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Implement fee_discount field, fix several bugs in claim_account_evalu…
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…ator steemit#2651
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@theoreticalbts
theoreticalbts committed Aug 13, 2018
1 parent 7ebe124 commit 53860c6
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Showing 6 changed files with 100 additions and 35 deletions.
115 changes: 83 additions & 32 deletions libraries/chain/steem_evaluator.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -88,6 +88,11 @@ void witness_update_evaluator::do_apply( const witness_update_operation& o )
if ( _db.has_hardfork( STEEM_HARDFORK_0_14__410 ) )
{
FC_ASSERT( o.props.account_creation_fee.symbol.is_canon() );
if( _db.has_hardfork( STEEM_HARDFORK_0_20__2651 ) || _db.is_producing() )
{
FC_TODO( "Move to validate() after HF20" );
FC_ASSERT( o.props.account_creation_fee.amount <= STEEM_MAX_ACCOUNT_CREATION_FEE, "account_creation_fee greater than maximum account creation fee" );
}
}
else if( !o.props.account_creation_fee.symbol.is_canon() )
{
Expand Down Expand Up @@ -162,6 +167,11 @@ void witness_set_properties_evaluator::do_apply( const witness_set_properties_op
if( flags.account_creation_changed )
{
fc::raw::unpack_from_vector( itr->second, props.account_creation_fee );
if( _db.has_hardfork( STEEM_HARDFORK_0_20__2651 ) || _db.is_producing() )
{
FC_TODO( "Move to validate() after HF20" );
FC_ASSERT( props.account_creation_fee.amount <= STEEM_MAX_ACCOUNT_CREATION_FEE, "account_creation_fee greater than maximum account creation fee" );
}
}

itr = o.props.find( "maximum_block_size" );
Expand Down Expand Up @@ -311,6 +321,12 @@ void account_create_evaluator::do_apply( const account_create_operation& o )

const witness_schedule_object& wso = _db.get_witness_schedule_object();

if( _db.has_hardfork( STEEM_HARDFORK_0_20__2651 ) || _db.is_producing() )
{
FC_TODO( "Move to validate() after HF20" );
FC_ASSERT( o.fee <= asset( STEEM_MAX_ACCOUNT_CREATION_FEE, STEEM_SYMBOL ), "Account creation fee cannot be too large" );
}

if( _db.has_hardfork( STEEM_HARDFORK_0_20__1771 ) )
{
FC_ASSERT( o.fee == wso.median_props.account_creation_fee, "Must pay the exact account creation fee. paid: ${p} fee: ${f}",
Expand Down Expand Up @@ -371,6 +387,12 @@ void account_create_with_delegation_evaluator::do_apply( const account_create_wi
{
FC_ASSERT( !_db.has_hardfork( STEEM_HARDFORK_0_20__1760 ), "Account creation with delegation is deprecated as of Hardfork 20" );

if( _db.has_hardfork( STEEM_HARDFORK_0_20__2651 ) || _db.is_producing() )
{
FC_TODO( "Move to validate() after HF20" );
FC_ASSERT( o.fee <= asset( STEEM_MAX_ACCOUNT_CREATION_FEE, STEEM_SYMBOL ), "Account creation fee cannot be too large" );
}

const auto& creator = _db.get_account( o.creator );
const auto& props = _db.get_dynamic_global_properties();
const witness_schedule_object& wso = _db.get_witness_schedule_object();
Expand Down Expand Up @@ -2329,19 +2351,62 @@ void claim_account_evaluator::do_apply( const claim_account_operation& o )

FC_ASSERT( creator.balance >= o.fee, "Insufficient balance to create account.", ( "creator.balance", creator.balance )( "required", o.fee ) );

const auto& creation_fee = wso.median_props.account_creation_fee;

asset paid_fee = o.fee;

if( paid_fee < creation_fee )
{
// This is optimized because STEEM_100_PERCENT == STEEM_ACCOUNT_SUBSIDY_PRECISION
uint64_t percent_unpaid = ( ( creation_fee.amount.value - paid_fee.amount.value ) * STEEM_100_PERCENT ) / creation_fee.amount.value;
FC_TODO( "Remove min() after HF20" );
int64_t creation_fee = std::min( wso.median_props.account_creation_fee.amount.value, STEEM_MAX_ACCOUNT_CREATION_FEE );

