PaymentChannelHelpers.cpp

#include <xrpl/ledger/helpers/PaymentChannelHelpers.h>
 
#include <xrpl/basics/Log.h>
#include <xrpl/basics/base_uint.h>
#include <xrpl/beast/utility/Journal.h>
#include <xrpl/beast/utility/instrumentation.h>
#include <xrpl/ledger/ApplyView.h>
#include <xrpl/ledger/View.h>
#include <xrpl/ledger/helpers/AccountRootHelpers.h>
#include <xrpl/protocol/AccountID.h>
#include <xrpl/protocol/Feature.h>
#include <xrpl/protocol/Indexes.h>
#include <xrpl/protocol/SField.h>
#include <xrpl/protocol/STLedgerEntry.h>
#include <xrpl/protocol/TER.h>
 
#include <algorithm>
#include <cstdint>
#include <limits>
#include <optional>
 
namespace xrpl {
 
TER
closeChannel(SLE::ref slep, ApplyView& view, uint256 const& key, beast::Journal j)
{
    AccountID const src = (*slep)[sfAccount];
    // Remove PayChan from owner directory
    {
        auto const page = (*slep)[sfOwnerNode];
        if (!view.dirRemove(keylet::ownerDir(src), page, key, true))
        {
            // LCOV_EXCL_START
            JLOG(j.fatal()) << "Could not remove paychan from src owner directory";
            return tefBAD_LEDGER;
            // LCOV_EXCL_STOP
        }
    }
 
    // Remove PayChan from recipient's owner directory, if present.
    if (auto const page = (*slep)[~sfDestinationNode])
    {
        auto const dst = (*slep)[sfDestination];
        if (!view.dirRemove(keylet::ownerDir(dst), *page, key, true))
        {
            // LCOV_EXCL_START
            JLOG(j.fatal()) << "Could not remove paychan from dst owner directory";
            return tefBAD_LEDGER;
            // LCOV_EXCL_STOP
        }
    }
 
    // Transfer amount back to owner, decrement owner count
    auto const sle = view.peek(keylet::account(src));
    if (!sle)
        return tefINTERNAL;  // LCOV_EXCL_LINE
 
    XRPL_ASSERT(
        (*slep)[sfAmount] >= (*slep)[sfBalance], "xrpl::closeChannel : minimum channel amount");
    (*sle)[sfBalance] = (*sle)[sfBalance] + (*slep)[sfAmount] - (*slep)[sfBalance];
    adjustOwnerCount(view, sle, -1, j);
    view.update(sle);
 
    // Remove PayChan from ledger
    view.erase(slep);
    return tesSUCCESS;
}
 
uint32_t
saturatingAdd(Rules const& rules, uint32_t const lhs, uint32_t const rhs)
{
    if (rules.enabled(fixCleanup3_2_0))
    {
        static constexpr auto kUint32Max =
            static_cast<uint64_t>(std::numeric_limits<uint32_t>::max());
        uint64_t const saturatedResult = std::min(uint64_t{lhs} + rhs, kUint32Max);
        return static_cast<uint32_t>(saturatedResult);
    }
 
    return lhs + rhs;
}
 
bool
isChannelExpired(ApplyView const& view, std::optional<uint32_t> timeField)
{
    if (!timeField)
        return false;
    if (view.rules().enabled(fixCleanup3_2_0))
        return after(view.header().parentCloseTime, *timeField);
    return view.header().parentCloseTime.time_since_epoch().count() >= *timeField;
}
 
}  // namespace xrpl