clean up consensus code

5 files changed, 78 insertions, 99 deletions

diff --git a/include/hotstuff/consensus.h b/include/hotstuff/consensus.h
index 5f781c5..a59c02f 100644
--- a/include/hotstuff/consensus.h
+++ b/include/hotstuff/consensus.h
@@ -38,7 +38,7 @@ class HotStuffCore {
     block_t b0;                                  /** the genesis block */
     /* === state variables === */
     /** block containing the QC for the highest block having one */
-    block_t bqc;
+    std::pair<block_t, quorum_cert_bt> hqc;
     block_t bexec;                            /**< last executed block */
     uint32_t vheight;          /**< height of the block last voted for */
     /* === auxilliary variables === */
@@ -49,16 +49,16 @@ class HotStuffCore {
     std::unordered_map<block_t, promise_t> qc_waiting;
     promise_t propose_waiting;
     promise_t receive_proposal_waiting;
-    promise_t bqc_update_waiting;
+    promise_t hqc_update_waiting;
     /* == feature switches == */
     /** always vote negatively, useful for some PaceMakers */
     bool neg_vote;
 
     block_t get_delivered_blk(const uint256_t &blk_hash);
     void sanity_check_delivered(const block_t &blk);
-    void check_commit(const block_t &_bqc);
-    bool update(const uint256_t &bqc_hash);
-    void on_bqc_update();
+    void update(const block_t &nblk);
+    void update_hqc(const block_t &_hqc, const quorum_cert_bt &qc);
+    void on_hqc_update();
     void on_qc_finish(const block_t &blk);
     void on_propose_(const Proposal &prop);
     void on_receive_proposal_(const Proposal &prop);
@@ -152,12 +152,12 @@ class HotStuffCore {
     promise_t async_wait_proposal();
     /** Get a promise resolved when a new proposal is received. */
     promise_t async_wait_receive_proposal();
-    /** Get a promise resolved when bqc is updated. */
-    promise_t async_bqc_update();
+    /** Get a promise resolved when hqc is updated. */
+    promise_t async_hqc_update();
 
     /* Other useful functions */
     const block_t &get_genesis() { return b0; }
-    const block_t &get_bqc() { return bqc; }
+    const block_t &get_hqc() { return hqc.first; }
     const ReplicaConfig &get_config() { return config; }
     ReplicaID get_id() const { return id; }
     const std::set<block_t, BlockHeightCmp> get_tails() const { return tails; }
@@ -168,34 +168,27 @@ class HotStuffCore {
 /** Abstraction for proposal messages. */
 struct Proposal: public Serializable {
     ReplicaID proposer;
-    /** hash for the block containing the highest QC */
-    uint256_t bqc_hash;
     /** block being proposed */
     block_t blk;
-
     /** handle of the core object to allow polymorphism. The user should use
      * a pointer to the object of the class derived from HotStuffCore */
     HotStuffCore *hsc;
 
     Proposal(): blk(nullptr), hsc(nullptr) {}
     Proposal(ReplicaID proposer,
-            const uint256_t &bqc_hash,
             const block_t &blk,
             HotStuffCore *hsc):
         proposer(proposer),
-        bqc_hash(bqc_hash),
         blk(blk), hsc(hsc) {}
 
     void serialize(DataStream &s) const override {
         s << proposer
-          << bqc_hash
           << *blk;
     }
 
     void unserialize(DataStream &s) override {
         assert(hsc != nullptr);
-        s >> proposer
-          >> bqc_hash;
+        s >> proposer;
         Block _blk;
         _blk.unserialize(s, hsc);
         blk = hsc->storage->add_blk(std::move(_blk), hsc->get_config());
@@ -205,7 +198,6 @@ struct Proposal: public Serializable {
         DataStream s;
         s << "<proposal "
           << "rid=" << std::to_string(proposer) << " "
-          << "bqc=" << get_hex10(bqc_hash) << " "
           << "blk=" << get_hex10(blk->get_hash()) << ">";
         return std::move(s);
     }
@@ -214,11 +206,9 @@ struct Proposal: public Serializable {
 /** Abstraction for vote messages. */
 struct Vote: public Serializable {
     ReplicaID voter;
-    /** hash for the block containing the highest QC */
-    uint256_t bqc_hash;
     /** block being voted */
     uint256_t blk_hash;
-    /** proof of validity for the vote (nullptr for a negative vote) */
+    /** proof of validity for the vote */
     part_cert_bt cert;
     
