1 /// <summary>Extracts all matrix blocks in a format we support from a stream.</summary>
 2 internal static List<MatlabMatrix> ParseFile(Stream stream)
 3 {
 4     var matrices = new List<MatlabMatrix>();
 5
 6     using (var reader = new BinaryReader(stream))
 7     {
 8         // skip header (116 bytes)
 9         // skip subsystem data offset (8 bytes)
10         // skip version (2 bytes)
11         reader.BaseStream.Position = 126;
12
13         // endian indicator (2 bytes)
14         if (reader.ReadByte() != LittleEndianIndicator)
15         {
16             throw new NotSupportedException(Resources.BigEndianNotSupported);
17         }
18
19         // set position to first data element, right after full file header (128 bytes)
20         reader.BaseStream.Position = 128;
21         var length = stream.Length;
22
23         // for each data element add a MATLAB object to the file.
24         while (reader.BaseStream.Position < length)
25         {
26             // small format: size (2 bytes), type (2 bytes), data (4 bytes)
27             // long format: type (4 bytes), size (4 bytes), data (size, aligned to 8 bytes)
28
29             DataType type;
30             int size;
31             bool smallBlock;
32             ReadElementTag(reader, out type, out size, out smallBlock);
33
34             // read element data of the size provided in the element header
35             // uncompress if compressed
36             byte[] data;
37             if (type == DataType.Compressed)
38             {
39                 data = UnpackCompressedBlock(reader.ReadBytes(size), out type);
40             }
41             else
42             {
43                 data = new byte[size];
44                 reader.Read(data, 0, size);
45                 SkipElementPadding(reader, size, smallBlock);
46             }
47
48             if (type == DataType.Matrix)
49             {
50                 using (var matrixStream = new MemoryStream(data))
51                 using (var matrixReader = new BinaryReader(matrixStream))
52                 {
53                     matrixReader.BaseStream.Seek(20, SeekOrigin.Current);
54                     var matrixDim = matrixReader.ReadInt32()/8;
55                     if (matrixDim > 2)
56                     {
57                         continue;
58                     }
59
60                     matrixReader.BaseStream.Seek(10, SeekOrigin.Current);
61                     int matrixSize = matrixReader.ReadInt16();
62                     if (matrixSize == 0)
63                     {
64                         matrixSize = matrixReader.ReadInt32();
65                     }
66
67                     var matrixName = Encoding.ASCII.GetString(matrixReader.ReadBytes(matrixSize));
68
69                     matrices.Add(new MatlabMatrix(matrixName, data));
70                 }
71             }
72         }
73     }
74
75     return matrices;
76 }

 1 /// <summary>Writes all matrix blocks to a stream.</summary>
 2 internal static void FormatFile(Stream stream, IEnumerable<MatlabMatrix> matrices)
 3 {
 4     using (var buffer = new BufferedStream(stream))
 5     using (var writer = new BinaryWriter(buffer))
 6     {
 7         // write header and subsystem data offset (116+8 bytes)
 8         var header = Encoding.ASCII.GetBytes(HeaderText + DateTime.Now.ToString(Resources.MatlabDateHeaderFormat));
 9         writer.Write(header);
10         Pad(writer, 116 - header.Length + 8, 32);
11
12         // write version (2 bytes)
13         writer.Write((short)0x100);
14
15         // write little endian indicator (2 bytes)
16         writer.Write((byte)0x49);
17         writer.Write((byte)0x4D);
18
19         foreach (var matrix in matrices)
20         {
21             // write data type
22             writer.Write((int)DataType.Compressed);
23
24             // compress data
25             var compressedData = PackCompressedBlock(matrix.Data, DataType.Matrix);
26
27             // write compressed data to file
28             writer.Write(compressedData.Length);
29             writer.Write(compressedData);
30         }
31
32         writer.Flush();
33         writer.Close();
34     }
35 }