Validations_test.cpp

#include <test/csf/Validation.h>
#include <test/unit_test/SuiteJournal.h>
 
#include <xrpld/consensus/Validations.h>
 
#include <xrpl/basics/tagged_integer.h>
#include <xrpl/beast/clock/manual_clock.h>
#include <xrpl/beast/unit_test.h>
 
#include <vector>
 
namespace xrpl {
namespace test {
namespace csf {
class Validations_test : public beast::unit_test::suite
{
    using clock_type = beast::abstract_clock<std::chrono::steady_clock> const;
 
    // Helper to convert steady_clock to a reasonable NetClock
    // This allows a single manual clock in the unit tests
    static NetClock::time_point
    toNetClock(clock_type const& c)
    {
        // We don't care about the actual epochs, but do want the
        // generated NetClock time to be well past its epoch to ensure
        // any subtractions are positive
        using namespace std::chrono;
        return NetClock::time_point(duration_cast<NetClock::duration>(c.now().time_since_epoch() + 86400s));
    }
 
    // Represents a node that can issue validations
    class Node
    {
        clock_type const& c_;
        PeerID nodeID_;
        bool trusted_ = true;
        std::size_t signIdx_{1};
        std::optional<std::uint32_t> loadFee_;
 
    public:
        Node(PeerID nodeID, clock_type const& c) : c_(c), nodeID_(nodeID)
        {
        }
 
        void
        untrust()
        {
            trusted_ = false;
        }
 
        void
        trust()
        {
            trusted_ = true;
        }
 
        void
        setLoadFee(std::uint32_t fee)
        {
            loadFee_ = fee;
        }
 
        PeerID
        nodeID() const
        {
            return nodeID_;
        }
 
        void
        advanceKey()
        {
            signIdx_++;
        }
 
        PeerKey
        currKey() const
        {
            return std::make_pair(nodeID_, signIdx_);
        }
 
        PeerKey
        masterKey() const
        {
            return std::make_pair(nodeID_, 0);
        }
        NetClock::time_point
        now() const
        {
            return toNetClock(c_);
        }
 
        // Issue a new validation with given sequence number and id and
        // with signing and seen times offset from the common clock
        Validation
        validate(
            Ledger::ID id,
            Ledger::Seq seq,
            NetClock::duration signOffset,
            NetClock::duration seenOffset,
            bool full) const
        {
            Validation v{id, seq, now() + signOffset, now() + seenOffset, currKey(), nodeID_, full, loadFee_};
            if (trusted_)
                v.setTrusted();
            return v;
        }
 
        Validation
        validate(Ledger ledger, NetClock::duration signOffset, NetClock::duration seenOffset) const
        {
            return validate(ledger.id(), ledger.seq(), signOffset, seenOffset, true);
        }
 
        Validation
        validate(Ledger ledger) const
        {
            return validate(ledger.id(), ledger.seq(), NetClock::duration{0}, NetClock::duration{0}, true);
        }
 
        Validation
        partial(Ledger ledger) const
        {
            return validate(ledger.id(), ledger.seq(), NetClock::duration{0}, NetClock::duration{0}, false);
        }
    };
 
    // Generic Validations adaptor
    class Adaptor
    {
        clock_type& c_;
        LedgerOracle& oracle_;
 
    public:
        // Non-locking mutex to avoid locks in generic Validations
        struct Mutex
        {
            void
            lock()
            {
            }
 
            void
            unlock()
            {
            }
        };
 
        using Validation = csf::Validation;
        using Ledger = csf::Ledger;
 
        Adaptor(clock_type& c, LedgerOracle& o) : c_{c}, oracle_{o}
        {
        }
 
        NetClock::time_point
        now() const
        {
            return toNetClock(c_);
        }
 
        std::optional<Ledger>
        acquire(Ledger::ID const& id)
        {
            return oracle_.lookup(id);
        }
    };
 
    // Specialize generic Validations using the above types
    using TestValidations = Validations<Adaptor>;
 
    // Gather the dependencies of TestValidations in a single class and provide
    // accessors for simplifying test logic
    class TestHarness
    {
        ValidationParms p_;
        beast::manual_clock<std::chrono::steady_clock> clock_;
        TestValidations tv_;
        PeerID nextNodeId_{0};
 
    public:
        explicit TestHarness(LedgerOracle& o) : tv_(p_, clock_, clock_, o)
        {
        }
 
        ValStatus
        add(Validation const& v)
        {
            return tv_.add(v.nodeID(), v);
        }
 
        TestValidations&
        vals()
        {
            return tv_;
        }
 
        Node
        makeNode()
        {
            return Node(nextNodeId_++, clock_);
        }
 
        ValidationParms
        parms() const
        {
            return p_;
        }
 
        auto&
        clock()
        {
            return clock_;
        }
    };
 
