internal BTreeNodeSearchResult SearchLeaf(Transaction trans, IPreparedComparison
preparedComparison, SearchTarget target)
{
ByteArrayBuffer reader = PrepareRead(trans);
Searcher s = Search(trans, preparedComparison, reader, target);
if (!_isLeaf)
{
return(Child(reader, s.Cursor()).SearchLeaf(trans, preparedComparison, target));
}
if (!s.FoundMatch() || target == SearchTarget.Any || target == SearchTarget.Highest)
{
return(new BTreeNodeSearchResult(trans, reader, Btree(), s, this));
}
if (target == SearchTarget.Lowest)
{
BTreeNodeSearchResult res = FindLowestLeafMatch(trans, preparedComparison, s.Cursor
() - 1);
if (res != null)
{
return(res);
}
return(CreateMatchingSearchResult(trans, reader, s.Cursor()));
}
throw new InvalidOperationException();
}
public virtual IBTreeRange CreateIncludingRange(Db4objects.Db4o.Internal.Btree.BTreeNodeSearchResult
end)
{
BTreePointer firstPointer = FirstValidPointer();
BTreePointer endPointer = end._foundMatch ? end._pointer.Next() : end.FirstValidPointer
();
return(new BTreeRangeSingle(_transaction, _btree, firstPointer, endPointer));
}
public virtual BTreeNodeSearchResult SearchLeaf(Transaction trans, IPreparedComparison
preparedComparison, SearchTarget target)
{
EnsureActive(trans);
BTreeNodeSearchResult result = _root.SearchLeaf(trans, preparedComparison, target
);
ConvertCacheEvictedNodesToReadMode();
return(result);
}
public virtual IBTreeRange CreateIncludingRange(BTreeNodeSearchResult
end)
{
var firstPointer = FirstValidPointer();
var endPointer = end._foundMatch
? end._pointer.Next()
: end.FirstValidPointer
();
return new BTreeRangeSingle(_transaction, _btree, firstPointer, endPointer);
}
public virtual IBTreeRange CreateIncludingRange(BTreeNodeSearchResult
end)
{
var firstPointer = FirstValidPointer();
var endPointer = end._foundMatch
? end._pointer.Next()
: end.FirstValidPointer
();
return(new BTreeRangeSingle(_transaction, _btree, firstPointer, endPointer));
}
private IBTreeRange SearchRange(Transaction trans, IPreparedComparison preparedComparison
)
{
EnsureActive(trans);
// TODO: Optimize the following.
// Part of the search operates against the same nodes.
// As long as the bounds are on one node, the search
// should walk the nodes in one go.
BTreeNodeSearchResult start = SearchLeaf(trans, preparedComparison, SearchTarget.
Lowest);
BTreeNodeSearchResult end = SearchLeaf(trans, preparedComparison, SearchTarget.Highest
);
IBTreeRange range = start.CreateIncludingRange(end);
ConvertCacheEvictedNodesToReadMode();
return(range);
}
private BTreePointer FirstBTreePointer()
{
// We don't want nulls included so we have to search for null and use the resulting pointer if we find one.
IIndexable4 keyHandler = Btree().KeyHandler();
if (keyHandler is ICanExcludeNullInQueries)
{
ICanExcludeNullInQueries canExcludeNullInQueries = (ICanExcludeNullInQueries)keyHandler;
if (canExcludeNullInQueries.ExcludeNull())
{
BTreeNodeSearchResult searchLeaf = Btree().SearchLeafByObject(Transaction(), null
, SearchTarget.Highest);
BTreePointer pointer = searchLeaf.FirstValidPointer();
if (pointer != null)
{
return(pointer);
}
}
}
return(Btree().FirstPointer(Transaction()));
}
private BTreeNodeSearchResult FindLowestLeafMatch(Transaction trans, IPreparedComparison
preparedComparison, ByteArrayBuffer reader, int index)
{
if (index >= 0)
{
if (!CompareEquals(preparedComparison, trans, reader, index))
{
return(null);
}
if (index > 0)
{
BTreeNodeSearchResult res = FindLowestLeafMatch(trans, preparedComparison, reader
, index - 1);
if (res != null)
{
return(res);
}
return(CreateMatchingSearchResult(trans, reader, index));
}
}
Db4objects.Db4o.Internal.Btree.BTreeNode node = PreviousNode();
if (node != null)
{
ByteArrayBuffer nodeReader = node.PrepareRead(trans);
BTreeNodeSearchResult res = node.FindLowestLeafMatch(trans, preparedComparison, nodeReader
, node.LastIndex());
if (res != null)
{
return(res);
}
}
if (index < 0)
{
return(null);
}
return(CreateMatchingSearchResult(trans, reader, index));
}
public virtual BTreePointer SearchPointer(Transaction trans, object key)
{
EnsureActive(trans);
KeyCantBeNull(key);
IPreparedComparison preparedComparison = KeyHandler().PrepareComparison(trans.Context
(), key);
BTreeNodeSearchResult start = SearchLeaf(trans, preparedComparison, SearchTarget.
Lowest);
BTreePointer bTreePointer = start.FirstValidPointer();
if (bTreePointer == null)
{
ConvertCacheEvictedNodesToReadMode();
return(null);
}
object found = bTreePointer.Key();
ConvertCacheEvictedNodesToReadMode();
if (preparedComparison.CompareTo(found) == 0)
{
return(bTreePointer);
}
return(null);
}
