/// <summary>
/// Adds new page to cache.
///
/// If page exists:
/// - LFU index of existing page is shifted.
/// - returns FALSE
///
/// If page with given address does not exist:
/// - page added to cache.
/// - some pages could be evicted
/// - return TRUE
///
/// </summary>
/// <param name="address"></param>
/// <returns>False if page is already exist</returns>
public bool Add(VTAddress virtualAddress, out int physicalAddress)
{
Page page;
if (cache.TryGetValue(virtualAddress, out page))
{
physicalAddress = page.Address;
return(false);
}
else
{
cache.Discard(out page);
var newPage = new Page(virtualAddress, page.Address, pageCount, physTexSize);
cache.Add(virtualAddress, newPage);
physicalAddress = newPage.Address;
return(true);
}
}