     /** handle of the core object to allow polymorphism */
@@ -226,18 +216,15 @@ struct Vote: public Serializable {
 
     Vote(): cert(nullptr), hsc(nullptr) {}
     Vote(ReplicaID voter,
-        const uint256_t &bqc_hash,
         const uint256_t &blk_hash,
         part_cert_bt &&cert,
         HotStuffCore *hsc):
         voter(voter),
-        bqc_hash(bqc_hash),
         blk_hash(blk_hash),
         cert(std::move(cert)), hsc(hsc) {}
 
     Vote(const Vote &other):
         voter(other.voter),
-        bqc_hash(other.bqc_hash),
         blk_hash(other.blk_hash),
         cert(other.cert ? other.cert->clone() : nullptr),
         hsc(other.hsc) {}
@@ -245,23 +232,13 @@ struct Vote: public Serializable {
     Vote(Vote &&other) = default;
     
     void serialize(DataStream &s) const override {
-        s << voter
-          << bqc_hash
-          << blk_hash;
-        if (cert == nullptr)
-            s << (uint8_t)0;
-        else
-            s << (uint8_t)1 << *cert;
+        s << voter << blk_hash << *cert;
     }
 
     void unserialize(DataStream &s) override {
         assert(hsc != nullptr);
-        uint8_t has_cert;
-        s >> voter
-          >> bqc_hash
-          >> blk_hash
-          >> has_cert;
-        cert = has_cert ? hsc->parse_part_cert(s) : nullptr;
+        s >> voter >> blk_hash;
+        cert = hsc->parse_part_cert(s);
     }
 
     bool verify() const {
@@ -281,9 +258,7 @@ struct Vote: public Serializable {
         DataStream s;
         s << "<vote "
           << "rid=" << std::to_string(voter) << " "
-          << "bqc=" << get_hex10(bqc_hash) << " "
-          << "blk=" << get_hex10(blk_hash) << " "
-          << "cert=" << (cert ? "yes" : "no") << ">";
+          << "blk=" << get_hex10(blk_hash) << ">";
         return std::move(s);
     }
 };
diff --git a/include/hotstuff/liveness.h b/include/hotstuff/liveness.h
index 903ac83..6d3c3cf 100644
--- a/include/hotstuff/liveness.h
+++ b/include/hotstuff/liveness.h
@@ -60,42 +60,42 @@ using pacemaker_bt = BoxObj<PaceMaker>;
  * direct parent, while including other tail blocks (up to parent_limit) as
  * uncles/aunts. */
 class PMAllParents: public virtual PaceMaker {
-    block_t bqc_tail;
+    block_t hqc_tail;
     const int32_t parent_limit;         /**< maximum number of parents */
     
-    void reg_bqc_update() {
-        hsc->async_bqc_update().then([this](const block_t &bqc) {
-            const auto &pref = bqc->get_qc_ref();
+    void reg_hqc_update() {
+        hsc->async_hqc_update().then([this](const block_t &hqc) {
+            const auto &pref = hqc;
             for (const auto &blk: hsc->get_tails())
             {
                 block_t b;
                 for (b = blk;
                     b->get_height() > pref->get_height();
                     b = b->get_parents()[0]);
-                if (b == pref && blk->get_height() > bqc_tail->get_height())
-                    bqc_tail = blk;
+                if (b == pref && blk->get_height() > hqc_tail->get_height())
+                    hqc_tail = blk;
             }
-            reg_bqc_update();
+            reg_hqc_update();
         });
     }
 
     void reg_proposal() {
         hsc->async_wait_proposal().then([this](const Proposal &prop) {
-            bqc_tail = prop.blk;
+            hqc_tail = prop.blk;
             reg_proposal();
         });
     }
 
