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7zip compress network stream

I will like to compress a file before sending it through the network. I think the best approach is 7zip because it is free and open source.

How I use 7zip with .net?

I know that 7zip is free and that they have the source code in c# but for some reason it is very slow on c# so I rather call the dll 7z.dll that comes when installing 7zip for performance reasons. So the way I am able to eassily marshal and call the methods in 7z.dll is with the help of the library called sevenzipsharp . For example adding that dll to my project will enable me to do:

enter image description here

        // if you installed 7zip 64bit version then make sure you change plataform target
        // like on the picture I showed above!
        SevenZip.SevenZipCompressor.SetLibraryPath(@"C:\Program Files\7-Zip\7z.dll");

        var stream = System.IO.File.OpenRead(@"SomeFileToCompress.txt");
        var outputStream = System.IO.File.Create("Output.7z");

        SevenZip.SevenZipCompressor compressor = new SevenZip.SevenZipCompressor();
        compressor.CompressionMethod = SevenZip.CompressionMethod.Lzma2;
        compressor.CompressionLevel = SevenZip.CompressionLevel.Ultra;
        compressor.CompressStream(stream, outputStream);

that's how I use 7zip within c#.

Now my question is:

I will like to send a compressed file over the network. I know I could compress it first then send it. The file is 4GB so I will have to wait a long time for it to compress. I will be wasting a lot of space on hard drive. then I will finally be able to send it. I think that is to complicated. I was wondering how it will be possible to send the file meanwhile it is being compressed.


It seems to be a problem with SevenZipSharp:

enter image description here

like image 659
Tono Nam Avatar asked Apr 26 '26 23:04

Tono Nam


1 Answers

Have you considered an alternate library - one that doesn't even require 7-Zip to be installed / available?

From the description posted at http://dotnetzip.codeplex.com/ :

creating zip files from stream content, saving to a stream, extracting to a stream, reading from a stream

Unlike 7-Zip, DotNetZip is designed to work with C# / .Net.

Plenty of examples - including streaming, are available at http://dotnetzip.codeplex.com/wikipage?title=CS-Examples&referringTitle=Examples .

Another option is to use the 7-Zip Command Line Version (7z.exe), and write to/read from standard in/out. This would allow you to use the 7-Zip file format, while also keeping all of the core work in native code (though there likely won't be much of a significant difference).

Looking back at SevenZipSharp:

Since the 0.29 release, streaming is supported.

Looking at http://sevenzipsharp.codeplex.com/SourceControl/changeset/view/59007#364711 :

it seems you'd want this method:

public void CompressStream(Stream inStream, Stream outStream)

Thank you for considering performance here! I think way too many people would do exactly what you're trying to avoid: compress to a temp file, then do something with the temp file.

like image 148
ziesemer Avatar answered Apr 29 '26 04:04

ziesemer



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