RecordIterator.cc

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/*****************************************************************************
 *                                                                           *
 *  Copyright 2018 Rice University                                           *
 *                                                                           *
 *  Licensed 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                                  *
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 *      http://www.apache.org/licenses/LICENSE-2.0                           *
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 *  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.                                           *
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#ifndef OBJECT_ITERATOR_CC
#define OBJECT_ITERATOR_CC


#include "RecordIterator.h"


RecordIterator::RecordIterator(PDBPagePtr page) {

    this->page = page;
    this->numObjectsIterated = 0;
    this->numObjectsInCurPage = page->getEmbeddedNumObjects();
    this->curPosInPage = (char*)page->getBytes();
}

RecordIterator::~RecordIterator() {}

Record<Object>* RecordIterator::next() {

    if (this->curPosInPage == 0) {
        return nullptr;
    }

    // 1st field: record data size
    size_t objectDataSize = *((size_t*)this->curPosInPage);

    // 2nd field: record data
    Record<Object>* ret = (Record<Object>*)(curPosInPage + sizeof(size_t));

    // compute offset of next record
    this->curPosInPage = this->curPosInPage + sizeof(size_t) + objectDataSize;

    this->numObjectsIterated++;
    return ret;
}

bool RecordIterator::hasNext() {
    if (this->numObjectsInCurPage == this->numObjectsIterated) {
        this->curPosInPage = 0;
        return false;
    } else {
        return true;
    }
}

#endif