Function db_sql_normal_function

lib/sqlite/lsqlite3.c:971–1028

scalar function to be called ** callback params: context, values... */

/* scalar function to be called
** callback params: context, values... */
static void db_sql_normal_function(sqlite3_context *context, int argc, sqlite3_value **argv) {
    sdb_func *func = (sdb_func*)sqlite3_user_data(context);
    lua_State *L = func->db->L;
    int n;
    lcontext *ctx;

    int top = lua_gettop(L);

    /* ensure there is enough space in the stack */
    lua_checkstack(L, argc + 3);

    lua_rawgeti(L, LUA_REGISTRYINDEX, func->fn_step);   /* function to call */

    if (!func->aggregate) {
        ctx = lsqlite_make_context(L); /* push context - used to set results */
    }
    else {
        /* reuse context userdata value */
        void *p = sqlite3_aggregate_context(context, 1);
        /* i think it is OK to use assume that using a light user data
        ** as an entry on LUA REGISTRY table will be unique */
        lua_pushlightuserdata(L, p);
        lua_rawget(L, LUA_REGISTRYINDEX);       /* context table */

        if (lua_isnil(L, -1)) { /* not yet created? */
            lua_pop(L, 1);
            ctx = lsqlite_make_context(L);
            lua_pushlightuserdata(L, p);
            lua_pushvalue(L, -2);
            lua_rawset(L, LUA_REGISTRYINDEX);
        }
        else
            ctx = lsqlite_getcontext(L, -1);
    }

    /* push params */
    for (n = 0; n < argc; ++n) {
        db_push_value(L, argv[n]);
    }

    /* set context */
    ctx->ctx = context;

    if (lua_pcall(L, argc + 1, 0, 0)) {
        const char *errmsg = lua_tostring(L, -1);
        int size = lua_strlen(L, -1);
        sqlite3_result_error(context, errmsg, size);
    }

    /* invalidate context */
    ctx->ctx = NULL;

    if (!func->aggregate) {
        luaL_unref(L, LUA_REGISTRYINDEX, ctx->ud);
    }

    lua_settop(L, top);
}