/// <summary>
/// Read from stream the sfp file header.
/// </summary>
/// <param name="strm">Sfp stream data.</param>
/// <returns>Sfp file header.</returns>
private static unsafe SfpHeader ReadHeader(Stream strm)
{
Byte[] data = new Byte[sizeof(SfpHeader)];
strm.Seek(0, SeekOrigin.Begin);
strm.Read(data, 0, data.Length);
return(SfpHeader.CreateFromBytes(data));
}
/// <summary>
/// Extract the content of a sfp file from a stream.
/// </summary>
/// <param name="strm">Sfp stream data.</param>
/// <param name="overwrite">Indicates whether the files should be overwritten.</param>
/// <param name="extractPath">Extraction path.</param>
private static void ExtractStream(Stream strm, Boolean overwrite, String extractPath)
{
SfpHeader header = ReadHeader(strm);
if (header.ArchiveSize == strm.Length) //1st Validation
{
IReadOnlyDictionary <Int64, String> nameTable = ReadNameTable(strm, header);
if (!nameTable.ContainsKey(0)) //2nd Validation
{
Dictionary <Int64, SfpEntry> entries = new Dictionary <Int64, SfpEntry>();
ReadEntry(strm, header.FirstEntryOffset, entries);
ExtractFiles(strm, nameTable, entries, overwrite, extractPath);
}
else
{
Console.WriteLine("Selected file is not a valid sfp. An error found in the file name table.");
}
}
else
{
Console.WriteLine("Selected file is not a valid sfp. An error found in the file header.");
}
}
/// <summary>
/// Read the table of names in the sfp file and index them by offset.
/// </summary>
/// <param name="strm">Sfp stream data.</param>
/// <param name="header">Sfp file header</param>
/// <returns>Sfp file name table indexed by offset.</returns>
private static IReadOnlyDictionary <Int64, String> ReadNameTable(Stream strm, SfpHeader header)
{
Dictionary <Int64, String> nameTable = new Dictionary <Int64, String>();
Byte[] data = new Byte[header.DataOffset - header.NameTableOffset];
strm.Seek(header.NameTableOffset, SeekOrigin.Begin);
strm.Read(data, 0, data.Length);
Int32 pos_ini = 0;
Int32 pos_fin = 0;
List <Byte> lista = data.ToList <Byte>();
foreach (Byte bytChar in lista)
{
pos_fin++;
if (bytChar == 0)
{
if (pos_fin - pos_ini > 1)
{
nameTable.Add(header.NameTableOffset + (Int64)pos_ini, Encoding.ASCII.GetString(lista.GetRange(pos_ini, pos_fin - pos_ini - 1).ToArray()));
}
pos_ini = pos_fin;
}
}
return(nameTable);
}
