Line data    Source code

       1             : 
       2             : /* Copyright (c) 2011-2016, Stefan Eilemann <eile@eyescale.ch>
       3             :  *
       4             :  * This file is part of Servus <https://github.com/HBPVIS/Servus>
       5             :  *
       6             :  * This library is free software; you can redistribute it and/or modify it under
       7             :  * the terms of the GNU Lesser General Public License version 3.0 as published
       8             :  * by the Free Software Foundation.
       9             :  *
      10             :  * This library is distributed in the hope that it will be useful, but WITHOUT
      11             :  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
      12             :  * FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more
      13             :  * details.
      14             :  *
      15             :  * You should have received a copy of the GNU Lesser General Public License
      16             :  * along with this library; if not, write to the Free Software Foundation, Inc.,
      17             :  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
      18             :  */
      19             : 
      20             : #include "uint128_t.h"
      21             : #include "md5/md5.hh"
      22             : 
      23             : #include <mutex>
      24             : #include <random>
      25             : 
      26             : #include <cassert>
      27             : #include <cstdlib> // for strtoull
      28             : #include <cstring> // for strcmp
      29             : 
      30             : #ifdef _MSC_VER
      31             : #define strtoull _strtoui64
      32             : #endif
      33             : 
      34             : using ScopedLock = std::unique_lock<std::mutex>;
      35             : namespace chrono = std::chrono;
      36             : 
      37             : namespace servus
      38             : {
      39           4 : uint128_t& uint128_t::operator=(const std::string& from)
      40             : {
      41           4 :     if (from.empty())
      42             :     {
      43           1 :         _high = 0;
      44           1 :         _low = 0;
      45           1 :         return *this;
      46             :     }
      47             : 
      48           3 :     char* next = 0;
      49           3 :     _high = ::strtoull(from.c_str(), &next, 16);
      50           3 :     assert(next != from.c_str());
      51             : 
      52           3 :     if (*next == '\0') // short representation, high was 0
      53             :     {
      54           1 :         _low = _high;
      55           1 :         _high = 0;
      56             :     }
      57             :     else
      58             :     {
      59           2 :         if (strncmp(next, "\\058" /* utf-8 ':' */, 4) == 0)
      60           1 :             next += 4;
      61             :         else
      62             :         {
      63             : #ifndef NDEBUG
      64           1 :             if (*next != ':')
      65           0 :                 std::cerr << from << ", " << next << std::endl;
      66             : #endif
      67           1 :             assert(*next == ':');
      68           1 :             ++next;
      69             :         }
      70           2 :         _low = ::strtoull(next, 0, 16);
      71             :     }
      72           3 :     return *this;
      73             : }
      74             : 
      75           5 : uint128_t make_uint128(const char* string)
      76             : {
      77           5 :     const md5::MD5 md5((unsigned char*)string);
      78           5 :     uint128_t value;
      79           5 :     md5.raw_digest(value.high(), value.low());
      80           5 :     return value;
      81             : }
      82             : 
      83       99983 : uint128_t make_UUID()
      84             : {
      85       99983 :     uint128_t value;
      86      299995 :     while (value.high() == 0)
      87             :     {
      88       99983 :         static std::random_device device;
      89       99983 :         static std::mt19937_64 engine(device());
      90             :         static std::uniform_int_distribution<uint64_t> generator(
      91       99983 :             0, std::numeric_limits<uint64_t>::max());
      92             : #ifndef _MSC_VER
      93             :         // The static state is hidden to users, so the function is made
      94             :         // thread safe for robustness over performance.
      95             :         // Also, creating a new generator each call seems to increases the
      96             :         // chances of collissions up to a noticeable level.
      97             : 
      98             :         // http://stackoverflow.com/questions/14711263
      99             :         static std::mutex mutex;
     100      199990 :         ScopedLock lock(mutex);
     101             : #endif
     102      100007 :         value.high() = generator(engine);
     103      100007 :         value.low() = generator(engine);
     104             :     }
     105      100007 :     return value;
     106             : }
     107          15 : }