static void publishOffer(
Transaction transaction, Attachment.MonetarySystemPublishExchangeOffer attachment) {
CurrencyBuyOffer previousOffer =
CurrencyBuyOffer.getOffer(attachment.getCurrencyId(), transaction.getSenderId());
if (previousOffer != null) {
removeOffer(previousOffer);
}
CurrencyBuyOffer.addOffer(transaction, attachment);
CurrencySellOffer.addOffer(transaction, attachment);
}
static void exchangeCurrencyForNXT(
Transaction transaction,
Account account,
final long currencyId,
final long rateNQT,
long units) {
long extraAmountNQT = 0;
long remainingUnits = units;
List<CurrencyBuyOffer> currencyBuyOffers = new ArrayList<>();
try (DbIterator<CurrencyBuyOffer> offers =
CurrencyBuyOffer.getOffers(
new ValidOffersDbClause(currencyId, rateNQT, true),
0,
-1,
" ORDER BY rate DESC, creation_height ASC, transaction_height ASC, transaction_index ASC ")) {
for (CurrencyBuyOffer offer : offers) {
currencyBuyOffers.add(offer);
}
}
for (CurrencyBuyOffer offer : currencyBuyOffers) {
if (remainingUnits == 0) {
break;
}
long curUnits = Math.min(Math.min(remainingUnits, offer.getSupply()), offer.getLimit());
long curAmountNQT = Math.multiplyExact(curUnits, offer.getRateNQT());
extraAmountNQT = Math.addExact(extraAmountNQT, curAmountNQT);
remainingUnits = Math.subtractExact(remainingUnits, curUnits);
offer.decreaseLimitAndSupply(curUnits);
long excess = offer.getCounterOffer().increaseSupply(curUnits);
Account counterAccount = Account.getAccount(offer.getAccountId());
counterAccount.addToBalanceNQT(-curAmountNQT);
counterAccount.addToCurrencyUnits(currencyId, curUnits);
counterAccount.addToUnconfirmedCurrencyUnits(currencyId, excess);
Exchange.addExchange(
transaction, currencyId, offer, account.getId(), offer.getAccountId(), curUnits);
}
account.addToBalanceAndUnconfirmedBalanceNQT(extraAmountNQT);
account.addToCurrencyUnits(currencyId, -(units - remainingUnits));
account.addToUnconfirmedCurrencyUnits(currencyId, remainingUnits);
}
static void removeOffer(CurrencyBuyOffer buyOffer) {
CurrencySellOffer sellOffer = buyOffer.getCounterOffer();
CurrencyBuyOffer.remove(buyOffer);
CurrencySellOffer.remove(sellOffer);
Account account = Account.getAccount(buyOffer.getAccountId());
account.addToUnconfirmedBalanceNQT(
Math.multiplyExact(buyOffer.getSupply(), buyOffer.getRateNQT()));
account.addToUnconfirmedCurrencyUnits(buyOffer.getCurrencyId(), sellOffer.getSupply());
}
static {
Nxt.getBlockchainProcessor()
.addListener(
block -> {
if (block.getHeight() <= Constants.MONETARY_SYSTEM_BLOCK) {
return;
}
List<CurrencyBuyOffer> expired = new ArrayList<>();
try (DbIterator<CurrencyBuyOffer> offers =
CurrencyBuyOffer.getOffers(
new DbClause.IntClause("expiration_height", block.getHeight()), 0, -1)) {
for (CurrencyBuyOffer offer : offers) {
expired.add(offer);
}
}
expired.forEach(CurrencyExchangeOffer::removeOffer);
},
BlockchainProcessor.Event.AFTER_BLOCK_APPLY);
}
