Compute scaled precision at compile time, use in tests (fixes failures by prev commit)

libraries/chain/asset_object.cpp

@@ -110,9 +110,7 @@ asset asset_object::amount_from_string(string amount_string) const
 
    share_type satoshis = 0;
 
-   share_type scaled_precision = 1;
+   share_type scaled_precision = asset::scaled_precision( precision );
-   for( uint8_t i = 0; i < precision; ++i )
-      scaled_precision *= 10;
 
    const auto decimal_pos = amount_string.find( '.' );
    const string lhs = amount_string.substr( negative_found, decimal_pos );

libraries/chain/include/graphene/chain/protocol/asset.hpp

@@ -21,6 +21,8 @@
 
 namespace graphene { namespace chain {
 
+   extern const int64_t scaled_precision_lut[];
+
    struct asset
    {
       asset( share_type a = 0, asset_id_type id = asset_id_type() )
@@ -80,6 +82,12 @@ namespace graphene { namespace chain {
          FC_ASSERT( a.asset_id == b.asset_id );
          return asset( a.amount + b.amount, a.asset_id );
       }
+
+      static share_type scaled_precision( uint8_t precision )
+      {
+         FC_ASSERT( precision < 19 );
+         return scaled_precision_lut[ precision ];
+      }
    };
 
    /**

libraries/chain/protocol/asset.cpp

@@ -146,4 +146,27 @@ namespace graphene { namespace chain {
          return (asset( cp.numerator(), settlement_price.base.asset_id ) / asset( cp.denominator(), settlement_price.quote.asset_id ));
       }
 
+// compile-time table of powers of 10 using template metaprogramming
+
+template< int N >
+struct p10
+{
+   static const int64_t v = 10 * p10<N-1>::v;
+};
+
+template<>
+struct p10<0>
+{
+   static const int64_t v = 1;
+};
+
+const int64_t scaled_precision_lut[19] =
+{
+   p10<  0 >::v, p10<  1 >::v, p10<  2 >::v, p10<  3 >::v,
+   p10<  4 >::v, p10<  5 >::v, p10<  6 >::v, p10<  7 >::v,
+   p10<  8 >::v, p10<  9 >::v, p10< 10 >::v, p10< 11 >::v,
+   p10< 12 >::v, p10< 13 >::v, p10< 14 >::v, p10< 15 >::v,
+   p10< 16 >::v, p10< 17 >::v, p10< 18 >::v
+};
+
 } } // graphene::chain

tests/tests/basic_tests.cpp

@@ -314,10 +314,40 @@ BOOST_AUTO_TEST_CASE( witness_rng_test_bits )
    } FC_LOG_AND_RETHROW()
 }
 
-
 BOOST_AUTO_TEST_CASE( exceptions )
 {
    GRAPHENE_CHECK_THROW(FC_THROW_EXCEPTION(balance_claim_invalid_claim_amount, "Etc"), balance_claim_invalid_claim_amount);
 }
 
+BOOST_AUTO_TEST_CASE( scaled_precision )
+{
+   const int64_t _k = 1000;
+   const int64_t _m = _k*_k;
+   const int64_t _g = _m*_k;
+   const int64_t _t = _g*_k;
+   const int64_t _p = _t*_k;
+   const int64_t _e = _p*_k;
+
+   BOOST_CHECK( asset::scaled_precision( 0) == share_type(   1   ) );
+   BOOST_CHECK( asset::scaled_precision( 1) == share_type(  10   ) );
+   BOOST_CHECK( asset::scaled_precision( 2) == share_type( 100   ) );
+   BOOST_CHECK( asset::scaled_precision( 3) == share_type(   1*_k) );
+   BOOST_CHECK( asset::scaled_precision( 4) == share_type(  10*_k) );
+   BOOST_CHECK( asset::scaled_precision( 5) == share_type( 100*_k) );
+   BOOST_CHECK( asset::scaled_precision( 6) == share_type(   1*_m) );
+   BOOST_CHECK( asset::scaled_precision( 7) == share_type(  10*_m) );
+   BOOST_CHECK( asset::scaled_precision( 8) == share_type( 100*_m) );
+   BOOST_CHECK( asset::scaled_precision( 9) == share_type(   1*_g) );
+   BOOST_CHECK( asset::scaled_precision(10) == share_type(  10*_g) );
+   BOOST_CHECK( asset::scaled_precision(11) == share_type( 100*_g) );
+   BOOST_CHECK( asset::scaled_precision(12) == share_type(   1*_t) );
+   BOOST_CHECK( asset::scaled_precision(13) == share_type(  10*_t) );
+   BOOST_CHECK( asset::scaled_precision(14) == share_type( 100*_t) );
+   BOOST_CHECK( asset::scaled_precision(15) == share_type(   1*_p) );
+   BOOST_CHECK( asset::scaled_precision(16) == share_type(  10*_p) );
+   BOOST_CHECK( asset::scaled_precision(17) == share_type( 100*_p) );
+   BOOST_CHECK( asset::scaled_precision(18) == share_type(   1*_e) );
+   GRAPHENE_CHECK_THROW( asset::scaled_precision(19), fc::exception );
+}
+
 BOOST_AUTO_TEST_SUITE_END()

tests/tests/operation_tests.cpp

@@ -921,7 +921,7 @@ BOOST_AUTO_TEST_CASE( uia_fees )
       const asset_dynamic_data_object& asset_dynamic = test_asset.dynamic_asset_data_id(db);
       const account_object& nathan_account = get_account("nathan");
       const account_object& committee_account = account_id_type()(db);
-      const auto prec = asset_id_type()(db).precision;
+      const share_type prec = asset::scaled_precision( asset_id_type()(db).precision );
 
       fund_fee_pool(committee_account, test_asset, 1000*prec);
       BOOST_CHECK(asset_dynamic.fee_pool == 1000*prec);
@@ -1128,7 +1128,7 @@ BOOST_AUTO_TEST_CASE( fill_order )
 BOOST_AUTO_TEST_CASE( witness_pay_test )
 { try {
 
-   const auto prec = asset_id_type()(db).precision;
+   const share_type prec = asset::scaled_precision( asset_id_type()(db).precision );
 
    // there is an immediate maintenance interval in the first block
    //   which will initialize last_budget_time
@@ -1188,7 +1188,7 @@ BOOST_AUTO_TEST_CASE( witness_pay_test )
    PUSH_TX( db, trx );
    auto pay_fee_time = db.head_block_time().sec_since_epoch();
    trx.clear();
-   BOOST_CHECK_EQUAL(get_balance(*nathan, *core), 20000*prec - account_upgrade_operation::fee_parameters_type().membership_lifetime_fee );;
+   BOOST_CHECK( get_balance(*nathan, *core) == 20000*prec - account_upgrade_operation::fee_parameters_type().membership_lifetime_fee );;
 
    generate_block();
    nathan = &get_account("nathan");
@@ -1215,7 +1215,7 @@ BOOST_AUTO_TEST_CASE( witness_pay_test )
 
    schedule_maint();
    // The 80% lifetime referral fee went to the committee account, which burned it. Check that it's here.
-   BOOST_CHECK_EQUAL( core->reserved(db).value, 8000*prec );
+   BOOST_CHECK( core->reserved(db).value == 8000*prec );
    generate_block();
    BOOST_CHECK_EQUAL( core->reserved(db).value, 999999406 );
    BOOST_CHECK_EQUAL( db.get_dynamic_global_properties().witness_budget.value, ref_budget );