    Ledger const genesisLedger{Ledger::MakeGenesis{}};
 
    void
    testAddValidation()
    {
        using namespace std::chrono_literals;
 
        testcase("Add validation");
        LedgerHistoryHelper h;
        Ledger ledgerA = h["a"];
        Ledger ledgerAB = h["ab"];
        Ledger ledgerAZ = h["az"];
        Ledger ledgerABC = h["abc"];
        Ledger ledgerABCD = h["abcd"];
        Ledger ledgerABCDE = h["abcde"];
 
        {
            TestHarness harness(h.oracle);
            Node n = harness.makeNode();
 
            auto const v = n.validate(ledgerA);
 
            // Add a current validation
            BEAST_EXPECT(ValStatus::current == harness.add(v));
 
            // Re-adding violates the increasing seq requirement for full
            // validations
            BEAST_EXPECT(ValStatus::badSeq == harness.add(v));
 
            harness.clock().advance(1s);
 
            BEAST_EXPECT(ValStatus::current == harness.add(n.validate(ledgerAB)));
 
            // Test the node changing signing key
 
            // Confirm old ledger on hand, but not new ledger
            BEAST_EXPECT(harness.vals().numTrustedForLedger(ledgerAB.id()) == 1);
            BEAST_EXPECT(harness.vals().numTrustedForLedger(ledgerABC.id()) == 0);
 
            // Rotate signing keys
            n.advanceKey();
 
            harness.clock().advance(1s);
 
            // Cannot re-do the same full validation sequence
            BEAST_EXPECT(ValStatus::conflicting == harness.add(n.validate(ledgerAB)));
            // Cannot send the same partial validation sequence
            BEAST_EXPECT(ValStatus::conflicting == harness.add(n.partial(ledgerAB)));
 
            // Now trusts the newest ledger too
            harness.clock().advance(1s);
            BEAST_EXPECT(ValStatus::current == harness.add(n.validate(ledgerABC)));
            BEAST_EXPECT(harness.vals().numTrustedForLedger(ledgerAB.id()) == 1);
            BEAST_EXPECT(harness.vals().numTrustedForLedger(ledgerABC.id()) == 1);
 
            // Processing validations out of order should ignore the older
            // validation
            harness.clock().advance(2s);
            auto const valABCDE = n.validate(ledgerABCDE);
 
            harness.clock().advance(4s);
            auto const valABCD = n.validate(ledgerABCD);
 
            BEAST_EXPECT(ValStatus::current == harness.add(valABCD));
 
            BEAST_EXPECT(ValStatus::stale == harness.add(valABCDE));
        }
 
        {
            // Process validations out of order with shifted times
 
            TestHarness harness(h.oracle);
            Node n = harness.makeNode();
 
            // Establish a new current validation
            BEAST_EXPECT(ValStatus::current == harness.add(n.validate(ledgerA)));
 
            // Process a validation that has "later" seq but early sign time
            BEAST_EXPECT(ValStatus::stale == harness.add(n.validate(ledgerAB, -1s, -1s)));
 
            // Process a validation that has a later seq and later sign
            // time
            BEAST_EXPECT(ValStatus::current == harness.add(n.validate(ledgerABC, 1s, 1s)));
        }
 
        {
            // Test stale on arrival validations
            TestHarness harness(h.oracle);
            Node n = harness.makeNode();
 
            BEAST_EXPECT(
                ValStatus::stale == harness.add(n.validate(ledgerA, -harness.parms().validationCURRENT_EARLY, 0s)));
 
            BEAST_EXPECT(
                ValStatus::stale == harness.add(n.validate(ledgerA, harness.parms().validationCURRENT_WALL, 0s)));
 
            BEAST_EXPECT(
                ValStatus::stale == harness.add(n.validate(ledgerA, 0s, harness.parms().validationCURRENT_LOCAL)));
        }
 
        {
            // Test that full or partials cannot be sent for older sequence
            // numbers, unless time-out has happened
            for (bool doFull : {true, false})
            {
                TestHarness harness(h.oracle);
                Node n = harness.makeNode();
 
                auto process = [&](Ledger& lgr) {
                    if (doFull)
                        return harness.add(n.validate(lgr));
                    return harness.add(n.partial(lgr));
                };
 
                BEAST_EXPECT(ValStatus::current == process(ledgerABC));
                harness.clock().advance(1s);
                BEAST_EXPECT(ledgerAB.seq() < ledgerABC.seq());
                BEAST_EXPECT(ValStatus::badSeq == process(ledgerAB));
 
                // If we advance far enough for AB to expire, we can fully
                // validate or partially validate that sequence number again
                BEAST_EXPECT(ValStatus::conflicting == process(ledgerAZ));
                harness.clock().advance(harness.parms().validationSET_EXPIRES + 1ms);
                BEAST_EXPECT(ValStatus::current == process(ledgerAZ));
            }
        }
    }
 
    void
    testOnStale()
    {
        testcase("Stale validation");
        // Verify validation becomes stale based solely on time passing, but
        // use different functions to trigger the check for staleness
 
