/* getcto.h -- calltrick util

   This file is part of the UPX executable compressor.

   Copyright (C) Markus Franz Xaver Johannes Oberhumer
   Copyright (C) Laszlo Molnar
   All Rights Reserved.

   UPX and the UCL library are free software; you can redistribute them
   and/or modify them 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; see the file COPYING.
   If not, write to the Free Software Foundation, Inc.,
   59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

   Markus F.X.J. Oberhumer              Laszlo Molnar
   <markus@oberhumer.com>               <ezerotven+github@gmail.com>
 */

/*************************************************************************
//
**************************************************************************/

static int getcto(Filter *f, const byte *buf, const int n = 256) {
    int ic = n;

    if (f->preferred_ctos) {
        for (const int *pc = f->preferred_ctos; *pc >= 0; pc++) {
            if (*pc < n && buf[*pc] == 0) {
                ic = *pc;
                break;
            }
        }
    }

#if 0
    // just a test to see if certain ctos would improve compression
    if (ic >= n)
        for (ic = 0; ic < n; ic += 16)
            if (buf[ic] == 0)
                break;
#endif
    if (ic >= n)
        for (ic = 0; ic < n; ic++)
            if (buf[ic] == 0)
                break;

    if (ic >= n)
        // throwCantPack("call trick problem");
        return -1;

    f->cto = (byte) ic;
    return ic;
}

/* vim:set ts=4 sw=4 et: */
