void database::_apply_block( const signed_block& next_block )
{ try {
uint32_t next_block_num = next_block.block_num();
uint32_t skip = get_node_properties().skip_flags;
_applied_ops.clear();
FC_ASSERT( (skip & skip_merkle_check) || next_block.transaction_merkle_root == next_block.calculate_merkle_root(), "", ("next_block.transaction_merkle_root",next_block.transaction_merkle_root)("calc",next_block.calculate_merkle_root())("next_block",next_block)("id",next_block.id()) );
const witness_object& signing_witness = validate_block_header(skip, next_block);
const auto& global_props = get_global_properties();
const auto& dynamic_global_props = get<dynamic_global_property_object>(dynamic_global_property_id_type());
bool maint_needed = (dynamic_global_props.next_maintenance_time <= next_block.timestamp);
_current_block_num = next_block_num;
_current_trx_in_block = 0;
for( const auto& trx : next_block.transactions )
{
/* We do not need to push the undo state for each transaction
* because they either all apply and are valid or the
* entire block fails to apply. We only need an "undo" state
* for transactions when validating broadcast transactions or
* when building a block.
*/
apply_transaction( trx, skip );
++_current_trx_in_block;
}
update_global_dynamic_data(next_block);
update_signing_witness(signing_witness, next_block);
update_last_irreversible_block();
// Are we at the maintenance interval?
if( maint_needed )
perform_chain_maintenance(next_block, global_props);
create_block_summary(next_block);
clear_expired_transactions();
clear_expired_proposals();
clear_expired_orders();
update_expired_feeds();
update_withdraw_permissions();
// n.b., update_maintenance_flag() happens this late
// because get_slot_time() / get_slot_at_time() is needed above
// TODO: figure out if we could collapse this function into
// update_global_dynamic_data() as perhaps these methods only need
// to be called for header validation?
update_maintenance_flag( maint_needed );
update_witness_schedule();
if( !_node_property_object.debug_updates.empty() )
apply_debug_updates();
// notify observers that the block has been applied
applied_block( next_block ); //emit
_applied_ops.clear();
notify_changed_objects();
} FC_CAPTURE_AND_RETHROW( (next_block.block_num()) ) }
void database::update_global_dynamic_data( const signed_block& b )
{
const dynamic_global_property_object& _dgp =
dynamic_global_property_id_type(0)(*this);
uint32_t missed_blocks = get_slot_at_time( b.timestamp );
assert( missed_blocks != 0 );
missed_blocks--;
// dynamic global properties updating
modify( _dgp, [&]( dynamic_global_property_object& dgp ){
if( BOOST_UNLIKELY( b.block_num() == 1 ) )
dgp.recently_missed_count = 0;
else if( _checkpoints.size() && _checkpoints.rbegin()->first >= b.block_num() )
dgp.recently_missed_count = 0;
else if( missed_blocks )
dgp.recently_missed_count += GRAPHENE_RECENTLY_MISSED_COUNT_INCREMENT*missed_blocks;
else if( dgp.recently_missed_count > GRAPHENE_RECENTLY_MISSED_COUNT_INCREMENT )
dgp.recently_missed_count -= GRAPHENE_RECENTLY_MISSED_COUNT_DECREMENT;
else if( dgp.recently_missed_count > 0 )
dgp.recently_missed_count--;
dgp.head_block_number = b.block_num();
dgp.head_block_id = b.id();
dgp.time = b.timestamp;
dgp.current_witness = b.witness;
dgp.recent_slots_filled = (
(dgp.recent_slots_filled << 1)
+ 1) << missed_blocks;
dgp.current_aslot += missed_blocks+1;
});
if( !(get_node_properties().skip_flags & skip_undo_history_check) )
{
GRAPHENE_ASSERT( _dgp.recently_missed_count < GRAPHENE_MAX_UNDO_HISTORY, undo_database_exception,
"The database does not have enough undo history to support a blockchain with so many missed blocks. "
"Please add a checkpoint if you would like to continue applying blocks beyond this point.",
("recently_missed",_dgp.recently_missed_count)("max_undo",GRAPHENE_MAX_UNDO_HISTORY) );
}
_undo_db.set_max_size( _dgp.recently_missed_count + GRAPHENE_MIN_UNDO_HISTORY );
_fork_db.set_max_size( _dgp.recently_missed_count + GRAPHENE_MIN_UNDO_HISTORY );
}
processed_transaction database::_apply_transaction(const signed_transaction& trx)
{ try {
uint32_t skip = get_node_properties().skip_flags;
if( true || !(skip&skip_validate) ) /* issue #505 explains why this skip_flag is disabled */
trx.validate();
auto& trx_idx = get_mutable_index_type<transaction_index>();
const chain_id_type& chain_id = get_chain_id();
auto trx_id = trx.id();
FC_ASSERT( (skip & skip_transaction_dupe_check) ||
trx_idx.indices().get<by_trx_id>().find(trx_id) == trx_idx.indices().get<by_trx_id>().end() );
transaction_evaluation_state eval_state(this);
const chain_parameters& chain_parameters = get_global_properties().parameters;
eval_state._trx = &trx;
if( !(skip & (skip_transaction_signatures | skip_authority_check) ) )
{
auto get_active = [&]( account_id_type id ) { return &id(*this).active; };
auto get_owner = [&]( account_id_type id ) { return &id(*this).owner; };
trx.verify_authority( chain_id, get_active, get_owner, get_global_properties().parameters.max_authority_depth );
}
//Skip all manner of expiration and TaPoS checking if we're on block 1; It's impossible that the transaction is
//expired, and TaPoS makes no sense as no blocks exist.
