NegativeUNLVote.h

//------------------------------------------------------------------------------
/*
    This file is part of rippled: https://github.com/ripple/rippled
    Copyright (c) 2020 Ripple Labs Inc.
 
    Permission to use, copy, modify, and/or distribute this software for any
    purpose  with  or without fee is hereby granted, provided that the above
    copyright notice and this permission notice appear in all copies.
 
    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
    ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
//==============================================================================
 
#ifndef RIPPLE_APP_MISC_NEGATIVEUNLVOTE_H_INCLUDED
#define RIPPLE_APP_MISC_NEGATIVEUNLVOTE_H_INCLUDED
 
#include <xrpld/app/ledger/Ledger.h>
#include <xrpl/beast/utility/Journal.h>
#include <xrpl/protocol/Protocol.h>
#include <xrpl/protocol/PublicKey.h>
#include <xrpl/protocol/UintTypes.h>
 
#include <optional>
 
namespace ripple {
 
template <class Adaptor>
class Validations;
class RCLValidationsAdaptor;
using RCLValidations = Validations<RCLValidationsAdaptor>;
class SHAMap;
namespace test {
class NegativeUNLVoteInternal_test;
class NegativeUNLVoteScoreTable_test;
}  // namespace test
 
class NegativeUNLVote final
{
public:
    static constexpr size_t negativeUNLLowWaterMark =
        FLAG_LEDGER_INTERVAL * 50 / 100;
    static constexpr size_t negativeUNLHighWaterMark =
        FLAG_LEDGER_INTERVAL * 80 / 100;
    static constexpr size_t negativeUNLMinLocalValsToVote =
        FLAG_LEDGER_INTERVAL * 90 / 100;
    static constexpr size_t newValidatorDisableSkip = FLAG_LEDGER_INTERVAL * 2;
    static constexpr float negativeUNLMaxListed = 0.25;
 
    enum NegativeUNLModify {
        ToDisable,  // UNLModify Tx is to disable a validator
        ToReEnable  // UNLModify Tx is to re-enable a validator
    };
 
    NegativeUNLVote(NodeID const& myId, beast::Journal j);
    ~NegativeUNLVote() = default;
 
    void
    doVoting(
        std::shared_ptr<Ledger const> const& prevLedger,
        hash_set<PublicKey> const& unlKeys,
        RCLValidations& validations,
        std::shared_ptr<SHAMap> const& initialSet);
 
    void
    newValidators(LedgerIndex seq, hash_set<NodeID> const& nowTrusted);
 
private:
    NodeID const myId_;
    beast::Journal j_;
    mutable std::mutex mutex_;
    hash_map<NodeID, LedgerIndex> newValidators_;
 
    struct Candidates
    {
        std::vector<NodeID> toDisableCandidates;
        std::vector<NodeID> toReEnableCandidates;
    };
 
    void
    addTx(
        LedgerIndex seq,
        PublicKey const& vp,
        NegativeUNLModify modify,
        std::shared_ptr<SHAMap> const& initialSet);
 
    NodeID
    choose(uint256 const& randomPadData, std::vector<NodeID> const& candidates);
 
    std::optional<hash_map<NodeID, std::uint32_t>>
    buildScoreTable(
        std::shared_ptr<Ledger const> const& prevLedger,
        hash_set<NodeID> const& unl,
        RCLValidations& validations);
 
    Candidates const
    findAllCandidates(
        hash_set<NodeID> const& unl,
        hash_set<NodeID> const& negUnl,
        hash_map<NodeID, std::uint32_t> const& scoreTable);
 
    void
    purgeNewValidators(LedgerIndex seq);
 
    friend class test::NegativeUNLVoteInternal_test;
    friend class test::NegativeUNLVoteScoreTable_test;
};
 
}  // namespace ripple
 
#endif