void_result asset_global_settle_evaluator::do_evaluate(const asset_global_settle_evaluator::operation_type& op)
{
const database& d = db();
asset_to_settle = &op.asset_to_settle(d);
FC_ASSERT(asset_to_settle->is_market_issued());
FC_ASSERT(asset_to_settle->can_global_settle());
FC_ASSERT(asset_to_settle->issuer == op.issuer );
FC_ASSERT(asset_to_settle->dynamic_data(d).current_supply > 0);
const auto& idx = d.get_index_type<call_order_index>().indices().get<by_collateral>();
assert( !idx.empty() );
auto itr = idx.lower_bound(boost::make_tuple(price::min(asset_to_settle->bitasset_data(d).options.short_backing_asset,
op.asset_to_settle)));
assert( itr != idx.end() && itr->debt_type() == op.asset_to_settle );
const call_order_object& least_collateralized_short = *itr;
FC_ASSERT(least_collateralized_short.get_debt() * op.settle_price <= least_collateralized_short.get_collateral(),
"Cannot force settle at supplied price: least collateralized short lacks sufficient collateral to settle.");
return void_result();
}
void database::clear_expired_orders()
{
detail::with_skip_flags( *this,
get_node_properties().skip_flags | skip_authority_check, [&](){
transaction_evaluation_state cancel_context(this);
//Cancel expired limit orders
auto& limit_index = get_index_type<limit_order_index>().indices().get<by_expiration>();
while( !limit_index.empty() && limit_index.begin()->expiration <= head_block_time() )
{
limit_order_cancel_operation canceler;
const limit_order_object& order = *limit_index.begin();
canceler.fee_paying_account = order.seller;
canceler.order = order.id;
apply_operation(cancel_context, canceler);
}
});
//Process expired force settlement orders
auto& settlement_index = get_index_type<force_settlement_index>().indices().get<by_expiration>();
if( !settlement_index.empty() )
{
asset_id_type current_asset = settlement_index.begin()->settlement_asset_id();
asset max_settlement_volume;
auto next_asset = [¤t_asset, &settlement_index] {
auto bound = settlement_index.upper_bound(current_asset);
if( bound == settlement_index.end() )
return false;
current_asset = bound->settlement_asset_id();
return true;
};
// At each iteration, we either consume the current order and remove it, or we move to the next asset
for( auto itr = settlement_index.lower_bound(current_asset);
itr != settlement_index.end();
itr = settlement_index.lower_bound(current_asset) )
{
const force_settlement_object& order = *itr;
auto order_id = order.id;
current_asset = order.settlement_asset_id();
const asset_object& mia_object = get(current_asset);
const asset_bitasset_data_object mia = mia_object.bitasset_data(*this);
// Has this order not reached its settlement date?
if( order.settlement_date > head_block_time() )
{
if( next_asset() )
continue;
break;
}
// Can we still settle in this asset?
if( mia.current_feed.settlement_price.is_null() )
{
ilog("Canceling a force settlement in ${asset} because settlement price is null",
("asset", mia_object.symbol));
cancel_order(order);
continue;
}
if( max_settlement_volume.asset_id != current_asset )
max_settlement_volume = mia_object.amount(mia.max_force_settlement_volume(mia_object.dynamic_data(*this).current_supply));
if( mia.force_settled_volume >= max_settlement_volume.amount )
{
/*
ilog("Skipping force settlement in ${asset}; settled ${settled_volume} / ${max_volume}",
("asset", mia_object.symbol)("settlement_price_null",mia.current_feed.settlement_price.is_null())
("settled_volume", mia.force_settled_volume)("max_volume", max_settlement_volume));
*/
if( next_asset() )
continue;
break;
}
auto& pays = order.balance;
auto receives = (order.balance * mia.current_feed.settlement_price);
receives.amount = (fc::uint128_t(receives.amount.value) *
(GRAPHENE_100_PERCENT - mia.options.force_settlement_offset_percent) / GRAPHENE_100_PERCENT).to_uint64();
assert(receives <= order.balance * mia.current_feed.settlement_price);
price settlement_price = pays / receives;
auto& call_index = get_index_type<call_order_index>().indices().get<by_collateral>();
asset settled = mia_object.amount(mia.force_settled_volume);
// Match against the least collateralized short until the settlement is finished or we reach max settlements
while( settled < max_settlement_volume && find_object(order_id) )
{
auto itr = call_index.lower_bound(boost::make_tuple(price::min(mia_object.bitasset_data(*this).options.short_backing_asset,
mia_object.get_id())));
// There should always be a call order, since asset exists!
assert(itr != call_index.end() && itr->debt_type() == mia_object.get_id());
asset max_settlement = max_settlement_volume - settled;
settled += match(*itr, order, settlement_price, max_settlement);
}
modify(mia, [settled](asset_bitasset_data_object& b) {
b.force_settled_volume = settled.amount;
});
}
}
}
