Improve block and tx processing efficiency by less repeat hashing

BlockchainLMDB::add_block()
  BlockchainLMDB::add_transaction_data()

  BlockchainDB::add_transaction()

src/cryptonote_core/BlockchainDB_impl/db_lmdb.cpp

@@ -152,12 +152,13 @@ void BlockchainLMDB::add_block( const block& blk
               , const size_t& block_size
               , const difficulty_type& cumulative_difficulty
               , const uint64_t& coins_generated
+              , const crypto::hash& blk_hash
               )
 {
   LOG_PRINT_L3("BlockchainLMDB::" << __func__);
   check_open();
 
-  MDB_val_copy<crypto::hash> val_h(get_block_hash(blk));
+  MDB_val_copy<crypto::hash> val_h(blk_hash);
   MDB_val unused;
   if (mdb_get(*m_write_txn, m_block_heights, &val_h, &unused) == 0)
     throw1(BLOCK_EXISTS("Attempting to add block that's already in the db"));
@@ -243,12 +244,12 @@ void BlockchainLMDB::remove_block()
       throw1(DB_ERROR("Failed to add removal of block hash to db transaction"));
 }
 
-void BlockchainLMDB::add_transaction_data(const crypto::hash& blk_hash, const transaction& tx)
+void BlockchainLMDB::add_transaction_data(const crypto::hash& blk_hash, const transaction& tx, const crypto::hash& tx_hash)
 {
   LOG_PRINT_L3("BlockchainLMDB::" << __func__);
   check_open();
 
-  MDB_val_copy<crypto::hash> val_h(get_transaction_hash(tx));
+  MDB_val_copy<crypto::hash> val_h(tx_hash);
   MDB_val unused;
   if (mdb_get(*m_write_txn, m_txs, &val_h, &unused) == 0)
       throw1(TX_EXISTS("Attempting to add transaction that's already in the db"));

src/cryptonote_core/BlockchainDB_impl/db_lmdb.h

@@ -184,11 +184,12 @@ private:
                 , const size_t& block_size
                 , const difficulty_type& cumulative_difficulty
                 , const uint64_t& coins_generated
+                , const crypto::hash& block_hash
                 );
 
   virtual void remove_block();
 
-  virtual void add_transaction_data(const crypto::hash& blk_hash, const transaction& tx);
+  virtual void add_transaction_data(const crypto::hash& blk_hash, const transaction& tx, const crypto::hash& tx_hash);
 
   virtual void remove_transaction_data(const crypto::hash& tx_hash, const transaction& tx);
 

src/cryptonote_core/blockchain_db.cpp

@@ -42,11 +42,21 @@ void BlockchainDB::pop_block()
   pop_block(blk, txs);
 }
 
-void BlockchainDB::add_transaction(const crypto::hash& blk_hash, const transaction& tx)
+void BlockchainDB::add_transaction(const crypto::hash& blk_hash, const transaction& tx, const crypto::hash* tx_hash_ptr)
 {
-  crypto::hash tx_hash = get_transaction_hash(tx);
+  crypto::hash tx_hash;
+  if (!tx_hash_ptr)
+  {
+    // should only need to compute hash for miner transactions
+    tx_hash = get_transaction_hash(tx);
+    LOG_PRINT_L3("null tx_hash_ptr - needed to compute: " << tx_hash);
+  }
+  else
+  {
+    tx_hash = *tx_hash_ptr;
+  }
 
-  add_transaction_data(blk_hash, tx);
+  add_transaction_data(blk_hash, tx, tx_hash);
 
   // iterate tx.vout using indices instead of C++11 foreach syntax because
   // we need the index
@@ -81,7 +91,7 @@ uint64_t BlockchainDB::add_block( const block& blk
 
   // call out to subclass implementation to add the block & metadata
   time1 = epee::misc_utils::get_tick_count();
-  add_block(blk, block_size, cumulative_difficulty, coins_generated);
+  add_block(blk, block_size, cumulative_difficulty, coins_generated, blk_hash);
   TIME_MEASURE_FINISH(time1);
   time_add_block1 += time1;
 
@@ -89,9 +99,13 @@ uint64_t BlockchainDB::add_block( const block& blk
 
   time1 = epee::misc_utils::get_tick_count();
   add_transaction(blk_hash, blk.miner_tx);
+  int tx_i = 0;
+  crypto::hash tx_hash = null_hash;
   for (const transaction& tx : txs)
   {
-    add_transaction(blk_hash, tx);
+    tx_hash = blk.tx_hashes[tx_i];
+    add_transaction(blk_hash, tx, &tx_hash);
+    ++tx_i;
   }
   TIME_MEASURE_FINISH(time1);
   time_add_transaction += time1;

src/cryptonote_core/blockchain_db.h

@@ -265,13 +265,14 @@ private:
                 , const size_t& block_size
                 , const difficulty_type& cumulative_difficulty
                 , const uint64_t& coins_generated
+                , const crypto::hash& blk_hash
                 ) = 0;
 
   // tells the subclass to remove data about the top block
   virtual void remove_block() = 0;
 
   // tells the subclass to store the transaction and its metadata
-  virtual void add_transaction_data(const crypto::hash& blk_hash, const transaction& tx) = 0;
+  virtual void add_transaction_data(const crypto::hash& blk_hash, const transaction& tx, const crypto::hash& tx_hash) = 0;
 
   // tells the subclass to remove data about a transaction
   virtual void remove_transaction_data(const crypto::hash& tx_hash, const transaction& tx) = 0;
@@ -296,7 +297,7 @@ private:
   void pop_block();
 
   // helper function for add_transactions, to add each individual tx
-  void add_transaction(const crypto::hash& blk_hash, const transaction& tx);
+  void add_transaction(const crypto::hash& blk_hash, const transaction& tx, const crypto::hash* tx_hash_ptr = NULL);
 
   // helper function to remove transaction from blockchain
   void remove_transaction(const crypto::hash& tx_hash);