asterixdb/asterix-om/src/main/java/org/apache/asterix/om/lazy/FixedListLazyVisitablePointable.java

/*
 * 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.asterix.om.lazy;

import org.apache.asterix.om.types.ATypeTag;
import org.apache.asterix.om.types.AbstractCollectionType;
import org.apache.asterix.om.types.IAType;
import org.apache.asterix.om.utils.NonTaggedFormatUtil;
import org.apache.hyracks.api.exceptions.HyracksDataException;

/**
 * This implementation is only for closed {@link ATypeTag#ARRAY} and {@link ATypeTag#MULTISET} with fixed-length
 * items.
 */
public class FixedListLazyVisitablePointable extends AbstractListLazyVisitablePointable {
    private final int itemSize;

    public FixedListLazyVisitablePointable(boolean tagged, AbstractCollectionType listType) {
        super(tagged, listType);
        ATypeTag itemTag = listType.getItemType().getTypeTag();
        currentChildTypeTag = itemTag.serialize();
        try {
            itemSize = NonTaggedFormatUtil.getFieldValueLength(null, -1, itemTag, false);
        } catch (HyracksDataException e) {
            throw new IllegalStateException(e);
        }

    }

    @Override
    public void nextChild() {
        byte[] data = getByteArray();
        int itemOffset = itemsOffset + currentIndex * itemSize;
        currentValue.set(data, itemOffset, itemSize);
        currentIndex++;
    }

    @Override
    public boolean isTaggedChild() {
        return false;
    }

    @Override
    AbstractLazyVisitablePointable createVisitablePointable(IAType itemType) {
        return createVisitable(itemType);
    }
}