Add compression level option to ExcelDataWriter.

MarkPflug · Aug 16, 2023 · 318192c · 318192c
1 parent 3eb8b16
commit 318192c
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Showing 6 changed files with 42 additions and 19 deletions.
diff --git a/docs/ReleaseNotes.md b/docs/ReleaseNotes.md
@@ -1,5 +1,10 @@
 # Sylvan.Data.Excel Release Notes
 
+_0.4.14_
+- Add `CompressionLevel` as a configuration option for ExcelDataWriter.
+    Changes the default compression level to `Fastest`, which produces 
+    *slightly* larger files, but takes significantly less time.
+
 _0.4.13_
 - Fix for .xlsx/.xlsb files that contain OpenPackage relations with rooted paths.
    Third party libraries sometimes write files in this way.

diff --git a/source/Sylvan.Data.Excel/ExcelDataWriterOptions.cs b/source/Sylvan.Data.Excel/ExcelDataWriterOptions.cs
@@ -1,5 +1,7 @@
 namespace Sylvan.Data.Excel;
 
+using System.IO.Compression;
+
 /// <summary>
 /// Options for controlling the behavior of an <see cref="ExcelDataWriter"/>.
 /// </summary>
@@ -12,9 +14,23 @@ public sealed class ExcelDataWriterOptions
 	// shared string behavior?
 	// binary as hex/basxe64
 
+	/// <summary>
+	/// Creates a new ExcelDataWriterOptions instance when the default settings.
+	/// </summary>
+	public ExcelDataWriterOptions()
+	{
+		this.TruncateStrings = false;
+		this.CompressionLevel = CompressionLevel.Fastest;
+	}
+
 	/// <summary>
 	/// Indicates if string values should be truncated to the limit of Excel, which allows a maximum of 32k characters.
 	/// </summary>
+	/// <remarks>When false, an exception will be thrown if a string values exceeds the limit.</remarks>
 	public bool TruncateStrings { get; set; }
 
+	/// <summary>
+	/// The compression level to use.
+	/// </summary>
+	public CompressionLevel CompressionLevel { get; set; }
 }
diff --git a/source/Sylvan.Data.Excel/OpenPackaging.cs b/source/Sylvan.Data.Excel/OpenPackaging.cs
@@ -145,7 +145,7 @@ static string MakeRelative(string root, string path)
 
 	internal static void WriteAppProps(ZipArchive zipArchive)
 	{
-		var appEntry = zipArchive.CreateEntry(AppPath, CompressionLevel.Optimal);
+		var appEntry = zipArchive.CreateEntry(AppPath, CompressionLevel.Fastest);
 		using var appStream = appEntry.Open();
 		using var xw = XmlWriter.Create(appStream, XmlSettings);
 		xw.WriteStartElement("Properties", PropNS);

diff --git a/source/Sylvan.Data.Excel/Sylvan.Data.Excel.csproj b/source/Sylvan.Data.Excel/Sylvan.Data.Excel.csproj
@@ -3,7 +3,7 @@
 	<PropertyGroup>
 		<TargetFrameworks>net6.0;netstandard2.1;netstandard2.0</TargetFrameworks>
 		<LangVersion>latest</LangVersion>
-		<VersionPrefix>0.4.13</VersionPrefix>
+		<VersionPrefix>0.4.14</VersionPrefix>
 		<Description>A cross-platform .NET library for reading Excel data files.</Description>
 		<PackageTags>excel;xls;xlsx;xlsb;datareader</PackageTags>
 		<Nullable>enable</Nullable>

diff --git a/source/Sylvan.Data.Excel/Xlsb/XlsbDataWriter.cs b/source/Sylvan.Data.Excel/Xlsb/XlsbDataWriter.cs
@@ -396,12 +396,13 @@ public int GetString(string str)
 		"hh:mm:ss",
 	};
 
-	const CompressionLevel Compression = CompressionLevel.Optimal;
+	CompressionLevel compression;
 
 	public XlsbDataWriter(Stream stream, ExcelDataWriterOptions options) : base(stream, options)
 	{
 		this.sharedStrings = new SharedStringTable();
 		this.zipArchive = new ZipArchive(stream, ZipArchiveMode.Create, true);
+		this.compression = options.CompressionLevel;
 		this.worksheets = new List<string>();
 	}
 
