Add preferred-blockchain filtering to /websockets/crosschain/tradeoffers via foreignBlockchain query param

src/main/java/org/qortal/api/websocket/TradeOffersWebSocket.java

@@ -3,6 +3,8 @@ package org.qortal.api.websocket;
 import java.io.IOException;
 import java.io.StringWriter;
 import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
@@ -42,18 +44,23 @@ public class TradeOffersWebSocket extends ApiWebSocket implements Listener {
 
 	private static final Logger LOGGER = LogManager.getLogger(TradeOffersWebSocket.class);
 
-	private static final Map<String, AcctMode> previousAtModes = new HashMap<>();
+	private static class CachedOfferInfo {
+		public final Map<String, AcctMode> previousAtModes = new HashMap<>();
 
 		// OFFERING
-	private static final Map<String, CrossChainOfferSummary> currentSummaries = new HashMap<>();
+		public final Map<String, CrossChainOfferSummary> currentSummaries = new HashMap<>();
 		// REDEEMED/REFUNDED/CANCELLED
-	private static final Map<String, CrossChainOfferSummary> historicSummaries = new HashMap<>();
+		public final Map<String, CrossChainOfferSummary> historicSummaries = new HashMap<>();
+	}
+	// Manual synchronization
+	private static final Map<String, CachedOfferInfo> cachedInfoByBlockchain = new HashMap<>();
 
 	private static final Predicate<CrossChainOfferSummary> isHistoric = offerSummary
 			-> offerSummary.getMode() == AcctMode.REDEEMED
 			|| offerSummary.getMode() == AcctMode.REFUNDED
 			|| offerSummary.getMode() == AcctMode.CANCELLED;
 
+	private static final Map<Session, String> sessionBlockchain = Collections.synchronizedMap(new HashMap<>());
 
 	@Override
 	public void configure(WebSocketServletFactory factory) {
@@ -79,7 +86,6 @@ public class TradeOffersWebSocket extends ApiWebSocket implements Listener {
 		BlockData blockData = ((Controller.NewBlockEvent) event).getBlockData();
 
 		// Process any new info
-		List<CrossChainOfferSummary> crossChainOfferSummaries = new ArrayList<>();
 
 		try (final Repository repository = RepositoryManager.getRepository()) {
 			// Find any new/changed trade ATs since this block
@@ -88,8 +94,14 @@ public class TradeOffersWebSocket extends ApiWebSocket implements Listener {
 			final Long expectedValue = null;
 			final Integer minimumFinalHeight = blockData.getHeight();
 
-			// Loop for all different types of trade offer?
+			for (SupportedBlockchain blockchain : SupportedBlockchain.values()) {
-			Map<ByteArray, Supplier<ACCT>> acctsByCodeHash = SupportedBlockchain.getAcctMap();
+				Map<ByteArray, Supplier<ACCT>> acctsByCodeHash = SupportedBlockchain.getFilteredAcctMap(blockchain);
+
+				List<CrossChainOfferSummary> crossChainOfferSummaries = new ArrayList<>();
+
+				synchronized (cachedInfoByBlockchain) {
+					CachedOfferInfo cachedInfo = cachedInfoByBlockchain.computeIfAbsent(blockchain.name(), k -> new CachedOfferInfo());
+
 					for (Map.Entry<ByteArray, Supplier<ACCT>> acctInfo : acctsByCodeHash.entrySet()) {
 						byte[] codeHash = acctInfo.getKey().value;
 						ACCT acct = acctInfo.getValue().get();
@@ -100,67 +112,94 @@ public class TradeOffersWebSocket extends ApiWebSocket implements Listener {
 
 						crossChainOfferSummaries.addAll(produceSummaries(repository, acct, atStates, blockData.getTimestamp()));
 					}
-		} catch (DataException e) {
-			// No output this time
-			return;
-		}
 
-		synchronized (previousAtModes) {
 					// Remove any entries unchanged from last time
-			crossChainOfferSummaries.removeIf(offerSummary -> previousAtModes.get(offerSummary.getQortalAtAddress()) == offerSummary.getMode());
+					crossChainOfferSummaries.removeIf(offerSummary -> cachedInfo.previousAtModes.get(offerSummary.getQortalAtAddress()) == offerSummary.getMode());
 
-			// Don't send anything if no results
+					// Skip to next blockchain if nothing has changed (for this blockchain)
 					if (crossChainOfferSummaries.isEmpty())
-				return;
+						continue;
 
