Further speedups of TradeStatistics3.isValid

Use a Map to speed up 'PaymentMethod.getPaymentMethod', called from
'isValid', instead of scanning the payment method list every invocation.
Make the list immutable to ensure the map never goes stale, which is OK
since no code modified it outside PaymentMethod's static initialisation.

Also speed up the global accessor 'TradeLimits.getMaxTradeLimit', by
caching the DAO param value in a volatile field, cleared upon each new
block arrival.

Furthermore, speed up 'TradeLimits.getFirstMonthRiskBasedTradeLimit' by
simplifying the rounding logic to avoid a pass through the (rather slow)
BigDecimal type.

core/src/main/java/bisq/core/payment/TradeLimits.java

@@ -19,9 +19,9 @@ package bisq.core.payment;
 
 import bisq.core.dao.governance.param.Param;
 import bisq.core.dao.governance.period.PeriodService;
+import bisq.core.dao.state.DaoStateListener;
 import bisq.core.dao.state.DaoStateService;
-
+import bisq.core.dao.state.model.blockchain.Block;
-import bisq.common.util.MathUtils;
 
 import org.bitcoinj.core.Coin;
 
@@ -37,7 +37,7 @@ import javax.annotation.Nullable;
 
 @Slf4j
 @Singleton
-public class TradeLimits {
+public class TradeLimits implements DaoStateListener {
     @Nullable
     @Getter
     private static TradeLimits INSTANCE;
@@ -45,10 +45,14 @@ public class TradeLimits {
     private final DaoStateService daoStateService;
     private final PeriodService periodService;
 
+    private volatile Coin cachedMaxTradeLimit;
+
     @Inject
     public TradeLimits(DaoStateService daoStateService, PeriodService periodService) {
         this.daoStateService = daoStateService;
         this.periodService = periodService;
+
+        daoStateService.addDaoStateListener(this);
         INSTANCE = this;
     }
 
@@ -58,6 +62,10 @@ public class TradeLimits {
         // guice.
     }
 
+    @Override
+    public void onParseBlockCompleteAfterBatchProcessing(Block block) {
+        cachedMaxTradeLimit = null;
+    }
 
     /**
      * The default trade limits defined as statics in PaymentMethod are only used until the DAO
@@ -67,7 +75,11 @@ public class TradeLimits {
      * @return the maximum trade limit set by the DAO.
      */
     public Coin getMaxTradeLimit() {
-        return daoStateService.getParamValueAsCoin(Param.MAX_TRADE_LIMIT, periodService.getChainHeight());
+        Coin limit = cachedMaxTradeLimit;
+        if (limit == null) {
+            cachedMaxTradeLimit = limit = daoStateService.getParamValueAsCoin(Param.MAX_TRADE_LIMIT, periodService.getChainHeight());
+        }
+        return limit;
     }
 
     // We possibly rounded value for the first month gets multiplied by 4 to get the trade limit after the account
@@ -98,8 +110,6 @@ public class TradeLimits {
         long smallestLimit = maxLimit / (4 * riskFactor);  // e.g. 100000000 / 32 = 3125000
         // We want to avoid more than 4 decimal places (100000000 / 32 = 3125000 or 1 BTC / 32 = 0.03125 BTC).
         // We want rounding to 0.0313 BTC
-        double decimalForm = MathUtils.scaleDownByPowerOf10((double) smallestLimit, 8);
+        return ((smallestLimit + 5000L) / 10000L) * 10000L;
-        double rounded = MathUtils.roundDouble(decimalForm, 4);
-        return MathUtils.roundDoubleToLong(MathUtils.scaleUpByPowerOf10(rounded, 8));
     }
 }

core/src/main/java/bisq/core/payment/payload/PaymentMethod.java

@@ -26,11 +26,13 @@ import bisq.common.proto.persistable.PersistablePayload;
 
 import org.bitcoinj.core.Coin;
 
-import java.util.ArrayList;
+import java.util.Comparator;
-import java.util.Arrays;
 import java.util.List;
+import java.util.Map;
 import java.util.Optional;
 import java.util.concurrent.TimeUnit;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
 
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
@@ -196,8 +198,7 @@ public final class PaymentMethod implements PersistablePayload, Comparable<Payme
 
     // The limit and duration assignment must not be changed as that could break old offers (if amount would be higher
     // than new trade limit) and violate the maker expectation when he created the offer (duration).
-    @Getter
+    private static final List<PaymentMethod> PAYMENT_METHODS = Stream.of(
-    private final static List<PaymentMethod> paymentMethods = new ArrayList<>(Arrays.asList(
             // EUR
             SEPA = new PaymentMethod(SEPA_ID, 6 * DAY, DEFAULT_TRADE_LIMIT_HIGH_RISK),
             SEPA_INSTANT = new PaymentMethod(SEPA_INSTANT_ID, DAY, DEFAULT_TRADE_LIMIT_HIGH_RISK),
@@ -277,18 +278,15 @@ public final class PaymentMethod implements PersistablePayload, Comparable<Payme
             BLOCK_CHAINS_INSTANT = new PaymentMethod(BLOCK_CHAINS_INSTANT_ID, TimeUnit.HOURS.toMillis(1), DEFAULT_TRADE_LIMIT_VERY_LOW_RISK),
             // BsqSwap
             BSQ_SWAP = new PaymentMethod(BSQ_SWAP_ID, 1, DEFAULT_TRADE_LIMIT_VERY_LOW_RISK)
-    ));
+    ).sorted(Comparator.comparing(
+            m -> m.id.equals(CLEAR_X_CHANGE_ID) ? "ZELLE" : m.id)
+    ).collect(Collectors.toUnmodifiableList());
 
-    static {
+    private static final Map<String, PaymentMethod> PAYMENT_METHOD_MAP = PAYMENT_METHODS.stream()
-        paymentMethods.sort((o1, o2) -> {
+            .collect(Collectors.toUnmodifiableMap(m -> m.id, m -> m));
-            String id1 = o1.getId();
+
-            if (id1.equals(CLEAR_X_CHANGE_ID))
+    public static List<PaymentMethod> getPaymentMethods() {
-                id1 = "ZELLE";
+        return PAYMENT_METHODS;
-            String id2 = o2.getId();
-            if (id2.equals(CLEAR_X_CHANGE_ID))
-                id2 = "ZELLE";
-            return id1.compareTo(id2);
-        });
     }
 
     public static PaymentMethod getDummyPaymentMethod(String id) {
@@ -371,9 +369,7 @@ public final class PaymentMethod implements PersistablePayload, Comparable<Payme
 
     // We look up only our active payment methods not retired ones.
     public static Optional<PaymentMethod> getActivePaymentMethod(String id) {
-        return paymentMethods.stream()
+        return Optional.ofNullable(PAYMENT_METHOD_MAP.get(id));
-                .filter(e -> e.getId().equals(id))
-                .findFirst();
     }
 
     public Coin getMaxTradeLimitAsCoin(String currencyCode) {