path: root/src/core.cpp

#include <stack>
#include "core.h"

using salticidae::DataStream;
using salticidae::static_pointer_cast;
using salticidae::get_hash;

#define LOG_INFO HOTSTUFF_LOG_INFO
#define LOG_DEBUG HOTSTUFF_LOG_DEBUG
#define LOG_WARN HOTSTUFF_LOG_WARN

namespace hotstuff {

void MsgHotStuff::gen_propose(const Proposal &proposal) {
    DataStream s;
    set_opcode(PROPOSE);
    s << proposal;
    set_payload(std::move(s));
}

void MsgHotStuff::parse_propose(Proposal &proposal) const {
    DataStream(get_payload()) >> proposal;
}

void MsgHotStuff::gen_vote(const Vote &vote) {
    DataStream s;
    set_opcode(VOTE);
    s << vote;
    set_payload(std::move(s));
}

void MsgHotStuff::parse_vote(Vote &vote) const {
    DataStream(get_payload()) >> vote;
}

void MsgHotStuff::gen_qfetchblk(const std::vector<uint256_t> &blk_hashes) {
    DataStream s;
    set_opcode(QUERY_FETCH_BLK);
    gen_hash_list(s, blk_hashes);
    set_payload(std::move(s));
}

void MsgHotStuff::parse_qfetchblk(std::vector<uint256_t> &blk_hashes) const {
    DataStream s(get_payload());
    parse_hash_list(s, blk_hashes);
}

void MsgHotStuff::gen_rfetchblk(const std::vector<block_t> &blks) {
    DataStream s;
    set_opcode(RESP_FETCH_BLK);
    s << htole((uint32_t)blks.size());
    for (auto blk: blks) s << *blk;
    set_payload(std::move(s));
}

void MsgHotStuff::parse_rfetchblk(std::vector<block_t> &blks, HotStuffCore *hsc) const {
    DataStream s;
    uint32_t size;
    s >> size;
    size = letoh(size);
    blks.resize(size);
    for (auto &blk: blks)
    {
        Block _blk;
        _blk.unserialize(s, hsc);
        if (!_blk.verify(hsc->get_config()))
            blk = hsc->storage->add_blk(std::move(_blk));
        else
        {
            blk = nullptr;
            LOG_WARN("block is invalid");
        }
    }
}

/* The core logic of HotStuff, is farily simple :) */
/*** begin HotStuff protocol logic ***/
HotStuffCore::HotStuffCore(ReplicaID id,
                            privkey_bt &&priv_key,
                            int32_t parent_limit):
        b0(new Block(true, 1)),
        bqc(b0),
        bexec(b0),
        vheight(0),
        priv_key(std::move(priv_key)),
        tails{bqc},
        id(id),
        parent_limit(parent_limit),
        storage(new EntityStorage()) {
    storage->add_blk(b0);
    b0->qc_ref = b0;
}

void HotStuffCore::sanity_check_delivered(const block_t &blk) {
    if (!blk->delivered)
        throw std::runtime_error("block not delivered");
}

block_t HotStuffCore::sanity_check_delivered(const uint256_t &blk_hash) {
    block_t blk = storage->find_blk(blk_hash);
    if (blk == nullptr || !blk->delivered)
        throw std::runtime_error("block not delivered");
    return std::move(blk);
}

bool HotStuffCore::on_deliver_blk(const block_t &blk) {
    if (blk->delivered)
    {
        LOG_WARN("attempt to deliver a block twice");
        return false;
    }
    blk->parents.clear();
    for (const auto &hash: blk->parent_hashes)
    {
        block_t p = sanity_check_delivered(hash);
        blk->parents.push_back(p);
    }
    blk->height = blk->parents[0]->height + 1;
    for (const auto &cmd: blk->cmds)
        cmd->container = blk;

    if (blk->qc)
    {
        block_t _blk = storage->find_blk(blk->qc->get_blk_hash());
        if (_blk == nullptr)
            throw std::runtime_error("block referred by qc not fetched");
        blk->qc_ref = std::move(_blk);
    } // otherwise blk->qc_ref remains null

    for (auto pblk: blk->parents) tails.erase(pblk);
    tails.insert(blk);

    blk->delivered = true;
    LOG_DEBUG("delivered %.10s", get_hex(blk->get_hash()).c_str());
    return true;
}