if( BOOST_LIKELY(head_block_num() > 0) )
{
if( !(skip & skip_tapos_check) )
{
const auto& tapos_block_summary = block_summary_id_type( trx.ref_block_num )(*this);
//Verify TaPoS block summary has correct ID prefix, and that this block's time is not past the expiration
FC_ASSERT( trx.ref_block_prefix == tapos_block_summary.block_id._hash[1] );
}
fc::time_point_sec now = head_block_time();
FC_ASSERT( trx.expiration <= now + chain_parameters.maximum_time_until_expiration, "",
("trx.expiration",trx.expiration)("now",now)("max_til_exp",chain_parameters.maximum_time_until_expiration));
FC_ASSERT( now <= trx.expiration, "", ("now",now)("trx.exp",trx.expiration) );
}
//Insert transaction into unique transactions database.
if( !(skip & skip_transaction_dupe_check) )
{
create<transaction_object>([&](transaction_object& transaction) {
transaction.trx_id = trx_id;
transaction.trx = trx;
});
}
eval_state.operation_results.reserve(trx.operations.size());
//Finally process the operations
processed_transaction ptrx(trx);
_current_op_in_trx = 0;
for( const auto& op : ptrx.operations )
{
eval_state.operation_results.emplace_back(apply_operation(eval_state, op));
++_current_op_in_trx;
}
ptrx.operation_results = std::move(eval_state.operation_results);
//Make sure the temp account has no non-zero balances
const auto& index = get_index_type<account_balance_index>().indices().get<by_account_asset>();
auto range = index.equal_range( boost::make_tuple( GRAPHENE_TEMP_ACCOUNT ) );
std::for_each(range.first, range.second, [](const account_balance_object& b) { FC_ASSERT(b.balance == 0); });
return ptrx;
} FC_CAPTURE_AND_RETHROW( (trx) ) }
signed_block database::_generate_block(
fc::time_point_sec when,
witness_id_type witness_id,
const fc::ecc::private_key& block_signing_private_key
)
{
try {
uint32_t skip = get_node_properties().skip_flags;
uint32_t slot_num = get_slot_at_time( when );
FC_ASSERT( slot_num > 0 );
witness_id_type scheduled_witness = get_scheduled_witness( slot_num );
FC_ASSERT( scheduled_witness == witness_id );
const auto& witness_obj = witness_id(*this);
if( !(skip & skip_witness_signature) )
FC_ASSERT( witness_obj.signing_key == block_signing_private_key.get_public_key() );
static const size_t max_block_header_size = fc::raw::pack_size( signed_block_header() ) + 4;
auto maximum_block_size = get_global_properties().parameters.maximum_block_size;
size_t total_block_size = max_block_header_size;
signed_block pending_block;
//
// The following code throws away existing pending_tx_session and
// rebuilds it by re-applying pending transactions.
//
// This rebuild is necessary because pending transactions' validity
// and semantics may have changed since they were received, because
// time-based semantics are evaluated based on the current block
// time. These changes can only be reflected in the database when
// the value of the "when" variable is known, which means we need to
// re-apply pending transactions in this method.
