.Dispose();
+}

SpreadCheetah.TestHelpers/Collections/IWorksheetList.cs

@@ -0,0 +1,5 @@
+using SpreadCheetah.TestHelpers.Assertions;
+
+namespace SpreadCheetah.TestHelpers.Collections;
+
+public interface IWorksheetList : IReadOnlyList<ISpreadsheetAssertSheet>, IDisposable;

SpreadCheetah/MetadataXml/WorksheetStartXml.cs

@@ -3,7 +3,7 @@
 
 namespace SpreadCheetah.MetadataXml;
 
-internal struct WorksheetStartXml : IXmlWriter
+internal struct WorksheetStartXml
 {
     private static ReadOnlySpan<byte> Header =>
         """<?xml version="1.0" encoding="utf-8"?>"""u8 +
@@ -14,43 +14,59 @@ internal struct WorksheetStartXml : IXmlWriter
 
     private readonly WorksheetOptions? _options;
     private readonly List<KeyValuePair<int, ColumnOptions>>? _columns;
+    private readonly SpreadsheetBuffer _buffer;
     private Element _next;
     private int _nextIndex;
     private bool _anyColumnWritten;
 
-    public WorksheetStartXml(WorksheetOptions? options)
+    private WorksheetStartXml(WorksheetOptions? options, SpreadsheetBuffer buffer)
     {
         _options = options;
         _columns = options?.ColumnOptions is { } columns ? [.. columns] : null;
+        _buffer = buffer;
     }
 
-    public bool TryWrite(Span<byte> bytes, out int bytesWritten)
+    public static async ValueTask WriteAsync(
+        WorksheetOptions? options,
+        SpreadsheetBuffer buffer,
+        Stream stream,
+        CancellationToken token)
     {
-        bytesWritten = 0;
+        var writer = new WorksheetStartXml(options, buffer);
 
-        if (_next == Element.Header && !Advance(Header.TryCopyTo(bytes, ref bytesWritten))) return false;
-        if (_next == Element.SheetViews && !Advance(TryWriteSheetViews(bytes, ref bytesWritten))) return false;
-        if (_next == Element.Columns && !Advance(TryWriteColumns(bytes, ref bytesWritten))) return false;
-        if (_next == Element.SheetDataBegin && !Advance(SheetDataBegin.TryCopyTo(bytes, ref bytesWritten))) return false;
-
-        return true;
+        foreach (var success in writer)
+        {
+            if (!success)
+                await buffer.FlushToStreamAsync(stream, token).ConfigureAwait(false);
+        }
     }
 
-    private bool Advance(bool success)
+    public readonly WorksheetStartXml GetEnumerator() => this;
+    public bool Current { get; private set; }
+
+    public bool MoveNext()
     {
-        if (success)
+        Current = _next switch
+        {
+            Element.Header => _buffer.TryWrite(Header),
+            Element.SheetViews => TryWriteSheetViews(_buffer),
+            Element.Columns => TryWriteColumns(_buffer),
+            _ => _buffer.TryWrite(SheetDataBegin)
+        };
+
+        if (Current)
             ++_next;
 
-        return success;
+        return _next < Element.Done;
     }
 
-    private readonly bool TryWriteSheetViews(Span<byte> bytes, ref int bytesWritten)
+    private readonly bool TryWriteSheetViews(SpreadsheetBuffer buffer)
     {
         var options = _options;
         if (options?.FrozenColumns is null && options?.FrozenRows is null)
             return true;
 
-        var span = bytes.Slice(bytesWritten);
+        var span = buffer.GetSpan();
         var written = 0;
 
         if (!"<sheetViews><sheetView workbookViewId=\"0\"><pane "u8.TryCopyTo(span, ref written)) return false;
@@ -88,7 +104,7 @@ private readonly bool TryWriteSheetViews(Span<byte> bytes, ref int bytesWritten)
 
         if (!"</sheetView></sheetViews>"u8.TryCopyTo(span, ref written)) return false;
 
-        bytesWritten += written;
+        _buffer.Advance(written);
         return true;
     }
 
@@ -112,7 +128,7 @@ private readonly bool TryWriteySplit(Span<byte> bytes, ref int bytesWritten)
         return "\" "u8.TryCopyTo(bytes, ref bytesWritten);
     }
 
-    private bool TryWriteColumns(Span<byte> bytes, ref int bytesWritten)
+    private bool TryWriteColumns(SpreadsheetBuffer buffer)
     {
         if (_columns is not { } columns) return true;
 
@@ -124,7 +140,7 @@ private bool TryWriteColumns(Span<byte> bytes, ref int bytesWritten)
             if (options.Width is null && !options.Hidden)
                 continue;
 
-            var span = bytes.Slice(bytesWritten);
+            var span = buffer.GetSpan();
             var written = 0;
 
             if (!anyColumnWritten)
@@ -149,10 +165,14 @@ private bool TryWriteColumns(Span<byte> bytes, ref int bytesWritten)
             if (!" />"u8.TryCopyTo(span, ref written)) return false;
 
             _anyColumnWritten = anyColumnWritten;
-            bytesWritten += written;
+
+            buffer.Advance(written);
         }
 
-        return !anyColumnWritten || "</cols>"u8.TryCopyTo(bytes, ref bytesWritten);
+        if (!anyColumnWritten)
+            return true;
+
+        return buffer.TryWrite("</cols>"u8);
     }
 
     private enum Element

SpreadCheetah/Worksheet.cs

@@ -50,8 +50,7 @@ public Worksheet(Stream stream, DefaultStyling? defaultStyling, SpreadsheetBuffe
 
     public async ValueTask WriteHeadAsync(WorksheetOptions? options, CancellationToken token)
     {
-        var writer = new WorksheetStartXml(options);
-        await writer.WriteAsync(_stream, _buffer, token).ConfigureAwait(false);
+        await WorksheetStartXml.WriteAsync(options, _buffer, _stream, token).ConfigureAwait(false);
 
         if (options?.AutoFilter is not null)
         {