 					// Update
 					for (CrossChainOfferSummary offerSummary : crossChainOfferSummaries) {
-				previousAtModes.put(offerSummary.qortalAtAddress, offerSummary.getMode());
+						cachedInfo.previousAtModes.put(offerSummary.qortalAtAddress, offerSummary.getMode());
 						LOGGER.trace(() -> String.format("Block height: %d, AT: %s, mode: %s", blockData.getHeight(), offerSummary.qortalAtAddress, offerSummary.getMode().name()));
 
 						switch (offerSummary.getMode()) {
 							case OFFERING:
-						currentSummaries.put(offerSummary.qortalAtAddress, offerSummary);
+								cachedInfo.currentSummaries.put(offerSummary.qortalAtAddress, offerSummary);
-						historicSummaries.remove(offerSummary.qortalAtAddress);
+								cachedInfo.historicSummaries.remove(offerSummary.qortalAtAddress);
 								break;
 
 							case REDEEMED:
 							case REFUNDED:
 							case CANCELLED:
-						currentSummaries.remove(offerSummary.qortalAtAddress);
+								cachedInfo.currentSummaries.remove(offerSummary.qortalAtAddress);
-						historicSummaries.put(offerSummary.qortalAtAddress, offerSummary);
+								cachedInfo.historicSummaries.put(offerSummary.qortalAtAddress, offerSummary);
 								break;
 
 							case TRADING:
-						currentSummaries.remove(offerSummary.qortalAtAddress);
+								cachedInfo.currentSummaries.remove(offerSummary.qortalAtAddress);
-						historicSummaries.remove(offerSummary.qortalAtAddress);
+								cachedInfo.historicSummaries.remove(offerSummary.qortalAtAddress);
 								break;
 						}
 					}
 
 					// Remove any historic offers that are over 24 hours old
 					final long tooOldTimestamp = NTP.getTime() - 24 * 60 * 60 * 1000L;
-			historicSummaries.values().removeIf(historicSummary -> historicSummary.getTimestamp() < tooOldTimestamp);
+					cachedInfo.historicSummaries.values().removeIf(historicSummary -> historicSummary.getTimestamp() < tooOldTimestamp);
 				}
 
 				// Notify sessions
-		for (Session session : getSessions())
+				for (Session session : getSessions()) {
+					// Only send if this session has this/no preferred blockchain
+					String preferredBlockchain = sessionBlockchain.get(session);
+
+					if (preferredBlockchain == null || preferredBlockchain.equals(blockchain.name()))
 						sendOfferSummaries(session, crossChainOfferSummaries);
 				}
 
+			}
+		} catch (DataException e) {
+			// No output this time
+		}
+	}
+
 	@OnWebSocketConnect
 	@Override
 	public void onWebSocketConnect(Session session) {
 		Map<String, List<String>> queryParams = session.getUpgradeRequest().getParameterMap();
 		final boolean includeHistoric = queryParams.get("includeHistoric") != null;
 
+		List<String> foreignBlockchains = queryParams.get("foreignBlockchain");
+		final String foreignBlockchain = foreignBlockchains == null ? null : foreignBlockchains.get(0);
+
+		// Make sure blockchain (if any) is valid
+		if (foreignBlockchain != null && SupportedBlockchain.fromString(foreignBlockchain) == null) {
+			session.close(4003, "unknown blockchain: " + foreignBlockchain);
+			return;
+		}
+
+		// save session's preferred blockchain (if any)
+		sessionBlockchain.put(session, foreignBlockchain);
+
 		List<CrossChainOfferSummary> crossChainOfferSummaries = new ArrayList<>();
 
-		synchronized (previousAtModes) {
+		synchronized (cachedInfoByBlockchain) {
-			crossChainOfferSummaries.addAll(currentSummaries.values());
+			Collection<CachedOfferInfo> cachedInfos;
+
+			if (foreignBlockchain == null)
+				// No preferred blockchain, so iterate through all of them
+				cachedInfos = cachedInfoByBlockchain.values();
+			else
+				cachedInfos = Collections.singleton(cachedInfoByBlockchain.computeIfAbsent(foreignBlockchain, k -> new CachedOfferInfo()));
+
+			for (CachedOfferInfo cachedInfo : cachedInfos) {
+				crossChainOfferSummaries.addAll(cachedInfo.currentSummaries.values());
 
 				if (includeHistoric)
-				crossChainOfferSummaries.addAll(historicSummaries.values());
+					crossChainOfferSummaries.addAll(cachedInfo.historicSummaries.values());
+			}
 		}
 
 		if (!sendOfferSummaries(session, crossChainOfferSummaries)) {
@@ -174,6 +213,9 @@ public class TradeOffersWebSocket extends ApiWebSocket implements Listener {
 	@OnWebSocketClose
 	@Override
 	public void onWebSocketClose(Session session, int statusCode, String reason) {
+		// clean up
+		sessionBlockchain.remove(session);
+
 		super.onWebSocketClose(session, statusCode, reason);
 	}
 
