From 780cfa4ee8faf4c2662f3c739e8a5c9f1c8a1826 Mon Sep 17 00:00:00 2001
From: Determinant <tederminant@gmail.com>
Date: Wed, 18 Jul 2018 14:34:43 -0400
Subject: move parent selection to PaceMaker

---
 src/consensus.cpp    | 34 +++++++++++++++-------------------
 src/hotstuff.cpp     |  9 ++++-----
 src/hotstuff_app.cpp |  9 ++++++---
 3 files changed, 25 insertions(+), 27 deletions(-)

(limited to 'src')

diff --git a/src/consensus.cpp b/src/consensus.cpp
index e42fb49..688c450 100644
--- a/src/consensus.cpp
+++ b/src/consensus.cpp
@@ -10,11 +10,10 @@
 
 namespace hotstuff {
 
-/* The core logic of HotStuff, is farily simple :) */
+/* The core logic of HotStuff, is fairly simple :). */
 /*** begin HotStuff protocol logic ***/
 HotStuffCore::HotStuffCore(ReplicaID id,
-                            privkey_bt &&priv_key,
-                            int32_t parent_limit):
+                            privkey_bt &&priv_key):
         b0(new Block(true, 1)),
         bqc(b0),
         bexec(b0),
@@ -22,7 +21,6 @@ HotStuffCore::HotStuffCore(ReplicaID id,
         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;
@@ -110,20 +108,12 @@ bool HotStuffCore::update(const uint256_t &bqc_hash) {
     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);
-    }
+void HotStuffCore::on_propose(const std::vector<command_t> &cmds,
+                            const std::vector<block_t> &parents) {
+    if (parents.empty())
+        throw std::runtime_error("empty parents");
+    for (const auto &_: parents) tails.erase(_);
+    block_t p = parents[0];
     quorum_cert_bt qc = nullptr;
     block_t qc_ref = nullptr;
     if (p != b0 && p->voted.size() >= config.nmajority)
@@ -211,7 +201,13 @@ void HotStuffCore::on_receive_vote(const Vote &vote) {
     size_t qsize = blk->voted.size();
     if (qsize <= config.nmajority)
     {
-        blk->self_qc->add_part(vote.voter, *vote.cert);
+        auto &qc = blk->self_qc;
+        if (qc == nullptr)
+        {
+            LOG_WARN("vote for block not proposed by itself");
+            qc = create_quorum_cert(blk->get_hash());
+        }
+        qc->add_part(vote.voter, *vote.cert);
         if (qsize == config.nmajority)
             on_qc_finish(blk);
     }
diff --git a/src/hotstuff.cpp b/src/hotstuff.cpp
index f4454d4..d0b42c3 100644
--- a/src/hotstuff.cpp
+++ b/src/hotstuff.cpp
@@ -84,7 +84,7 @@ ReplicaID HotStuffBase::add_command(command_t cmd) {
             cmd_pending.pop();
         }
         pmaker->beat().then([this, cmds = std::move(cmds)]() {
-            on_propose(cmds);
+            on_propose(cmds, pmaker->get_parents());
         });
     }
     return proposer;
@@ -383,13 +383,12 @@ promise_t HotStuffBase::async_decide(const uint256_t &cmd_hash) {
 }
 
 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),
+                    pacemaker_bt pmaker,
+                    EventContext eb):
+        HotStuffCore(rid, std::move(priv_key)),
         listen_addr(listen_addr),
         blk_size(blk_size),
         eb(eb),
diff --git a/src/hotstuff_app.cpp b/src/hotstuff_app.cpp
index 5f21fec..e1eec1b 100644
--- a/src/hotstuff_app.cpp
+++ b/src/hotstuff_app.cpp
@@ -61,6 +61,7 @@ class HotStuffApp: public HotStuff {
     Event ev_stat_timer;
     /** the binding address for client RPC */
     NetAddr clisten_addr;
+    int32_t parent_limit;
 
     using conn_client_t = MsgNetwork<MsgClient>::conn_t;
 
@@ -209,12 +210,14 @@ HotStuffApp::HotStuffApp(uint32_t blk_size,
                         NetAddr plisten_addr,
                         NetAddr clisten_addr,
                         const EventContext &eb):
-    HotStuff(blk_size, parent_limit, idx, raw_privkey,
-            plisten_addr, eb, new hotstuff::PaceMakerDummyFixed(1)),
+    HotStuff(blk_size, idx, raw_privkey,
+            plisten_addr,
+            new hotstuff::PaceMakerDummyFixed(1, parent_limit), eb),
     stat_period(stat_period),
     eb(eb),
     cn(eb),
-    clisten_addr(clisten_addr) {
+    clisten_addr(clisten_addr),
+    parent_limit(parent_limit) {
     /* register the handlers for msg from clients */
     cn.reg_handler(hotstuff::REQ_CMD, std::bind(&HotStuffApp::client_request_cmd_handler, this, _1, _2));
     cn.reg_handler(hotstuff::CHK_CMD, std::bind(&HotStuffApp::client_check_cmd_handler, this, _1, _2));
-- 
cgit v1.2.3