        LedgerHistoryHelper h;
        Ledger ledgerA = h["a"];
        Ledger ledgerAB = h["ab"];
 
        using Trigger = std::function<void(TestValidations&)>;
 
        std::vector<Trigger> triggers = {
            [&](TestValidations& vals) { vals.currentTrusted(); },
            [&](TestValidations& vals) { vals.getCurrentNodeIDs(); },
            [&](TestValidations& vals) { vals.getPreferred(genesisLedger); },
            [&](TestValidations& vals) { vals.getNodesAfter(ledgerA, ledgerA.id()); }};
        for (Trigger trigger : triggers)
        {
            TestHarness harness(h.oracle);
            Node n = harness.makeNode();
 
            BEAST_EXPECT(ValStatus::current == harness.add(n.validate(ledgerAB)));
            trigger(harness.vals());
            BEAST_EXPECT(harness.vals().getNodesAfter(ledgerA, ledgerA.id()) == 1);
            BEAST_EXPECT(harness.vals().getPreferred(genesisLedger) == std::make_pair(ledgerAB.seq(), ledgerAB.id()));
            harness.clock().advance(harness.parms().validationCURRENT_LOCAL);
 
            // trigger check for stale
            trigger(harness.vals());
 
            BEAST_EXPECT(harness.vals().getNodesAfter(ledgerA, ledgerA.id()) == 0);
            BEAST_EXPECT(harness.vals().getPreferred(genesisLedger) == std::nullopt);
        }
    }
 
    void
    testGetNodesAfter()
    {
        // Test getting number of nodes working on a validation descending
        // a prescribed one. This count should only be for trusted nodes, but
        // includes partial and full validations
 
        using namespace std::chrono_literals;
        testcase("Get nodes after");
 
        LedgerHistoryHelper h;
        Ledger ledgerA = h["a"];
        Ledger ledgerAB = h["ab"];
        Ledger ledgerABC = h["abc"];
        Ledger ledgerAD = h["ad"];
 
        TestHarness harness(h.oracle);
        Node a = harness.makeNode(), b = harness.makeNode(), c = harness.makeNode(), d = harness.makeNode();
        c.untrust();
 
        // first round a,b,c agree, d has is partial
        BEAST_EXPECT(ValStatus::current == harness.add(a.validate(ledgerA)));
        BEAST_EXPECT(ValStatus::current == harness.add(b.validate(ledgerA)));
        BEAST_EXPECT(ValStatus::current == harness.add(c.validate(ledgerA)));
        BEAST_EXPECT(ValStatus::current == harness.add(d.partial(ledgerA)));
 
        for (Ledger const& ledger : {ledgerA, ledgerAB, ledgerABC, ledgerAD})
            BEAST_EXPECT(harness.vals().getNodesAfter(ledger, ledger.id()) == 0);
 
        harness.clock().advance(5s);
 
        BEAST_EXPECT(ValStatus::current == harness.add(a.validate(ledgerAB)));
        BEAST_EXPECT(ValStatus::current == harness.add(b.validate(ledgerABC)));
        BEAST_EXPECT(ValStatus::current == harness.add(c.validate(ledgerAB)));
        BEAST_EXPECT(ValStatus::current == harness.add(d.partial(ledgerABC)));
 
        BEAST_EXPECT(harness.vals().getNodesAfter(ledgerA, ledgerA.id()) == 3);
        BEAST_EXPECT(harness.vals().getNodesAfter(ledgerAB, ledgerAB.id()) == 2);
        BEAST_EXPECT(harness.vals().getNodesAfter(ledgerABC, ledgerABC.id()) == 0);
        BEAST_EXPECT(harness.vals().getNodesAfter(ledgerAD, ledgerAD.id()) == 0);
 
        // If given a ledger inconsistent with the id, is still able to check
        // using slower method
        BEAST_EXPECT(harness.vals().getNodesAfter(ledgerAD, ledgerA.id()) == 1);
        BEAST_EXPECT(harness.vals().getNodesAfter(ledgerAD, ledgerAB.id()) == 2);
    }
 
    void
    testCurrentTrusted()
    {
        using namespace std::chrono_literals;
        testcase("Current trusted validations");
 
        LedgerHistoryHelper h;
        Ledger ledgerA = h["a"];
        Ledger ledgerB = h["b"];
        Ledger ledgerAC = h["ac"];
 
        TestHarness harness(h.oracle);
        Node a = harness.makeNode(), b = harness.makeNode();
        b.untrust();
 
        BEAST_EXPECT(ValStatus::current == harness.add(a.validate(ledgerA)));
        BEAST_EXPECT(ValStatus::current == harness.add(b.validate(ledgerB)));
 