     void reg_receive_proposal() {
         hsc->async_wait_receive_proposal().then([this](const Proposal &prop) {
-            const auto &pref = hsc->get_bqc()->get_qc_ref();
+            const auto &pref = hsc->get_hqc();
             const auto &blk = prop.blk;
             block_t b;
             for (b = blk;
                 b->get_height() > pref->get_height();
                 b = b->get_parents()[0]);
-            if (b == pref && blk->get_height() > bqc_tail->get_height())
-                bqc_tail = blk;
+            if (b == pref && blk->get_height() > hqc_tail->get_height())
+                hqc_tail = blk;
             reg_receive_proposal();
         });
     }
@@ -103,15 +103,15 @@ class PMAllParents: public virtual PaceMaker {
     public:
     PMAllParents(int32_t parent_limit): parent_limit(parent_limit) {}
     void init() {
-        bqc_tail = hsc->get_genesis();
-        reg_bqc_update();
+        hqc_tail = hsc->get_genesis();
+        reg_hqc_update();
         reg_proposal();
         reg_receive_proposal();
     }
 
     std::vector<block_t> get_parents() override {
         const auto &tails = hsc->get_tails();
-        std::vector<block_t> parents{bqc_tail};
+        std::vector<block_t> parents{hqc_tail};
         auto nparents = tails.size();
         if (parent_limit > 0)
             nparents = std::min(nparents, (size_t)parent_limit);
@@ -119,7 +119,7 @@ class PMAllParents: public virtual PaceMaker {
         /* add the rest of tails as "uncles/aunts" */
         for (const auto &blk: tails)
         {
-            if (blk != bqc_tail)
+            if (blk != hqc_tail)
             {
                 parents.push_back(blk);
                 if (!--nparents) break;
@@ -386,7 +386,7 @@ class PMStickyProposer: virtual public PaceMaker {
         HOTSTUFF_LOG_PROTO("got block %s from %d", std::string(*prop.blk).c_str(), _proposer);
         p.reject();
         (p = hsc->async_qc_finish(prop.blk)).then([this, blk=prop.blk, _proposer]() {
-            if (hsc->get_bqc()->get_qc_ref() == blk)
+            if (hsc->get_hqc() == blk)
                 to_follower(_proposer);
         });
         reg_cp_receive_proposal();
@@ -423,7 +423,7 @@ class PMStickyProposer: virtual public PaceMaker {
             to_candidate();
         });
         reg_cp_receive_proposal();
-        proposer_propose(Proposal(-1, uint256_t(), hsc->get_genesis(), nullptr));
+        proposer_propose(Proposal(-1, hsc->get_genesis(), nullptr));
     }
 
     void to_candidate() {
@@ -675,7 +675,7 @@ class PMRoundRobinProposer: virtual public PaceMaker {
             /* proposer unable to get a QC in time */
             to_candidate();
         });
-        proposer_propose(Proposal(-1, uint256_t(), hsc->get_genesis(), nullptr));
+        proposer_propose(Proposal(-1, hsc->get_genesis(), nullptr));
     }
 
     void to_candidate() {
diff --git a/salticidae b/salticidae
-Subproject 07d197a2d049aedb77536edeb3b20e51cc8c958
+Subproject 8a0d8fbaf59be7acc536b2a753caa27aa1fbae2
diff --git a/src/consensus.cpp b/src/consensus.cpp
index 8b6e977..b57e258 100644
--- a/src/consensus.cpp
+++ b/src/consensus.cpp
@@ -33,16 +33,14 @@ namespace hotstuff {
 HotStuffCore::HotStuffCore(ReplicaID id,
                             privkey_bt &&priv_key):
         b0(new Block(true, 1)),
-        bqc(b0),
         bexec(b0),
         vheight(0),
         priv_key(std::move(priv_key)),
-        tails{bqc},
+        tails{b0},
         neg_vote(false),
         id(id),
         storage(new EntityStorage()) {
     storage->add_blk(b0);
-    b0->qc_ref = b0;
 }
 
 void HotStuffCore::sanity_check_delivered(const block_t &blk) {
@@ -84,8 +82,20 @@ bool HotStuffCore::on_deliver_blk(const block_t &blk) {
     return true;
 }
 
