ApplyContext.cpp

#include <xrpl/basics/Log.h>
#include <xrpl/beast/utility/instrumentation.h>
#include <xrpl/json/to_string.h>
#include <xrpl/tx/ApplyContext.h>
#include <xrpl/tx/InvariantCheck.h>
 
namespace xrpl {
 
ApplyContext::ApplyContext(
    ServiceRegistry& registry_,
    OpenView& base,
    std::optional<uint256 const> const& parentBatchId,
    STTx const& tx_,
    TER preclaimResult_,
    XRPAmount baseFee_,
    ApplyFlags flags,
    beast::Journal journal_)
    : registry(registry_)
    , tx(tx_)
    , preclaimResult(preclaimResult_)
    , baseFee(baseFee_)
    , journal(journal_)
    , base_(base)
    , flags_(flags)
    , parentBatchId_(parentBatchId)
{
    XRPL_ASSERT(
        parentBatchId.has_value() == ((flags_ & tapBATCH) == tapBATCH),
        "Parent Batch ID should be set if batch apply flag is set");
    view_.emplace(&base_, flags_);
}
 
void
ApplyContext::discard()
{
    view_.emplace(&base_, flags_);
}
 
std::optional<TxMeta>
ApplyContext::apply(TER ter)
{
    return view_->apply(base_, tx, ter, parentBatchId_, flags_ & tapDRY_RUN, journal);
}
 
std::size_t
ApplyContext::size()
{
    return view_->size();
}
 
void
ApplyContext::visit(
    std::function<void(
        uint256 const&,
        bool,
        std::shared_ptr<SLE const> const&,
        std::shared_ptr<SLE const> const&)> const& func)
{
    view_->visit(base_, func);
}
 
TER
ApplyContext::failInvariantCheck(TER const result)
{
    // If we already failed invariant checks before and we are now attempting to
    // only charge a fee, and even that fails the invariant checks something is
    // very wrong. We switch to tefINVARIANT_FAILED, which does NOT get included
    // in a ledger.
 
    return (result == tecINVARIANT_FAILED || result == tefINVARIANT_FAILED)
        ? TER{tefINVARIANT_FAILED}
        : TER{tecINVARIANT_FAILED};
}
 
template <std::size_t... Is>
TER
ApplyContext::checkInvariantsHelper(
    TER const result,
    XRPAmount const fee,
    std::index_sequence<Is...>)
{
    try
    {
        auto checkers = getInvariantChecks();
 
        // call each check's per-entry method
        visit([&checkers](
                  uint256 const& index,
                  bool isDelete,
                  std::shared_ptr<SLE const> const& before,
                  std::shared_ptr<SLE const> const& after) {
            (..., std::get<Is>(checkers).visitEntry(isDelete, before, after));
        });
 
        // Note: do not replace this logic with a `...&&` fold expression.
        // The fold expression will only run until the first check fails (it
        // short-circuits). While the logic is still correct, the log
        // message won't be. Every failed invariant should write to the log,
        // not just the first one.
        std::array<bool, sizeof...(Is)> finalizers{
            {std::get<Is>(checkers).finalize(tx, result, fee, *view_, journal)...}};
 
        // call each check's finalizer to see that it passes
        if (!std::all_of(finalizers.cbegin(), finalizers.cend(), [](auto const& b) { return b; }))
        {
            JLOG(journal.fatal()) << "Transaction has failed one or more invariants: "
                                  << to_string(tx.getJson(JsonOptions::none));
 
            return failInvariantCheck(result);
        }
    }
    catch (std::exception const& ex)
    {
        JLOG(journal.fatal()) << "Transaction caused an exception in an invariant"
                              << ", ex: " << ex.what()
                              << ", tx: " << to_string(tx.getJson(JsonOptions::none));
 
        return failInvariantCheck(result);
    }
 
    return result;
}
 
TER
ApplyContext::checkInvariants(TER const result, XRPAmount const fee)
{
    XRPL_ASSERT(
        isTesSuccess(result) || isTecClaim(result),
        "xrpl::ApplyContext::checkInvariants : is tesSUCCESS or tecCLAIM");
 
    return checkInvariantsHelper(
        result, fee, std::make_index_sequence<std::tuple_size<InvariantChecks>::value>{});
}
 
}  // namespace xrpl