        // Only a is trusted
        BEAST_EXPECT(harness.vals().currentTrusted().size() == 1);
        BEAST_EXPECT(harness.vals().currentTrusted()[0].ledgerID() == ledgerA.id());
        BEAST_EXPECT(harness.vals().currentTrusted()[0].seq() == ledgerA.seq());
 
        harness.clock().advance(3s);
 
        for (auto const& node : {a, b})
            BEAST_EXPECT(ValStatus::current == harness.add(node.validate(ledgerAC)));
 
        // New validation for a
        BEAST_EXPECT(harness.vals().currentTrusted().size() == 1);
        BEAST_EXPECT(harness.vals().currentTrusted()[0].ledgerID() == ledgerAC.id());
        BEAST_EXPECT(harness.vals().currentTrusted()[0].seq() == ledgerAC.seq());
 
        // Pass enough time for it to go stale
        harness.clock().advance(harness.parms().validationCURRENT_LOCAL);
        BEAST_EXPECT(harness.vals().currentTrusted().empty());
    }
 
    void
    testGetCurrentPublicKeys()
    {
        using namespace std::chrono_literals;
        testcase("Current public keys");
 
        LedgerHistoryHelper h;
        Ledger ledgerA = h["a"];
        Ledger ledgerAC = h["ac"];
 
        TestHarness harness(h.oracle);
        Node a = harness.makeNode(), b = harness.makeNode();
        b.untrust();
 
        for (auto const& node : {a, b})
            BEAST_EXPECT(ValStatus::current == harness.add(node.validate(ledgerA)));
 
        {
            hash_set<PeerID> const expectedKeys = {a.nodeID(), b.nodeID()};
            BEAST_EXPECT(harness.vals().getCurrentNodeIDs() == expectedKeys);
        }
 
        harness.clock().advance(3s);
 
        // Change keys and issue partials
        a.advanceKey();
        b.advanceKey();
 
        for (auto const& node : {a, b})
            BEAST_EXPECT(ValStatus::current == harness.add(node.partial(ledgerAC)));
 
        {
            hash_set<PeerID> const expectedKeys = {a.nodeID(), b.nodeID()};
            BEAST_EXPECT(harness.vals().getCurrentNodeIDs() == expectedKeys);
        }
 
        // Pass enough time for them to go stale
        harness.clock().advance(harness.parms().validationCURRENT_LOCAL);
        BEAST_EXPECT(harness.vals().getCurrentNodeIDs().empty());
    }
 
    void
    testTrustedByLedgerFunctions()
    {
        // Test the Validations functions that calculate a value by ledger ID
        using namespace std::chrono_literals;
        testcase("By ledger functions");
 
        // Several Validations functions return a set of values associated
        // with trusted ledgers sharing the same ledger ID.  The tests below
        // exercise this logic by saving the set of trusted Validations, and
        // verifying that the Validations member functions all calculate the
        // proper transformation of the available ledgers.
 
        LedgerHistoryHelper h;
        TestHarness harness(h.oracle);
 
        Node a = harness.makeNode(), b = harness.makeNode(), c = harness.makeNode(), d = harness.makeNode(),
             e = harness.makeNode();
 
        c.untrust();
        // Mix of load fees
        a.setLoadFee(12);
        b.setLoadFee(1);
        c.setLoadFee(12);
        e.setLoadFee(12);
 
        hash_map<std::pair<Ledger::ID, Ledger::Seq>, std::vector<Validation>> trustedValidations;
 
        //----------------------------------------------------------------------
        // checkers
        auto sorted = [](auto vec) {
            std::sort(vec.begin(), vec.end());
            return vec;
        };
        auto compare = [&]() {
            for (auto& it : trustedValidations)
            {
                auto const& id = it.first.first;
                auto const& seq = it.first.second;
                auto const& expectedValidations = it.second;
 
                BEAST_EXPECT(harness.vals().numTrustedForLedger(id) == expectedValidations.size());
                BEAST_EXPECT(sorted(harness.vals().getTrustedForLedger(id, seq)) == sorted(expectedValidations));
 
                std::uint32_t baseFee = 0;
                std::vector<uint32_t> expectedFees;
                for (auto const& val : expectedValidations)
                {
                    expectedFees.push_back(val.loadFee().value_or(baseFee));
                }
 
                BEAST_EXPECT(sorted(harness.vals().fees(id, baseFee)) == sorted(expectedFees));
            }
        };
 
        //----------------------------------------------------------------------
        Ledger ledgerA = h["a"];
        Ledger ledgerB = h["b"];
        Ledger ledgerAC = h["ac"];
 
        // Add a dummy ID to cover unknown ledger identifiers
        trustedValidations[{Ledger::ID{100}, Ledger::Seq{100}}] = {};
 
