public PagerState(AbstractPager pager)
{
_pager = pager;
#if DEBUG_PAGER_STATE
Instances[this] = new StackTrace(true);
#endif
}
public static int WritePage(this AbstractPager pager, Page page, long?pageNumber = null)
{
var startPage = pageNumber ?? page.PageNumber;
var toWrite = page.IsOverflow ? pager.GetNumberOfOverflowPages(page.OverflowSize) : 1;
return(pager.WriteDirect(page.Pointer, startPage, toWrite));
}
public CryptoPager(AbstractPager inner) : base(inner.Options, inner.UsePageProtection)
{
if (inner.Options.EncryptionEnabled == false)
{
throw new InvalidOperationException("Cannot use CryptoPager if EncryptionEnabled is false (no key defined)");
}
Inner = inner;
_encryptionBuffersPool = new EncryptionBuffersPool();
_masterKey = inner.Options.MasterKey;
UniquePhysicalDriveId = Inner.UniquePhysicalDriveId;
FileName = inner.FileName;
_pagerState = inner.PagerState;
inner.PagerStateChanged += state => _pagerState = state;
}
public static byte *AcquirePagePointerWithOverflowHandling <T>(this AbstractPager pager, T tx, long pageNumber) where T : IPagerLevelTransactionState
{
// Case 1: Page is not overflow ==> no problem, returning a pointer to existing mapping
var pageHeader = (PageHeader *)pager.AcquirePagePointer(tx, pageNumber);
if ((pageHeader->Flags & PageFlags.Overflow) != PageFlags.Overflow)
{
return((byte *)pageHeader);
}
// Case 2: Page is overflow and already mapped large enough ==> no problem, returning a pointer to existing mapping
if (pager.EnsureMapped(tx, pageNumber, GetNumberOfOverflowPages(pageHeader->OverflowSize)) == false)
{
return((byte *)pageHeader);
}
// Case 3: Page is overflow and was ensuredMapped above, view was re-mapped so we need to acquire a pointer to the new mapping.
return(pager.AcquirePagePointer(tx, pageNumber));
}
public static bool WillRequireExtension(this AbstractPager pager, long requestedPageNumber, int numberOfPages)
{
return(requestedPageNumber + numberOfPages > pager.NumberOfAllocatedPages);
}
public static Page ReadPage(this AbstractPager pager, LowLevelTransaction tx, long pageNumber, PagerState pagerState = null)
{
return(new Page(pager.AcquirePagePointer(tx, pageNumber, pagerState), pager));
}
public static int GetNumberOfOverflowPages(this AbstractPager pager, int overflowSize)
{
overflowSize += Constants.TreePageHeaderSize;
return((overflowSize / pager.PageSize) + (overflowSize % pager.PageSize == 0 ? 0 : 1));
}
public static TreePage Read(this AbstractPager pager, LowLevelTransaction tx, long pageNumber, PagerState pagerState = null)
{
return(new TreePage(pager.AcquirePagePointer(tx, pageNumber, pagerState), pager.DebugInfo, pager.PageSize));
}
public Simple4KbBatchWrites(AbstractPager abstractPager)
{
_abstractPager = abstractPager;
_pagerState = _abstractPager.GetPagerStateAndAddRefAtomically();
}
public static int GetNumberOfOverflowPages(this AbstractPager pager, long overflowSize)
{
overflowSize += Constants.Tree.PageHeaderSize;
return(checked ((int)(overflowSize / pager.PageSize) + (overflowSize % pager.PageSize == 0 ? 0 : 1)));
}
public static int GetNumberOfPages(this AbstractPager pager, Page page)
{
return(page.IsOverflow ? pager.GetNumberOfOverflowPages(page.OverflowSize) : 1);
}