FC_ASSERT( o.fee.amount.value + o.fee_discount.amount.value == creation_fee, "Incorrect fee: Fee ${f} plus discount ${d} does not add up to median account creation fee ${m}",
("m", wso.median_props.account_creation_fee)
("f", o.fee)
("d", o.fee_discount) );

if( o.fee_discount.amount.value > 0 )
{
// The calculation we want to do is:
//
// current_subsidy = fee_discount / creation_fee
//
// However, this value is between 0 and 1, so we multiply by STEEM_ACCOUNT_SUBSIDY_PRECISION.
// To make sure the numerator doesn't overflow, we want to statically enforce that:
//
// x < numeric_limits<int64_t>::max()
//
// where x, y are the numerator, denominator:
//
// x = fee_discount * STEEM_ACCOUNT_SUBSIDY_PRECISION
// y = creation_fee
//
// In order to round-against-the-user, we actually want the division to round up, i.e.
//
// current_subsidy = ceil(x/y) = floor( (x+y-1)/y )
//
// (The second step is actually an identity which applies to any integers x, y with
// y > 0.) We now need to make sure that the numerator x+y-1 does not overflow.
// We know that:
//
// fee_discount <= STEEM_MAX_ACCOUNT_CREATION_FEE
// y-1 < STEEM_MAX_ACCOUNT_CREATION_FEE
//
// So we know that:
//
// x+y-1 = fee_discount * STEEM_ACCOUNT_SUBSIDY_PRECISION + y-1
// < STEEM_MAX_ACCOUNT_CRAETION_FEE * STEEM_ACCOUNT_SUBSIDY_PRECISION + STEEM_MAX_ACCOUNT_CREATION_FEE
// = STEEM_MAX_ACCOUNT_CREATION_FEE * (STEEM_ACCOUNT_SUBSIDY_PRECISION + 1)
//
// To check that this product does not exceed numeric_limits< int64_t >::max(), we can rearrange
// the inequality, obtaining:
//
// STEEM_MAX_ACCOUNT_CREATION_FEE < numeric_limits<int64_t>::max() / (STEEM_ACCOUNT_SUBSIDY_PRECISION + 1)
//
static_assert( STEEM_MAX_ACCOUNT_CREATION_FEE < (std::numeric_limits< int64_t >::max() / (STEEM_ACCOUNT_SUBSIDY_PRECISION + 1)),
"Following computation will overflow" );

// creation_fee cannot be zero since fee_discount > 0 and validate() enforces fee, fee_discount are non-negative and add to creation_fee
int64_t current_subsidy = ( o.fee_discount.amount.value * STEEM_ACCOUNT_SUBSIDY_PRECISION + creation_fee - 1 ) / creation_fee;
const auto& gpo = _db.get_dynamic_global_properties();

// This block is a little wierd. We want to enforce that only elected witnesses can include the transaction, but
// This block is a little weird. We want to enforce that only elected witnesses can include the transaction, but
// we do not want to prevent the transaction from propogating on the p2p network. Because we do not know what type of
// witness will have produced the last block whent he tx in broadcast, we need to disregard this assertion when the tx
// witness will have produced the including block when the tx is broadcast, we need to disregard this assertion when the tx
// is propogating, but require it when applying the block.
if( !_db.is_pending_tx() )
{
Expand All @@ -2352,20 +2417,11 @@ void claim_account_evaluator::do_apply( const claim_account_operation& o )
uint32_t delta_time = ( _db.head_block_time() - current_witness.last_subsidy_update ).to_seconds();

// linear decay to enforce no more than 10% max by a single witness over 48 hours.
uint64_t recovered_subsidies = ( delta_time * STEEM_100_PERCENT * wso.single_witness_subsidy_limit )
/ ( fc::days( STEEM_ACCOUNT_SUBSIDY_BURST_DAYS ).to_seconds() * STEEM_100_PERCENT );
uint64_t new_subsidies = current_witness.recent_account_subsidies;
uint64_t recovered_subsidies = ( uint64_t( delta_time ) * uint64_t( wso.single_witness_subsidy_limit ) )
/ (STEEM_ACCOUNT_SUBSIDY_BURST_DAYS * 60 * 60 * 24);
uint64_t new_subsidies = current_witness.recent_account_subsidies - std::min( current_witness.recent_account_subsidies, recovered_subsidies );

if( recovered_subsidies > new_subsidies )
{
new_subsidies = 0;
}
else
{
new_subsidies -= recovered_subsidies;
}

new_subsidies += STEEM_ACCOUNT_SUBSIDY_PRECISION;
new_subsidies += current_subsidy;

