Zabbix

/*

** Copyright (C) 2001-2024 Zabbix SIA

**

** This program is free software: you can redistribute it and/or modify it under the terms of

** the GNU Affero General Public License as published by the Free Software Foundation, version 3.

**

** 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 Affero General Public License for more details.

**

** You should have received a copy of the GNU Affero General Public License along with this program.

** If not, see <https://www.gnu.org/licenses/>.

**/

​

#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;

    }

}

​

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

 *                                                                            *

 * Purpose: deserialize 31 bit unsigned integer from utf-8 like byte stream   *

 *                                                                            *

 * Parameters: ptr   - [IN] the byte stream                                   *

 *             value - [OUT] the deserialized value                           *

 *                                                                            *

 * Return value: The number of bytes read from byte stream.                   *

 *                                                                            *

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

zbx_uint32_t    zbx_deserialize_uint31_compact(const unsigned char *ptr, zbx_uint32_t *value)

{

    if (0 == (*ptr & 0x80))

    {

        *value = *ptr;

        return 1;

    }

    else

    {

        zbx_uint32_t    pos = 2, i;

​

        while (0 != (*ptr & (0x80 >> pos)))

            pos++;

​

        *value = *ptr & (0xff >> (pos + 1));

​

        for (i = 1; i < pos; i++)

        {

            *value <<= 6;

            *value |= (*(++ptr)) & 0x3f;

        }

​