driver_state.c

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/*!
 * \file db/dbmi_driver/driver_state.c
 *
 * \brief DBMI Library (driver) - drivers state
 *
 * (C) 1999-2008 by the GRASS Development Team
 *
 * This program is free software under the GNU General Public
 * License (>=v2). Read the file COPYING that comes with GRASS
 * for details.
 *
 * \author Joel Jones (CERL/UIUC), Radim Blazek
 */
 
#include <stdlib.h>
#include <grass/dbmi.h>
#include "dbstubs.h"
 
static dbDriverState state;
 
/*!
   \brief Initialize driver state
 */
void db__init_driver_state(void)
{
    db_zero((void *)&state, sizeof(state));
}
 
/*!
   \brief Get driver state
 
   \return pointer to dbDriverState
 */
dbDriverState *db__get_driver_state(void)
{
    return &state;
}
 
/*!
   \brief Test database connection
 
   \return 1 opened
   \return 0 closed
 */
int db__test_database_open(void)
{
    return state.open ? 1 : 0;
}
 
/*!
   \brief Mark database as opened
 
   \param dbname database name
   \param dbschema database schema name
 */
void db__mark_database_open(const char *dbname, const char *dbschema)
{
    state.dbname = db_store(dbname);
    state.dbschema = db_store(dbschema);
    state.open = 1;
}
 
/*!
   \brief Mark database as closed
 */
void db__mark_database_closed(void)
{
    db_free(state.dbname);
    db_free(state.dbschema);
    state.open = 0;
}
 
/*!
   \brief Add cursor do driver state
 
   \param cursor db cursor to be added
 */
void db__add_cursor_to_driver_state(dbCursor *cursor)
{
    dbCursor **list;
    int i;
 
    /* find an empty slot in the cursor list */
    list = state.cursor_list;
    for (i = 0; i < state.ncursors; i++)
        if (list[i] == NULL)
            break;
 
    /* if not found, extend list */
    if (i >= state.ncursors) {
        list =
            (dbCursor **)db_realloc((void *)list, (i + 1) * sizeof(dbCursor *));
        if (list == NULL)
            return;
        state.cursor_list = list;
        state.ncursors = i + 1;
    }
 
    /* add it in */
    list[i] = cursor;
}
 
/*!
   \brief Drop cursor from driver state
 
   \param cursor db cursor to be dropped
 */
void db__drop_cursor_from_driver_state(dbCursor *cursor)
{
    int i;
 
    for (i = 0; i < state.ncursors; i++)
        if (state.cursor_list[i] == cursor)
            state.cursor_list[i] = NULL;
}
 
/*!
   \brief Close all cursors
 */
void db__close_all_cursors(void)
{
    int i;
 
    for (i = 0; i < state.ncursors; i++)
        if (state.cursor_list[i])
            db_driver_close_cursor(state.cursor_list[i]);
 
    if (state.cursor_list)
        db_free(state.cursor_list);
 
    state.ncursors = 0;
    state.cursor_list = NULL;
}