private long AllocateFromSmallActiveSection(int size)
{
long id;
if (ActiveDataSmallSection.TryAllocate(size, out id) == false)
{
InactiveSections.Add(_activeDataSmallSection.PageNumber);
using (var it = ActiveCandidateSection.Iterate())
{
if (it.Seek(long.MinValue))
{
do
{
var sectionPageNumber = it.CurrentKey;
_activeDataSmallSection = new ActiveRawDataSmallSection(_tx.LowLevelTransaction,
sectionPageNumber);
_activeDataSmallSection.DataMoved += OnDataMoved;
if (_activeDataSmallSection.TryAllocate(size, out id))
{
ActiveCandidateSection.Delete(sectionPageNumber);
return(id);
}
} while (it.MoveNext());
}
}
var newNumberOfPages = Math.Max((ushort)(ActiveDataSmallSection.NumberOfPages * 2), ushort.MaxValue);
_activeDataSmallSection = ActiveRawDataSmallSection.Create(_tx.LowLevelTransaction, Name, newNumberOfPages);
_activeDataSmallSection.DataMoved += OnDataMoved;
Slice pageNumber;
var val = _activeDataSmallSection.PageNumber;
using (Slice.External(_tx.Allocator, (byte *)&val, sizeof(long), out pageNumber))
{
_tableTree.Add(TableSchema.ActiveSectionSlice, pageNumber);
}
var allocationResult = _activeDataSmallSection.TryAllocate(size, out id);
Debug.Assert(allocationResult);
}
return(id);
}
private long AllocateFromSmallActiveSection(int size)
{
long id;
if (ActiveDataSmallSection.TryAllocate(size, out id) == false)
{
InactiveSections.Add(_activeDataSmallSection.PageNumber);
using (var it = ActiveCandidateSection.Iterate())
{
if (it.Seek(long.MinValue))
{
do
{
var sectionPageNumber = it.CurrentKey;
_activeDataSmallSection = new ActiveRawDataSmallSection(_tx.LowLevelTransaction,
sectionPageNumber);
if (_activeDataSmallSection.TryAllocate(size, out id))
{
ActiveCandidateSection.Delete(sectionPageNumber);
return(id);
}
} while (it.MoveNext());
}
}
_activeDataSmallSection = ActiveRawDataSmallSection.Create(_tx.LowLevelTransaction, Name);
var pageNumber = Slice.From(_tx.Allocator, EndianBitConverter.Little.GetBytes(_activeDataSmallSection.PageNumber), ByteStringType.Immutable);
_tableTree.Add(TableSchema.ActiveSection, pageNumber);
var allocationResult = _activeDataSmallSection.TryAllocate(size, out id);
Debug.Assert(allocationResult);
}
return(id);
}
public void Delete(long id)
{
int size;
var ptr = DirectRead(id, out size);
if (ptr == null)
{
return;
}
var stats = (TableSchemaStats *)_tableTree.DirectAdd(TableSchema.StatsSlice, 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);
_overflowPageCount -= numberOfPages;
stats->OverflowPageCount = _overflowPageCount;
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);
}