-void HotStuffCore::check_commit(const block_t &_blk) {
-    const block_t &blk = _blk->qc_ref;
+void HotStuffCore::update_hqc(const block_t &_hqc, const quorum_cert_bt &qc) {
+    if (_hqc->height > hqc.first->height)
+    {
+        hqc = std::make_pair(_hqc, qc->clone());
+        on_hqc_update();
+    }
+}
+
+void HotStuffCore::update(const block_t &nblk) {
+    const block_t &blk = nblk->qc_ref;
+    if (blk == nullptr)
+        throw std::runtime_error("empty qc_ref");
+    update_hqc(blk, nblk->qc);
+    /* check for commit */
     if (blk->qc_ref == nullptr) return;
     /* decided blk could possible be incomplete due to pruning */
     if (blk->decision) return;
@@ -117,18 +127,6 @@ void HotStuffCore::check_commit(const block_t &_blk) {
     bexec = p;
 }
 
-bool HotStuffCore::update(const uint256_t &bqc_hash) {
-    block_t _bqc = get_delivered_blk(bqc_hash);
-    if (_bqc->qc_ref == nullptr) return false;
-    check_commit(_bqc);
-    if (_bqc->qc_ref->height > bqc->qc_ref->height)
-    {
-        bqc = _bqc;
-        on_bqc_update();
-    }
-    return true;
-}
-
 void HotStuffCore::on_propose(const std::vector<uint256_t> &cmds,
                             const std::vector<block_t> &parents,
                             bytearray_t &&extra) {
@@ -139,7 +137,7 @@ void HotStuffCore::on_propose(const std::vector<uint256_t> &cmds,
     quorum_cert_bt qc = nullptr;
     block_t qc_ref = nullptr;
     /* a block can optionally carray a QC */
-    if (p != b0 && p->voted.size() >= config.nmajority)
+    if (p->voted.size() >= config.nmajority)
     {
         qc = p->self_qc->clone();
         qc_ref = p;
@@ -155,15 +153,15 @@ void HotStuffCore::on_propose(const std::vector<uint256_t> &cmds,
     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);
+    update(bnew);
+    Proposal prop(id, bnew, nullptr);
     LOG_PROTO("propose %s", std::string(*bnew).c_str());
     /* self-vote */
     if (bnew->height <= vheight)
         throw std::runtime_error("new block should be higher than vheight");
     vheight = bnew->height;
     on_receive_vote(
-        Vote(id, bqc->get_hash(), bnew_hash,
+        Vote(id, bnew_hash,
             create_part_cert(*priv_key, bnew_hash), this));
     on_propose_(prop);
     /* boradcast to other replicas */
@@ -171,14 +169,14 @@ void HotStuffCore::on_propose(const std::vector<uint256_t> &cmds,
 }
 
 void HotStuffCore::on_receive_proposal(const Proposal &prop) {
-    if (!update(prop.bqc_hash)) return;
     LOG_PROTO("got %s", std::string(prop).c_str());
     block_t bnew = prop.blk;
     sanity_check_delivered(bnew);
+    update(bnew);
     bool opinion = false;
     if (bnew->height > vheight)
     {
-        block_t pref = bqc->qc_ref;
+        block_t pref = hqc.first;
         block_t b;
         for (b = bnew;
             b->height > pref->height;
@@ -195,14 +193,11 @@ void HotStuffCore::on_receive_proposal(const Proposal &prop) {
     on_receive_proposal_(prop);
     if (opinion && !neg_vote)
         do_vote(prop.proposer,
-            Vote(id,
-                bqc->get_hash(),
-                bnew->get_hash(),
+            Vote(id, bnew->get_hash(),
                 create_part_cert(*priv_key, bnew->get_hash()), this));
 }
 
 void HotStuffCore::on_receive_vote(const Vote &vote) {
-    if (!update(vote.bqc_hash)) return;
     LOG_PROTO("got %s", std::string(vote).c_str());
     LOG_PROTO("now state: %s", std::string(*this).c_str());
     block_t blk = get_delivered_blk(vote.blk_hash);
@@ -225,10 +220,18 @@ void HotStuffCore::on_receive_vote(const Vote &vote) {
     {
         qc->compute();
         on_qc_finish(blk);
+        update_hqc(blk, qc);
     }
 }
 /*** end HotStuff protocol logic ***/
-void HotStuffCore::on_init(uint32_t nfaulty) { config.nmajority = 2 * nfaulty + 1; }
+void HotStuffCore::on_init(uint32_t nfaulty) {
+    config.nmajority = 2 * nfaulty + 1;
+    b0->qc = create_quorum_cert(b0->get_hash());
+    b0->qc->compute();
+    b0->self_qc = b0->qc->clone();
+    b0->qc_ref = b0;
+    hqc = std::make_pair(b0, b0->qc->clone());
+}
 
 void HotStuffCore::prune(uint32_t staleness) {
     block_t start;
@@ -292,9 +295,9 @@ promise_t HotStuffCore::async_wait_receive_proposal() {
     });
 }
 