        // first round a,b,c agree
        for (auto const& node : {a, b, c})
        {
            auto const val = node.validate(ledgerA);
            BEAST_EXPECT(ValStatus::current == harness.add(val));
            if (val.trusted())
                trustedValidations[{val.ledgerID(), val.seq()}].emplace_back(val);
        }
        // d disagrees
        {
            auto const val = d.validate(ledgerB);
            BEAST_EXPECT(ValStatus::current == harness.add(val));
            trustedValidations[{val.ledgerID(), val.seq()}].emplace_back(val);
        }
        // e only issues partials
        {
            BEAST_EXPECT(ValStatus::current == harness.add(e.partial(ledgerA)));
        }
 
        harness.clock().advance(5s);
        // second round, a,b,c move to ledger 2
        for (auto const& node : {a, b, c})
        {
            auto const val = node.validate(ledgerAC);
            BEAST_EXPECT(ValStatus::current == harness.add(val));
            if (val.trusted())
                trustedValidations[{val.ledgerID(), val.seq()}].emplace_back(val);
        }
        // d now thinks ledger 1, but cannot re-issue a previously used seq
        // and attempting it should generate a conflict.
        {
            BEAST_EXPECT(ValStatus::conflicting == harness.add(d.partial(ledgerA)));
        }
        // e only issues partials
        {
            BEAST_EXPECT(ValStatus::current == harness.add(e.partial(ledgerAC)));
        }
 
        compare();
    }
 
    void
    testExpire()
    {
        // Verify expiring clears out validations stored by ledger
        testcase("Expire validations");
        SuiteJournal j("Validations_test", *this);
        LedgerHistoryHelper h;
        TestHarness harness(h.oracle);
        Node const a = harness.makeNode();
        constexpr Ledger::Seq one(1);
        constexpr Ledger::Seq two(2);
 
        // simple cases
        Ledger const ledgerA = h["a"];
        BEAST_EXPECT(ValStatus::current == harness.add(a.validate(ledgerA)));
        BEAST_EXPECT(harness.vals().numTrustedForLedger(ledgerA.id()) == 1);
        harness.vals().expire(j);
        BEAST_EXPECT(harness.vals().numTrustedForLedger(ledgerA.id()) == 1);
        harness.clock().advance(harness.parms().validationSET_EXPIRES);
        harness.vals().expire(j);
        BEAST_EXPECT(harness.vals().numTrustedForLedger(ledgerA.id()) == 0);
 
        // use setSeqToKeep to keep the validation from expire
        Ledger const ledgerB = h["ab"];
        BEAST_EXPECT(ValStatus::current == harness.add(a.validate(ledgerB)));
        BEAST_EXPECT(harness.vals().numTrustedForLedger(ledgerB.id()) == 1);
        harness.vals().setSeqToKeep(ledgerB.seq(), ledgerB.seq() + one);
        harness.clock().advance(harness.parms().validationSET_EXPIRES);
        harness.vals().expire(j);
        BEAST_EXPECT(harness.vals().numTrustedForLedger(ledgerB.id()) == 1);
        // change toKeep
        harness.vals().setSeqToKeep(ledgerB.seq() + one, ledgerB.seq() + two);
        // advance clock slowly
        int const loops = harness.parms().validationSET_EXPIRES / harness.parms().validationFRESHNESS + 1;
        for (int i = 0; i < loops; ++i)
        {
            harness.clock().advance(harness.parms().validationFRESHNESS);
            harness.vals().expire(j);
        }
        BEAST_EXPECT(harness.vals().numTrustedForLedger(ledgerB.id()) == 0);
 
        // Allow the validation with high seq to expire
        Ledger const ledgerC = h["abc"];
        BEAST_EXPECT(ValStatus::current == harness.add(a.validate(ledgerC)));
        BEAST_EXPECT(harness.vals().numTrustedForLedger(ledgerC.id()) == 1);
        harness.vals().setSeqToKeep(ledgerC.seq() - one, ledgerC.seq());
        harness.clock().advance(harness.parms().validationSET_EXPIRES);
        harness.vals().expire(j);
        BEAST_EXPECT(harness.vals().numTrustedForLedger(ledgerC.id()) == 0);
    }
 
    void
    testFlush()
    {
        // Test final flush of validations
        using namespace std::chrono_literals;
        testcase("Flush validations");
 
        LedgerHistoryHelper h;
        TestHarness harness(h.oracle);
        Node a = harness.makeNode(), b = harness.makeNode(), c = harness.makeNode();
        c.untrust();
 
        Ledger ledgerA = h["a"];
        Ledger ledgerAB = h["ab"];
 
        hash_map<PeerID, Validation> expected;
        for (auto const& node : {a, b, c})
        {
            auto const val = node.validate(ledgerA);
            BEAST_EXPECT(ValStatus::current == harness.add(val));
            expected.emplace(node.nodeID(), val);
        }
 
