rippled/src/libxrpl/protocol/STVar.cpp

#include <xrpl/basics/contract.h>
#include <xrpl/beast/utility/instrumentation.h>
#include <xrpl/protocol/SField.h>
#include <xrpl/protocol/STAccount.h>
#include <xrpl/protocol/STAmount.h>
#include <xrpl/protocol/STArray.h>
#include <xrpl/protocol/STBase.h>
#include <xrpl/protocol/STBitString.h>
#include <xrpl/protocol/STBlob.h>
#include <xrpl/protocol/STCurrency.h>
#include <xrpl/protocol/STInteger.h>
#include <xrpl/protocol/STIssue.h>
#include <xrpl/protocol/STNumber.h>
#include <xrpl/protocol/STObject.h>
#include <xrpl/protocol/STPathSet.h>
#include <xrpl/protocol/STVector256.h>
#include <xrpl/protocol/STXChainBridge.h>
#include <xrpl/protocol/Serializer.h>
#include <xrpl/protocol/detail/STVar.h>

#include <stdexcept>
#include <tuple>
#include <type_traits>

namespace xrpl {
namespace detail {

defaultObject_t defaultObject;
nonPresentObject_t nonPresentObject;

//------------------------------------------------------------------------------

STVar::~STVar()
{
    destroy();
}

STVar::STVar(STVar const& other)
{
    if (other.p_ != nullptr)
        p_ = other.p_->copy(max_size, &d_);
}

STVar::STVar(STVar&& other)
{
    if (other.on_heap())
    {
        p_ = other.p_;
        other.p_ = nullptr;
    }
    else
    {
        p_ = other.p_->move(max_size, &d_);
    }
}

STVar&
STVar::operator=(STVar const& rhs)
{
    if (&rhs != this)
    {
        destroy();
        if (rhs.p_)
            p_ = rhs.p_->copy(max_size, &d_);
        else
            p_ = nullptr;
    }

    return *this;
}

STVar&
STVar::operator=(STVar&& rhs)
{
    if (&rhs != this)
    {
        destroy();
        if (rhs.on_heap())
        {
            p_ = rhs.p_;
            rhs.p_ = nullptr;
        }
        else
        {
            p_ = rhs.p_->move(max_size, &d_);
        }
    }

    return *this;
}

STVar::STVar(defaultObject_t, SField const& name) : STVar(name.fieldType, name)
{
}

STVar::STVar(nonPresentObject_t, SField const& name) : STVar(STI_NOTPRESENT, name)
{
}

STVar::STVar(SerialIter& sit, SField const& name, int depth)
{
    if (depth > 10)
        Throw<std::runtime_error>("Maximum nesting depth of STVar exceeded");
    constructST(name.fieldType, depth, sit, name);
}

STVar::STVar(SerializedTypeID id, SField const& name)
{
    XRPL_ASSERT(
        (id == STI_NOTPRESENT) || (id == name.fieldType),
        "xrpl::detail::STVar::STVar(SerializedTypeID) : valid type input");
    constructST(id, 0, name);
}

void
STVar::destroy()
{
    if (on_heap())
        delete p_;
    else
        p_->~STBase();

    p_ = nullptr;
}

template <typename... Args>
    requires ValidConstructSTArgs<Args...>
void
STVar::constructST(SerializedTypeID id, int depth, Args&&... args)
{
    auto constructWithDepth = [&]<typename T>() {
        if constexpr (std::is_same_v<std::tuple<std::remove_cvref_t<Args>...>, std::tuple<SField>>)
        {
            construct<T>(std::forward<Args>(args)...);
        }
        else if constexpr (
            std::
                is_same_v<std::tuple<std::remove_cvref_t<Args>...>, std::tuple<SerialIter, SField>>)
        {
            construct<T>(std::forward<Args>(args)..., depth);
        }
        else
        {
            constexpr bool alwaysFalse = !std::is_same_v<std::tuple<Args...>, std::tuple<Args...>>;
            static_assert(alwaysFalse, "Invalid STVar constructor arguments");
        }
    };

    switch (id)
    {
        case STI_NOTPRESENT: {
            // Last argument is always SField
            SField const& field = std::get<sizeof...(args) - 1>(std::forward_as_tuple(args...));
            construct<STBase>(field);
            return;
        }
        case STI_UINT8:
            construct<STUInt8>(std::forward<Args>(args)...);
            return;
        case STI_UINT16:
            construct<STUInt16>(std::forward<Args>(args)...);
            return;
        case STI_UINT32:
            construct<STUInt32>(std::forward<Args>(args)...);
            return;
        case STI_UINT64:
            construct<STUInt64>(std::forward<Args>(args)...);
            return;
        case STI_AMOUNT:
            construct<STAmount>(std::forward<Args>(args)...);
            return;
        case STI_NUMBER:
            construct<STNumber>(std::forward<Args>(args)...);
            return;
        case STI_UINT128:
            construct<STUInt128>(std::forward<Args>(args)...);
            return;
        case STI_UINT160:
            construct<STUInt160>(std::forward<Args>(args)...);
            return;
        case STI_UINT192:
            construct<STUInt192>(std::forward<Args>(args)...);
            return;
        case STI_UINT256:
            construct<STUInt256>(std::forward<Args>(args)...);
            return;
        case STI_INT32:
            construct<STInt32>(std::forward<Args>(args)...);
            return;
        case STI_VECTOR256:
            construct<STVector256>(std::forward<Args>(args)...);
            return;
        case STI_VL:
            construct<STBlob>(std::forward<Args>(args)...);
            return;
        case STI_ACCOUNT:
            construct<STAccount>(std::forward<Args>(args)...);
            return;
        case STI_PATHSET:
            construct<STPathSet>(std::forward<Args>(args)...);
            return;
        case STI_OBJECT:
            constructWithDepth.template operator()<STObject>();
            return;
        case STI_ARRAY:
            constructWithDepth.template operator()<STArray>();
            return;
        case STI_ISSUE:
            construct<STIssue>(std::forward<Args>(args)...);
            return;
        case STI_XCHAIN_BRIDGE:
            construct<STXChainBridge>(std::forward<Args>(args)...);
            return;
        case STI_CURRENCY:
            construct<STCurrency>(std::forward<Args>(args)...);
            return;
        default:
            Throw<std::runtime_error>("Unknown object type");
    }
}

}  // namespace detail
}  // namespace xrpl