ReversedCellsReader.cpp

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/*******************************************************************************
 *
 * Copyright (c) 2010-2015   Edans Sandes
 *
 * This file is part of MASA-Core.
 * 
 * MASA-Core is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 * 
 * MASA-Core 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 General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with MASA-Core.  If not, see <http://www.gnu.org/licenses/>.
 *
 ******************************************************************************/

#include "ReversedCellsReader.hpp"

#include <stdio.h>

ReversedCellsReader::ReversedCellsReader(SeekableCellsReader* reader) {
        this->reader = reader;
        this->position = position;
}

ReversedCellsReader::~ReversedCellsReader() {
        close();
}

void ReversedCellsReader::close() {
        if (reader == NULL) {
                reader->close();
                reader = NULL;
        }
}

int ReversedCellsReader::getType() {
        return INIT_WITH_CUSTOM_DATA;
}

int ReversedCellsReader::read(cell_t* buf, int len) {
        if (len > position) {
                len = position;
        }
        position -= len;
        reader->seek(position);
        reader->read(buf, len);

        // Reverse buffer order
        for (int i=0; i<len/2; i++) {
                cell_t aux = buf[i];
                buf[i] = buf[len-1-i];
                buf[len-1-i] = aux;
        }

        return len;
}


void ReversedCellsReader::seek(int position) {
        this->position = position;
}

int ReversedCellsReader::getOffset() {
        return position;
}