LoanBrokerInvariant.h

#pragma once
 
#include <xrpl/basics/base_uint.h>
#include <xrpl/beast/utility/Journal.h>
#include <xrpl/ledger/ReadView.h>
#include <xrpl/protocol/STLedgerEntry.h>
#include <xrpl/protocol/STTx.h>
#include <xrpl/protocol/TER.h>
#include <xrpl/protocol/XRPAmount.h>
 
#include <map>
#include <vector>
 
namespace xrpl {

class ValidLoanBroker
{
    // Not all of these elements will necessarily be populated. Remaining items
    // will be looked up as needed.
    struct BrokerInfo
    {
        SLE::const_pointer brokerBefore = nullptr;
        // After is used for most of the checks, except
        // those that check changed values.
        SLE::const_pointer brokerAfter = nullptr;
    };
    // Collect all the LoanBrokers found directly or indirectly through
    // pseudo-accounts. Key is the brokerID / index. It will be used to find the
    // LoanBroker object if brokerBefore and brokerAfter are nullptr
    std::map<UInt256, BrokerInfo> brokers_;
    // The broker whose ledger entry was deleted by this transaction, if any.
    // Only ttLOAN_BROKER_DELETE removes a broker, and it removes exactly one.
    // This is the pre-transaction state, which is what LoanBrokerDelete::preclaim
    // reads when it decides whether the broker may be deleted, so the deletion invariants inspect
    // the same DebtTotal and OwnerCount that the transactor did.
    SLE::const_pointer deletedBroker_ = nullptr;
    // Set if visitEntry observes more than one ltLOAN_BROKER deletion in the
    // same transaction. Enforced as its own invariant in finalize.
    bool multipleBrokerDeletions_ = false;
    // Collect all the modified trust lines. Their high and low accounts will be
    // loaded to look for LoanBroker pseudo-accounts.
    std::vector<SLE::const_pointer> lines_;
    // Collect all the modified MPTokens. Their accounts will be loaded to look
    // for LoanBroker pseudo-accounts.
    std::vector<SLE::const_pointer> mpts_;
 
    static bool
    goodZeroDirectory(ReadView const& view, SLE::ConstRef dir, beast::Journal const& j);
 
public:
    void
    visitEntry(bool, SLE::ConstRef, SLE::ConstRef);
 
    bool
    finalize(STTx const&, TER const, XRPAmount const, ReadView const&, beast::Journal const&);
};
 
}  // namespace xrpl