Merge branch 'hotstuff_integration' into finish_add_block_ext

libraries/chain/block_state.cpp

@@ -57,5 +57,33 @@ void block_state::set_trxs_metas( deque<transaction_metadata_ptr>&& trxs_metas,
    cached_trxs = std::move( trxs_metas );
 }
 
-
+std::optional<quorum_certificate> block_state::get_best_qc() const {
+   auto block_number = block_num();
+
+   // if pending_qc does not have a valid QC, consider valid_qc only
+   if( !pending_qc.is_quorum_met() ) {
+      if( valid_qc ) {
+         return quorum_certificate{ block_number, *valid_qc };
+      } else {
+         return std::nullopt;;
+      }
+   }
+
+#warning TODO valid_quorum_certificate constructor can assert. Implement an extract method in pending_quorum_certificate for this.
+   // extract valid QC from pending_qc
+   valid_quorum_certificate valid_qc_from_pending(pending_qc);
+
+   // if valid_qc does not have value, consider valid_qc_from_pending only
+   if( !valid_qc ) {
+      return quorum_certificate{ block_number, valid_qc_from_pending };
+   }
+
+   // Both valid_qc and valid_qc_from_pending have value. Compare them and select a better one.
+   // Strong beats weak. Tie break by valid_qc.
+   const auto& best_qc =
+      valid_qc->is_strong() == valid_qc_from_pending.is_strong() ?
+      *valid_qc : // tie broke by valid_qc
+      valid_qc->is_strong() ? *valid_qc : valid_qc_from_pending; // strong beats weak
+   return quorum_certificate{ block_number, best_qc };
+}   
 } /// eosio::chain

libraries/chain/hotstuff/hotstuff.cpp

@@ -192,4 +192,4 @@ quorum_certificate_message valid_quorum_certificate::to_msg() const {
    };
 }
 
-} // namespace eosio::chain
+} // namespace eosio::chain

libraries/chain/include/eosio/chain/block_state.hpp

@@ -17,8 +17,7 @@ struct block_state : public block_header_state {     // block_header_state provi
    digest_type                weak_digest;           // finalizer_digest (weak, cached so we can quickly validate votes)
    pending_quorum_certificate pending_qc;            // where we accumulate votes we receive
    std::optional<valid_quorum_certificate> valid_qc; // best qc received from the network inside block extension
-
-
+
    // ------ data members caching information available elsewhere ----------------------
    bool                       pub_keys_recovered = false;
    deque<transaction_metadata_ptr> cached_trxs;
@@ -32,6 +31,7 @@ struct block_state : public block_header_state {     // block_header_state provi
    bool                   is_valid()          const { return validated; }
    void                   set_valid(bool b)         { validated = b; }
    uint32_t               irreversible_blocknum() const { return 0; } // [greg todo] equivalent of dpos_irreversible_blocknum
+   std::optional<quorum_certificate> get_best_qc() const;
 
    protocol_feature_activation_set_ptr get_activated_protocol_features() const { return block_header_state::activated_protocol_features; }
    bool                                is_pub_keys_recovered() const { return pub_keys_recovered; }