Update block construction document and store only qc in `assembled_bl…

…ock_if`

libraries/chain/controller.cpp

@@ -336,7 +336,7 @@ struct assembled_block {
       deque<transaction_metadata_ptr>   trx_metas;                 // Comes from building_block::pending_trx_metas
                                                                    // Carried over to put into block_state (optimization for fork reorgs)
       deque<transaction_receipt>        trx_receipts;              // Comes from building_block::pending_trx_receipts
-      std::optional<qc_data_t>          qc_data;                   // QC to add as block extension to new block
+      std::optional<quorum_certificate> qc;                        // QC to add as block extension to new block
 
       block_header_state& get_bhs() { return bhs; }
    };
@@ -761,7 +761,8 @@ struct building_block {
                   qc_data ? qc_data->qc_info : std::optional<qc_info_t>{} };
 
                assembled_block::assembled_block_if ab{bb.active_producer_authority, bb.parent.next(bhs_input),
-                                                      bb.pending_trx_metas, bb.pending_trx_receipts, qc_data};
+                                                      bb.pending_trx_metas, bb.pending_trx_receipts,
+                                                      qc_data ? std::move(qc_data->qc) : std::optional<quorum_certificate>{}};
 
                return assembled_block{.v = std::move(ab)};
             }},

libraries/chain/hotstuff/block_construction_data_flow.md

@@ -190,16 +190,17 @@ struct building_block_input {
 When done with building the block, from `building_block` we can extract:
 
 ```c++
+struct qc_info_t {
+   uint32_t last_qc_block_num; // The block height of the most recent ancestor block that has a QC justification
+   bool     is_last_qc_strong; // Whether the QC for the block referenced by last_qc_block_height is strong or weak.
+};
 
 struct block_header_state_input : public building_block_input {
    digest_type                       transaction_mroot;    // Comes from std::get<checksum256_type>(building_block::trx_mroot_or_receipt_digests)
    digest_type                       action_mroot;         // Compute root from  building_block::action_receipt_digests
    std::optional<proposer_policy>    new_proposer_policy;  // Comes from building_block::new_proposer_policy
    std::optional<finalizer_policy>   new_finalizer_policy; // Comes from building_block::new_finalizer_policy
-   std::optional<quorum_certificate> qc;                   // Comes from traversing branch from parent and calling get_best_qc()
-                                                           // assert(qc->block_num <= num_from_id(previous));
-   uint32_t                          last_qc_block_num;
-   bool                              is_last_qc_strong;
+   std::optional<qc_info_t>          qc_info; 
    // ... ?
 };
 ```