public Page GetPage(PageNumberInfo number)
{
if (ModifiedPages.TryGetValue(number, out var dirtyPage))
{
return(dirtyPage);
}
if (AllocatedPages.Contains(number))
{
return(CreatePage(number));
}
var poolPage = Pool.GetEntry(number);
if (poolPage != null)
{
return(poolPage);
}
var page = PageManager.GetPage(number);
if (page == null)
{
throw null;
}
Pool.AddEntry(page, PageEntryState.None);
return(page);
}
public Page ModifyPage(PageNumberInfo number)
{
if (ModifiedPages.TryGetValue(number, out var page))
{
return(page);
}
var oldPage = GetPage(number);
var newPage = ModifyPage(oldPage);
if (!ModifiedPages.TryAdd(number, newPage))
{
throw new InvalidOperationException($"modify page {number.PageNumber} failed!");
}
return(newPage);
}