SharpCompress - a fully native C# library for RAR, 7Zip, Zip, Tar, GZip, BZip2

Commented Unassigned: "cannot determine compressed stream type" on 7Zip archive with ReaderFactory [37]

sevanmarc — Sat, 25 May 2013 20:42:40 GMT

I need to open up an archive created with a recent build of 7Zip and read the contents of a single small (<1k) file, ignoring everything else.

ArchiveFactory.Open() opens the file fine, however it is incredibly slow (>30 seconds) when the archive is 50MB and on a network share.

I was hoping that ReaderFactory would be quicker, but ReaderFactory.Open() generates a "Cannot determine compressed stream type" error when opening the archive.

Test project and test data attached
Comments: Ah, I see. Yes, a exception with a message (much like your comment above!) would be more informative, at least then it would be obvious that it was expected behaviour rather than a bug.

Commented Unassigned: "cannot determine compressed stream type" on 7Zip archive with ReaderFactory [37]

adamhathcock — Sat, 25 May 2013 09:11:20 GMT

I need to open up an archive created with a recent build of 7Zip and read the contents of a single small (<1k) file, ignoring everything else.

ArchiveFactory.Open() opens the file fine, however it is incredibly slow (>30 seconds) when the archive is 50MB and on a network share.

I was hoping that ReaderFactory would be quicker, but ReaderFactory.Open() generates a "Cannot determine compressed stream type" error when opening the archive.

Test project and test data attached
Comments: 7Zip files aren't supported in the IReader interface as they require a seekable stream. I guess I could just support the format and throw an exception when given a non-seekable stream.

Created Unassigned: "cannot determine compressed stream type" on 7Zip archive with ReaderFactory [37]

sevanmarc — Thu, 23 May 2013 23:27:14 GMT

Commented Unassigned: Protect against double-disposal in Streams [36]

EMonk — Tue, 21 May 2013 21:32:16 GMT

In certain situations it is possible to have the Dispose method of a stream called multiple times. When this happens in the various compression streams in SharpCompress it can cause exceptions when the stream's Dispose code tries to finalize the compression algorithm multiple times.

For instance, in PpmdStream.cs
```
protected override void Dispose(bool isDisposing)
{
if (isDisposing)
{
if (compress)
model.EncodeBlock(stream, new MemoryStream(), true);
}
base.Dispose(isDisposing);
}
```

If this is called twice, the model.EncodeBlock method will result in an exception deep in the model's code, with no easy link back to the source of the exception.

Either the compression stream classes or their models should check for the encoding process being finalized before trying to finalize it a second time. A _disposed_ flag in the stream class for instance, or a flag in the model that is set when the encoding is finalized, with appropriate error messages for attempts to continue to use a finalized model.
Comments: Thanks for the library :)

New Post: EntryStream Position and Lenght Exception

flonex — Mon, 20 May 2013 08:46:47 GMT

Yes, it worked just fine with MemoryStream.

Thanks!

Commented Unassigned: Protect against double-disposal in Streams [36]

adamhathcock — Mon, 20 May 2013 08:15:04 GMT

Created Unassigned: Protect against double-disposal in Streams [36]

EMonk — Sun, 19 May 2013 03:54:09 GMT

New Post: EntryStream Position and Lenght Exception

adamhathcock — Sat, 18 May 2013 09:51:15 GMT

Rather than do that with a byte array, make a MemoryStream then use CopyTo from the EntryStream. Then get the byte array from the memory stream.

For reading that text, you can use a StreamReader wrapping the EntryStream and call ReadToEnd on the reader.

EntryStreams are forward only reading. They don't know their length.

New Post: EntryStream Position and Lenght Exception

flonex — Fri, 17 May 2013 11:05:23 GMT

Hi,

For my application, I don't need to write the files into an output directory/file (as I saw in all your examples), I just need to read the current file into a string/xml and process it.

