gnc-sql-object-backend.hpp

/***********************************************************************\
 * gnc-sql-object-backend.hpp: Encapsulate per-class table schema.     *
 *                                                                     *
 * Copyright 2016 John Ralls <jralls@ceridwen.us>                      *
 *                                                                     *
 * This program 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 2 of      *
 * the License, or (at your option) any later version.                 *
 *                                                                     *
 * This program 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 this program; if not, contact:                           *
 *                                                                     *
 * Free Software Foundation           Voice:  +1-617-542-5942          *
 * 51 Franklin Street, Fifth Floor    Fax:    +1-617-542-2652          *
 * Boston, MA  02110-1301,  USA       gnu@gnu.org                      *
\***********************************************************************/
 
#ifndef __GNC_SQL_OBJECT_BACKEND_HPP__
#define __GNC_SQL_OBJECT_BACKEND_HPP__
 
#include <qof.h>
 
#include <memory>
#include <string>
#include <vector>
 
class GncSqlBackend;
class GncSqlColumnTableEntry;
using GncSqlColumnTableEntryPtr = std::shared_ptr<GncSqlColumnTableEntry>;
using EntryVec = std::vector<GncSqlColumnTableEntryPtr>;
 
#define GNC_SQL_BACKEND "gnc:sql:1"
 
class GncSqlObjectBackend
{
public:
    GncSqlObjectBackend (int version, const std::string& type,
                         const std::string& table, const EntryVec& vec) :
        m_table_name{table}, m_version{version}, m_type_name{type},
        m_col_table(vec) {}
    virtual ~GncSqlObjectBackend() = default;
    virtual void load_all (GncSqlBackend* sql_be) = 0;
    virtual void create_tables (GncSqlBackend* sql_be);
    virtual bool commit (GncSqlBackend* sql_be, QofInstance* inst);
    virtual bool write (GncSqlBackend* sql_be) { return true; }
    const char* type () const noexcept { return m_type_name.c_str(); }
    const bool is_version (int version) const noexcept {
        return version == m_version;
    }
    bool instance_in_db(const GncSqlBackend* sql_be,
                        QofInstance* inst) const noexcept;
protected:
    const std::string m_table_name;
    const int m_version;
    const std::string m_type_name; 
    const EntryVec& m_col_table;   
};
 
using GncSqlObjectBackendPtr = std::shared_ptr<GncSqlObjectBackend>;
 
using OBEEntry = std::tuple<std::string, GncSqlObjectBackendPtr>;
using OBEVec = std::vector<OBEEntry>;
 
struct write_objects_t
{
    write_objects_t() = default;
    write_objects_t (GncSqlBackend* sql_be, bool o, GncSqlObjectBackend* e) :
        be{sql_be}, is_ok{o}, obe{e} {}
    void commit (QofInstance* inst) {
        if (is_ok) is_ok = obe->commit (be, inst);
    }
    GncSqlBackend* be = nullptr;
    bool is_ok = false;
    GncSqlObjectBackend* obe = nullptr;
};
 
 
#endif //__GNC_SQL_OBJECT_BACKEND_HPP__