/// <summary>
/// Create a new VolumeHeader from a Stream and version
/// </summary>
public static VolumeHeader Create(Stream stream, int version)
{
var header = new VolumeHeader();
if (version <= 5)
{
if (stream.Length - stream.Position < Constants.VOLUME_HEADER_SIZE_V5)
{
return(null);
}
header.DataOffset = stream.ReadUInt32();
stream.Seek(4, SeekOrigin.Current);
header.FirstFileIndex = stream.ReadUInt32();
header.LastFileIndex = stream.ReadUInt32();
header.FirstFileOffset = stream.ReadUInt32();
header.FirstFileSizeExpanded = stream.ReadUInt32();
header.FirstFileSizeCompressed = stream.ReadUInt32();
header.LastFileOffset = stream.ReadUInt32();
header.LastFileSizeExpanded = stream.ReadUInt32();
header.LastFileSizeCompressed = stream.ReadUInt32();
if (header.LastFileOffset == 0)
{
header.LastFileOffset = int.MaxValue;
}
}
else
{
if (stream.Length - stream.Position < Constants.VOLUME_HEADER_SIZE_V6)
{
return(null);
}
header.DataOffset = stream.ReadUInt32();
header.DataOffsetHigh = stream.ReadUInt32();
header.FirstFileIndex = stream.ReadUInt32();
header.LastFileIndex = stream.ReadUInt32();
header.FirstFileOffset = stream.ReadUInt32();
header.FirstFileOffsetHigh = stream.ReadUInt32();
header.FirstFileSizeExpanded = stream.ReadUInt32();
header.FirstFileSizeExpandedHigh = stream.ReadUInt32();
header.FirstFileSizeCompressed = stream.ReadUInt32();
header.FirstFileSizeCompressedHigh = stream.ReadUInt32();
header.LastFileOffset = stream.ReadUInt32();
header.LastFileOffsetHigh = stream.ReadUInt32();
header.LastFileSizeExpanded = stream.ReadUInt32();
header.LastFileSizeExpandedHigh = stream.ReadUInt32();
header.LastFileSizeCompressed = stream.ReadUInt32();
header.LastFileSizeCompressedHigh = stream.ReadUInt32();
}
return(header);
}
/// <summary>
/// Open the volume at the inputted index
/// </summary>
public bool OpenVolume(int volume)
{
this.VolumeFile?.Close();
this.VolumeFile = this.Cabinet.OpenFileForReading(volume, Constants.CABINET_SUFFIX);
if (this.VolumeFile == null)
{
Console.Error.WriteLine($"Failed to open input cabinet file {volume}");
return(false);
}
var commonHeader = CommonHeader.Create(this.VolumeFile);
if (commonHeader == default)
{
return(false);
}
this.VolumeHeader = VolumeHeader.Create(this.VolumeFile, this.Cabinet.HeaderList.MajorVersion);
if (this.VolumeHeader == null)
{
return(false);
}
// enable support for split archives for IS5
if (this.Cabinet.HeaderList.MajorVersion == 5)
{
if (this.Index < (this.Cabinet.HeaderList.Descriptor.FileCount - 1) &&
this.Index == this.VolumeHeader.LastFileIndex &&
this.VolumeHeader.LastFileSizeCompressed != this.FileDescriptor.CompressedSize)
{
this.FileDescriptor.Flags |= FileDescriptorFlag.FILE_SPLIT;
}
else if (this.Index > 0 &&
this.Index == this.VolumeHeader.FirstFileIndex &&
this.VolumeHeader.FirstFileSizeCompressed != this.FileDescriptor.CompressedSize)
{
this.FileDescriptor.Flags |= FileDescriptorFlag.FILE_SPLIT;
}
}
ulong dataOffset, volumeBytesLeftCompressed, volumeBytesLeftExpanded;
if (this.FileDescriptor.Flags.HasFlag(FileDescriptorFlag.FILE_SPLIT))
{
if (this.Index == this.VolumeHeader.LastFileIndex && this.VolumeHeader.LastFileOffset != 0x7FFFFFFF)
{
// can be first file too
dataOffset = this.VolumeHeader.LastFileOffset;
volumeBytesLeftExpanded = this.VolumeHeader.LastFileSizeExpanded;
volumeBytesLeftCompressed = this.VolumeHeader.LastFileSizeCompressed;
}
else if (this.Index == this.VolumeHeader.FirstFileIndex)
{
dataOffset = this.VolumeHeader.FirstFileOffset;
volumeBytesLeftExpanded = this.VolumeHeader.FirstFileSizeExpanded;
volumeBytesLeftCompressed = this.VolumeHeader.FirstFileSizeCompressed;
}
else
{
return(true);
}
}
else
{
dataOffset = this.FileDescriptor.DataOffset;
volumeBytesLeftExpanded = this.FileDescriptor.ExpandedSize;
volumeBytesLeftCompressed = this.FileDescriptor.CompressedSize;
}
if (this.FileDescriptor.Flags.HasFlag(FileDescriptorFlag.FILE_COMPRESSED))
{
this.VolumeBytesLeft = volumeBytesLeftCompressed;
}
else
{
this.VolumeBytesLeft = volumeBytesLeftExpanded;
}
this.VolumeFile.Seek((long)dataOffset, SeekOrigin.Begin);
this.Volume = volume;
return(true);
}
