rippled/include/xrpl/tx/paths/detail/FlowDebugInfo.h

#pragma once

#include <xrpl/ledger/PaymentSandbox.h>
#include <xrpl/protocol/IOUAmount.h>
#include <xrpl/protocol/XRPAmount.h>
#include <xrpl/tx/paths/detail/AmountSpec.h>

#include <boost/container/flat_map.hpp>

#include <chrono>
#include <optional>
#include <sstream>

namespace xrpl::path::detail {
// Track performance information of a single payment
struct FlowDebugInfo
{
    using clock = std::chrono::high_resolution_clock;
    using time_point = clock::time_point;
    boost::container::flat_map<std::string, std::pair<time_point, time_point>> timePoints;
    boost::container::flat_map<std::string, std::size_t> counts;

    struct PassInfo
    {
        PassInfo() = delete;
        PassInfo(bool nativeIn, bool nativeOut) : nativeIn(nativeIn), nativeOut(nativeOut)
        {
        }
        bool const nativeIn;
        bool const nativeOut;
        std::vector<EitherAmount> in;
        std::vector<EitherAmount> out;
        std::vector<size_t> numActive;

        std::vector<std::vector<EitherAmount>> liquiditySrcIn;
        std::vector<std::vector<EitherAmount>> liquiditySrcOut;

        void
        reserve(size_t s)
        {
            in.reserve(s);
            out.reserve(s);
            liquiditySrcIn.reserve(s);
            liquiditySrcOut.reserve(s);
            numActive.reserve(s);
        }

        [[nodiscard]] size_t
        size() const
        {
            return in.size();
        }

        void
        pushBack(EitherAmount const& inAmt, EitherAmount const& outAmt, std::size_t active)
        {
            in.push_back(inAmt);
            out.push_back(outAmt);
            numActive.push_back(active);
        }

        void
        pushLiquiditySrc(EitherAmount const& eIn, EitherAmount const& eOut)
        {
            XRPL_ASSERT(
                !liquiditySrcIn.empty(),
                "xrpl::path::detail::FlowDebugInfo::pushLiquiditySrc : "
                "non-empty liquidity source");
            liquiditySrcIn.back().push_back(eIn);
            liquiditySrcOut.back().push_back(eOut);
        }

        void
        newLiquidityPass()
        {
            auto const s = liquiditySrcIn.size();
            size_t const r = !numActive.empty() ? numActive.back() : 16;
            liquiditySrcIn.resize(s + 1);
            liquiditySrcIn.back().reserve(r);
            liquiditySrcOut.resize(s + 1);
            liquiditySrcOut.back().reserve(r);
        }
    };

    PassInfo passInfo;

    FlowDebugInfo() = delete;
    FlowDebugInfo(bool nativeIn, bool nativeOut) : passInfo(nativeIn, nativeOut)
    {
        timePoints.reserve(16);
        counts.reserve(16);
        passInfo.reserve(64);
    }

    [[nodiscard]] auto
    duration(std::string const& tag) const
    {
        auto i = timePoints.find(tag);
        if (i == timePoints.end())
        {
            // LCOV_EXCL_START
            UNREACHABLE(
                "xrpl::path::detail::FlowDebugInfo::duration : timepoint not "
                "found");
            return std::chrono::duration<double>(0);
            // LCOV_EXCL_STOP
        }
        auto const& t = i->second;
        return std::chrono::duration_cast<std::chrono::duration<double>>(t.second - t.first);
    }

    [[nodiscard]] std::size_t
    count(std::string const& tag) const
    {
        auto i = counts.find(tag);
        if (i == counts.end())
            return 0;
        return i->second;
    }

    // Time the duration of the existence of the result
    auto
    timeBlock(std::string name)
    {
        struct Stopper
        {
            std::string tag;
            FlowDebugInfo* info;
            Stopper(std::string name, FlowDebugInfo& pi) : tag(std::move(name)), info(&pi)
            {
                auto const start = FlowDebugInfo::clock::now();
                info->timePoints.emplace(tag, std::make_pair(start, start));
            }
            ~Stopper()
            {
                auto const end = FlowDebugInfo::clock::now();
                info->timePoints[tag].second = end;
            }
            Stopper(Stopper&&) = default;
        };
        return Stopper(std::move(name), *this);
    }

    void
    inc(std::string const& tag)
    {
        auto i = counts.find(tag);
        if (i == counts.end())
        {
            counts[tag] = 1;
        }
        ++i->second;
    }

    void
    setCount(std::string const& tag, std::size_t c)
    {
        counts[tag] = c;
    }

