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/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.cassandra.utils.btree;

import java.util.Comparator;

import org.apache.cassandra.utils.SearchIterator;

import static org.apache.cassandra.utils.btree.BTree.getKeyEnd;

public class BTreeSearchIterator extends Path implements SearchIterator
{

    final Comparator comparator;
    public BTreeSearchIterator(Object[] btree, Comparator comparator)
    {
        init(btree);
        this.comparator = comparator;
    }

    public V next(K target)
    {
        while (depth > 0)
        {
            byte successorParentDepth = findSuccessorParentDepth();
            if (successorParentDepth < 0)
                break; // we're in last section of tree, so can only search down
            int successorParentIndex = indexes[successorParentDepth] + 1;
            Object[] successParentNode = path[successorParentDepth];
            Object successorParentKey = successParentNode[successorParentIndex];
            int c = BTree.compare(comparator, target, successorParentKey);
            if (c < 0)
                break;
            if (c == 0)
            {
                depth = successorParentDepth;
                indexes[successorParentDepth]++;
                return (V) successorParentKey;
            }
            depth = successorParentDepth;
            indexes[successorParentDepth]++;
        }
        if (find(comparator, target, Op.CEIL, true))
            return (V) currentKey();
        return null;
    }

    public boolean hasNext()
    {
        return depth != 0 || indexes[0] != getKeyEnd(path[0]);
    }
}




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