@@ -437,7 +438,7 @@ async Task<WriteResult> WriteInternal(DbDataReader data, string? worksheetName,
 		this.worksheets.Add(worksheetName);
 		var idx = this.worksheets.Count;
 		var entryName = "xl/worksheets/sheet" + idx + ".bin";
-		var entry = zipArchive.CreateEntry(entryName, Compression);
+		var entry = zipArchive.CreateEntry(entryName, compression);
 		using var es = entry.Open();
 		using var bs = new BufferedStream(es, 0x8000);
 		using var bw = new BinaryWriter(bs);
@@ -558,7 +559,7 @@ async Task<WriteResult> WriteInternal(DbDataReader data, string? worksheetName,
 
 	void WriteSharedStrings()
 	{
-		var e = this.zipArchive.CreateEntry("xl/sharedStrings.bin", Compression);
+		var e = this.zipArchive.CreateEntry("xl/sharedStrings.bin", compression);
 		using var s = e.Open();
 		using var bw = new BinaryWriter(s);
 
@@ -584,7 +585,7 @@ void WriteSharedStrings()
 	void WriteWorkbook()
 	{
 		var wbName = WorkbookPath;
-		var e = this.zipArchive.CreateEntry(wbName, Compression);
+		var e = this.zipArchive.CreateEntry(wbName, compression);
 
 		using var s = e.Open();
 		using var bw = new BinaryWriter(s);
@@ -605,7 +606,7 @@ void WritePkgMeta()
 	{
 		// pkg rels
 		{
-			var entry = zipArchive.CreateEntry("_rels/.rels", Compression);
+			var entry = zipArchive.CreateEntry("_rels/.rels", compression);
 			using var appStream = entry.Open();
 			using var xw = XmlWriter.Create(appStream, XmlSettings);
 			xw.WriteStartElement("Relationships", PkgRelNS);
@@ -629,7 +630,7 @@ void WritePkgMeta()
 
 		// workbook rels
 		{
-			var entry = zipArchive.CreateEntry("xl/_rels/workbook.bin.rels", Compression);
+			var entry = zipArchive.CreateEntry("xl/_rels/workbook.bin.rels", compression);
 			using var appStream = entry.Open();
 			using var xw = XmlWriter.Create(appStream, XmlSettings);
 			xw.WriteStartElement("Relationships", PkgRelNS);
@@ -661,7 +662,7 @@ void WritePkgMeta()
 
 		// content types
 		{
-			var entry = zipArchive.CreateEntry("[Content_Types].xml", Compression);
+			var entry = zipArchive.CreateEntry("[Content_Types].xml", compression);
 			using var appStream = entry.Open();
 			using var xw = XmlWriter.Create(appStream, XmlSettings);
 			xw.WriteStartElement("Types", ContentTypeNS);
@@ -706,7 +707,7 @@ static void Override(XmlWriter xw, string path, string type)
 
 	void WriteStyles()
 	{
-		var styleEntry = zipArchive.CreateEntry("xl/styles.bin", Compression);
+		var styleEntry = zipArchive.CreateEntry("xl/styles.bin", compression);
 		using var styleStream = styleEntry.Open();
 		using var bs = new BufferedStream(styleStream, 0x4000);
 		using var bw = new BinaryWriter(bs);

diff --git a/source/Sylvan.Data.Excel/Xlsx/XlsxDataWriter.cs b/source/Sylvan.Data.Excel/Xlsx/XlsxDataWriter.cs
@@ -89,12 +89,13 @@ public string GetString(string str)
 		"hh:mm:ss",
 	};
 
-	const CompressionLevel Compression = CompressionLevel.Optimal;
+	CompressionLevel compression;
 
 	public XlsxDataWriter(Stream stream, ExcelDataWriterOptions options) : base(stream, options)
 	{
 		this.sharedStrings = new SharedStringTable();
 		this.zipArchive = new ZipArchive(stream, ZipArchiveMode.Create, true);
+		this.compression = options.CompressionLevel;
 		this.worksheets = new List<string>();
 	}
 
