public void Delete(long id)
{
int size;
var ptr = DirectRead(id, out size);
if (ptr == null)
{
return;
}
var stats = (TableSchemaStats *)_tableTree.DirectAdd(TableSchema.Stats, sizeof(TableSchemaStats));
NumberOfEntries--;
stats->NumberOfEntries = NumberOfEntries;
DeleteValueFromIndex(id, new TableValueReader(ptr, size));
var largeValue = (id % _pageSize) == 0;
if (largeValue)
{
var page = _tx.LowLevelTransaction.GetPage(id / _pageSize);
var numberOfPages = _tx.LowLevelTransaction.DataPager.GetNumberOfOverflowPages(page.OverflowSize);
for (int i = 0; i < numberOfPages; i++)
{
_tx.LowLevelTransaction.FreePage(page.PageNumber + i);
}
return;
}
var density = ActiveDataSmallSection.Free(id);
if (ActiveDataSmallSection.Contains(id) || density > 0.5)
{
return;
}
var sectionPageNumber = ActiveDataSmallSection.GetSectionPageNumber(id);
if (density > 0.15)
{
ActiveCandidateSection.Add(sectionPageNumber);
return;
}
// move all the data to the current active section (maybe creating a new one
// if this is busy)
// if this is in the active candidate list, remove it so it cannot be reused if the current
// active is full and need a new one
ActiveCandidateSection.Delete(sectionPageNumber);
var idsInSection = ActiveDataSmallSection.GetAllIdsInSectionContaining(id);
foreach (var idToMove in idsInSection)
{
int itemSize;
var pos = ActiveDataSmallSection.DirectRead(idToMove, out itemSize);
var newId = AllocateFromSmallActiveSection(itemSize);
OnDataMoved(idToMove, newId, pos, itemSize);
byte *writePos;
if (ActiveDataSmallSection.TryWriteDirect(newId, itemSize, out writePos) == false)
{
throw new InvalidDataException($"Cannot write to newly allocated size in {Name} during delete");
}
Memory.Copy(writePos, pos, itemSize);
}
ActiveDataSmallSection.DeleteSection(sectionPageNumber);
}