subscribe to script hash updates for new mempool txes

src/main/java/com/sparrowwallet/sparrow/event/WalletBlockHeightChangedEvent.java

@@ -3,8 +3,8 @@ package com.sparrowwallet.sparrow.event;
 import com.sparrowwallet.drongo.wallet.Wallet;
 
 /**
- * This event is posted if the wallet block height has changed.
- * Note that it is not posted if the wallet history has also changed - this event is used mainly to ensure the new block height is saved
+ * This event is posted if the wallet's stored block height has changed.
+ *
  */
 public class WalletBlockHeightChangedEvent extends WalletChangedEvent {
     private final Integer blockHeight;

src/main/java/com/sparrowwallet/sparrow/event/WalletChangedEvent.java

@@ -3,7 +3,7 @@ package com.sparrowwallet.sparrow.event;
 import com.sparrowwallet.drongo.wallet.Wallet;
 
 /**
- * The base class for all wallet events that should also trigger saving of the wallet
+ * The base class for all wallet events
  */
 public class WalletChangedEvent {
     private final Wallet wallet;

src/main/java/com/sparrowwallet/sparrow/event/WalletDataChangedEvent.java

@@ -0,0 +1,13 @@
+package com.sparrowwallet.sparrow.event;
+
+import com.sparrowwallet.drongo.wallet.Wallet;
+
+/**
+ * Indicates that the internal data (non-settings) of the wallet has changed, either from a blockchain update or entry label change etc.
+ * Used to trigger a background save of the wallet
+ */
+public class WalletDataChangedEvent extends WalletChangedEvent {
+    public WalletDataChangedEvent(Wallet wallet) {
+        super(wallet);
+    }
+}

src/main/java/com/sparrowwallet/sparrow/event/WalletEntryLabelChangedEvent.java

@@ -3,7 +3,11 @@ package com.sparrowwallet.sparrow.event;
 import com.sparrowwallet.drongo.wallet.Wallet;
 import com.sparrowwallet.sparrow.wallet.Entry;
 
-public class WalletEntryLabelChangedEvent extends WalletChangedEvent {
+/**
+ * This event is fired when a wallet entry (transaction, txi or txo) label is changed.
+ * Extends WalletDataChangedEvent so triggers a background save.
+ */
+public class WalletEntryLabelChangedEvent extends WalletDataChangedEvent {
     private final Entry entry;
 
     public WalletEntryLabelChangedEvent(Wallet wallet, Entry entry) {

src/main/java/com/sparrowwallet/sparrow/event/WalletHistoryChangedEvent.java

@@ -9,13 +9,13 @@ import java.util.stream.Collectors;
 
 /**
  * This is posted by WalletForm once the history of the wallet has been refreshed, and new transactions detected
- * Extends WalletChangedEvent so also saves the wallet.
+ *
  */
-public class WalletHistoryChangedEvent extends WalletBlockHeightChangedEvent {
+public class WalletHistoryChangedEvent extends WalletChangedEvent {
     private final List<WalletNode> historyChangedNodes;
 
-    public WalletHistoryChangedEvent(Wallet wallet, Integer blockHeight, List<WalletNode> historyChangedNodes) {
-        super(wallet, blockHeight);
+    public WalletHistoryChangedEvent(Wallet wallet, List<WalletNode> historyChangedNodes) {
+        super(wallet);
         this.historyChangedNodes = historyChangedNodes;
     }
 

src/main/java/com/sparrowwallet/sparrow/event/WalletNodeHistoryChangedEvent.java

@@ -0,0 +1,43 @@
+package com.sparrowwallet.sparrow.event;
+
+import com.sparrowwallet.drongo.KeyPurpose;
+import com.sparrowwallet.drongo.wallet.Wallet;
+import com.sparrowwallet.drongo.wallet.WalletNode;
+import com.sparrowwallet.sparrow.io.ElectrumServer;
+
+import java.util.List;
+
+/**
+ * Used to notify that a wallet node (identified by it's script hash) has been updated on the blockchain.
+ * Does not extend WalletChangedEvent as the wallet is not known when this is fired.
+ */
+public class WalletNodeHistoryChangedEvent {
+    private final String scriptHash;
+
+    public WalletNodeHistoryChangedEvent(String scriptHash) {
+        this.scriptHash = scriptHash;
+    }
+
+    public WalletNode getWalletNode(Wallet wallet) {
+        List<KeyPurpose> keyPurposes = List.of(KeyPurpose.RECEIVE, KeyPurpose.CHANGE);
+        for(KeyPurpose keyPurpose : keyPurposes) {
+            WalletNode changedNode = getWalletNode(wallet, keyPurpose);
+            if(changedNode != null) {
+                return changedNode;
+            }
+        }
+
+        return null;
+    }
+
+    private WalletNode getWalletNode(Wallet wallet, KeyPurpose keyPurpose) {
+        WalletNode purposeNode  = wallet.getNode(keyPurpose);
+        for(WalletNode addressNode : purposeNode.getChildren()) {
+            if(ElectrumServer.getScriptHash(wallet, addressNode).equals(scriptHash)) {
+                return addressNode;
+            }
+        }
+
+        return null;
+    }
+}

