random_tests.cpp

// 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_raptoreum.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
                g_mock_deterministic_tests = true;
        FastRandomContext ctx1(true);
        FastRandomContext ctx2(true);

        for (int i = 10; i > 0; --i) {
            BOOST_CHECK_EQUAL(GetRand(std::numeric_limits<uint64_t>::max()), uint64_t{10393729187455219830U});
            BOOST_CHECK_EQUAL(GetRandInt(std::numeric_limits<int>::max()), int{769702006});
        }
        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
        g_mock_deterministic_tests = false;
        for (int i = 10; i > 0; --i) {
            BOOST_CHECK(GetRand(std::numeric_limits<uint64_t>::max()) != uint64_t{10393729187455219830U});
            BOOST_CHECK(GetRandInt(std::numeric_limits<int>::max()) != int{769702006});
        }
        {
            FastRandomContext ctx3, ctx4;
            BOOST_CHECK(ctx3.rand64() != ctx4.rand64()); // extremely unlikely to be equal
        }
        {
            FastRandomContext ctx3, ctx4;
            BOOST_CHECK(ctx3.rand256() != ctx4.rand256());
        }
        {
            FastRandomContext ctx3, ctx4;
            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());
            }
            Shuffle(test.begin(), test.end(), ctx);
            for (int j = 1; j <= 10; ++j) {
                BOOST_CHECK(std::find(test.begin(), test.end(), j) != test.end());
            }
        }
        }

/** Test that Shuffle reaches every permutation with equal probability. */
BOOST_AUTO_TEST_CASE(shuffle_stat_test)
        {
                FastRandomContext ctx(true);
        uint32_t counts[5 * 5 * 5 * 5 * 5] = { 0 };
        for (int i = 0; i < 12000; ++i) {
            int data[5] = {0, 1, 2, 3, 4};
            Shuffle(std::begin(data), std::end(data), ctx);
            int pos = data[0] + data[1] * 5 + data[2] * 25 + data[3] * 125 + data[4] * 625;
            ++counts[pos];
        }
        unsigned int sum = 0;
        double chi_score = 0.0;
        for (int i = 0; i < 5 * 5 * 5 * 5 * 5; ++i) {
            int i1 = i % 5, i2 = (i / 5) % 5, i3 = (i / 25) % 5, i4 = (i / 125) % 5, i5 = i / 625;
            uint32_t count = counts[i];
            if (i1 == i2 || i1 == i3 || i1 == i4 || i1 == i5 || i2 == i3 || i2 == i4 || i2 == i5 || i3 == i4 ||
                i3 == i5 || i4 == i5) {
                BOOST_CHECK(count == 0);
            } else {
                chi_score += ((count - 100.0) * (count - 100.0)) / 100.0;
                BOOST_CHECK(count > 50);
                BOOST_CHECK(count < 150);
                sum += count;
            }
        }
        BOOST_CHECK(chi_score > 58.1411); // 99.9999% confidence interval
        BOOST_CHECK(chi_score < 210.275);
        BOOST_CHECK_EQUAL(sum, 12000);
        }

BOOST_AUTO_TEST_SUITE_END()