57 lines
1.7 KiB
C
57 lines
1.7 KiB
C
/* *****************************************************************************
|
|
* utils/skip.c -- skip some bytes (useful for debugging).
|
|
* Copyright (C) 2017 Thomas "Cakeisalie5" Touhey <thomas@touhey.fr>
|
|
*
|
|
* This file is part of libg1m.
|
|
* libg1m 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 3.0 of the License,
|
|
* or (at your option) any later version.
|
|
*
|
|
* libg1m 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 libg1m; if not, see <http://www.gnu.org/licenses/>.
|
|
* ************************************************************************** */
|
|
#include <libg1m/internals.h>
|
|
|
|
/**
|
|
* g1m_skip:
|
|
* Skip some bytes.
|
|
*
|
|
* @arg buffer the buffer from which to read.
|
|
* @arg size the size to skip.
|
|
* @arg checksum pointer to the checksum variable if there is one.
|
|
*/
|
|
|
|
int g1m_skip(g1m_buffer_t *buffer, size_t size, uint32_t *checksum)
|
|
{
|
|
uint8_t buf[1024]; int err;
|
|
uint32_t add = 0;
|
|
size_t orig = size;
|
|
|
|
while (size) {
|
|
/* read that much */
|
|
size_t curlen = min(size, 1024);
|
|
size -= curlen;
|
|
buffer->_offset += curlen;
|
|
if ((err = (*buffer->read)(buffer->cookie, buf, curlen))) {
|
|
log_error("Skipping has failed after %" PRIuSIZE " bytes",
|
|
orig - size);
|
|
return (err);
|
|
}
|
|
|
|
/* feed the checksum */
|
|
add = g1m_checksum32(buf, curlen, add);
|
|
}
|
|
|
|
/* add to checksum */
|
|
if (checksum) *checksum += add;
|
|
|
|
/* no error */
|
|
return (0);
|
|
}
|