public MergingIterator(Comparator comparator, Iterator[] children)
{
comparator_ = comparator;
children_ = new IteratorWrapper[children.Length];
current_ = null;
direction_ = Direction.kForward;
for (int i = 0; i < children.Length; i++)
children_[i] = new IteratorWrapper(children[i]);
}
public TwoLevelIterator(
Iterator index_iter,
BlockFunctionDelegate block_function,
object arg,
ReadOptions options)
{
block_function_ = block_function;
arg_ = arg;
options_ = options;
index_iter_ = new IteratorWrapper(index_iter);
data_iter_ = null;
}
internal static Iterator NewTwoLevelIterator(
Iterator index_iter, BlockFunctionDelegate block_function, object arg, ReadOptions options)
{
return new TwoLevelIterator(index_iter, block_function, arg, options);
}
internal static Iterator NewMergingIterator(Comparator comparator, Iterator[] children)
{
Debug.Assert(children.Length >= 0);
if (children.Length == 0)
{
return EmptyIterator;
}
else if (children.Length == 1)
{
return children[0];
}
else
{
return new MergingIterator(comparator, children);
}
}
public IteratorWrapper(Iterator iter)
{
Iterator = iter;
}
public IteratorWrapper()
{
iter_ = null;
valid_ = false;
}
void SetDataIterator(Iterator data_iter)
{
if (data_iter_.Iterator != null)
SaveError(data_iter_.Status);
data_iter_.Iterator = data_iter;
}