    [[nodiscard]] std::size_t
    passCount() const
    {
        return passInfo.size();
    }

    void
    pushPass(EitherAmount const& in, EitherAmount const& out, std::size_t activeStrands)
    {
        passInfo.pushBack(in, out, activeStrands);
    }

    void
    pushLiquiditySrc(EitherAmount const& in, EitherAmount const& out)
    {
        passInfo.pushLiquiditySrc(in, out);
    }

    void
    newLiquidityPass()
    {
        passInfo.newLiquidityPass();
    }

    [[nodiscard]] std::string
    toString(bool writePassInfo) const
    {
        std::ostringstream ostr;

        auto const d = duration("main");

        ostr << "duration: " << d.count() << ", pass_count: " << passCount();

        if (writePassInfo)
        {
            auto writeList = [&ostr](auto const& vals, auto&& fun, char delim = ';') {
                ostr << '[';
                if (!vals.empty())
                {
                    ostr << fun(vals[0]);
                    for (size_t i = 1, e = vals.size(); i < e; ++i)
                        ostr << delim << fun(vals[i]);
                }
                ostr << ']';
            };
            auto writeXrpAmtList = [&writeList](
                                       std::vector<EitherAmount> const& amts, char delim = ';') {
                auto getVal = [](EitherAmount const& a) -> std::string {
                    return xrpl::to_string(a.get<XRPAmount>());
                };
                writeList(amts, getVal, delim);
            };
            auto writeIouAmtList = [&writeList](
                                       std::vector<EitherAmount> const& amts, char delim = ';') {
                auto getVal = [](EitherAmount const& a) -> std::string {
                    return xrpl::to_string(a.get<IOUAmount>());
                };
                writeList(amts, getVal, delim);
            };
            auto writeIntList = [&writeList](std::vector<size_t> const& vals, char delim = ';') {
                // NOLINTNEXTLINE(bugprone-return-const-ref-from-parameter)
                auto getVal = [](size_t const& v) -> size_t const& { return v; };
                writeList(vals, getVal);
            };
            auto writeNestedIouAmtList =
                [&ostr, &writeIouAmtList](std::vector<std::vector<EitherAmount>> const& amts) {
                    ostr << '[';
                    if (!amts.empty())
                    {
                        writeIouAmtList(amts[0], '|');
                        for (size_t i = 1, e = amts.size(); i < e; ++i)
                        {
                            ostr << ';';
                            writeIouAmtList(amts[i], '|');
                        }
                    }
                    ostr << ']';
                };
            auto writeNestedXrpAmtList =
                [&ostr, &writeXrpAmtList](std::vector<std::vector<EitherAmount>> const& amts) {
                    ostr << '[';
                    if (!amts.empty())
                    {
                        writeXrpAmtList(amts[0], '|');
                        for (size_t i = 1, e = amts.size(); i < e; ++i)
                        {
                            ostr << ';';
                            writeXrpAmtList(amts[i], '|');
                        }
                    }
                    ostr << ']';
                };

            ostr << ", in_pass: ";
            if (passInfo.nativeIn)
            {
                writeXrpAmtList(passInfo.in);
            }
            else
            {
                writeIouAmtList(passInfo.in);
            }
            ostr << ", out_pass: ";
            if (passInfo.nativeOut)
            {
                writeXrpAmtList(passInfo.out);
            }
            else
            {
                writeIouAmtList(passInfo.out);
            }
            ostr << ", num_active: ";
            writeIntList(passInfo.numActive);
            if (!passInfo.liquiditySrcIn.empty() && !passInfo.liquiditySrcIn.back().empty())
            {
                ostr << ", l_src_in: ";
                if (passInfo.nativeIn)
                {
                    writeNestedXrpAmtList(passInfo.liquiditySrcIn);
                }
                else
                {
                    writeNestedIouAmtList(passInfo.liquiditySrcIn);
                }
                ostr << ", l_src_out: ";
                if (passInfo.nativeOut)
                {
                    writeNestedXrpAmtList(passInfo.liquiditySrcOut);
                }
                else
                {
                    writeNestedIouAmtList(passInfo.liquiditySrcOut);
                }
            }
        }

        return ostr.str();
    }
};

inline void
writeDiffElement(
    std::ostringstream& ostr,
    std::pair<std::tuple<AccountID, AccountID, Currency>, STAmount> const& elem)
{
    using namespace std;
    auto const k = elem.first;
    auto const v = elem.second;
    ostr << '[' << get<0>(k) << '|' << get<1>(k) << '|' << get<2>(k) << '|' << v << ']';
};

template <class Iter>
void
writeDiffs(std::ostringstream& ostr, Iter begin, Iter end)
{
    ostr << '[';
    if (begin != end)
    {
        writeDiffElement(ostr, *begin);
        ++begin;
    }
    for (; begin != end; ++begin)
    {
        ostr << ';';
        writeDiffElement(ostr, *begin);
    }
    ostr << ']';
};

}  // namespace xrpl::path::detail