FC_ASSERT( new_subsidies <= wso.single_witness_subsidy_limit, "Witness has claimed too many subsidized accounts recents. Claimed: ${claimed} Limit: ${limit}",
("claimed", new_subsidies)("limit", wso.single_witness_subsidy_limit) );
Expand All @@ -2377,24 +2433,19 @@ void claim_account_evaluator::do_apply( const claim_account_operation& o )
});
}

FC_ASSERT( gpo.available_account_subsidies >= percent_unpaid, "There are not enough subsidized accounts to claim" );
FC_ASSERT( uint64_t( current_subsidy ) <= gpo.available_account_subsidies, "There are not enough subsidized accounts to claim" );

_db.modify( gpo, [&]( dynamic_global_property_object& gpo )
{
gpo.available_account_subsidies -= percent_unpaid;
gpo.available_account_subsidies -= current_subsidy;
});
}
else
{
// operation fee could be higher that witness specified fee
FC_ASSERT( paid_fee == creation_fee, "Cannot pay more than account creation fee. paid: ${p} fee: ${f}", ("p", paid_fee)("f", creation_fee) );
}

_db.adjust_balance( _db.get_account( STEEM_NULL_ACCOUNT ), paid_fee );
_db.adjust_balance( _db.get_account( STEEM_NULL_ACCOUNT ), o.fee );

_db.modify( creator, [&]( account_object& a )
{
a.balance -= paid_fee;
a.balance -= o.fee;
a.pending_claimed_accounts++;
});
}
Expand Down
6 changes: 5 additions & 1 deletion libraries/chain/witness_schedule.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -84,7 +84,11 @@ void update_median_witness_props( database& db )
_wso.account_subsidy_print_rate =
( uint64_t( median_account_subsidy_daily_rate ) * STEEM_ACCOUNT_SUBSIDY_PRECISION ) / STEEM_BLOCKS_PER_DAY;
_wso.single_witness_subsidy_limit =
( median_account_subsidy_daily_rate * STEEM_ACCOUNT_SUBSIDY_PRECISION * median_account_subsidy_pool_cap * STEEM_WITNESS_SUBSIDY_PERCENT ) / STEEM_100_PERCENT;
( uint64_t( median_account_subsidy_daily_rate )
* uint64_t( median_account_subsidy_pool_cap )
* ( uint64_t( STEEM_ACCOUNT_SUBSIDY_PRECISION )
* uint64_t( STEEM_WITNESS_SUBSIDY_PERCENT ) )
) / STEEM_100_PERCENT;
} );

db.modify( db.get_dynamic_global_properties(), [&]( dynamic_global_property_object& _dgpo )
Expand Down
1 change: 1 addition & 0 deletions libraries/protocol/hardfork.d/0_20.hf
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Original file line number Diff line number Diff line change
Expand Up @@ -23,6 +23,7 @@
#define STEEM_HARDFORK_0_20__2428 (STEEM_HARDFORK_0_20)
#define STEEM_HARDFORK_0_20__2539 (STEEM_HARDFORK_0_20)
#define STEEM_HARDFORK_0_20__2642 (STEEM_HARDFORK_0_20)
#define STEEM_HARDFORK_0_20__2651 (STEEM_HARDFORK_0_20)

#define STEEM_HARDFORK_0_20_VERSION hardfork_version( 0, 20 )

Expand Down
2 changes: 2 additions & 0 deletions libraries/protocol/include/steem/protocol/config.hpp
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Original file line number Diff line number Diff line change
Expand Up @@ -30,6 +30,7 @@


#define STEEM_MIN_ACCOUNT_CREATION_FEE 0
#define STEEM_MAX_ACCOUNT_CREATION_FEE int64_t(1000000000)

#define STEEM_OWNER_AUTH_RECOVERY_PERIOD fc::seconds(60)
#define STEEM_ACCOUNT_RECOVERY_REQUEST_EXPIRATION_PERIOD fc::seconds(12)
Expand Down Expand Up @@ -62,6 +63,7 @@
#define STEEM_UPVOTE_LOCKOUT_HF17 (fc::seconds(12))