void HotStuffCore::check_commit(const block_t &_blk) {
    const block_t &blk = _blk->qc_ref;
    if (blk->qc_ref == nullptr) return;
    if (blk->decision) return;
    block_t p = blk->parents[0];
    if (p == blk->qc_ref)
    { /* commit */
        std::vector<block_t> commit_queue;
        block_t b;
        for (b = p; b->height > bexec->height; b = b->parents[0])
        { /* todo: also commit the uncles/aunts */
            commit_queue.push_back(b);
        }
        if (b != bexec)
            throw std::runtime_error("safety breached :(");
        for (auto it = commit_queue.rbegin(); it != commit_queue.rend(); it++)
        {
            const block_t &blk = *it;
            blk->decision = 1;
#ifdef HOTSTUFF_ENABLE_LOG_PROTO
            LOG_INFO("commit blk %.10s", get_hex10(blk->get_hash()).c_str());
#endif
            for (auto cmd: blk->cmds)
                do_decide(cmd);
        }
        bexec = p;
    }
}

bool HotStuffCore::update(const uint256_t &bqc_hash) {
    block_t _bqc = sanity_check_delivered(bqc_hash);
    if (_bqc->qc_ref == nullptr) return false;
    check_commit(_bqc);
    if (_bqc->qc_ref->height > bqc->qc_ref->height)
        bqc = _bqc;
    return true;
}

void HotStuffCore::on_propose(const std::vector<command_t> &cmds) {
    size_t nparents = parent_limit < 1 ? tails.size() : parent_limit;
    assert(tails.size() > 0);
    block_t p = *tails.rbegin();
    std::vector<block_t> parents{p};
    tails.erase(p);
    nparents--;
    /* add the rest of tails as "uncles/aunts" */
    while (nparents--)
    {
        auto it = tails.begin();
        parents.push_back(*it);
        tails.erase(it);
    }
    quorum_cert_bt qc = nullptr;
    block_t qc_ref = nullptr;
    if (p != b0 && p->voted.size() >= config.nmajority)
    {
        qc = p->self_qc->clone();
        qc->compute();
        qc_ref = p;
    }
    /* create a new block */
    block_t bnew = storage->add_blk(
        Block(
            parents,
            cmds,
            p->height + 1,
            std::move(qc), qc_ref,
            nullptr
        ));
    const uint256_t bnew_hash = bnew->get_hash();
    bnew->self_qc = create_quorum_cert(bnew_hash);
    on_deliver_blk(bnew);
    update(bnew_hash);
    Proposal prop(id, bqc->get_hash(), bnew, nullptr);
#ifdef HOTSTUFF_ENABLE_LOG_PROTO
    LOG_INFO("propose %s", std::string(*bnew).c_str());
#endif
    /* self-vote */
    on_receive_vote(
        Vote(id, bqc->get_hash(), bnew_hash,
            create_part_cert(*priv_key, bnew_hash), this));
    on_propose_(bnew);
    /* boradcast to other replicas */
    do_broadcast_proposal(prop);
}

void HotStuffCore::on_receive_proposal(const Proposal &prop) {
    if (!update(prop.bqc_hash)) return;
#ifdef HOTSTUFF_ENABLE_LOG_PROTO
    LOG_INFO("got %s", std::string(prop).c_str());
#endif
    block_t bnew = prop.blk;
    sanity_check_delivered(bnew);
    bool opinion = false;
    if (bnew->height > vheight)
    {
        block_t pref = bqc->qc_ref;
        block_t b;
        for (b = bnew;
            b->height > pref->height;
            b = b->parents[0]);
        opinion = b == pref;
        vheight = bnew->height;
    }
#ifdef HOTSTUFF_ENABLE_LOG_PROTO
    LOG_INFO("now state: %s", std::string(*this).c_str());
#endif
    do_vote(prop.proposer,
        Vote(id,
            bqc->get_hash(),
            bnew->get_hash(),
            (opinion ?
                create_part_cert(*priv_key, bnew->get_hash()) :
                nullptr),
            nullptr));
}

void HotStuffCore::on_receive_vote(const Vote &vote) {
    if (!update(vote.bqc_hash)) return;
#ifdef HOTSTUFF_ENABLE_LOG_PROTO
    LOG_INFO("got %s", std::string(vote).c_str());
    LOG_INFO("now state: %s", std::string(*this).c_str());
#endif

