/**
* Copyright (C) 2009-2013 FoundationDB, LLC
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package com.foundationdb.qp.storeadapter.indexcursor;
import com.persistit.Key;
import static com.foundationdb.qp.storeadapter.indexcursor.IndexCursor.INDEX_TRAVERSE;
class MixedOrderScanStateRemainingSegments<S> extends MixedOrderScanState<S>
{
@Override
public boolean startScan()
{
if (subtreeRootKey == null) {
subtreeRootKey = new Key(cursor.key());
} else {
cursor.key().copyTo(subtreeRootKey);
}
INDEX_TRAVERSE.hit();
return cursor.traverse(Key.GT, true);
}
@Override
public boolean advance()
{
INDEX_TRAVERSE.hit();
boolean more = ascending ? cursor.nextInternal(true) : cursor.prevInternal(true);
if (more) {
more = cursor.key().firstUniqueByteIndex(subtreeRootKey) >= subtreeRootKey.getEncodedSize();
}
if (!more) {
// Restore exchange key to where it was before exploring this subtree. But also attach one
// more key segment since IndexCursorMixedOrder is going to cut one.
subtreeRootKey.copyTo(cursor.key());
cursor.key().append(Key.BEFORE);
}
return more;
}
@Override
public boolean jump(S fieldValue)
{
return startScan();
}
public MixedOrderScanStateRemainingSegments(IndexCursorMixedOrder indexCursor, int field)
{
super(indexCursor, field, true);
}
private Key subtreeRootKey;
}