Tx.h

#pragma once
 
#include <xrpl/beast/hash/hash_append.h>
#include <xrpl/beast/hash/uhash.h>
 
#include <boost/container/flat_set.hpp>
#include <boost/iterator/function_output_iterator.hpp>
 
#include <algorithm>
#include <map>
#include <ostream>
#include <sstream>
#include <string>
#include <type_traits>
#include <utility>
 
namespace xrpl::test::csf {

class Tx
{
public:
    using ID = std::uint32_t;
 
    Tx(ID i) : id_{i}
    {
    }
 
    template <typename T, typename = std::enable_if_t<std::is_same_v<T, Tx>>>
    Tx(T const* t) : id_{t->id_}
    {
    }
 
    [[nodiscard]] ID const&
    id() const
    {
        return id_;
    }
 
    bool
    operator<(Tx const& o) const
    {
        return id_ < o.id_;
    }
 
    bool
    operator==(Tx const& o) const
    {
        return id_ == o.id_;
    }
 
private:
    ID id_;
};

using TxSetType = boost::container::flat_set<Tx>;

class TxSet
{
public:
    using ID = beast::Uhash<>::result_type;
    using Tx = csf::Tx;
 
    static ID
    calcID(TxSetType const& txs)
    {
        return beast::Uhash<>{}(txs);
    }
 
    class MutableTxSet
    {
        friend class TxSet;
 
        TxSetType txs_;
 
    public:
        MutableTxSet(TxSet const& s) : txs_{s.txs_}
        {
        }
 
        bool
        insert(Tx const& t)
        {
            return txs_.insert(t).second;
        }
 
        bool
        erase(Tx::ID const& txId)
        {
            return txs_.erase(Tx{txId}) > 0;
        }
    };
 
    TxSet() = default;
    TxSet(TxSetType s) : txs_{std::move(s)}, id_{calcID(txs_)}
    {
    }
 
    TxSet(MutableTxSet&& m)  // NOLINT(cppcoreguidelines-rvalue-reference-param-not-moved)
        : txs_{m.txs_}, id_{calcID(txs_)}
    {
    }
 
    [[nodiscard]] bool
    exists(Tx::ID const txId) const
    {
        auto it = txs_.find(Tx{txId});
        return it != txs_.end();
    }
 
    [[nodiscard]] Tx const*
    find(Tx::ID const& txId) const
    {
        auto it = txs_.find(Tx{txId});
        if (it != txs_.end())
            return &(*it);
        return nullptr;
    }
 
    [[nodiscard]] TxSetType const&
    txs() const
    {
        return txs_;
    }
 
    [[nodiscard]] ID
    id() const
    {
        return id_;
    }

    [[nodiscard]] std::map<Tx::ID, bool>
    compare(TxSet const& other) const
    {
        std::map<Tx::ID, bool> res;
 
        auto populateDiffs = [&res](auto const& a, auto const& b, bool s) {
            auto populator = [&](auto const& tx) { res[tx.id()] = s; };
            std::set_difference(
                a.begin(),
                a.end(),
                b.begin(),
                b.end(),
                boost::make_function_output_iterator(std::ref(populator)));
        };
 
        populateDiffs(txs_, other.txs_, true);
        populateDiffs(other.txs_, txs_, false);
        return res;
    }
 
private:
    TxSetType txs_;

    ID id_{};
};
 
//------------------------------------------------------------------------------
// Helper functions for debug printing
 
inline std::ostream&
operator<<(std::ostream& o, Tx const& t)
{
    return o << t.id();
}
 
template <class T>
inline std::ostream&
operator<<(std::ostream& o, boost::container::flat_set<T> const& ts)
{
    o << "{ ";
    bool doComma = false;
    for (auto const& t : ts)
    {
        if (doComma)
        {
            o << ", ";
        }
        else
        {
            doComma = true;
        }
        o << t;
    }
    o << " }";
    return o;
}
 
inline std::string
to_string(TxSetType const& txs)
{
    std::stringstream ss;
    ss << txs;
    return ss.str();
}
 
template <class Hasher>
inline void
hash_append(Hasher& h, Tx const& tx)
{
    using beast::hash_append;
    hash_append(h, tx.id());
}
 
}  // namespace xrpl::test::csf