refactor generated transactions in block header

libraries/chain/database.cpp

@@ -431,25 +431,18 @@ void database::_apply_block(const signed_block& next_block)
     * for transactions when validating broadcast transactions or
     * when building a block.
     */
-   for (const auto& cycle : next_block.cycles)
-      for (const auto& thread : cycle)
-         for(const auto& trx : thread.input_transactions)
-         {
-            struct {
-               using result_type = void;
-               void operator()(const signed_transaction& trx) {
-                  db.apply_transaction(trx);
-               }
-               void operator()(generated_transaction_id_type) {
+   for (const auto& cycle : next_block.cycles) {
+      for (const auto& thread : cycle) {
+         for(const auto& trx : thread.generated_input ) {
 #warning TODO: Process generated transaction
-               }
-
-               database& db;
-            } visitor{*this};
-
-            trx.visit(visitor);
             ++_current_trx_in_block;
          }
+         for(const auto& trx : thread.user_input ) {
+            apply_transaction(trx);
+            ++_current_trx_in_block;
+         }
+      }
+   }
 
    update_global_dynamic_data(next_block);
    update_signing_producer(signing_producer, next_block);

libraries/chain/include/eos/chain/protocol/block.hpp

@@ -49,19 +49,9 @@ namespace eos { namespace chain {
    };
 
    struct thread {
-      using input_transaction = static_variant<signed_transaction, generated_transaction_id_type>;
-      struct input_transaction_digest_visitor {
-         using result_type = digest_type;
-         result_type operator() (const signed_transaction& t) const {
-            return t.merkle_digest();
-         }
-         result_type operator() (const generated_transaction_id_type& id) const {
-            return id;
-         }
-      };
-
-      vector<input_transaction> input_transactions;
-      vector<generated_transaction> output_transactions;
+      vector<generated_transaction_id_type> generated_input;
+      vector<signed_transaction>            user_input; 
+      vector<generated_transaction>         output_transactions;
 
       digest_type merkle_digest() const;
    };
@@ -78,5 +68,5 @@ namespace eos { namespace chain {
 
 FC_REFLECT(eos::chain::block_header, (previous)(timestamp)(producer)(transaction_merkle_root))
 FC_REFLECT_DERIVED(eos::chain::signed_block_header, (eos::chain::block_header), (producer_signature))
-FC_REFLECT(eos::chain::thread, (input_transactions)(output_transactions))
+FC_REFLECT(eos::chain::thread, (generated_input)(user_input)(output_transactions))
 FC_REFLECT_DERIVED(eos::chain::signed_block, (eos::chain::signed_block_header), (cycles))

libraries/chain/protocol/block.cpp

@@ -88,12 +88,20 @@ namespace eos { namespace chain {
    }
 
    digest_type thread::merkle_digest() const {
-      vector<digest_type> ids;
-      input_transaction_digest_visitor v;
-      std::transform(input_transactions.begin(), input_transactions.end(), std::back_inserter(ids),
-                     [v = input_transaction_digest_visitor()](const input_transaction& t) { return t.visit(v); });
-      std::transform(output_transactions.begin(), output_transactions.end(), std::back_inserter(ids),
-                     std::bind(&generated_transaction::merkle_digest, std::placeholders::_1));
+      vector<digest_type> ids = generated_input;
+      ids.reserve( ids.size() + user_input.size() + output_transactions.size() );
+
+      for( const auto& trx : user_input )
+         ids.push_back( trx.digest() );
+
+      /**
+       *  When generating the merkle hash of an output transaction we hash it
+       *  a second time. This is because the transaction has not been confirmed as
+       *  "valid and applied" just "produced".  Later, when this transaction is included
+       *  as part of "generated input" its ID will be used without the extra hash.
+       */
+      for( const auto& trx : output_transactions )
+         ids.push_back( digest_type::hash(trx.digest()) );
 
       return merkle(ids);
    }