    block_t blk = sanity_check_delivered(vote.blk_hash);
    if (vote.cert == nullptr) return;
    if (!vote.verify())
    {
        LOG_WARN("invalid vote");
        return;
    }
    if (!blk->voted.insert(vote.voter).second)
    {
        LOG_WARN("duplicate votes");
        return;
    }
    size_t qsize = blk->voted.size();
    if (qsize <= config.nmajority)
    {
        blk->self_qc->add_part(vote.voter, *vote.cert);
        if (qsize == config.nmajority)
            on_qc_finish(blk);
    }
}
/*** end HotStuff protocol logic ***/

void HotStuffCore::prune(uint32_t staleness) {
    block_t start;
    /* skip the blocks */
    for (start = bexec; staleness; staleness--, start = start->parents[0])
        if (!start->parents.size()) return;
    std::stack<block_t> s;
    start->qc_ref = nullptr;
    s.push(start);
    while (!s.empty())
    {
        auto &blk = s.top();
        if (blk->parents.empty())
        {
            storage->try_release_blk(blk);
            s.pop();
            continue;
        }
        blk->qc_ref = nullptr;
        s.push(blk->parents.back());
        blk->parents.pop_back();
    }
}

int8_t HotStuffCore::get_cmd_decision(const uint256_t &cmd_hash) {
    auto cmd = storage->find_cmd(cmd_hash);
    return cmd != nullptr ? cmd->get_decision() : 0;
}

void HotStuffCore::add_replica(ReplicaID rid, const NetAddr &addr,
                                pubkey_bt &&pub_key) {
    config.add_replica(rid, 
            ReplicaInfo(rid, addr, std::move(pub_key)));
    b0->voted.insert(rid);
}

promise_t HotStuffCore::async_qc_finish(const block_t &blk) {
    if (blk->voted.size() >= config.nmajority)
        return promise_t([](promise_t &pm) {
            pm.resolve();
        });
    auto it = qc_waiting.find(blk);
    if (it == qc_waiting.end())
        it = qc_waiting.insert(std::make_pair(blk, promise_t())).first;
    return it->second;
}

void HotStuffCore::on_qc_finish(const block_t &blk) {
    auto it = qc_waiting.find(blk);
    if (it != qc_waiting.end())
    {
        it->second.resolve();
        qc_waiting.erase(it);
    }
}

promise_t HotStuffCore::async_wait_propose() {
    return propose_waiting;
}

void HotStuffCore::on_propose_(const block_t &blk) {
    auto t = std::move(propose_waiting);
    propose_waiting = promise_t();
    t.resolve(blk);
}

HotStuffCore::operator std::string () const {
    DataStream s;
    s << "<hotstuff "
      << "bqc=" << get_hex10(bqc->get_hash()) << " "
      << "bexec=" << get_hex10(bqc->get_hash()) << " "
      << "vheight=" << std::to_string(vheight) << " "
      << "tails=" << std::to_string(tails.size()) << ">";
    return std::string(std::move(s));
}

void HotStuffBase::add_replica(ReplicaID idx, const NetAddr &addr,
                                pubkey_bt &&pub_key) {
    HotStuffCore::add_replica(idx, addr, std::move(pub_key));
    if (addr != listen_addr)
        pn.add_peer(addr);
}

void HotStuffBase::on_fetch_blk(const block_t &blk) {
#ifdef HOTSTUFF_ENABLE_TX_PROFILE
    blk_profiler.get_tx(blk->get_hash());
#endif
    LOG_DEBUG("fetched %.10s", get_hex(blk->get_hash()).c_str());
    part_fetched++;
    fetched++;
    for (auto cmd: blk->get_cmds()) on_fetch_cmd(cmd);
    const uint256_t &blk_hash = blk->get_hash();
    auto it = blk_fetch_waiting.find(blk_hash);
    if (it != blk_fetch_waiting.end())
    {
        it->second.resolve(blk);
        blk_fetch_waiting.erase(it);
    }
}

void HotStuffBase::on_fetch_cmd(const command_t &cmd) {
    const uint256_t &cmd_hash = cmd->get_hash();
    auto it = cmd_fetch_waiting.find(cmd_hash);
    if (it != cmd_fetch_waiting.end())
    {
        it->second.resolve(cmd);
        cmd_fetch_waiting.erase(it);
    }
}