src/main/java/com/sparrowwallet/sparrow/io/ElectrumServer.java

@@ -18,6 +18,7 @@ import com.sparrowwallet.sparrow.EventManager;
 import com.sparrowwallet.sparrow.event.ConnectionEvent;
 import com.sparrowwallet.sparrow.event.FeeRatesUpdatedEvent;
 import com.sparrowwallet.sparrow.event.NewBlockEvent;
+import com.sparrowwallet.sparrow.event.WalletNodeHistoryChangedEvent;
 import com.sparrowwallet.sparrow.wallet.SendController;
 import javafx.application.Platform;
 import javafx.concurrent.ScheduledService;
@@ -37,6 +38,7 @@ import java.security.cert.CertificateException;
 import java.security.cert.CertificateFactory;
 import java.security.cert.X509Certificate;
 import java.util.*;
+import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.locks.ReentrantLock;
 import java.util.stream.Collectors;
 
@@ -47,6 +49,8 @@ public class ElectrumServer {
 
     private static Transport transport;
 
+    private static final Map<String, String> subscribedScriptHashes = Collections.synchronizedMap(new HashMap<>());
+
     private static synchronized Transport getTransport() throws ServerException {
         if(transport == null) {
             try {
@@ -171,6 +175,7 @@ public class ElectrumServer {
 
     public void getHistory(Wallet wallet, Collection<WalletNode> nodes, Map<WalletNode, Set<BlockTransactionHash>> nodeTransactionMap, int startIndex) throws ServerException {
         getReferences(wallet, "blockchain.scripthash.get_history", nodes, nodeTransactionMap, startIndex);
+        subscribeWalletNodes(wallet, nodes, startIndex);
     }
 
     public void getMempool(Wallet wallet, Collection<WalletNode> nodes, Map<WalletNode, Set<BlockTransactionHash>> nodeTransactionMap, int startIndex) throws ServerException {
@@ -231,6 +236,50 @@ public class ElectrumServer {
         }
     }
 
+    public void subscribeWalletNodes(Wallet wallet, Collection<WalletNode> nodes, int startIndex) throws ServerException {
+        try {
+            JsonRpcClient client = new JsonRpcClient(getTransport());
+            BatchRequestBuilder<String, String> batchRequest = client.createBatchRequest().keysType(String.class).returnType(String.class);
+
+            Set<String> scriptHashes = new HashSet<>();
+            for(WalletNode node : nodes) {
+                if(node.getIndex() >= startIndex) {
+                    String scriptHash = getScriptHash(wallet, node);
+                    if(!subscribedScriptHashes.containsKey(scriptHash)) {
+                        scriptHashes.add(scriptHash);
+                        batchRequest.add(node.getDerivationPath(), "blockchain.scripthash.subscribe", scriptHash);
+                    }
+                }
+            }
+
+            if(scriptHashes.isEmpty()) {
+                return;
+            }
+
+            Map<String, String> result;
+            try {
+                result = batchRequest.execute();
+            } catch(JsonRpcBatchException e) {
+                //Even if we have some successes, failure to subscribe for all script hashes will result in outdated wallet view. Don't proceed.
+                throw new IllegalStateException("Failed to subscribe for updates for paths: " + e.getErrors().keySet());
+            }
+
+            for(String path : result.keySet()) {
+                String status = result.get(path);
+
+                Optional<WalletNode> optionalNode = nodes.stream().filter(n -> n.getDerivationPath().equals(path)).findFirst();
+                if(optionalNode.isPresent()) {
+                    WalletNode node = optionalNode.get();
+                    subscribedScriptHashes.put(getScriptHash(wallet, node), status);
+                }
+            }
+        } catch (IllegalStateException e) {
+            throw new ServerException(e.getCause());
+        } catch (Exception e) {
+            throw new ServerException(e);
+        }
+    }
+
     @SuppressWarnings("unchecked")
     public List<Set<BlockTransactionHash>> getOutputTransactionReferences(Transaction transaction, int indexStart, int indexEnd) throws ServerException {
         try {
@@ -545,7 +594,7 @@ public class ElectrumServer {
         return targetBlocksFeeRatesSats;
     }
 
