Zabbix

/*

** Zabbix

** Copyright (C) 2001-2023 Zabbix SIA

**

** This program is free software; you can redistribute it and/or modify

** it 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; if not, write to the Free Software

** Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.

**/

​

#include "zbxserialize.h"

​

#include "string.h"

#include "zbxtypes.h"

​

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

 *                                                                            *

 * Purpose: serialize 31 bit unsigned integer into utf-8 like byte stream     *

 *                                                                            *

 * Parameters: ptr   - [OUT] the output buffer                                *

 *             value - [IN] the value to serialize                            *

 *                                                                            *

 * Return value: The number of bytes written to the buffer.                   *

 *                                                                            *

 * Comments: This serialization method should be used with variables usually  *

 *           having small value while still supporting larger values.         *

 *                                                                            *

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

zbx_uint32_t    zbx_serialize_uint31_compact(unsigned char *ptr, zbx_uint32_t value)

{

    if (0x7f >= value)

    {

        ptr[0] = (unsigned char)value;

        return 1;

    }

    else

    {

        unsigned char   buf[6];

        zbx_uint32_t    len, pos = (zbx_uint32_t)(sizeof(buf) - 1);

​

        while (value > (zbx_uint32_t)(0x7f >> (sizeof(buf) - pos)))

        {

            buf[pos] = (unsigned char)(0x80 | (value & 0x3f));

            value >>= 6;

            pos--;

        }

​

        buf[pos] = (unsigned char)(value | (0xfe << (pos + 1)));

​

        len = (zbx_uint32_t)(sizeof(buf) - pos);

        memcpy(ptr, buf + pos, len);

        return len;

    }

}