mcs/class/System.IO.Compression/SharpCompress/Common/Zip/StreamingZipFilePart.cs

   1 using System;
   2 using System.IO;
   3 using System.IO.Compression;
   4 using SharpCompress.Common.Zip.Headers;
   5 using SharpCompress.IO;
   6
   7 namespace SharpCompress.Common.Zip
   8 {
   9     internal class StreamingZipFilePart : ZipFilePart
  10     {
  11         private Stream decompressionStream;
  12
  13         internal StreamingZipFilePart(ZipFileEntry header, Stream stream)
  14             : base(header, stream)
  15         {
  16         }
  17
  18         protected override Stream CreateBaseStream()
  19         {
  20             return Header.PackedStream;
  21         }
  22
  23         internal override Stream GetCompressedStream()
  24         {
  25             if (!Header.HasData)
  26             {
  27                 return Stream.Null;
  28             }
  29             decompressionStream = CreateDecompressionStream(GetCryptoStream(CreateBaseStream()));
  30             if (LeaveStreamOpen)
  31             {
  32                 return new NonDisposingStream(decompressionStream);
  33             }
  34             return decompressionStream;
  35         }
  36
  37         internal BinaryReader FixStreamedFileLocation(ref RewindableStream rewindableStream)
  38         {
  39             if (Header.IsDirectory)
  40             {
  41                 return new BinaryReader(rewindableStream);
  42             }
  43             if (Header.HasData)
  44             {
  45                 if (decompressionStream == null)
  46                 {
  47                     decompressionStream = GetCompressedStream();
  48                 }
  49                 decompressionStream.SkipAll();
  50
  51                 DeflateStream deflateStream = decompressionStream as DeflateStream;
  52                 if (deflateStream != null)
  53                 {
  54                     rewindableStream.Rewind(deflateStream.BaseStream as MemoryStream);
  55                 }
  56             }
  57             var reader = new BinaryReader(rewindableStream);
  58             decompressionStream = null;
  59             return reader;
  60         }
  61     }
  62 }