Database.h

/* vim:set et ts=4 sts=4:
 *
 * libpyzy - The Chinese PinYin and Bopomofo conversion library.
 *
 * Copyright (c) 2019 Yuanle Song <sylecn@gmail.com>
 * Copyright (c) 2008-2010 Peng Huang <shawn.p.huang@gmail.com>
 *
 * 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 Street, Fifth Floor, Boston, MA  02110-1301
 * USA
 */
#ifndef __PYZY_DATABASE_H_
#define __PYZY_DATABASE_H_

#include "PhraseArray.h"
#include "String.h"
#include "Types.h"
#include "Util.h"
#include "sqlite3_util.h"

typedef struct sqlite3 sqlite3;

namespace PyZy {

class PinyinArray;
struct Phrase;

class SQLStmt;
typedef std::shared_ptr<SQLStmt> SQLStmtPtr;

class Database;

class Query {
public:
    Query (const PinyinArray    & pinyin,
           size_t                 pinyin_begin,
           size_t                 pinyin_len,
           unsigned int           option);
    ~Query (void);
    int fill (PhraseArray &phrases, int count);

private:
    const PinyinArray & m_pinyin;
    size_t m_pinyin_begin;
    size_t m_pinyin_len;
    unsigned int m_option;
    SQLStmtPtr m_stmt;
};

class Database {
public:
    ~Database ();
protected:
    Database (const std::string &user_data_dir);

public:
    static bool init (const std::string &data_dir);
    static Database & instance (void)
    {
	    if (m_instance == NULL) {
		    g_error ("Error: Please call InputContext::init () !");
		    g_assert_not_reached ();
	    }
	    return *m_instance;
    }
    static void finalize (void);

    SQLStmtPtr query (const PinyinArray   & pinyin,
                      size_t                pinyin_begin,
                      size_t                pinyin_len,
                      int                   m,
                      unsigned int          option);
    void commit (const PhraseArray  & phrases);
    void remove (const Phrase & phrase);

private:
    bool initDB (void);
    static bool initUserDB (sqlite3* userdb, const char* schema);
    String getMainDBFile (void);
    String getUserDBFile (void);
    gboolean createUserDBFile (void);
    bool setPragmaOnMainDB (void);
    void prefetch (void);
    void phraseSql (const Phrase & p, String & sql);
    void phraseWhereSql (const Phrase & p, String & sql);
    static gboolean cb_saveUserDB (gpointer user_data);
    void modified (void);

private:
    sqlite3 *m_db;              /* db handler to access maindb and userdb */
    String m_user_data_dir;
    String m_main_db_file;	/* main db file name with full path */
    String m_user_db_file;	/* user db file name with full path */

private:
    static std::unique_ptr<Database> m_instance;
};

};  // namespace PyZy

#endif  // __PYZY_DATABASE_H_