@@ -208,7 +250,11 @@ public class TradeOffersWebSocket extends ApiWebSocket implements Listener {
 		Long expectedValue = (long) AcctMode.OFFERING.value;
 		Integer minimumFinalHeight = null;
 
-		Map<ByteArray, Supplier<ACCT>> acctsByCodeHash = SupportedBlockchain.getAcctMap();
+		for (SupportedBlockchain blockchain : SupportedBlockchain.values()) {
+			Map<ByteArray, Supplier<ACCT>> acctsByCodeHash = SupportedBlockchain.getFilteredAcctMap(blockchain);
+
+			CachedOfferInfo cachedInfo = cachedInfoByBlockchain.computeIfAbsent(blockchain.name(), k -> new CachedOfferInfo());
+
 			for (Map.Entry<ByteArray, Supplier<ACCT>> acctInfo : acctsByCodeHash.entrySet()) {
 				byte[] codeHash = acctInfo.getKey().value;
 				ACCT acct = acctInfo.getValue().get();
@@ -222,13 +268,14 @@ public class TradeOffersWebSocket extends ApiWebSocket implements Listener {
 					throw new DataException("Couldn't fetch current trades from repository");
 
 				// Save initial AT modes
-			previousAtModes.putAll(initialAtStates.stream().collect(Collectors.toMap(ATStateData::getATAddress, atState -> AcctMode.OFFERING)));
+				cachedInfo.previousAtModes.putAll(initialAtStates.stream().collect(Collectors.toMap(ATStateData::getATAddress, atState -> AcctMode.OFFERING)));
 
 				// Convert to offer summaries
-			currentSummaries.putAll(produceSummaries(repository, acct, initialAtStates, null).stream()
+				cachedInfo.currentSummaries.putAll(produceSummaries(repository, acct, initialAtStates, null).stream()
 										.collect(Collectors.toMap(CrossChainOfferSummary::getQortalAtAddress, offerSummary -> offerSummary)));
 			}
 		}
+	}
 
 	private static void populateHistoricSummaries(Repository repository) throws DataException {
 		// We want REDEEMED/REFUNDED/CANCELLED trades over the last 24 hours
@@ -243,7 +290,11 @@ public class TradeOffersWebSocket extends ApiWebSocket implements Listener {
 		Long expectedValue = null;
 		++minimumFinalHeight; // because height is just *before* timestamp
 
-		Map<ByteArray, Supplier<ACCT>> acctsByCodeHash = SupportedBlockchain.getAcctMap();
+		for (SupportedBlockchain blockchain : SupportedBlockchain.values()) {
+			Map<ByteArray, Supplier<ACCT>> acctsByCodeHash = SupportedBlockchain.getFilteredAcctMap(blockchain);
+
+			CachedOfferInfo cachedInfo = cachedInfoByBlockchain.computeIfAbsent(blockchain.name(), k -> new CachedOfferInfo());
+
 			for (Map.Entry<ByteArray, Supplier<ACCT>> acctInfo : acctsByCodeHash.entrySet()) {
 				byte[] codeHash = acctInfo.getKey().value;
 				ACCT acct = acctInfo.getValue().get();
@@ -262,10 +313,11 @@ public class TradeOffersWebSocket extends ApiWebSocket implements Listener {
 						continue;
 
 					// Add summary to initial burst
-				historicSummaries.put(historicOfferSummary.getQortalAtAddress(), historicOfferSummary);
+					cachedInfo.historicSummaries.put(historicOfferSummary.getQortalAtAddress(), historicOfferSummary);
 
 					// Save initial AT mode
-				previousAtModes.put(historicOfferSummary.getQortalAtAddress(), historicOfferSummary.getMode());
+					cachedInfo.previousAtModes.put(historicOfferSummary.getQortalAtAddress(), historicOfferSummary.getMode());
+				}
 			}
 		}
 	}

src/main/java/org/qortal/crosschain/SupportedBlockchain.java

@@ -67,6 +67,10 @@ public enum SupportedBlockchain {
 		return supportedAcctsByCodeHash;
 	}
 
+	public static SupportedBlockchain fromString(String name) {
+		return blockchainsByName.get(name);
+	}
+
 	public static Map<ByteArray, Supplier<ACCT>> getFilteredAcctMap(SupportedBlockchain blockchain) {
 		if (blockchain == null)
 			return getAcctMap();