wallet.cpp: Ask remote DB for accounts on startup

libraries/wallet/wallet.cpp

@@ -649,15 +649,49 @@ public:
             ("wallet.chain_id", _wallet.chain_id)
             ("chain_id", _chain_id) );
 
-      vector< account_id_type > my_account_ids;
-      my_account_ids.reserve( _wallet.my_accounts.size() );
-      for( const account_object& acct : _wallet.my_accounts )
-         my_account_ids.push_back( acct.id );
-      // TODO:  Batch requests using _remote_db->get_accounts()
-      // to reduce number of round-trips.  Remember get_accounts() has
-      // a limit of 100 results per call!
-      for( const account_id_type& acct_id : my_account_ids )
-         _wallet.update_account( get_account( acct_id ) );
+      size_t account_pagination = 100;
+      vector< account_id_type > account_ids_to_send;
+      size_t n = _wallet.my_accounts.size();
+      account_ids_to_send.reserve( std::min( account_pagination, n ) );
+      auto it = _wallet.my_accounts.begin();
+
+      for( size_t start=0; start<n; start+=account_pagination )
+      {
+         size_t end = std::min( start+account_pagination, n );
+         assert( end > start );
+         account_ids_to_send.clear();
+         std::vector< account_object > old_accounts;
+         for( size_t i=start; i<end; i++ )
+         {
+            assert( it != _wallet.my_accounts.end() );
+            old_accounts.push_back( *it );
+            account_ids_to_send.push_back( old_accounts.back().id );
+            ++it;
+         }
+         std::vector< optional< account_object > > accounts = _remote_db->get_accounts(account_ids_to_send);
+         // server response should be same length as request
+         FC_ASSERT( accounts.size() == account_ids_to_send.size() );
+         size_t i = 0;
+         for( const optional< account_object >& acct : accounts )
+         {
+            account_object& old_acct = old_accounts[i];
+            if( !acct.valid() )
+            {
+               elog( "Could not find account ${id} : \"${name}\" does not exist on the chain!", ("id", old_acct.id)("name", old_acct.name) );
+               i++;
+               continue;
+            }
+            // this check makes sure the server didn't send results
+            // in a different order, or accounts we didn't request
+            FC_ASSERT( acct->id == old_acct.id );
+            if( fc::json::to_string(*acct) != fc::json::to_string(old_acct) )
+            {
+               wlog( "Account ${id} : \"${name}\" updated on chain", ("id", acct->id)("name", acct->name) );
+            }
+            _wallet.update_account( *acct );
+            i++;
+         }
+      }
 
       return true;
    }