void HotStuffBase::on_deliver_blk(const block_t &blk) {
    const uint256_t &blk_hash = blk->get_hash();
    bool valid;
    /* sanity check: all parents must be delivered */
    for (const auto &p: blk->get_parent_hashes())
        assert(storage->is_blk_delivered(p));
    if ((valid = HotStuffCore::on_deliver_blk(blk)))
    {
        LOG_DEBUG("block %.10s delivered",
                get_hex(blk_hash).c_str());
        part_parent_size += blk->get_parent_hashes().size();
        part_delivered++;
        delivered++;
    }
    else
    {
        LOG_WARN("dropping invalid block");
    }

    auto it = blk_delivery_waiting.find(blk_hash);
    if (it != blk_delivery_waiting.end())
    {
        auto &pm = it->second;
        if (valid)
        {
            pm.elapsed.stop(false);
            auto sec = pm.elapsed.elapsed_sec;
            part_delivery_time += sec;
            part_delivery_time_min = std::min(part_delivery_time_min, sec);
            part_delivery_time_max = std::max(part_delivery_time_max, sec);

            pm.resolve(blk);
        }
        else
        {
            pm.reject(blk);
            // TODO: do we need to also free it from storage?
        }
        blk_delivery_waiting.erase(it);
    }
}

promise_t HotStuffBase::async_fetch_blk(const uint256_t &blk_hash,
                                        const NetAddr *replica_id,
                                        bool fetch_now) {
    if (storage->is_blk_fetched(blk_hash))
        return promise_t([this, &blk_hash](promise_t pm){
            pm.resolve(storage->find_blk(blk_hash));
        });
    auto it = blk_fetch_waiting.find(blk_hash);
    if (it == blk_fetch_waiting.end())
    {
#ifdef HOTSTUFF_ENABLE_TX_PROFILE
        blk_profiler.rec_tx(blk_hash, false);
#endif
        it = blk_fetch_waiting.insert(
            std::make_pair(
                blk_hash,
                BlockFetchContext(blk_hash, this))).first;
    }
    if (replica_id != nullptr)
        it->second.add_replica(*replica_id, fetch_now);
    return static_cast<promise_t &>(it->second);
}

promise_t HotStuffBase::async_fetch_cmd(const uint256_t &cmd_hash,
                                    const NetAddr *replica_id,
                                    bool fetch_now) {
    if (storage->is_cmd_fetched(cmd_hash))
        return promise_t([this, &cmd_hash](promise_t pm){
            pm.resolve(storage->find_cmd(cmd_hash));
        });
    auto it = cmd_fetch_waiting.find(cmd_hash);
    if (it == cmd_fetch_waiting.end())
    {
        it = cmd_fetch_waiting.insert(
            std::make_pair(cmd_hash, CmdFetchContext(cmd_hash, this))).first;
    }
    if (replica_id != nullptr)
        it->second.add_replica(*replica_id, fetch_now);
    return static_cast<promise_t &>(it->second);
}

promise_t HotStuffBase::async_deliver_blk(const uint256_t &blk_hash,
                                        const NetAddr &replica_id) {
    if (storage->is_blk_delivered(blk_hash))
        return promise_t([this, &blk_hash](promise_t pm) {
            pm.resolve(storage->find_blk(blk_hash));
        });
    auto it = blk_delivery_waiting.find(blk_hash);
    if (it != blk_delivery_waiting.end())
        return static_cast<promise_t &>(it->second);
    BlockDeliveryContext pm{[](promise_t){}};
    it = blk_delivery_waiting.insert(std::make_pair(blk_hash, pm)).first;
    /* otherwise the on_deliver_batch will resolve */
    async_fetch_blk(blk_hash, &replica_id).then([this, replica_id](block_t blk) {
        /* qc_ref should be fetched */
        std::vector<promise_t> pms;
        const auto &qc = blk->get_qc();
        if (qc)
            pms.push_back(async_fetch_blk(qc->get_blk_hash(), &replica_id));
        /* the parents should be delivered */
        for (const auto &phash: blk->get_parent_hashes())
            pms.push_back(async_deliver_blk(phash, replica_id));
        promise::all(pms).then([this, blk]() {
            on_deliver_blk(blk);
        });
    });
    return static_cast<promise_t &>(pm);
}

void HotStuffBase::propose_handler(const MsgHotStuff &msg, conn_t conn_) {
    auto conn = static_pointer_cast<PeerNetwork<MsgHotStuff>::Conn>(conn_);
    const NetAddr &peer = conn->get_peer();
    Proposal prop(this);
    msg.parse_propose(prop);
    block_t blk = prop.blk;
    promise::all(std::vector<promise_t>{
        async_deliver_blk(prop.bqc_hash, peer),
        async_deliver_blk(blk->get_hash(), peer),
    }).then([this, prop = std::move(prop)]() {
        on_receive_proposal(prop);
    });
}