#define STEEM_MIN_ACCOUNT_CREATION_FEE 1
#define STEEM_MAX_ACCOUNT_CREATION_FEE int64_t(1000000000)

#define STEEM_OWNER_AUTH_RECOVERY_PERIOD fc::days(30)
#define STEEM_ACCOUNT_RECOVERY_REQUEST_EXPIRATION_PERIOD fc::days(1)
Expand Down
3 changes: 2 additions & 1 deletion libraries/protocol/include/steem/protocol/steem_operations.hpp
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Original file line number Diff line number Diff line change
Expand Up @@ -206,6 +206,7 @@ namespace steem { namespace protocol {
{
account_name_type creator;
asset fee;
asset fee_discount;
extensions_type extensions;

void get_required_active_authorities( flat_set< account_name_type >& a ) const { a.insert( creator ); }
Expand Down Expand Up @@ -1142,7 +1143,7 @@ FC_REFLECT( steem::protocol::escrow_transfer_operation, (from)(to)(sbd_amount)(s
FC_REFLECT( steem::protocol::escrow_approve_operation, (from)(to)(agent)(who)(escrow_id)(approve) );
FC_REFLECT( steem::protocol::escrow_dispute_operation, (from)(to)(agent)(who)(escrow_id) );
FC_REFLECT( steem::protocol::escrow_release_operation, (from)(to)(agent)(who)(receiver)(escrow_id)(sbd_amount)(steem_amount) );
FC_REFLECT( steem::protocol::claim_account_operation, (creator)(fee)(extensions) );
FC_REFLECT( steem::protocol::claim_account_operation, (creator)(fee)(fee_discount)(extensions) );
FC_REFLECT( steem::protocol::create_claimed_account_operation, (creator)(new_account_name)(owner)(active)(posting)(memo_key)(json_metadata)(extensions) );
FC_REFLECT( steem::protocol::request_account_recovery_operation, (recovery_account)(account_to_recover)(new_owner_authority)(extensions) );
FC_REFLECT( steem::protocol::recover_account_operation, (account_to_recover)(new_owner_authority)(recent_owner_authority)(extensions) );
Expand Down
8 changes: 7 additions & 1 deletion libraries/protocol/steem_operations.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -141,6 +141,12 @@ namespace steem { namespace protocol {
validate_account_name( creator );
FC_ASSERT( is_asset_type( fee, STEEM_SYMBOL ), "Account creation fee must be STEEM" );
FC_ASSERT( fee >= asset( 0, STEEM_SYMBOL ), "Account creation fee cannot be negative" );
FC_ASSERT( fee <= asset( STEEM_MAX_ACCOUNT_CREATION_FEE, STEEM_SYMBOL ), "Account creation fee cannot be too large" );
FC_ASSERT( is_asset_type( fee_discount, STEEM_SYMBOL ), "Fee discount must be STEEM" );
FC_ASSERT( fee_discount >= asset( 0, STEEM_SYMBOL ), "Fee discount cannot be negative" );
FC_ASSERT( fee_discount <= asset( STEEM_MAX_ACCOUNT_CREATION_FEE, STEEM_SYMBOL ), "Fee discount cannot be too large" );
FC_ASSERT( fee + fee_discount <= asset( STEEM_MAX_ACCOUNT_CREATION_FEE, STEEM_SYMBOL ), "Sum of fee and discount cannot be too large" );

FC_ASSERT( extensions.size() == 0, "There are no extensions for claim_account_operation." );
}

Expand Down Expand Up @@ -227,7 +233,7 @@ namespace steem { namespace protocol {
asset account_creation_fee;
fc::raw::unpack_from_vector( itr->second, account_creation_fee );
FC_ASSERT( account_creation_fee.symbol == STEEM_SYMBOL, "account_creation_fee must be in STEEM" );
FC_ASSERT( account_creation_fee.amount >= STEEM_MIN_ACCOUNT_CREATION_FEE , "account_creation_fee smaller than minimum account creation fee" );
FC_ASSERT( account_creation_fee.amount >= STEEM_MIN_ACCOUNT_CREATION_FEE, "account_creation_fee smaller than minimum account creation fee" );
}

itr = props.find( "maximum_block_size" );
Expand Down

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