//
_pending_tx_session.reset();
_pending_tx_session = _undo_db.start_undo_session();
uint64_t postponed_tx_count = 0;
// pop pending state (reset to head block state)
for( const processed_transaction& tx : _pending_tx )
{
size_t new_total_size = total_block_size + fc::raw::pack_size( tx );
// postpone transaction if it would make block too big
if( new_total_size >= maximum_block_size )
{
postponed_tx_count++;
continue;
}
try
{
auto temp_session = _undo_db.start_undo_session();
processed_transaction ptx = _apply_transaction( tx );
temp_session.merge();
// We have to recompute pack_size(ptx) because it may be different
// than pack_size(tx) (i.e. if one or more results increased
// their size)
total_block_size += fc::raw::pack_size( ptx );
pending_block.transactions.push_back( ptx );
}
catch ( const fc::exception& e )
{
// Do nothing, transaction will not be re-applied
wlog( "Transaction was not processed while generating block due to ${e}", ("e", e) );
wlog( "The transaction was ${t}", ("t", tx) );
}
}
if( postponed_tx_count > 0 )
{
wlog( "Postponed ${n} transactions due to block size limit", ("n", postponed_tx_count) );
}
_pending_tx_session.reset();
// We have temporarily broken the invariant that
// _pending_tx_session is the result of applying _pending_tx, as
// _pending_tx now consists of the set of postponed transactions.
// However, the push_block() call below will re-create the
// _pending_tx_session.
pending_block.previous = head_block_id();
pending_block.timestamp = when;
pending_block.transaction_merkle_root = pending_block.calculate_merkle_root();
pending_block.witness = witness_id;
if( !(skip & skip_witness_signature) )
pending_block.sign( block_signing_private_key );
// TODO: Move this to _push_block() so session is restored.
if( !(skip & skip_block_size_check) )
{
FC_ASSERT( fc::raw::pack_size(pending_block) <= get_global_properties().parameters.maximum_block_size );
}
push_block( pending_block, skip );
return pending_block;
} FC_CAPTURE_AND_RETHROW( (witness_id) ) }
bool database::_push_block(const signed_block& new_block)
{ try {
uint32_t skip = get_node_properties().skip_flags;
if( !(skip&skip_fork_db) )
{
/// TODO: if the block is greater than the head block and before the next maitenance interval
// verify that the block signer is in the current set of active witnesses.
shared_ptr<fork_item> new_head = _fork_db.push_block(new_block);
//If the head block from the longest chain does not build off of the current head, we need to switch forks.
if( new_head->data.previous != head_block_id() )
{
//If the newly pushed block is the same height as head, we get head back in new_head
//Only switch forks if new_head is actually higher than head
if( new_head->data.block_num() > head_block_num() )
{
wlog( "Switching to fork: ${id}", ("id",new_head->data.id()) );
auto branches = _fork_db.fetch_branch_from(new_head->data.id(), head_block_id());
// pop blocks until we hit the forked block
while( head_block_id() != branches.second.back()->data.previous )
pop_block();
// push all blocks on the new fork
for( auto ritr = branches.first.rbegin(); ritr != branches.first.rend(); ++ritr )
{
ilog( "pushing blocks from fork ${n} ${id}", ("n",(*ritr)->data.block_num())("id",(*ritr)->data.id()) );
optional<fc::exception> except;
try {
undo_database::session session = _undo_db.start_undo_session();
apply_block( (*ritr)->data, skip );
_block_id_to_block.store( (*ritr)->id, (*ritr)->data );
session.commit();
}
catch ( const fc::exception& e ) { except = e; }
if( except )
{
wlog( "exception thrown while switching forks ${e}", ("e",except->to_detail_string() ) );
// remove the rest of branches.first from the fork_db, those blocks are invalid
while( ritr != branches.first.rend() )
{
_fork_db.remove( (*ritr)->data.id() );
++ritr;
}
_fork_db.set_head( branches.second.front() );
// pop all blocks from the bad fork
while( head_block_id() != branches.second.back()->data.previous )
pop_block();
// restore all blocks from the good fork
for( auto ritr = branches.second.rbegin(); ritr != branches.second.rend(); ++ritr )
{
auto session = _undo_db.start_undo_session();
apply_block( (*ritr)->data, skip );
_block_id_to_block.store( new_block.id(), (*ritr)->data );
session.commit();
}
throw *except;
}
}
return true;
}
else return false;
}
}
try {
auto session = _undo_db.start_undo_session();
apply_block(new_block, skip);
_block_id_to_block.store(new_block.id(), new_block);
session.commit();
} catch ( const fc::exception& e ) {
elog("Failed to push new block:\n${e}", ("e", e.to_detail_string()));
_fork_db.remove(new_block.id());
throw;
}
return false;
} FC_CAPTURE_AND_RETHROW( (new_block) ) }
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;
});
}
}
}