        // Send in a new validation for a, saving the new one into the expected
        // map after setting the proper prior ledger ID it replaced
        harness.clock().advance(1s);
        auto newVal = a.validate(ledgerAB);
        BEAST_EXPECT(ValStatus::current == harness.add(newVal));
        expected.find(a.nodeID())->second = newVal;
    }
 
    void
    testGetPreferredLedger()
    {
        using namespace std::chrono_literals;
        testcase("Preferred Ledger");
 
        LedgerHistoryHelper h;
        TestHarness harness(h.oracle);
        Node a = harness.makeNode(), b = harness.makeNode(), c = harness.makeNode(), d = harness.makeNode();
        c.untrust();
 
        Ledger ledgerA = h["a"];
        Ledger ledgerB = h["b"];
        Ledger ledgerAC = h["ac"];
        Ledger ledgerACD = h["acd"];
 
        using Seq = Ledger::Seq;
 
        auto pref = [](Ledger ledger) { return std::make_pair(ledger.seq(), ledger.id()); };
 
        // Empty (no ledgers)
        BEAST_EXPECT(harness.vals().getPreferred(ledgerA) == std::nullopt);
 
        // Single ledger
        BEAST_EXPECT(ValStatus::current == harness.add(a.validate(ledgerB)));
        BEAST_EXPECT(harness.vals().getPreferred(ledgerA) == pref(ledgerB));
        BEAST_EXPECT(harness.vals().getPreferred(ledgerB) == pref(ledgerB));
 
        // Minimum valid sequence
        BEAST_EXPECT(harness.vals().getPreferred(ledgerA, Seq{10}) == ledgerA.id());
 
        // Untrusted doesn't impact preferred ledger
        // (ledgerB has tie-break over ledgerA)
        BEAST_EXPECT(ValStatus::current == harness.add(b.validate(ledgerA)));
        BEAST_EXPECT(ValStatus::current == harness.add(c.validate(ledgerA)));
        BEAST_EXPECT(ledgerB.id() > ledgerA.id());
        BEAST_EXPECT(harness.vals().getPreferred(ledgerA) == pref(ledgerB));
        BEAST_EXPECT(harness.vals().getPreferred(ledgerB) == pref(ledgerB));
 
        // Partial does break ties
        BEAST_EXPECT(ValStatus::current == harness.add(d.partial(ledgerA)));
        BEAST_EXPECT(harness.vals().getPreferred(ledgerA) == pref(ledgerA));
        BEAST_EXPECT(harness.vals().getPreferred(ledgerB) == pref(ledgerA));
 
        harness.clock().advance(5s);
 
        // Parent of preferred-> stick with ledger
        for (auto const& node : {a, b, c, d})
            BEAST_EXPECT(ValStatus::current == harness.add(node.validate(ledgerAC)));
        // Parent of preferred stays put
        BEAST_EXPECT(harness.vals().getPreferred(ledgerA) == pref(ledgerA));
        // Earlier different chain, switch
        BEAST_EXPECT(harness.vals().getPreferred(ledgerB) == pref(ledgerAC));
        // Later on chain, stays where it is
        BEAST_EXPECT(harness.vals().getPreferred(ledgerACD) == pref(ledgerACD));
 
        // Any later grandchild or different chain is preferred
        harness.clock().advance(5s);
        for (auto const& node : {a, b, c, d})
            BEAST_EXPECT(ValStatus::current == harness.add(node.validate(ledgerACD)));
        for (auto const& ledger : {ledgerA, ledgerB, ledgerACD})
            BEAST_EXPECT(harness.vals().getPreferred(ledger) == pref(ledgerACD));
    }
 
    void
    testGetPreferredLCL()
    {
        using namespace std::chrono_literals;
        testcase("Get preferred LCL");
 
        LedgerHistoryHelper h;
        TestHarness harness(h.oracle);
        Node a = harness.makeNode();
 
        Ledger ledgerA = h["a"];
        Ledger ledgerB = h["b"];
        Ledger ledgerC = h["c"];
 
        using ID = Ledger::ID;
        using Seq = Ledger::Seq;
 
        hash_map<ID, std::uint32_t> peerCounts;
 
        // No trusted validations or counts sticks with current ledger
        BEAST_EXPECT(harness.vals().getPreferredLCL(ledgerA, Seq{0}, peerCounts) == ledgerA.id());
 
        ++peerCounts[ledgerB.id()];
 
        // No trusted validations, rely on peer counts
        BEAST_EXPECT(harness.vals().getPreferredLCL(ledgerA, Seq{0}, peerCounts) == ledgerB.id());
 
        ++peerCounts[ledgerC.id()];
        // No trusted validations, tied peers goes with larger ID
        BEAST_EXPECT(ledgerC.id() > ledgerB.id());
 
        BEAST_EXPECT(harness.vals().getPreferredLCL(ledgerA, Seq{0}, peerCounts) == ledgerC.id());
 
        peerCounts[ledgerC.id()] += 1000;
 
