store.h

/******************************************************************************
 *
 * 
 *
 * Copyright (C) 1997-2015 by Dimitri van Heesch.
 *
 * Permission to use, copy, modify, and distribute this software and its
 * documentation under the terms of the GNU General Public License is hereby 
 * granted. No representations are made about the suitability of this software 
 * for any purpose. It is provided "as is" without express or implied warranty.
 * See the GNU General Public License for more details.
 *
 * Documents produced by Doxygen are derivative works derived from the
 * input used in their production; they are not affected by this license.
 *
 */

#ifndef STORE_H
#define STORE_H

#include <qglobal.h>
#include <stdio.h>

#include "portable.h"

class StorageIntf
{
  public:
    virtual ~StorageIntf() {}
    virtual int read(char *buf,uint size) = 0;
    virtual int write(const char *buf,uint size) = 0;
};

class Store : public StorageIntf
{
  public:
    Store();

   ~Store();

    int open(const char *name);

    portable_off_t alloc();

    int write(const char *buf,uint size);

    void end();

    void release(portable_off_t handle);

    void close();

    void seek(portable_off_t handle);

    int read(char *buf,uint size);

    void printStats();

    portable_off_t pos() const { return m_cur; }

    void dumpBlock(portable_off_t start,portable_off_t end);

  private:
    enum State
    {
      Init,
      Reading,
      Writing
    };
    struct Node
    {
      portable_off_t pos;
      struct Node *next;
    };
    void printFreeList();
    FILE *m_file;
    portable_off_t m_front;
    portable_off_t m_cur;
    Node *m_head;
    State m_state;
    int m_reads;
    int m_writes;
};

#endif