private void UpdateCache(Session s, BinaryReader r, DatFile.Mft mft, CustomEntry c)
{
using (var w = new BinaryWriter(r.BaseStream))
{
var entry = mft.entries[INDEX_ENTRIES];
//write the data
w.BaseStream.Position = mft.entries[c.index].offset;
var size = c.WriteTo(w.BaseStream, s.compressor);
if (size != c.entry.size)
{
//rewrite the size of the entry
w.BaseStream.Position = entry.offset + (c.index + 1) * 24 + 8;
w.Write(size);
//note that although the data for this entry has changed, the crc hasn't due to how it's calculated
//calculate the crc of the main entry
r.BaseStream.Position = entry.offset;
var buffer = r.ReadBytes(entry.size);
var crc32 = new Crc32();
for (var i = 0; i < buffer.Length; i++)
{
if (i < 72 || i >= 96) //skip 3rd entry
{
crc32.Add(buffer[i]);
}
}
//rewrite the crc
w.BaseStream.Position = entry.offset + (INDEX_ENTRIES + 1) * 24 + 20;
w.Write(crc32.CRC);
}
}
}