private bool TryOverwriteOverflowPages(TreeNodeHeader *updatedNode, int len, out byte *pos)
{
if (updatedNode->Flags == TreeNodeFlags.PageRef)
{
var readOnlyOverflowPage = GetReadOnlyTreePage(updatedNode->PageNumber);
if (len <= readOnlyOverflowPage.OverflowSize)
{
var availableOverflows = _llt.DataPager.GetNumberOfOverflowPages(readOnlyOverflowPage.OverflowSize);
var requestedOverflows = _llt.DataPager.GetNumberOfOverflowPages(len);
var overflowsToFree = availableOverflows - requestedOverflows;
for (int i = 0; i < overflowsToFree; i++)
{
_llt.FreePage(readOnlyOverflowPage.PageNumber + requestedOverflows + i);
}
State.RecordFreedPage(readOnlyOverflowPage, overflowsToFree);
var writtableOverflowPage = AllocateNewPage(_llt, TreePageFlags.Value, requestedOverflows, updatedNode->PageNumber);
writtableOverflowPage.Flags = PageFlags.Overflow | PageFlags.VariableSizeTreePage;
writtableOverflowPage.OverflowSize = len;
pos = writtableOverflowPage.Base + Constants.Tree.PageHeaderSize;
PageModified?.Invoke(writtableOverflowPage.PageNumber);
return(true);
}
}
pos = null;
return(false);
}
internal TreePage NewPage(TreePageFlags flags, int num)
{
var page = AllocateNewPage(_llt, flags, num);
State.RecordNewPage(page, num);
PageModified?.Invoke(page.PageNumber);
return(page);
}
public TreePage ModifyPage(long pageNumber)
{
var newPage = _llt.ModifyPage(pageNumber).ToTreePage();
newPage.Dirty = true;
_recentlyFoundPages.Reset(pageNumber);
PageModified?.Invoke(pageNumber);
return(newPage);
}
internal TreePage NewPage(TreePageFlags flags, long nearbyPage)
{
var newPage = _newPageAllocator?.AllocateSinglePage(nearbyPage) ?? _llt.AllocatePage(1);
var page = PrepareTreePage(flags, 1, newPage);
State.RecordNewPage(page, 1);
PageModified?.Invoke(page.PageNumber, page.Flags);
return(page);
}
private long WriteToOverflowPages(int overflowSize, out byte *dataPos)
{
var numberOfPages = _llt.DataPager.GetNumberOfOverflowPages(overflowSize);
var overflowPageStart = AllocateNewPage(_llt, TreePageFlags.Value, numberOfPages);
overflowPageStart.Flags = PageFlags.Overflow | PageFlags.VariableSizeTreePage;
overflowPageStart.OverflowSize = overflowSize;
dataPos = overflowPageStart.Base + Constants.TreePageHeaderSize;
State.RecordNewPage(overflowPageStart, numberOfPages);
PageModified?.Invoke(overflowPageStart.PageNumber);
return(overflowPageStart.PageNumber);
}
public TreePage ModifyPage(long pageNumber)
{
var newPage = GetWriteableTreePage(pageNumber);
newPage.Dirty = true;
_recentlyFoundPages.Reset(pageNumber);
if (IsLeafCompressionSupported && newPage.IsCompressed)
{
DecompressionsCache.Invalidate(pageNumber, DecompressionUsage.Read);
}
PageModified?.Invoke(pageNumber);
return(newPage);
}
private long WriteToOverflowPages(int overflowSize, out byte *dataPos)
{
var numberOfPages = VirtualPagerLegacyExtensions.GetNumberOfOverflowPages(overflowSize);
var newPage = _llt.AllocatePage(numberOfPages);
TreePage overflowPageStart = PrepareTreePage(TreePageFlags.Value, numberOfPages, newPage);
overflowPageStart.Flags = PageFlags.Overflow | PageFlags.VariableSizeTreePage;
overflowPageStart.OverflowSize = overflowSize;
dataPos = overflowPageStart.Base + Constants.Tree.PageHeaderSize;
State.RecordNewPage(overflowPageStart, numberOfPages);
PageModified?.Invoke(overflowPageStart.PageNumber, overflowPageStart.Flags);
return(overflowPageStart.PageNumber);
}