-    private String getScriptHash(Wallet wallet, WalletNode node) {
+    public static String getScriptHash(Wallet wallet, WalletNode node) {
         byte[] hash = Sha256Hash.hash(wallet.getOutputScript(node).getProgram());
         byte[] reversed = Utils.reverseBytes(hash);
         return Utils.bytesToHex(reversed);
@@ -630,6 +679,16 @@ public class ElectrumServer {
         public void newBlockHeaderTip(@JsonRpcParam("header") final BlockHeaderTip header) {
             Platform.runLater(() -> EventManager.get().post(new NewBlockEvent(header.height, header.getBlockHeader())));
         }
+
+        @JsonRpcMethod("blockchain.scripthash.subscribe")
+        public void scriptHashStatusUpdated(@JsonRpcParam("scripthash") final String scriptHash, @JsonRpcParam("status") final String status) {
+            String oldStatus = subscribedScriptHashes.put(scriptHash, status);
+            if(Objects.equals(oldStatus, status)) {
+                System.out.println("Received script hash status update, but status has not changed");
+            }
+
+            Platform.runLater(() -> EventManager.get().post(new WalletNodeHistoryChangedEvent(scriptHash)));
+        }
     }
 
     public static class TcpTransport implements Transport, Closeable {
@@ -886,6 +945,7 @@ public class ElectrumServer {
                         BlockHeaderTip tip;
                         if(subscribe) {
                             tip = electrumServer.subscribeBlockHeaders();
+                            subscribedScriptHashes.clear();
                         } else {
                             tip = new BlockHeaderTip();
                         }

src/main/java/com/sparrowwallet/sparrow/wallet/WalletForm.java

@@ -60,8 +60,7 @@ public class WalletForm {
         if(wallet.isValid() && AppController.isOnline()) {
             ElectrumServer.TransactionHistoryService historyService = new ElectrumServer.TransactionHistoryService(wallet);
             historyService.setOnSucceeded(workerStateEvent -> {
-                wallet.setStoredBlockHeight(blockHeight);
-                notifyIfChanged(previousWallet, blockHeight);
+                updateWallet(previousWallet, blockHeight);
             });
             historyService.setOnFailed(workerStateEvent -> {
                 workerStateEvent.getSource().getException().printStackTrace();
@@ -70,15 +69,32 @@ public class WalletForm {
         }
     }
 
+    private void updateWallet(Wallet previousWallet, Integer blockHeight) {
+        if(blockHeight != null) {
+            wallet.setStoredBlockHeight(blockHeight);
+        }
+
+        notifyIfChanged(previousWallet, blockHeight);
+    }
+
     private void notifyIfChanged(Wallet previousWallet, Integer blockHeight) {
         List<WalletNode> historyChangedNodes = new ArrayList<>();
         historyChangedNodes.addAll(getHistoryChangedNodes(previousWallet.getNode(KeyPurpose.RECEIVE).getChildren(), wallet.getNode(KeyPurpose.RECEIVE).getChildren()));
         historyChangedNodes.addAll(getHistoryChangedNodes(previousWallet.getNode(KeyPurpose.CHANGE).getChildren(), wallet.getNode(KeyPurpose.CHANGE).getChildren()));
 
+        boolean changed = false;
         if(!historyChangedNodes.isEmpty()) {
-            Platform.runLater(() -> EventManager.get().post(new WalletHistoryChangedEvent(wallet, blockHeight, historyChangedNodes)));
-        } else if(blockHeight != null && !blockHeight.equals(previousWallet.getStoredBlockHeight())) {
+            Platform.runLater(() -> EventManager.get().post(new WalletHistoryChangedEvent(wallet, historyChangedNodes)));
+            changed = true;
+        }
+
+        if(blockHeight != null && !blockHeight.equals(previousWallet.getStoredBlockHeight())) {
             Platform.runLater(() -> EventManager.get().post(new WalletBlockHeightChangedEvent(wallet, blockHeight)));
+            changed = true;
+        }
+
+        if(changed) {
+            Platform.runLater(() -> EventManager.get().post(new WalletDataChangedEvent(wallet)));
         }
     }
 
@@ -146,20 +162,13 @@ public class WalletForm {
     }
 
     @Subscribe
-    public void walletLabelChanged(WalletEntryLabelChangedEvent event) {
-        if(event.getWallet().equals(wallet)) {
-            backgroundSaveWallet(event);
-        }
-    }
-
-    @Subscribe
-    public void walletBlockHeightChanged(WalletBlockHeightChangedEvent event) {
+    public void walletDataChanged(WalletDataChangedEvent event) {
         if(event.getWallet().equals(wallet)) {
-            backgroundSaveWallet(event);
+            backgroundSaveWallet();
         }
     }
 
-    private void backgroundSaveWallet(WalletChangedEvent event) {
+    private void backgroundSaveWallet() {
         try {
             save();
         } catch (IOException e) {
@@ -182,11 +191,18 @@ public class WalletForm {
 
     @Subscribe
     public void newBlock(NewBlockEvent event) {
-        refreshHistory(event.getHeight());
+        updateWallet(wallet, event.getHeight());
     }
 
     @Subscribe
     public void connected(ConnectionEvent event) {
         refreshHistory(event.getBlockHeight());
     }
+
+    @Subscribe
+    public void walletNodeHistoryChanged(WalletNodeHistoryChangedEvent event) {
+        if(event.getWalletNode(wallet) != null) {
+            refreshHistory(AppController.getCurrentBlockHeight());
+        }
+    }
 }