AmendmentTable.h

#pragma once
 
#include <xrpl/ledger/ReadView.h>
#include <xrpl/ledger/View.h>
#include <xrpl/protocol/Feature.h>
#include <xrpl/protocol/Protocol.h>
#include <xrpl/protocol/STValidation.h>
#include <xrpl/shamap/SHAMap.h>
 
#include <optional>
#include <utility>
 
namespace xrpl {
 
class ServiceRegistry;

class AmendmentTable
{
public:
    struct FeatureInfo
    {
        FeatureInfo() = delete;
        FeatureInfo(std::string n, uint256 const& f, VoteBehavior v)
            : name(std::move(n)), feature(f), vote(v)
        {
        }
 
        std::string const name;
        uint256 const feature;
        VoteBehavior const vote;
    };
 
    virtual ~AmendmentTable() = default;
 
    [[nodiscard]] virtual uint256
    find(std::string const& name) const = 0;
 
    virtual bool
    veto(uint256 const& amendment) = 0;
    virtual bool
    unVeto(uint256 const& amendment) = 0;
 
    virtual bool
    enable(uint256 const& amendment) = 0;
 
    [[nodiscard]] virtual bool
    isEnabled(uint256 const& amendment) const = 0;
    [[nodiscard]] virtual bool
    isSupported(uint256 const& amendment) const = 0;

    [[nodiscard]] virtual bool
    hasUnsupportedEnabled() const = 0;
 
    [[nodiscard]] virtual std::optional<NetClock::time_point>
    firstUnsupportedExpected() const = 0;
 
    [[nodiscard]] virtual json::Value
    getJson(bool isAdmin) const = 0;

    [[nodiscard]] virtual json::Value
    getJson(uint256 const& amendment, bool isAdmin) const = 0;

    void
    doValidatedLedger(std::shared_ptr<ReadView const> const& lastValidatedLedger)
    {
        if (needValidatedLedger(lastValidatedLedger->seq()))
        {
            doValidatedLedger(
                lastValidatedLedger->seq(),
                getEnabledAmendments(*lastValidatedLedger),
                getMajorityAmendments(*lastValidatedLedger));
        }
    }

    [[nodiscard]] virtual bool
    needValidatedLedger(LedgerIndex seq) const = 0;
 
    virtual void
    doValidatedLedger(
        LedgerIndex ledgerSeq,
        std::set<uint256> const& enabled,
        majorityAmendments_t const& majority) = 0;
 
    // Called when the set of trusted validators changes.
    virtual void
    trustChanged(hash_set<PublicKey> const& allTrusted) = 0;
 
    // Called by the consensus code when we need to
    // inject pseudo-transactions
    virtual std::map<uint256, std::uint32_t>
    doVoting(
        Rules const& rules,
        NetClock::time_point closeTime,
        std::set<uint256> const& enabledAmendments,
        majorityAmendments_t const& majorityAmendments,
        std::vector<std::shared_ptr<STValidation>> const& valSet) = 0;
 
    // Called by the consensus code when we need to
    // add feature entries to a validation
    [[nodiscard]] virtual std::vector<uint256>
    doValidation(std::set<uint256> const& enabled) const = 0;
 
    // The set of amendments to enable in the genesis ledger
    // This will return all known, non-vetoed amendments.
    // If we ever have two amendments that should not both be
    // enabled at the same time, we should ensure one is vetoed.
    [[nodiscard]] virtual std::vector<uint256>
    getDesired() const = 0;
 
    // The function below adapts the API callers expect to the
    // internal amendment table API. This allows the amendment
    // table implementation to be independent of the ledger
    // implementation. These APIs will merge when the view code
    // supports a full ledger API
 
    void
    doVoting(
        std::shared_ptr<ReadView const> const& lastClosedLedger,
        std::vector<std::shared_ptr<STValidation>> const& parentValidations,
        std::shared_ptr<SHAMap> const& initialPosition,
        beast::Journal j)
    {
        // Ask implementation what to do
        auto actions = doVoting(
            lastClosedLedger->rules(),
            lastClosedLedger->parentCloseTime(),
            getEnabledAmendments(*lastClosedLedger),
            getMajorityAmendments(*lastClosedLedger),
            parentValidations);
 
        // Inject appropriate pseudo-transactions
        for (auto const& it : actions)
        {
            STTx const amendTx(ttAMENDMENT, [&it, seq = lastClosedLedger->seq() + 1](auto& obj) {
                obj.setAccountID(sfAccount, AccountID());
                obj.setFieldH256(sfAmendment, it.first);
                obj.setFieldU32(sfLedgerSequence, seq);
 
                if (it.second != 0)
                    obj.setFieldU32(sfFlags, it.second);
            });
 
            Serializer s;
            amendTx.add(s);
 
            JLOG(j.debug()) << "Amendments: Adding pseudo-transaction: "
                            << amendTx.getTransactionID() << ": " << strHex(s.slice()) << ": "
                            << amendTx;
 
            initialPosition->addGiveItem(
                SHAMapNodeType::TnTransactionNm,
                makeShamapitem(amendTx.getTransactionID(), s.slice()));
        }
    }
};
 
std::unique_ptr<AmendmentTable>
makeAmendmentTable(
    ServiceRegistry& registry,
    std::chrono::seconds majorityTime,
    std::vector<AmendmentTable::FeatureInfo> const& supported,
    Section const& enabled,
    Section const& vetoed,
    beast::Journal journal);
 
}  // namespace xrpl