public PakCatalog(ILogger logger)
{
_logger = logger;
_fileName = ConfigurationManager.AppSettings["sharperbot.PakCatalog"];
_entries = new List<PakEntry>();
_logger.Debug("Loading PAK catalog - filename={0}", _fileName);
if (!File.Exists(_fileName))
{
_logger.Error("File not found - filename={0}", _fileName);
throw new FileNotFoundException(_fileName);
}
var buffer = File.ReadAllBytes(_fileName);
for (int i = 0; i < buffer.Length; i++)
{
buffer[i] ^= PakKey;
}
using (var ms = new MemoryStream(buffer))
{
using (var br = new BinaryReader(ms))
{
// Validate header
var expectedHeader = new byte[] { 0xc0, 0x4a, 0xc0, 0xba };
for (int i = 0; i < 4; i++)
{
var actual = br.ReadByte();
if (actual != expectedHeader[i])
{
_logger.Error("Invalid PAK header - filename={0}", _fileName);
throw new FormatException("Invalid PAK header");
}
}
// Read TOC
ms.Seek(9, SeekOrigin.Begin);
long offset;
while (true)
{
var entry = new PakEntry();
byte fileNameLength = br.ReadByte();
entry.Name = Encoding.ASCII.GetString(br.ReadBytes(fileNameLength));
entry.Length = br.ReadUInt32();
br.ReadBytes(8); // skip
_entries.Add(entry);
byte flag = br.ReadByte();
if (flag == EndOfContents)
{
// Entry contents start here
offset = ms.Position;
break;
}
}
// Calculate offsets
foreach (var item in _entries)
{
item.Offset = offset;
offset += item.Length;
}
}
}
}
private byte[] GetEntryBytes(PakEntry entry)
{
_logger.Debug(
"Reading PAK entry - filename={0}, entry={1}, offset={2}, bytes={3}",
_fileName,
entry.Name,
entry.Offset,
entry.Length);
using (var file = File.OpenRead(_fileName))
{
file.Seek((int)entry.Offset, SeekOrigin.Begin);
var buffer = new byte[entry.Length];
file.Read(buffer, 0, (int)entry.Length);
for (int i = 0; i < buffer.Length; i++)
{
buffer[i] ^= PakKey;
}
return buffer;
}
}