NVRAM.h

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/*
 * NVRAM.h - Byte-wise storage for Virtual Pages.
 * Original Copyright (c) 2017 Frank Holtz.  All right reserved.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
*/
#pragma once
 
#include "Flash.h"
#include "VirtualPage.h"
#include <Arduino.h>
 
class NVRAMClass
{
public:
    //----------------------------------------------------------------------------
    NVRAMClass() {};
    //----------------------------------------------------------------------------
    void begin() {};
    //----------------------------------------------------------------------------
    void end() {};
    //----------------------------------------------------------------------------
    uint16_t length() const;
    //----------------------------------------------------------------------------
    void read_block(uint8_t *dst, uint16_t idx, uint16_t n);
    //----------------------------------------------------------------------------
    uint8_t read(const uint16_t idx);
    //----------------------------------------------------------------------------
    bool write_block(uint8_t *src, uint16_t idx, uint16_t n);
    //----------------------------------------------------------------------------
    bool write(const uint16_t idx, uint8_t value);
    //----------------------------------------------------------------------------
    int write_prepare(uint16_t number);
    //----------------------------------------------------------------------------
    void clean_up(uint16_t write_preserve);
 
private:
    // Return a virtual page
    uint32_t *get_page();
    // Get actual log position
    uint16_t get_log_position(uint32_t *vpage);
    // Read a byte from page
    uint8_t get_byte_from_page(uint32_t *vpage, uint16_t log_start,
                               uint16_t log_end, uint16_t idx);
    // switch a page
    uint32_t *switch_page(uint32_t *old_vpage, uint16_t *log_start,
                          uint16_t *log_end);
};
 
extern NVRAMClass NVRAM;