private byte[] BuildMetaData(PartitionFileSystemType type)
{
if (type == PartitionFileSystemType.Hashed)
{
CalculateHashes();
}
int entryTableSize = Entries.Count * PartitionFileEntry.GetEntrySize(type);
int stringTableSize = CalcStringTableSize(HeaderSize + entryTableSize, type);
int metaDataSize = HeaderSize + entryTableSize + stringTableSize;
var metaData = new byte[metaDataSize];
var writer = new BinaryWriter(new MemoryStream(metaData));
writer.WriteUTF8(GetMagicValue(type));
writer.Write(Entries.Count);
writer.Write(stringTableSize);
writer.Write(0);
int stringOffset = 0;
foreach (Entry entry in Entries)
{
writer.Write(entry.Offset);
writer.Write(entry.Length);
writer.Write(stringOffset);
if (type == PartitionFileSystemType.Standard)
{
writer.Write(0);
}
else
{
writer.Write(entry.HashLength);
writer.Write(entry.HashOffset);
writer.Write(entry.Hash);
}
stringOffset += entry.NameLength + 1;
}
foreach (Entry entry in Entries)
{
writer.WriteUTF8Z(entry.Name);
}
return(metaData);
}
public PartitionFileSystemHeader(BinaryReader reader)
{
Magic = reader.ReadAscii(4);
NumFiles = reader.ReadInt32();
StringTableSize = reader.ReadInt32();
Reserved = reader.ReadInt32();
switch (Magic)
{
case "PFS0":
Type = PartitionFileSystemType.Standard;
break;
case "HFS0":
Type = PartitionFileSystemType.Hashed;
break;
default:
throw new InvalidDataException($"Invalid Partition FS type \"{Magic}\"");
}
int entrySize = PartitionFileEntry.GetEntrySize(Type);
int stringTableOffset = 16 + entrySize * NumFiles;
HeaderSize = stringTableOffset + StringTableSize;
Files = new PartitionFileEntry[NumFiles];
for (int i = 0; i < NumFiles; i++)
{
Files[i] = new PartitionFileEntry(reader, Type)
{
Index = i
};
}
for (int i = 0; i < NumFiles; i++)
{
reader.BaseStream.Position = stringTableOffset + Files[i].StringTableOffset;
Files[i].Name = reader.ReadAsciiZ();
}
}
public IFile OpenFile(PartitionFileEntry entry, OpenMode mode)
{
return(new PartitionFile(BaseStorage, HeaderSize + entry.Offset, entry.Size, mode));
}