void HotStuffBase::vote_handler(const MsgHotStuff &msg, conn_t conn_) {
    auto conn = static_pointer_cast<PeerNetwork<MsgHotStuff>::Conn>(conn_);
    const NetAddr &peer = conn->get_peer();
    Vote vote(this);
    msg.parse_vote(vote);
    promise::all(std::vector<promise_t>{
        async_deliver_blk(vote.bqc_hash, peer),
        async_deliver_blk(vote.blk_hash, peer)
    }).then([this, vote = std::move(vote)]() {
        on_receive_vote(vote);
    });
}

void HotStuffBase::query_fetch_blk_handler(const MsgHotStuff &msg, conn_t conn_) {
    auto conn = static_pointer_cast<PeerNetwork<MsgHotStuff>::Conn>(conn_);
    const NetAddr replica = conn->get_peer();
    std::vector<uint256_t> blk_hashes;
    msg.parse_qfetchblk(blk_hashes);

    std::vector<promise_t> pms;
    for (const auto &h: blk_hashes)
        pms.push_back(async_fetch_blk(h, nullptr));
    promise::all(pms).then([replica, this](const promise::values_t values) {
        MsgHotStuff resp;
        std::vector<block_t> blks;
        for (auto &v: values)
        {
            auto blk = promise::any_cast<block_t>(v);
            blks.push_back(blk);
        }
        resp.gen_rfetchblk(blks);
        pn.send_msg(resp, replica);
    });
}

void HotStuffBase::resp_fetch_blk_handler(const MsgHotStuff &msg, conn_t) {
    std::vector<block_t> blks;
    msg.parse_rfetchblk(blks, this);
    for (const auto &blk: blks)
        if (blk) on_fetch_blk(blk);
}

void HotStuffBase::print_stat() const {
    LOG_INFO("===== begin stats =====");
    LOG_INFO("-------- queues -------");
    LOG_INFO("blk_fetch_waiting: %lu", blk_fetch_waiting.size());
    LOG_INFO("blk_delivery_waiting: %lu", blk_delivery_waiting.size());
    LOG_INFO("cmd_fetch_waiting: %lu", cmd_fetch_waiting.size());
    LOG_INFO("decision_waiting: %lu", decision_waiting.size());
    LOG_INFO("-------- misc ---------");
    LOG_INFO("fetched: %lu", fetched);
    LOG_INFO("delivered: %lu", delivered);
    LOG_INFO("cmd_cache: %lu", storage->get_cmd_cache_size());
    LOG_INFO("blk_cache: %lu", storage->get_blk_cache_size());
    LOG_INFO("------ misc (10s) -----");
    LOG_INFO("fetched: %lu", part_fetched);
    LOG_INFO("delivered: %lu", part_delivered);
    LOG_INFO("decided: %lu", part_decided);
    LOG_INFO("gened: %lu", part_gened);
    LOG_INFO("avg. parent_size: %.3f",
            part_delivered ? part_parent_size / double(part_delivered) : 0);
    LOG_INFO("delivery time: %.3f avg, %.3f min, %.3f max",
            part_delivered ? part_delivery_time / double(part_delivered) : 0,
            part_delivery_time_min == double_inf ? 0 : part_delivery_time_min,
            part_delivery_time_max);