@@ -136,7 +137,7 @@ async Task<WriteResult> WriteInternal(DbDataReader data, string? worksheetName,
 		this.worksheets.Add(worksheetName);
 		var idx = this.worksheets.Count;
 		var entryName = "xl/worksheets/sheet" + idx + ".xml";
-		var entry = zipArchive.CreateEntry(entryName, Compression);
+		var entry = zipArchive.CreateEntry(entryName, compression);
 		using var es = entry.Open();
 		using var xw = new StreamWriter(es, Encoding.UTF8, 0x4000);
 		xw.Write($"<worksheet xmlns=\"{NS}\">");
@@ -245,7 +246,7 @@ async Task<WriteResult> WriteInternal(DbDataReader data, string? worksheetName,
 
 	void WriteSharedStrings()
 	{
-		var e = this.zipArchive.CreateEntry("xl/sharedStrings.xml", Compression);
+		var e = this.zipArchive.CreateEntry("xl/sharedStrings.xml", compression);
 		using var s = e.Open();
 		using var xw = XmlWriter.Create(s, OpenPackaging.XmlSettings);
 		xw.WriteStartElement("sst", NS);
@@ -290,7 +291,7 @@ void WriteWorkbook()
 	{
 		var ns = "http://schemas.openxmlformats.org/spreadsheetml/2006/main";
 		var wbName = "xl/workbook.xml";
-		var e = this.zipArchive.CreateEntry(wbName, Compression);
+		var e = this.zipArchive.CreateEntry(wbName, compression);
 
 		using var s = e.Open();
 		using var xw = XmlWriter.Create(s, OpenPackaging.XmlSettings);
@@ -324,7 +325,7 @@ void WriteWorkbook()
 
 	void WriteCoreProps()
 	{
-		var appEntry = zipArchive.CreateEntry("docProps/core.xml", Compression);
+		var appEntry = zipArchive.CreateEntry("docProps/core.xml", compression);
 		using var appStream = appEntry.Open();
 		using var xw = XmlWriter.Create(appStream, OpenPackaging.XmlSettings);
 		xw.WriteStartElement("coreProperties", CoreNS);
@@ -339,7 +340,7 @@ void WritePkgMeta()
 	{
 		// pkg rels
 		{
-			var entry = zipArchive.CreateEntry("_rels/.rels", Compression);
+			var entry = zipArchive.CreateEntry("_rels/.rels", compression);
 			using var appStream = entry.Open();
 			using var xw = XmlWriter.Create(appStream, OpenPackaging.XmlSettings);
 			xw.WriteStartElement("Relationships", PkgRelNS);
@@ -363,7 +364,7 @@ void WritePkgMeta()
 
 		// workbook rels
 		{
-			var entry = zipArchive.CreateEntry("xl/_rels/workbook.xml.rels", Compression);
+			var entry = zipArchive.CreateEntry("xl/_rels/workbook.xml.rels", compression);
 			using var appStream = entry.Open();
 			using var xw = XmlWriter.Create(appStream, OpenPackaging.XmlSettings);
 			xw.WriteStartElement("Relationships", PkgRelNS);
@@ -395,7 +396,7 @@ void WritePkgMeta()
 
 		// content types
 		{
-			var entry = zipArchive.CreateEntry("[Content_Types].xml", Compression);
+			var entry = zipArchive.CreateEntry("[Content_Types].xml", compression);
 			using var appStream = entry.Open();
 			using var xw = XmlWriter.Create(appStream, OpenPackaging.XmlSettings);
 			xw.WriteStartElement("Types", ContentTypeNS);
@@ -434,7 +435,7 @@ static void Override(XmlWriter xw, string path, string type)
 
 	void WriteStyles()
 	{
-		var appEntry = zipArchive.CreateEntry("xl/styles.xml", Compression);
+		var appEntry = zipArchive.CreateEntry("xl/styles.xml", compression);
 		using var appStream = appEntry.Open();
 		using var wx = XmlWriter.Create(appStream, OpenPackaging.XmlSettings);
 		wx.WriteStartElement("styleSheet", NS);