ConsensusTypes.h

//------------------------------------------------------------------------------
/*
    This file is part of rippled: https://github.com/ripple/rippled
    Copyright (c) 2012-2017 Ripple Labs Inc.
 
    Permission to use, copy, modify, and/or distribute this software for any
    purpose  with  or without fee is hereby granted, provided that the above
    copyright notice and this permission notice appear in all copies.
 
    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
    ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
//==============================================================================
 
#ifndef RIPPLE_CONSENSUS_CONSENSUS_TYPES_H_INCLUDED
#define RIPPLE_CONSENSUS_CONSENSUS_TYPES_H_INCLUDED
 
#include <ripple/basics/chrono.h>
#include <ripple/consensus/DisputedTx.h>
#include <chrono>
#include <map>
 
namespace ripple {
 
enum class ConsensusMode {
    proposing,
    observing,
    wrongLedger,
    switchedLedger
};
 
inline std::string
to_string(ConsensusMode m)
{
    switch (m)
    {
        case ConsensusMode::proposing:
            return "proposing";
        case ConsensusMode::observing:
            return "observing";
        case ConsensusMode::wrongLedger:
            return "wrongLedger";
        case ConsensusMode::switchedLedger:
            return "switchedLedger";
        default:
            return "unknown";
    }
}
 
enum class ConsensusPhase {
    open,
 
    establish,
 
    accepted,
};
 
inline std::string
to_string(ConsensusPhase p)
{
    switch (p)
    {
        case ConsensusPhase::open:
            return "open";
        case ConsensusPhase::establish:
            return "establish";
        case ConsensusPhase::accepted:
            return "accepted";
        default:
            return "unknown";
    }
}
 
class ConsensusTimer
{
    using time_point = std::chrono::steady_clock::time_point;
    time_point start_;
    std::chrono::milliseconds dur_;
 
public:
    std::chrono::milliseconds
    read() const
    {
        return dur_;
    }
 
    void
    tick(std::chrono::milliseconds fixed)
    {
        dur_ += fixed;
    }
 
    void
    reset(time_point tp)
    {
        start_ = tp;
        dur_ = std::chrono::milliseconds{0};
    }
 
    void
    tick(time_point tp)
    {
        using namespace std::chrono;
        dur_ = duration_cast<milliseconds>(tp - start_);
    }
};
 
struct ConsensusCloseTimes
{
    explicit ConsensusCloseTimes() = default;
 
    std::map<NetClock::time_point, int> peers;
 
    NetClock::time_point self;
};
 
enum class ConsensusState {
    No,       
    MovedOn,  
    Yes       
};
 
template <class NodeID_t, class LedgerID_t, class Position_t, class Seq>
class ConsensusProposal;
template <class Traits>
struct ConsensusResult
{
    using Ledger_t = typename Traits::Ledger_t;
    using TxSet_t = typename Traits::TxSet_t;
    using NodeID_t = typename Traits::NodeID_t;
 
    using Tx_t = typename TxSet_t::Tx;
    using Proposal_t = ConsensusProposal<
        NodeID_t,
        typename Ledger_t::ID,
        typename TxSet_t::ID,
        typename Ledger_t::Seq>;
    using Dispute_t = DisputedTx<Tx_t, NodeID_t>;
 
    ConsensusResult(TxSet_t&& s, Proposal_t&& p)
        : txns{std::move(s)}, position{std::move(p)}
    {
        assert(txns.id() == position.position());
    }
 
    TxSet_t txns;
 
    Proposal_t position;
 
    hash_map<typename Tx_t::ID, Dispute_t> disputes;
 
    // Set of TxSet ids we have already compared/created disputes
    hash_set<typename TxSet_t::ID> compares;
 
    // Measures the duration of the establish phase for this consensus round
    ConsensusTimer roundTime;
 
    // Indicates state in which consensus ended.  Once in the accept phase
    // will be either Yes or MovedOn
    ConsensusState state = ConsensusState::No;
 
    // The number of peers proposing during the round
    std::size_t proposers = 0;
};
}  // namespace ripple
 
#endif