LoanBrokerDelete.cpp

#include <xrpl/tx/transactors/lending/LoanBrokerDelete.h>
 
#include <xrpl/basics/Log.h>
#include <xrpl/basics/Number.h>
#include <xrpl/beast/utility/Zero.h>
#include <xrpl/ledger/helpers/AccountRootHelpers.h>
#include <xrpl/ledger/helpers/LendingHelpers.h>
#include <xrpl/ledger/helpers/TokenHelpers.h>
#include <xrpl/protocol/Asset.h>
#include <xrpl/protocol/Feature.h>
#include <xrpl/protocol/Indexes.h>
#include <xrpl/protocol/SField.h>
#include <xrpl/protocol/STAmount.h>
#include <xrpl/protocol/STLedgerEntry.h>
#include <xrpl/protocol/STTakesAsset.h>
#include <xrpl/protocol/STTx.h>
#include <xrpl/protocol/TER.h>
#include <xrpl/protocol/XRPAmount.h>
#include <xrpl/tx/Transactor.h>
 
namespace xrpl {
 
bool
LoanBrokerDelete::checkExtraFeatures(PreflightContext const& ctx)
{
    return checkLendingProtocolDependencies(ctx.rules, ctx.tx);
}
 
NotTEC
LoanBrokerDelete::preflight(PreflightContext const& ctx)
{
    if (ctx.tx[sfLoanBrokerID] == beast::kZero)
        return temINVALID;
 
    return tesSUCCESS;
}
 
TER
LoanBrokerDelete::preclaim(PreclaimContext const& ctx)
{
    auto const& tx = ctx.tx;
 
    auto const account = tx[sfAccount];
    auto const brokerID = tx[sfLoanBrokerID];
 
    auto const sleBroker = ctx.view.read(keylet::loanBroker(brokerID));
    if (!sleBroker)
    {
        JLOG(ctx.j.warn()) << "LoanBroker does not exist.";
        return tecNO_ENTRY;
    }
 
    auto const brokerOwner = sleBroker->at(sfOwner);
 
    if (account != brokerOwner)
    {
        JLOG(ctx.j.warn()) << "Account is not the owner of the LoanBroker.";
        return tecNO_PERMISSION;
    }
    if (auto const ownerCount = sleBroker->at(sfOwnerCount); ownerCount != 0)
    {
        JLOG(ctx.j.warn()) << "LoanBrokerDelete: Owner count is " << ownerCount;
        return tecHAS_OBLIGATIONS;
    }
 
    auto const vault = ctx.view.read(keylet::vault(sleBroker->at(sfVaultID)));
    if (!vault)
    {
        // LCOV_EXCL_START
        JLOG(ctx.j.fatal()) << "Vault is missing for Broker " << brokerID;
        return tefBAD_LEDGER;
        // LCOV_EXCL_STOP
    }
 
    Asset const asset = vault->at(sfAsset);
 
    if (auto const debtTotal = sleBroker->at(sfDebtTotal); debtTotal != beast::kZero)
    {
        // Any remaining debt should have been wiped out by the last Loan
        // Delete. This check is purely defensive.
        auto const scale = getAssetsTotalScale(vault);
 
        auto const rounded =
            roundToAsset(asset, debtTotal, scale, Number::RoundingMode::TowardsZero);
 
        if (rounded != beast::kZero)
        {
            // LCOV_EXCL_START
            JLOG(ctx.j.warn()) << "LoanBrokerDelete: Debt total is " << debtTotal
                               << ", which rounds to " << rounded;
            return tecHAS_OBLIGATIONS;
            // LCOV_EXCL_STOP
        }
    }
 
    auto const coverAvailable = STAmount{asset, sleBroker->at(sfCoverAvailable)};
    // If there are assets in the cover, broker will receive them on deletion.
    // So we need to check if the broker owner is deep frozen for that asset.
    if (coverAvailable > beast::kZero)
    {
        if (auto const ret = checkDeepFrozen(ctx.view, brokerOwner, asset))
        {
            JLOG(ctx.j.warn()) << "Broker owner account is frozen.";
            return ret;
        }
    }
 
    if (ctx.view.rules().enabled(fixCleanup3_2_0))
    {
        if (coverAvailable > beast::kZero)
        {
            auto const brokerPseudo = sleBroker->at(sfAccount);
            if (auto const ret = checkFrozen(ctx.view, brokerPseudo, asset))
            {
                JLOG(ctx.j.warn()) << "Broker pseudo-account is frozen/locked.";
                return ret;
            }
        }
    }
 
    return tesSUCCESS;
}
 
TER
LoanBrokerDelete::doApply()
{
    auto const& tx = ctx_.tx;
 
    auto const brokerID = tx[sfLoanBrokerID];
 
