/// <summary>
/// Read meta information <see cref="Entity"/>
/// </summary>
/// <param name="stream">Stream.</param>
/// <param name="decryptor">Decryptor.</param>
/// <param name="decryptIndexBlock">Index Decrypt Block.</param>
/// <param name="endian">File endian.</param>
/// <param name="version">File version.</param>
/// <returns></returns>
public static Entity Read(Stream stream, IDecryptor decryptor, ref ulong decryptIndexBlock, Endian endian)
{
var cryptBlockCount = 0ul;
var nextDecrIndex = 0ul;
var type = decryptor.ReadInt32(stream, decryptIndexBlock + cryptBlockCount, ref nextDecrIndex, endian);
var blockSize = (ulong)Marshal.SizeOf(type);
cryptBlockCount += (blockSize + Decryptor.CryptBlockSize - 1) / Decryptor.CryptBlockSize;
var size = decryptor.ReadInt32(stream, decryptIndexBlock + cryptBlockCount, ref nextDecrIndex, endian);
blockSize = (ulong)Marshal.SizeOf(size);
cryptBlockCount += (blockSize + Decryptor.CryptBlockSize - 1) / Decryptor.CryptBlockSize;
var startDecryptIndexBlock = decryptIndexBlock + cryptBlockCount;
var offset = stream.Position;
cryptBlockCount += (ulong)((size + Decryptor.CryptBlockSize - 1) / Decryptor.CryptBlockSize);
stream.Seek(size, SeekOrigin.Current);
decryptIndexBlock += cryptBlockCount;
return(new Entity
{
Type = type,
Size = size,
OffsetRawBlock = offset,
DecryptIndexBlock = startDecryptIndexBlock,
});
}
public ICollection <Entity> GetEntities()
{
try
{
using (var stream = File.OpenRead(FilePath)) // TODO: Don't open the file stream twice for the parsing process
{
FileHeader.Read(stream);
var cryptBlockIndex = 0ul;
var countEntities = _decryptor.ReadInt32(stream, cryptBlockIndex, ref cryptBlockIndex, Endian);
if (countEntities < 0 || countEntities > 1e6) // I don't think any i3d file would contain more than a million shapes..
{
throw new DecryptFailureException();
}
return(Enumerable.Range(0, countEntities)
.Select(v => Entity.Read(stream, _decryptor, ref cryptBlockIndex, Endian))
.ToArray());
}
}
catch (Exception e)
{
if (e is ArgumentOutOfRangeException || e is IOException || e is OutOfMemoryException)
{
throw new DecryptFailureException();
}
throw;
}
}
private static ICollection <Entity> ReadEntities(IDecryptor decryptor, string fileName)
{
using (var stream = File.OpenRead(fileName))
{
var header = ReadHeader(stream);
var endian = GetEndian(header.Version);
var cryptBlockIndex = 0ul;
var countEntities = decryptor.ReadInt32(stream, cryptBlockIndex, ref cryptBlockIndex, endian);
return(Enumerable.Range(0, countEntities)
.Select(v => Entity.Read(stream, decryptor, ref cryptBlockIndex, endian))
.ToArray());
}
}
