| private TryRemoveMultiValueTree ( Voron.Trees.Tree parentTree, MemorySlice key ) : bool | ||
| parentTree | Voron.Trees.Tree | |
| key | MemorySlice | |
| return | bool | |
public void MultiDelete(Transaction tx, Slice key, Slice value, ushort? version = null)
{
State.IsModified = true;
Lazy<Cursor> lazy;
var page = FindPageFor(tx, key, out lazy);
if (page == null || page.LastMatch != 0)
{
return; //nothing to delete - key not found
}
page = tx.ModifyPage(page.PageNumber, page);
var item = page.GetNode(page.LastSearchPosition);
if (item->Flags == NodeFlags.MultiValuePageRef) //multi-value tree exists
{
var tree = OpenOrCreateMultiValueTree(tx, key, item);
tree.Delete(tx, value, version);
// previously, we would convert back to a simple model if we dropped to a single entry
// however, it doesn't really make sense, once you got enough values to go to an actual nested
// tree, you are probably going to remain that way, or be removed completely.
if (tree.State.EntriesCount != 0)
return;
tx.TryRemoveMultiValueTree(this, key);
tx.FreePage(tree.State.RootPageNumber);
Delete(tx, key);
}
else // we use a nested page here
{
var nestedPage = new Page(NodeHeader.DirectAccess(tx, item), "multi tree", (ushort)NodeHeader.GetDataSize(tx, item));
var nestedItem = nestedPage.Search(value, NativeMethods.memcmp);
if (nestedItem == null) // value not found
return;
CheckConcurrency(key, value, version, nestedItem->Version, TreeActionType.Delete);
nestedPage.RemoveNode(nestedPage.LastSearchPosition);
if (nestedPage.NumberOfEntries == 0)
Delete(tx, key);
}
}
public void MultiDelete(Transaction tx, Slice key, Slice value, ushort? version = null)
{
State.IsModified = true;
Lazy<Cursor> lazy;
var page = FindPageFor(tx, key, out lazy);
if (page == null || page.LastMatch != 0)
{
return; //nothing to delete - key not found
}
page = tx.ModifyPage(page.PageNumber, page);
var item = page.GetNode(page.LastSearchPosition);
if (item->Flags == NodeFlags.MultiValuePageRef) //multi-value tree exists
{
var tree = OpenOrCreateMultiValueTree(tx, key, item);
tree.Delete(tx, value, version);
if (tree.State.EntriesCount > 1)
return;
// convert back to simple key/val
var iterator = tree.Iterate(tx);
if (!iterator.Seek(Slice.BeforeAllKeys))
throw new InvalidDataException(
"MultiDelete() failed : sub-tree is empty where it should not be, this is probably a Voron bug.");
var dataToSave = iterator.CurrentKey;
var ptr = DirectAdd(tx, key, dataToSave.Size);
dataToSave.CopyTo(ptr);
tx.TryRemoveMultiValueTree(this, key);
tx.FreePage(tree.State.RootPageNumber);
}
else //the regular key->value pattern
{
Delete(tx, key, version);
}
}
