lbrycrd/src/test/random_tests.cpp
Pieter Wuille 1ec1602a45 Make FastRandomContext support standard C++11 RNG interface
This makes it possible to plug it into the various standard C++11 random
distribution algorithms and other functions like std::shuffle.
2018-03-20 21:24:49 -07:00

82 lines
2.6 KiB
C++

// Copyright (c) 2017 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
#include <random.h>
#include <test/test_bitcoin.h>
#include <boost/test/unit_test.hpp>
#include <random>
#include <algorithm>
BOOST_FIXTURE_TEST_SUITE(random_tests, BasicTestingSetup)
BOOST_AUTO_TEST_CASE(osrandom_tests)
{
BOOST_CHECK(Random_SanityCheck());
}
BOOST_AUTO_TEST_CASE(fastrandom_tests)
{
// Check that deterministic FastRandomContexts are deterministic
FastRandomContext ctx1(true);
FastRandomContext ctx2(true);
BOOST_CHECK_EQUAL(ctx1.rand32(), ctx2.rand32());
BOOST_CHECK_EQUAL(ctx1.rand32(), ctx2.rand32());
BOOST_CHECK_EQUAL(ctx1.rand64(), ctx2.rand64());
BOOST_CHECK_EQUAL(ctx1.randbits(3), ctx2.randbits(3));
BOOST_CHECK(ctx1.randbytes(17) == ctx2.randbytes(17));
BOOST_CHECK(ctx1.rand256() == ctx2.rand256());
BOOST_CHECK_EQUAL(ctx1.randbits(7), ctx2.randbits(7));
BOOST_CHECK(ctx1.randbytes(128) == ctx2.randbytes(128));
BOOST_CHECK_EQUAL(ctx1.rand32(), ctx2.rand32());
BOOST_CHECK_EQUAL(ctx1.randbits(3), ctx2.randbits(3));
BOOST_CHECK(ctx1.rand256() == ctx2.rand256());
BOOST_CHECK(ctx1.randbytes(50) == ctx2.randbytes(50));
// Check that a nondeterministic ones are not
FastRandomContext ctx3;
FastRandomContext ctx4;
BOOST_CHECK(ctx3.rand64() != ctx4.rand64()); // extremely unlikely to be equal
BOOST_CHECK(ctx3.rand256() != ctx4.rand256());
BOOST_CHECK(ctx3.randbytes(7) != ctx4.randbytes(7));
}
BOOST_AUTO_TEST_CASE(fastrandom_randbits)
{
FastRandomContext ctx1;
FastRandomContext ctx2;
for (int bits = 0; bits < 63; ++bits) {
for (int j = 0; j < 1000; ++j) {
uint64_t rangebits = ctx1.randbits(bits);
BOOST_CHECK_EQUAL(rangebits >> bits, 0);
uint64_t range = ((uint64_t)1) << bits | rangebits;
uint64_t rand = ctx2.randrange(range);
BOOST_CHECK(rand < range);
}
}
}
/** Does-it-compile test for compatibility with standard C++11 RNG interface. */
BOOST_AUTO_TEST_CASE(stdrandom_test)
{
FastRandomContext ctx;
std::uniform_int_distribution<int> distribution(3, 9);
for (int i = 0; i < 100; ++i) {
int x = distribution(ctx);
BOOST_CHECK(x >= 3);
BOOST_CHECK(x <= 9);
std::vector<int> test{1,2,3,4,5,6,7,8,9,10};
std::shuffle(test.begin(), test.end(), ctx);
for (int j = 1; j <= 10; ++j) {
BOOST_CHECK(std::find(test.begin(), test.end(), j) != test.end());
}
}
}
BOOST_AUTO_TEST_SUITE_END()