        // Single trusted always wins over peer counts
        BEAST_EXPECT(ValStatus::current == harness.add(a.validate(ledgerA)));
        BEAST_EXPECT(harness.vals().getPreferredLCL(ledgerA, Seq{0}, peerCounts) == ledgerA.id());
        BEAST_EXPECT(harness.vals().getPreferredLCL(ledgerB, Seq{0}, peerCounts) == ledgerA.id());
        BEAST_EXPECT(harness.vals().getPreferredLCL(ledgerC, Seq{0}, peerCounts) == ledgerA.id());
 
        // Stick with current ledger if trusted validation ledger has too old
        // of a sequence
        BEAST_EXPECT(harness.vals().getPreferredLCL(ledgerB, Seq{2}, peerCounts) == ledgerB.id());
    }
 
    void
    testAcquireValidatedLedger()
    {
        using namespace std::chrono_literals;
        testcase("Acquire validated ledger");
 
        LedgerHistoryHelper h;
        TestHarness harness(h.oracle);
        Node a = harness.makeNode();
        Node b = harness.makeNode();
 
        using ID = Ledger::ID;
        using Seq = Ledger::Seq;
 
        // Validate the ledger before it is actually available
        Validation val = a.validate(ID{2}, Seq{2}, 0s, 0s, true);
 
        BEAST_EXPECT(ValStatus::current == harness.add(val));
        // Validation is available
        BEAST_EXPECT(harness.vals().numTrustedForLedger(ID{2}) == 1);
        // but ledger based data is not
        BEAST_EXPECT(harness.vals().getNodesAfter(genesisLedger, ID{0}) == 0);
        // Initial preferred branch falls back to the ledger we are trying to
        // acquire
        BEAST_EXPECT(harness.vals().getPreferred(genesisLedger) == std::make_pair(Seq{2}, ID{2}));
 
        // After adding another unavailable validation, the preferred ledger
        // breaks ties via higher ID
        BEAST_EXPECT(ValStatus::current == harness.add(b.validate(ID{3}, Seq{2}, 0s, 0s, true)));
        BEAST_EXPECT(harness.vals().getPreferred(genesisLedger) == std::make_pair(Seq{2}, ID{3}));
 
        // Create the ledger
        Ledger ledgerAB = h["ab"];
        // Now it should be available
        BEAST_EXPECT(harness.vals().getNodesAfter(genesisLedger, ID{0}) == 1);
 
        // Create a validation that is not available
        harness.clock().advance(5s);
        Validation val2 = a.validate(ID{4}, Seq{4}, 0s, 0s, true);
        BEAST_EXPECT(ValStatus::current == harness.add(val2));
        BEAST_EXPECT(harness.vals().numTrustedForLedger(ID{4}) == 1);
        BEAST_EXPECT(harness.vals().getPreferred(genesisLedger) == std::make_pair(ledgerAB.seq(), ledgerAB.id()));
 
        // Another node requesting that ledger still doesn't change things
        Validation val3 = b.validate(ID{4}, Seq{4}, 0s, 0s, true);
        BEAST_EXPECT(ValStatus::current == harness.add(val3));
        BEAST_EXPECT(harness.vals().numTrustedForLedger(ID{4}) == 2);
        BEAST_EXPECT(harness.vals().getPreferred(genesisLedger) == std::make_pair(ledgerAB.seq(), ledgerAB.id()));
 
        // Switch to validation that is available
        harness.clock().advance(5s);
        Ledger ledgerABCDE = h["abcde"];
        BEAST_EXPECT(ValStatus::current == harness.add(a.partial(ledgerABCDE)));
        BEAST_EXPECT(ValStatus::current == harness.add(b.partial(ledgerABCDE)));
        BEAST_EXPECT(harness.vals().getPreferred(genesisLedger) == std::make_pair(ledgerABCDE.seq(), ledgerABCDE.id()));
    }
 
    void
    testNumTrustedForLedger()
    {
        testcase("NumTrustedForLedger");
        LedgerHistoryHelper h;
        TestHarness harness(h.oracle);
        Node a = harness.makeNode();
        Node b = harness.makeNode();
        Ledger ledgerA = h["a"];
 
        BEAST_EXPECT(ValStatus::current == harness.add(a.partial(ledgerA)));
        BEAST_EXPECT(harness.vals().numTrustedForLedger(ledgerA.id()) == 0);
 
        BEAST_EXPECT(ValStatus::current == harness.add(b.validate(ledgerA)));
        BEAST_EXPECT(harness.vals().numTrustedForLedger(ledgerA.id()) == 1);
    }
 
    void
    testSeqEnforcer()
    {
        testcase("SeqEnforcer");
        using Seq = Ledger::Seq;
        using namespace std::chrono;
 
        beast::manual_clock<steady_clock> clock;
        SeqEnforcer<Seq> enforcer;
 
        ValidationParms p;
 