-promise_t HotStuffCore::async_bqc_update() {
-    return bqc_update_waiting.then([this]() {
-        return bqc;
+promise_t HotStuffCore::async_hqc_update() {
+    return hqc_update_waiting.then([this]() {
+        return hqc.first;
     });
 }
 
@@ -310,17 +313,17 @@ void HotStuffCore::on_receive_proposal_(const Proposal &prop) {
     t.resolve(prop);
 }
 
-void HotStuffCore::on_bqc_update() {
-    auto t = std::move(bqc_update_waiting);
-    bqc_update_waiting = promise_t();
+void HotStuffCore::on_hqc_update() {
+    auto t = std::move(hqc_update_waiting);
+    hqc_update_waiting = promise_t();
     t.resolve();
 }
 
 HotStuffCore::operator std::string () const {
     DataStream s;
     s << "<hotstuff "
-      << "bqc=" << get_hex10(bqc->get_hash()) << " "
-      << "bqc.rheight=" << std::to_string(bqc->qc_ref->height) << " "
+      << "hqc=" << get_hex10(hqc.first->get_hash()) << " "
+      << "hqc.height=" << std::to_string(hqc.first->height) << " "
       << "bexec=" << get_hex10(bexec->get_hash()) << " "
       << "vheight=" << std::to_string(vheight) << " "
       << "tails=" << std::to_string(tails.size()) << ">";
diff --git a/src/hotstuff.cpp b/src/hotstuff.cpp
index 4a84927..9b36fa2 100644
--- a/src/hotstuff.cpp
+++ b/src/hotstuff.cpp
@@ -223,7 +223,8 @@ promise_t HotStuffBase::async_deliver_blk(const uint256_t &blk_hash,
         /* the parents should be delivered */
         for (const auto &phash: blk->get_parent_hashes())
             pms.push_back(async_deliver_blk(phash, replica_id));
-        pms.push_back(blk->verify(get_config(), vpool));
+        if (blk != get_genesis())
+            pms.push_back(blk->verify(get_config(), vpool));
         promise::all(pms).then([this, blk]() {
             on_deliver_blk(blk);
         });
@@ -238,8 +239,7 @@ void HotStuffBase::propose_handler(MsgPropose &&msg, const Net::conn_t &conn) {
     block_t blk = prop.blk;
     if (!blk) return;
     promise::all(std::vector<promise_t>{
-        async_deliver_blk(prop.bqc_hash, peer),
-        async_deliver_blk(blk->get_hash(), peer),
+        async_deliver_blk(blk->get_hash(), peer)
     }).then([this, prop = std::move(prop)]() {
         on_receive_proposal(prop);
     });
@@ -251,11 +251,10 @@ void HotStuffBase::vote_handler(MsgVote &&msg, const Net::conn_t &conn) {
     //auto &vote = msg.vote;
     RcObj<Vote> v(new Vote(std::move(msg.vote)));
     promise::all(std::vector<promise_t>{
-        async_deliver_blk(v->bqc_hash, peer),
         async_deliver_blk(v->blk_hash, peer),
         v->verify(vpool),
     }).then([this, v=std::move(v)](const promise::values_t values) {
-        if (!promise::any_cast<bool>(values[2]))
+        if (!promise::any_cast<bool>(values[1]))
             LOG_WARN("invalid vote from %d", v->voter);
         else
             on_receive_vote(*v);
@@ -415,7 +414,9 @@ void HotStuffBase::do_decide(Finality &&fin) {
 
 HotStuffBase::~HotStuffBase() {}
 
-void HotStuffBase::start(std::vector<std::pair<NetAddr, pubkey_bt>> &&replicas, bool ec_loop) {
+void HotStuffBase::start(
+        std::vector<std::pair<NetAddr, pubkey_bt>> &&replicas,
+        bool ec_loop) {
     for (size_t i = 0; i < replicas.size(); i++)
     {
         auto &addr = replicas[i].first;