Add TempFileZipPackage

openxml4Net/OPC/Internal/FileHelper.cs

@@ -60,6 +60,15 @@ public static String GetFilename(string filepath)
             return "";
         }
 
+        public static FileStream GetTempFileStream()
+        {
+            string fileName = Path.Combine(Path.GetTempPath(), Path.GetRandomFileName());
+
+            return File.Create(
+                fileName,
+                8192,
+                FileOptions.DeleteOnClose | FileOptions.Asynchronous);
+        }
     }
 
 }

openxml4Net/OPC/Internal/TempFilePackagePart.cs

@@ -0,0 +1,70 @@
+using System.IO;
+using NPOI.OpenXml4Net.OPC.Internal.Marshallers;
+
+namespace NPOI.OpenXml4Net.OPC.Internal;
+
+public class TempFilePackagePart : PackagePart
+{
+    internal Stream _data;
+
+    public TempFilePackagePart(OPCPackage pack, PackagePartName partName, string contentType)
+        : base(pack, partName, contentType)
+    {
+    }
+
+    public TempFilePackagePart(OPCPackage pack, PackagePartName partName, string contentType, bool loadRelationships)
+        : base(pack, partName, new ContentType(contentType), loadRelationships)
+    {
+    }
+
+    protected override Stream GetInputStreamImpl()
+    {
+        FileStream stream = FileHelper.GetTempFileStream();
+
+        if (_data is null)
+        {
+            return stream;
+        }
+
+        StreamHelper.CopyStream(_data, stream);
+        stream.Position = 0;
+
+        return stream;
+    }
+
+    protected override Stream GetOutputStreamImpl()
+    {
+        return new TempFilePackagePartOutputStream(this);
+    }
+
+    public override long Size => _data?.Length ?? 0;
+
+    public override void Clear()
+    {
+        _data?.Dispose();
+        _data = null;
+    }
+
+    public override bool Save(Stream zos)
+    {
+        return new ZipPartMarshaller().Marshall(this, zos);
+    }
+
+    public override bool Load(Stream ios)
+    {
+        // Save it
+        StreamHelper.CopyStream(ios, _data);
+        // All done
+        return true;
+    }
+
+    public override void Close()
+    {
+        // Do nothing
+    }
+
+    public override void Flush()
+    {
+        // Do nothing
+    }
+}

openxml4Net/OPC/Internal/TempFilePackagePartOutputStream.cs

@@ -0,0 +1,84 @@
+using System.IO;
+using System;
+
+namespace NPOI.OpenXml4Net.OPC.Internal;
+
+public sealed class TempFilePackagePartOutputStream : Stream
+{
+    private readonly Stream _buff;
+
+    public TempFilePackagePartOutputStream(TempFilePackagePart part)
+    {
+        part._data = FileHelper.GetTempFileStream();
+        _buff = part._data;
+    }
+
+    public override bool CanRead => false;
+
+    public override bool CanWrite => true;
+
+    public override bool CanSeek => false;
+
+    public override long Length => _buff.Length;
+
+    public override long Position
+    {
+        get => _buff.Position;
+        set => _buff.Position = value;
+    }
+
+    public override int Read(byte[] buffer, int offset, int count)
+    {
+        throw new NotImplementedException();
+    }
+
+    public override void SetLength(long value)
+    {
+        _buff.SetLength(value);
+    }
+
+    public override long Seek(long offset, SeekOrigin origin)
+    {
+        return _buff.Seek(offset, origin);
+    }
+
+    /**
+     * Close this stream and flush the content.
+     * @see #flush()
+     */
+    public override void Close()
+    {
+        Flush();
+    }
+
+    /**
+     * Flush this output stream. This method is called by the close() method.
+     * Warning : don't call this method for output consistency.
+     * @see #close()
+     */
+    public override void Flush()
+    {
+        _buff.Flush();
+
+        /*
+         * Clear this streams buffer, in case flush() is called a second time
+         * Fix bug 1921637 - provided by Rainer Schwarze
+         */
+        _buff.Position = 0;
+    }
+
+    public void Write(int b)
+    {
+        _buff.WriteByte((byte)b);
+    }
+
+    public override void Write(byte[] buffer, int offset, int count)
+    {
+        _buff.Write(buffer, offset, count);
+    }
+
+    public void Write(byte[] buffer)
+    {
+        _buff.Write(buffer, (int)_buff.Position, buffer.Length);
+    }
+}

openxml4Net/OPC/TempFileZipPackage.cs

@@ -0,0 +1,33 @@
+using NPOI.OpenXml4Net.Exceptions;
+using System.IO;
+using NPOI.OpenXml4Net.OPC.Internal;
+
+namespace NPOI.OpenXml4Net.OPC;
+
+public class TempFileZipPackage : ZipPackage
+{
+    public TempFileZipPackage()
+    {
+    }
+
+    public TempFileZipPackage(Stream in1, PackageAccess access)
+        : base(in1, access)
+    {
+    }
+
+    protected override PackagePart CreatePartImpl(PackagePartName partName, string contentType, bool loadRelationships)
+    {
+        try
+        {
+            return new TempFilePackagePart(
+                this,
+                partName,
+                contentType,
+                loadRelationships);
+        }
+        catch (InvalidFormatException)
+        {
+            return null;
+        }
+    }
+}