/// <summary>
/// Checks if the cabinet file contains a valid cabinet header.
/// </summary>
/// <returns>True if the file is a valid cabinet file; false otherwise.</returns>
internal virtual bool IsValid()
{
using (Stream stream = this.fileInfo.OpenRead())
{
return(Cabinet.FindCabinetOffset(stream) >= 0);
}
}
/// <summary>
/// Geats a stream for reading from the cabinet file. For use by subclasses.
/// </summary>
protected internal Stream GetCabinetReadStream()
{
Stream stream = this.fileInfo.OpenRead();
long offset = Cabinet.FindCabinetOffset(new DuplicateStream(stream));
if (offset > 0)
{
stream = new OffsetStream(stream, offset);
}
return(stream);
}
/// <summary>
/// Geats a stream for writing to the cabinet file. For use by subclasses.
/// </summary>
protected internal Stream GetCabinetWriteStream()
{
Stream stream = this.fileInfo.Open(FileMode.OpenOrCreate, FileAccess.ReadWrite);
long offset = Cabinet.FindCabinetOffset(new DuplicateStream(stream));
// If this is not a cabinet file, append the cab to it.
if (offset < 0)
{
offset = stream.Length;
}
if (offset > 0)
{
stream = new OffsetStream(stream, offset);
}
return(stream);
}