        BEAST_EXPECT(enforcer(clock.now(), Seq{1}, p));
        BEAST_EXPECT(enforcer(clock.now(), Seq{10}, p));
        BEAST_EXPECT(!enforcer(clock.now(), Seq{5}, p));
        BEAST_EXPECT(!enforcer(clock.now(), Seq{9}, p));
        clock.advance(p.validationSET_EXPIRES - 1ms);
        BEAST_EXPECT(!enforcer(clock.now(), Seq{1}, p));
        clock.advance(2ms);
        BEAST_EXPECT(enforcer(clock.now(), Seq{1}, p));
    }
 
    void
    testTrustChanged()
    {
        testcase("TrustChanged");
        using namespace std::chrono;
 
        auto checker =
            [this](TestValidations& vals, hash_set<PeerID> const& listed, std::vector<Validation> const& trustedVals) {
                Ledger::ID testID = trustedVals.empty() ? this->genesisLedger.id() : trustedVals[0].ledgerID();
                Ledger::Seq testSeq = trustedVals.empty() ? this->genesisLedger.seq() : trustedVals[0].seq();
                BEAST_EXPECT(vals.currentTrusted() == trustedVals);
                BEAST_EXPECT(vals.getCurrentNodeIDs() == listed);
                BEAST_EXPECT(vals.getNodesAfter(this->genesisLedger, genesisLedger.id()) == trustedVals.size());
                if (trustedVals.empty())
                    BEAST_EXPECT(vals.getPreferred(this->genesisLedger) == std::nullopt);
                else
                    BEAST_EXPECT(vals.getPreferred(this->genesisLedger)->second == testID);
                BEAST_EXPECT(vals.getTrustedForLedger(testID, testSeq) == trustedVals);
                BEAST_EXPECT(vals.numTrustedForLedger(testID) == trustedVals.size());
            };
 
        {
            // Trusted to untrusted
            LedgerHistoryHelper h;
            TestHarness harness(h.oracle);
            Node a = harness.makeNode();
            Ledger ledgerAB = h["ab"];
            Validation v = a.validate(ledgerAB);
            BEAST_EXPECT(ValStatus::current == harness.add(v));
 
            hash_set<PeerID> listed({a.nodeID()});
            std::vector<Validation> trustedVals({v});
            checker(harness.vals(), listed, trustedVals);
 
            trustedVals.clear();
            harness.vals().trustChanged({}, {a.nodeID()});
            checker(harness.vals(), listed, trustedVals);
        }
 
        {
            // Untrusted to trusted
            LedgerHistoryHelper h;
            TestHarness harness(h.oracle);
            Node a = harness.makeNode();
            a.untrust();
            Ledger ledgerAB = h["ab"];
            Validation v = a.validate(ledgerAB);
            BEAST_EXPECT(ValStatus::current == harness.add(v));
 
            hash_set<PeerID> listed({a.nodeID()});
            std::vector<Validation> trustedVals;
            checker(harness.vals(), listed, trustedVals);
 
            trustedVals.push_back(v);
            harness.vals().trustChanged({a.nodeID()}, {});
            checker(harness.vals(), listed, trustedVals);
        }
 
        {
            // Trusted but not acquired -> untrusted
            LedgerHistoryHelper h;
            TestHarness harness(h.oracle);
            Node a = harness.makeNode();
            Validation v = a.validate(Ledger::ID{2}, Ledger::Seq{2}, 0s, 0s, true);
            BEAST_EXPECT(ValStatus::current == harness.add(v));
 
            hash_set<PeerID> listed({a.nodeID()});
            std::vector<Validation> trustedVals({v});
            auto& vals = harness.vals();
            BEAST_EXPECT(vals.currentTrusted() == trustedVals);
            BEAST_EXPECT(vals.getPreferred(genesisLedger)->second == v.ledgerID());
            BEAST_EXPECT(vals.getNodesAfter(genesisLedger, genesisLedger.id()) == 0);
 
            trustedVals.clear();
            harness.vals().trustChanged({}, {a.nodeID()});
            // make acquiring ledger available
            h["ab"];
            BEAST_EXPECT(vals.currentTrusted() == trustedVals);
            BEAST_EXPECT(vals.getPreferred(genesisLedger) == std::nullopt);
            BEAST_EXPECT(vals.getNodesAfter(genesisLedger, genesisLedger.id()) == 0);
        }
    }
 
    void
    run() override
    {
        testAddValidation();
        testOnStale();
        testGetNodesAfter();
        testCurrentTrusted();
        testGetCurrentPublicKeys();
        testTrustedByLedgerFunctions();
        testExpire();
        testFlush();
        testGetPreferredLedger();
        testGetPreferredLCL();
        testAcquireValidatedLedger();
        testNumTrustedForLedger();
        testSeqEnforcer();
        testTrustChanged();
    }
};
 
BEAST_DEFINE_TESTSUITE(Validations, consensus, xrpl);
}  // namespace csf
}  // namespace test
}  // namespace xrpl