    part_parent_size = 0;
    part_fetched = 0;
    part_delivered = 0;
    part_decided = 0;
    part_gened = 0;
    part_delivery_time = 0;
    part_delivery_time_min = double_inf;
    part_delivery_time_max = 0;
    LOG_INFO("-- sent opcode (10s) --");
    auto &sent_op = pn.get_sent_by_opcode();
    for (auto &op: sent_op)
    {
        auto &val = op.second;
        LOG_INFO("%02x: %lu, %.2fBpm", op.first,
                val.first, val.first ? val.second / double(val.first) : 0);
        val.first = val.second = 0;
    }
    LOG_INFO("-- recv opcode (10s) --");
    auto &recv_op = pn.get_recv_by_opcode();
    for (auto &op: recv_op)
    {
        auto &val = op.second;
        LOG_INFO("%02x: %lu, %.2fBpm", op.first,
                val.first, val.first ? val.second / double(val.first) : 0);
        val.first = val.second = 0;
    }
    LOG_INFO("--- replica msg. (10s) ---");
    size_t _nsent = 0;
    size_t _nrecv = 0;
    for (const auto &replica: pn.all_peers())
    {
        auto conn = pn.get_peer_conn(replica);
        size_t ns = conn->get_nsent();
        size_t nr = conn->get_nrecv();
        conn->clear_nsent();
        conn->clear_nrecv();
        LOG_INFO("%s: %u, %u, %u",
            std::string(replica).c_str(), ns, nr, part_fetched_replica[replica]);
        _nsent += ns;
        _nrecv += nr;
        part_fetched_replica[replica] = 0;
    }
    nsent += _nsent;
    nrecv += _nrecv;
    LOG_INFO("sent: %lu", _nsent);
    LOG_INFO("recv: %lu", _nrecv);
    LOG_INFO("--- replica msg. total ---");
    LOG_INFO("sent: %lu", nsent);
    LOG_INFO("recv: %lu", nrecv);
    LOG_INFO("====== end stats ======");
}

promise_t HotStuffBase::async_decide(const uint256_t &cmd_hash) {
    if (get_cmd_decision(cmd_hash))
        return promise_t([this, cmd_hash](promise_t pm){
            pm.resolve(storage->find_cmd(cmd_hash));
        });
    /* otherwise the do_decide will resolve the promise */
    auto it = decision_waiting.find(cmd_hash);
    if (it == decision_waiting.end())
    {
        promise_t pm{[](promise_t){}};
        it = decision_waiting.insert(std::make_pair(cmd_hash, pm)).first;
    }
    return it->second;
}

HotStuffBase::HotStuffBase(uint32_t blk_size,
                    int32_t parent_limit,
                    ReplicaID rid,
                    privkey_bt &&priv_key,
                    NetAddr listen_addr,
                    EventContext eb,
                    pacemaker_bt pmaker):
        HotStuffCore(rid, std::move(priv_key), parent_limit),
        listen_addr(listen_addr),
        blk_size(blk_size),
        eb(eb),
        pmaker(std::move(pmaker)),
        pn(eb),

        fetched(0), delivered(0),
        nsent(0), nrecv(0),
        part_parent_size(0),
        part_fetched(0),
        part_delivered(0),
        part_decided(0),
        part_gened(0),
        part_delivery_time(0),
        part_delivery_time_min(double_inf),
        part_delivery_time_max(0)
{
    if (pmaker == nullptr)
        this->pmaker = new PaceMakerDummy(this);
    /* register the handlers for msg from replicas */
    pn.reg_handler(PROPOSE, std::bind(&HotStuffBase::propose_handler, this, _1, _2));
    pn.reg_handler(VOTE, std::bind(&HotStuffBase::vote_handler, this, _1, _2));
    pn.reg_handler(QUERY_FETCH_BLK, std::bind(&HotStuffBase::query_fetch_blk_handler, this, _1, _2));
    pn.reg_handler(RESP_FETCH_BLK, std::bind(&HotStuffBase::resp_fetch_blk_handler, this, _1, _2));
    pn.init(listen_addr);
}

void HotStuffBase::do_broadcast_proposal(const Proposal &prop) {
    MsgHotStuff prop_msg;
    prop_msg.gen_propose(prop);
    for (const auto &replica: pn.all_peers())
        pn.send_msg(prop_msg, replica);
}

void HotStuffBase::do_vote(ReplicaID last_proposer, const Vote &vote) {
    MsgHotStuff vote_msg;
    vote_msg.gen_vote(vote);
    pmaker->next_proposer(last_proposer)
            .then([this, vote_msg](ReplicaID proposer) {
        pn.send_msg(vote_msg, get_config().get_addr(proposer));
    });
}

void HotStuffBase::do_decide(const command_t &cmd) {
    auto it = decision_waiting.find(cmd->get_hash());
    if (it != decision_waiting.end())
    {
        it->second.resolve(cmd);
        decision_waiting.erase(it);
    }
}

HotStuffBase::~HotStuffBase() {}

void HotStuffBase::start(bool eb_loop) {
    /* ((n - 1) + 1 - 1) / 3 */
    uint32_t nfaulty = pn.all_peers().size() / 3;
    if (nfaulty == 0)
        LOG_WARN("too few replicas in the system to tolerate any failure");
    on_init(nfaulty);
    if (eb_loop)
        eb.dispatch();
}

}