/// <returns>Insert index</returns>
public int InsertSorted(BlockBTreeEntry entryToInsert)
{
int insertIndex = GetSortedInsertIndex(entryToInsert);
BlockEntryList.Insert(insertIndex, entryToInsert);
return(insertIndex);
}
/// <summary>
/// The caller must update its reference to point to the new root
/// </summary>
public virtual void SaveChanges()
{
foreach (ulong blockID in m_blocksToWrite)
{
Block block = m_blockBuffer[blockID];
long offset = AllocationHelper.AllocateSpaceForBlock(m_file, block.TotalLength);
block.WriteToStream(m_file.BaseStream, offset);
m_file.BlockBTree.InsertBlockEntry(block.BlockID, offset, block.DataLength);
}
foreach (ulong blockID in m_blocksToFree)
{
BlockBTreeEntry entry = m_file.FindBlockEntryByBlockID(blockID);
entry.cRef--;
// Any leaf BBT entry that points to a BID holds a reference count to it.
if (entry.cRef == 1)
{
// we can mark the allocation to be freed and delete the entry,
// We should not free the allocation until the BBT is committed.
m_file.MarkAllocationToBeFreed(entry.BREF.ib, Block.GetTotalBlockLength(entry.cb));
m_file.BlockBTree.DeleteBlockEntry(entry.BREF.bid);
}
else
{
m_file.BlockBTree.UpdateBlockEntry(entry.BREF.bid, entry.cRef);
}
}
m_blocksToWrite.Clear();
m_blocksToFree.Clear();
}
public override void PopulateEntries(byte[] buffer, byte numberOfEntries)
{
for (int index = 0; index < numberOfEntries; index++)
{
int offset = index * cbEnt;
BlockBTreeEntry entry = new BlockBTreeEntry(buffer, offset);
BlockEntryList.Add(entry);
}
}
public void InsertBlockEntry(BlockID blockID, long offset, int dataLength)
{
BlockBTreeEntry entryToInsert = new BlockBTreeEntry();
entryToInsert.BREF.bid = blockID;
entryToInsert.BREF.ib = (ulong)offset;
entryToInsert.cb = (ushort)dataLength;
entryToInsert.cRef = 2; // Any leaf BBT entry that points to a BID holds a reference count to it
InsertBlockEntry(entryToInsert);
}
private int GetSortedInsertIndex(BlockBTreeEntry entryToInsert)
{
ulong key = entryToInsert.BREF.bid.Value;
int insertIndex = 0;
while (insertIndex < BlockEntryList.Count && key > BlockEntryList[insertIndex].BREF.bid.Value)
{
insertIndex++;
}
return(insertIndex);
}
public Block FindBlockByBlockID(ulong blockID)
{
BlockBTreeEntry entry = FindBlockEntryByBlockID(blockID);
if (entry != null)
{
return(Block.ReadFromStream(m_stream, entry.BREF, entry.cb, Header.bCryptMethod));
}
else
{
return(null);
}
}
public void InsertBlockEntry(BlockBTreeEntry entryToInsert)
{
ulong key = entryToInsert.BREF.bid.Value;
BlockBTreeLeafPage page = (BlockBTreeLeafPage)FindLeafBTreePage(key);
if (page.BlockEntryList.Count < BlockBTreeLeafPage.MaximumNumberOfEntries)
{
int insertIndex = page.InsertSorted(entryToInsert);
UpdatePageAndReferences(page);
if (insertIndex == 0 && page.ParentPage != null)
{
// page key has been modified, we must update the parent
UpdateIndexEntry(page.ParentPage, page.BlockID, page.PageKey);
}
}
else
{
// We have to split the tree node
BlockBTreeLeafPage newPage = page.Split();
if (newPage.PageKey < key)
{
newPage.InsertSorted(entryToInsert);
}
else
{
int insertIndex = page.InsertSorted(entryToInsert);
if (insertIndex == 0 && page.ParentPage != null)
{
// page key has been modified, we must update the parent
UpdateIndexEntry(page.ParentPage, page.BlockID, page.PageKey);
}
}
UpdatePageAndReferences(page);
AddPage(newPage);
if (page.ParentPage == null)
{
// this is a root page and it's full, we have to create a new root
CreateNewRoot();
}
InsertIndexEntry(page.ParentPage, newPage.PageKey, newPage.BlockID);
}
}
public void IncrementBlockEntryReferenceCount(BlockID blockID)
{
BlockBTreeEntry entry = FindBlockEntryByBlockID(blockID.LookupValue);
UpdateBlockEntry(blockID, (ushort)(entry.cRef + 1));
}