    // Delete the loan broker
    auto broker = view().peek(keylet::loanBroker(brokerID));
    if (!broker)
        return tefBAD_LEDGER;  // LCOV_EXCL_LINE
    auto const vaultID = broker->at(sfVaultID);
    auto const sleVault = view().read(keylet::vault(vaultID));
    if (!sleVault)
        return tefBAD_LEDGER;  // LCOV_EXCL_LINE
    auto const vaultPseudoID = sleVault->at(sfAccount);
    auto const vaultAsset = sleVault->at(sfAsset);
 
    auto const brokerPseudoID = broker->at(sfAccount);
 
    if (!view().dirRemove(
            keylet::ownerDir(accountID_), broker->at(sfOwnerNode), broker->key(), false))
    {
        return tefBAD_LEDGER;  // LCOV_EXCL_LINE
    }
    if (!view().dirRemove(
            keylet::ownerDir(vaultPseudoID), broker->at(sfVaultNode), broker->key(), false))
    {
        return tefBAD_LEDGER;  // LCOV_EXCL_LINE
    }
 
    {
        auto const coverAvailable = STAmount{vaultAsset, broker->at(sfCoverAvailable)};
        if (auto const ter = accountSend(
                view(), brokerPseudoID, accountID_, coverAvailable, j_, WaiveTransferFee::Yes))
            return ter;
    }
 
    if (auto ter = removeEmptyHolding(view(), brokerPseudoID, vaultAsset, j_))
        return ter;
 
    auto brokerPseudoSLE = view().peek(keylet::account(brokerPseudoID));
    if (!brokerPseudoSLE)
        return tefBAD_LEDGER;  // LCOV_EXCL_LINE
 
    // Making the payment and removing the empty holding should have deleted any
    // obligations associated with the broker or broker pseudo-account.
    if (*brokerPseudoSLE->at(sfBalance))
    {
        JLOG(j_.warn()) << "LoanBrokerDelete: Pseudo-account has a balance";
        return tecHAS_OBLIGATIONS;  // LCOV_EXCL_LINE
    }
    if (brokerPseudoSLE->at(sfOwnerCount) != 0)
    {
        JLOG(j_.warn()) << "LoanBrokerDelete: Pseudo-account still owns objects";
        return tecHAS_OBLIGATIONS;  // LCOV_EXCL_LINE
    }
    if (auto const directory = keylet::ownerDir(brokerPseudoID); view().read(directory))
    {
        JLOG(j_.warn()) << "LoanBrokerDelete: Pseudo-account has a directory";
        return tecHAS_OBLIGATIONS;  // LCOV_EXCL_LINE
    }
 
    view().erase(brokerPseudoSLE);
 
    view().erase(broker);
 
    {
        auto owner = view().peek(keylet::account(accountID_));
        if (!owner)
            return tefBAD_LEDGER;  // LCOV_EXCL_LINE
 
        // Decreases the owner count by two: one for the LoanBroker object, and
        // one for the pseudo-account.
        adjustOwnerCount(view(), owner, -2, j_);
    }
 
    associateAsset(*broker, vaultAsset);
 
    return tesSUCCESS;
}
 
void
LoanBrokerDelete::visitInvariantEntry(bool, SLE::const_ref, SLE::const_ref)
{
    // No transaction-specific invariants yet (future work).
}
 
bool
LoanBrokerDelete::finalizeInvariants(
    STTx const&,
    TER,
    XRPAmount,
    ReadView const&,
    beast::Journal const&)
{
    // No transaction-specific invariants yet (future work).
    return true;
}
 
//------------------------------------------------------------------------------
 
}  // namespace xrpl