Because I couldn't find any example of using EntryStream or WriteEntryTo(Stream writableStream) method in the code examples or unit tests, I decided to make the following test.

using (Stream stream = File.OpenRead(file))
{
    using (var reader = RarReader.Open(stream))
    {
        while (reader.MoveToNextEntry())
        {
            if (!reader.Entry.IsDirectory && Path.GetExtension(reader.Entry.FilePath).Equals(".xml"))
            {
                using (var entryStream = reader.OpenEntryStream())
                {    
                  byte[] bytes = new byte[entryStream.Length];
                  entryStream.Position = 0;
                  entryStream.Read(bytes, 0, (int)entryStream.Length);
                  string result = Encoding.ASCII.GetString(bytes);
                 }
             }
        }
    }
}

This code throws two exceptions "The method or operation is not implemented." - at entryStream.Position and entryStream.Lenght.

Am I doing something wrong here? If so, can you please, provide a similar example?

Thanks!
Diana

Reviewed: SharpCompress 0.9 (5 15, 2013)

putin — Wed, 15 May 2013 12:35:21 GMT

Rated 1 Stars (out of 5) - this is debug build. Windows Store cant use debug build..

New Post: RarReader Entry CRC issue

jsheares — Sat, 11 May 2013 20:35:52 GMT

Thanks for the clarification.

New Post: RarReader Entry CRC issue

adamhathcock — Sat, 11 May 2013 10:22:37 GMT

The CRC is only loaded as the file is written. It's expected behavior at the moment.

New Post: RarReader Entry CRC issue

jsheares — Sat, 11 May 2013 02:34:38 GMT

I seem to be having an issue with the entry CRC property. Before calling reader.WriteEntryToDirectory, reader.Entry.Crc is incorrect. After calling reader.WriteEntryToDirectory, reader.Entry.Crc is now correct. Is this a bug?

reader.Entry.Crc <- wrong
execute reader.WriteEntryToDirectory
reader.Entry.Crc < - correct

Commented Unassigned: Open tar archive from stream [35]

pjakobczyk — Tue, 07 May 2013 16:33:46 GMT

When I try to open tar archive from stream using method ArchiveFactory.Open(Stream, Options), the archive is recognize as rar. In consequence, when I try to read archive entries I get InvalidFormatException (Invalid Rar Header).
Comments: Thanks a lot for a quick fix. BTW. SharpCompress is very smart and useful library.

Commented Unassigned: Open tar archive from stream [35]

adamhathcock — Tue, 07 May 2013 13:33:00 GMT

When I try to open tar archive from stream using method ArchiveFactory.Open(Stream, Options), the archive is recognize as rar. In consequence, when I try to read archive entries I get InvalidFormatException (Invalid Rar Header).
Comments: Fix for what you found: https://github.com/adamhathcock/sharpcompress/commit/483f2e564a49c5ac17a92f8ae97f00db3424a514

Commented Unassigned: Open tar archive from stream [35]

pjakobczyk — Tue, 07 May 2013 13:04:36 GMT

When I try to open tar archive from stream using method ArchiveFactory.Open(Stream, Options), the archive is recognize as rar. In consequence, when I try to read archive entries I get InvalidFormatException (Invalid Rar Header).
Comments: I took a look at the problem closer. The problem is not with tar header but with method ArchiveFactory.Open taking Stream argument. ArchiveFactory.Open method which take FileInfo works fine. It seems that there is no LookForHeader option in RarArchive.IsRarFile invocation and the archive stream is recognized as rar.

Commented Unassigned: Open tar archive from stream [35]

adamhathcock — Tue, 07 May 2013 12:24:46 GMT

Created Unassigned: Open tar archive from stream [35]

pjakobczyk — Tue, 07 May 2013 10:43:21 GMT

New Post: WinRT / Metro support

adamhathcock — Sun, 05 May 2013 08:56:38 GMT

In Version 0.9, I changed the project layout and added a WindowsStore assembly. I'm also playing around with a WinMD project.

Created Release: SharpCompress 0.9 (May 04, 2013)

adamhathcock — Sat, 04 May 2013 16:13:04 GMT

https://nuget.org/packages/sharpcompress/0.9

New source location: https://github.com/adamhathcock/sharpcompress

New 7Zip reading code
Redid assemblies to have three versions
- .NET 4.5
- Portable
- Windows Store
Other Minor Fixes (found in source history)