public static void WriteIso(UmdDisc disc, string filename)
{
using var stream = new FileStream(filename, FileMode.Open, FileAccess.Write);
using var writer = new BinaryWriter(stream);
foreach (var sector in disc.Sectors)
{
}
}
public static byte[] DecodeData(UmdDiscSector sector, UmdDisc disc, UmdDisc parentDisc)
{
return(sector.Encoding switch
{
UmdEncoding.None => sector.Data ?? throw new InvalidOperationException("No data in sector"),
UmdEncoding.InternalLink => DecodeInternalLink(sector, disc) ?? throw new InvalidOperationException("Internally linked sector has no data."),
UmdEncoding.ExternalLink => DecodeExternalLink(sector, parentDisc) ?? throw new InvalidOperationException("Internally linked sector has no data."),
_ => throw new InvalidOperationException("Unsupported encoding")
});
// TODO: optimize this method
public static async Task Merge(UmdDisc masterDisc, UmdDisc disc)
{
var masterSectors = masterDisc.Sectors.Where(s => s.Encoding == UmdEncoding.None).OrderBy(s => s.Crc32).ToList();
var sectors = disc.Sectors.Where(s => s.Encoding == UmdEncoding.None).OrderBy(s => s.Crc32).ToList();
// if nothing to compare return
if ((masterSectors == null) ||
(sectors == null) ||
(!masterSectors.Any()) ||
(!sectors.Any()))
{
return;
}
int masterCursor = 0, cursor = 0;
// sync cursors
while ((masterCursor < masterSectors.Count) && (cursor < sectors.Count))
{
if (masterSectors[masterCursor].Crc32 == sectors[cursor].Crc32)
{
int subCursor = 0;
while ((masterCursor + subCursor < masterSectors.Count) && (masterSectors[masterCursor].Crc32 == masterSectors[masterCursor + subCursor].Crc32))
{
if ((masterSectors[masterCursor + subCursor].Data != null) &&
(sectors[cursor].Data != null) &&
(await BinaryComparer.Compare(masterSectors[masterCursor + subCursor].Data, 0, sectors[cursor].Data, 0, UmdDisc.SectorSize)))
{
sectors[cursor].Encoding = UmdEncoding.ExternalLink;
sectors[cursor].Data = GetLinkData(masterSectors[masterCursor + subCursor].Id);
sectors[cursor].Length = 4;
sectors[cursor].Crc32 = Crc32Algorithm.Compute(sectors[cursor].Data, 0, 4);
break;
}
subCursor++;
}
cursor++;
continue;
}
if (masterSectors[masterCursor].Crc32 < sectors[cursor].Crc32)
{
masterCursor++;
continue;
}
if (masterSectors[masterCursor].Crc32 > sectors[cursor].Crc32)
{
cursor++;
continue;
}
}
}
public static async Task InternalMerge(UmdDisc disc)
{
IEnumerable <UmdDiscSector> sectors = disc.Sectors.Where(s => s.Encoding == UmdEncoding.None).ToList();
uint pass = 1;
while (sectors.Any())
{
System.Console.WriteLine($"Internal merge pass {pass}: {sectors.Count()} sectors.");
sectors = await InternalMergePass(sectors);
pass++;
}
}
public static UmdDisc?ReadFromIso(string filename, bool withData = false)
{
const ushort sectorSize = 2048;
try
{
var result = new UmdDisc();
var fileInfo = new FileInfo(filename);
if (fileInfo.Length % sectorSize != 0)
{
return(null);
}
var buffer = new byte[sectorSize];
using var stream = new FileStream(filename, FileMode.Open, FileAccess.Read);
using var reader = new BinaryReader(stream);
uint sectorCount = (uint)(fileInfo.Length / sectorSize);
for (uint i = 0; i < sectorCount; i++)
{
reader.Read(buffer, 0, sectorSize);
var sector = new UmdDiscSector
{
Id = i,
Crc32 = Crc32Algorithm.Compute(buffer, 0, sectorSize),
Length = sectorSize,
StartPostiion = (uint)(i * sectorSize)
};
if (withData)
{
sector.Data = buffer;
buffer = new byte[sectorSize];
}
result.Sectors.Add(sector);
}
return(result);
}
catch
{
return(null);
}
}
private static byte[]? DecodeInternalLink(UmdDiscSector sector, UmdDisc disc)
{
var sectorId = BitConverter.ToInt32(sector.Data);
return(disc.Sectors[sectorId].Data);
}
