ceph/src/boost/libs/uuid/test/test_random_generator.cpp

   1 //  (C) Copyright Andy Tompkins 2010. Permission to copy, use, modify, sell and
   2 //  distribute this software is granted provided this copyright notice appears
   3 //  in all copies. This software is provided "as is" without express or implied
   4 //  warranty, and with no claim as to its suitability for any purpose.
   5
   6 // Distributed under the Boost Software License, Version 1.0. (See
   7 // accompanying file LICENSE_1_0.txt or copy at
   8 // http://www.boost.org/LICENSE_1_0.txt)
   9
  10 //  libs/uuid/test/test_random_generator.cpp  -------------------------------//
  11
  12 #include <boost/core/ignore_unused.hpp>
  13 #include <boost/detail/lightweight_test.hpp>
  14 #include <boost/predef/library/c/cloudabi.h>
  15 #include <boost/random.hpp>
  16 #include <boost/uuid/entropy_error.hpp>
  17 #include <boost/uuid/random_generator.hpp>
  18 #include <boost/uuid/uuid_io.hpp>
  19 #include <boost/uuid/uuid.hpp>
  20
  21 template <typename RandomUuidGenerator>
  22 void check_random_generator(RandomUuidGenerator& uuid_gen)
  23 {
  24     boost::uuids::uuid u1 = uuid_gen();
  25     boost::uuids::uuid u2 = uuid_gen();
  26
  27     BOOST_TEST_NE(u1, u2);
  28
  29     // check variant
  30     BOOST_TEST_EQ(u1.variant(), boost::uuids::uuid::variant_rfc_4122);
  31
  32     // version
  33     BOOST_TEST_EQ(u1.version(), boost::uuids::uuid::version_random_number_based);
  34 }
  35
  36 // This is the example block from the documentation - ensure it works!
  37 void test_examples()
  38 {
  39     // Depending on the platform there may be a setup cost in
  40     // initializing the generator so plan to reuse it if you can.
  41     boost::uuids::random_generator gen;
  42     boost::uuids::uuid id = gen();
  43     boost::uuids::uuid id2 = gen();
  44 #if !BOOST_LIB_C_CLOUDABI
  45     std::cout << id << std::endl;
  46     std::cout << id2 << std::endl;
  47 #endif
  48     BOOST_TEST_NE(id, id2);
  49     boost::ignore_unused(id);
  50     boost::ignore_unused(id2);
  51
  52     // You can still use a PseudoRandomNumberGenerator to create
  53     // UUIDs, however this is not the preferred mechanism.  For
  54     // large numbers of UUIDs this may be more CPU efficient but
  55     // it comes with all the perils of a PRNG.  The test code
  56     // in test_bench_random identifies the transition point for
  57     // a given system.
  58     boost::uuids::random_generator_mt19937 bulkgen;
  59     for (size_t i = 0; i < 1000; ++i)
  60     {
  61         boost::uuids::uuid u = bulkgen();
  62         // do something with u
  63         boost::ignore_unused(u);
  64     }
  65 }
  66
  67 int main(int, char*[])
  68 {
  69     using namespace boost::uuids;
  70
  71     // default random number generator
  72     random_generator uuid_gen1;
  73     check_random_generator(uuid_gen1);
  74
  75     // specific random number generator
  76     basic_random_generator<boost::rand48> uuid_gen2;
  77     check_random_generator(uuid_gen2);
  78
  79     // pass by reference
  80     boost::ecuyer1988 ecuyer1988_gen;
  81     basic_random_generator<boost::ecuyer1988> uuid_gen3(ecuyer1988_gen);
  82     check_random_generator(uuid_gen3);
  83
  84     // pass by pointer
  85     boost::lagged_fibonacci607 lagged_fibonacci607_gen;
  86     basic_random_generator<boost::lagged_fibonacci607> uuid_gen4(&lagged_fibonacci607_gen);
  87     check_random_generator(uuid_gen4);
  88
  89     // there was a bug in basic_random_generator where it did not
  90     // produce very random numbers.  This checks for that bug.
  91     random_generator_mt19937 bulkgen;
  92     uuid u = bulkgen();
  93     if ((u.data[4] == u.data[12]) &&
  94         (u.data[5] == u.data[9] && u.data[5] == u.data[13]) &&
  95         (u.data[7] == u.data[11] && u.data[7] == u.data[15]) &&
  96         (u.data[10] == u.data[14]))
  97     {
  98         BOOST_ERROR("basic_random_generator is not producing random uuids");
  99     }
 100
 101     // pseudo
 102     check_random_generator(bulkgen);
 103
 104     // make sure default construction seeding is happening for PRNGs
 105     random_generator_mt19937 gen1;
 106     random_generator_mt19937 gen2;
 107     BOOST_TEST_NE(gen1(), gen2());
 108
 109     // The example code snippet in the documentation
 110     test_examples();
 111
 112 #if !BOOST_LIB_C_CLOUDABI
 113     // dump 10 of them to cout for observation
 114     for (size_t i = 0; i < 10; ++i)
 115     {
 116         std::cout << uuid_gen1() << std::endl;
 117     }
 118 #endif
 119
 120     return boost::report_errors();
 121 }