[OPT] Optimize max memory usage of SaveAsByTemplate #750 (#752)

* [OPT] Optimize max memory usage of SaveAsByTemplate #750

* Specify create and update mode

Author: shps951023

samples/linqpad/[MiniExcel]Issue 750.linq

@@ -0,0 +1,104 @@
+<Query Kind="Program">
+  <Namespace>System.IO.Compression</Namespace>
+</Query>
+
+void Main(){
+	Issue750.Main();
+}
+
+public class Issue750
+{
+	public static void Main()
+	{
+		var templatePath = @"D:\git\MiniExcel\samples\xlsx\TestIssue20250403_SaveAsByTemplate_OPT.xlsx";
+		var path = Path.GetTempPath() + Guid.NewGuid() + ".xlsx";
+		Stream _outputFileStream;
+		Console.WriteLine(path);
+		using (var stream = File.Create(path))
+		using (var templateStream = FileHelper.OpenSharedRead(templatePath))
+		{
+			_outputFileStream = stream;
+			templateStream.CopyTo(_outputFileStream);
+			var outputZipFile = new MiniExcelZipArchive(_outputFileStream, mode: ZipArchiveMode.Update, true, Encoding.UTF8);
+
+			var templateSheets = outputZipFile.Entries
+				.Where(w =>
+					w.FullName.StartsWith("xl/worksheets/sheet", StringComparison.OrdinalIgnoreCase) ||
+					w.FullName.StartsWith("/xl/worksheets/sheet", StringComparison.OrdinalIgnoreCase))
+				.ToList();
+			var templateSheet = templateSheets[0];
+			var fullName = templateSheet.FullName;
+			var outputSheetStream = outputZipFile.CreateEntry(fullName);
+			using (var outputZipSheetStream = templateSheet.Open())
+			{
+				var doc = new XmlDocument();
+				doc.Load(outputZipSheetStream);
+				outputZipSheetStream.Dispose();
+
+
+
+				templateSheet.Delete(); // ZipArchiveEntry can't update directly, so need to delete then create logic
+
+
+
+
+				XmlNamespaceManager _ns;
+				_ns = new XmlNamespaceManager(new NameTable());
+				_ns.AddNamespace("x", Config.SpreadsheetmlXmlns);
+				_ns.AddNamespace("x14ac", Config.SpreadsheetmlXml_x14ac);
+
+				var worksheet = doc.SelectSingleNode("/x:worksheet", _ns);
+				var sheetData = doc.SelectSingleNode("/x:worksheet/x:sheetData", _ns);
+				var newSheetData = sheetData?.Clone(); //avoid delete lost data
+
+				var rows = newSheetData?.SelectNodes("x:row", _ns);
+
+
+				sheetData.RemoveAll();
+				sheetData.InnerText = "{{{{{{split}}}}}}"; //TODO: bad code smell
+
+				var contents = doc.InnerXml.Split(new[] { $"<sheetData>{{{{{{{{{{{{split}}}}}}}}}}}}</sheetData>" }, StringSplitOptions.None);
+
+				using (var writer = new StreamWriter(stream, Encoding.UTF8))
+				{
+					writer.Write(contents[0]);
+					writer.Write($"<sheetData>"); // prefix problem
+
+					for (int i = 0; i < 10000000; i++)
+					{
+						writer.Write($"{Guid.NewGuid}{Guid.NewGuid}{Guid.NewGuid}{Guid.NewGuid}{Guid.NewGuid}");
+					}
+					writer.Write($"<sheetData>");
+				}
+			}
+		}
+
+	}
+	internal class Config
+	{
+		public const string SpreadsheetmlXmlns = "http://schemas.openxmlformats.org/spreadsheetml/2006/main";
+		public const string SpreadsheetmlXmlStrictns = "http://purl.oclc.org/ooxml/spreadsheetml/main";
+		public const string SpreadsheetmlXmlRelationshipns = "http://schemas.openxmlformats.org/officeDocument/2006/relationships";
+		public const string SpreadsheetmlXmlStrictRelationshipns = "http://purl.oclc.org/ooxml/officeDocument/relationships";
+		public const string SpreadsheetmlXml_x14ac = "http://schemas.microsoft.com/office/spreadsheetml/2009/9/ac";
+	}
+	// You can define other methods, fields, classes and namespaces here
+	public class MiniExcelZipArchive : ZipArchive
+	{
+		public MiniExcelZipArchive(Stream stream, ZipArchiveMode mode, bool leaveOpen, Encoding entryNameEncoding)
+		   : base(stream, mode, leaveOpen, entryNameEncoding)
+		{
+		}
+
+		public new void Dispose()
+		{
+			Dispose(disposing: true);
+			GC.SuppressFinalize(this);
+		}
+	}
+
+	internal static partial class FileHelper
+	{
+		public static FileStream OpenSharedRead(string path) => File.Open(path, FileMode.Open, FileAccess.Read, FileShare.ReadWrite);
+	}
+}

samples/xlsx/TestIssue20250403_SaveAsByTemplate_OPT.xlsx

@@ -22,7 +22,7 @@ internal class ExcelOpenXmlSheetReader : IExcelReader
         internal IDictionary<int, string> _sharedStrings;
         private MergeCells _mergeCells;
         private ExcelOpenXmlStyles _style;
-        private readonly ExcelOpenXmlZip _archive;
+        internal readonly ExcelOpenXmlZip _archive;
         private readonly OpenXmlConfiguration _config;
 
         private static readonly XmlReaderSettings _xmlSettings = new XmlReaderSettings
@@ -32,7 +32,7 @@ internal class ExcelOpenXmlSheetReader : IExcelReader
             XmlResolver = null
         };
 
-        public ExcelOpenXmlSheetReader(Stream stream, IConfiguration configuration)
+        public ExcelOpenXmlSheetReader(Stream stream, IConfiguration configuration, bool isUpdateMode = true)
         {
             _archive = new ExcelOpenXmlZip(stream);
             _config = (OpenXmlConfiguration)configuration ?? OpenXmlConfiguration.DefaultConfig;