support electrs batching and improve batching read timeout handling

src/main/java/com/sparrowwallet/sparrow/net/BatchedElectrumServerRpc.java

@@ -21,8 +21,8 @@ import java.util.stream.Collectors;
 
 public class BatchedElectrumServerRpc implements ElectrumServerRpc {
     private static final Logger log = LoggerFactory.getLogger(BatchedElectrumServerRpc.class);
-    private static final int MAX_RETRIES = 3;
+    private static final int MAX_RETRIES = 5;
-    private static final int RETRY_DELAY = 0;
+    private static final int RETRY_DELAY = 1;
 
     private final AtomicLong idCounter = new AtomicLong();
 
@@ -82,7 +82,7 @@ public class BatchedElectrumServerRpc implements ElectrumServerRpc {
         }
 
         try {
-            return new RetryLogic<Map<String, ScriptHashTx[]>>(MAX_RETRIES, RETRY_DELAY, IllegalStateException.class).getResult(batchRequest::execute);
+            return new RetryLogic<Map<String, ScriptHashTx[]>>(MAX_RETRIES, RETRY_DELAY, List.of(IllegalStateException.class, IllegalArgumentException.class)).getResult(batchRequest::execute);
         } catch (JsonRpcBatchException e) {
             if(failOnError) {
                 throw new ElectrumServerRpcException("Failed to retrieve transaction history for paths: " + getScriptHashesAbbreviation((Collection<String>)e.getErrors().keySet()), e);
@@ -110,7 +110,7 @@ public class BatchedElectrumServerRpc implements ElectrumServerRpc {
         }
 
         try {
-            return new RetryLogic<Map<String, ScriptHashTx[]>>(MAX_RETRIES, RETRY_DELAY, IllegalStateException.class).getResult(batchRequest::execute);
+            return new RetryLogic<Map<String, ScriptHashTx[]>>(MAX_RETRIES, RETRY_DELAY, List.of(IllegalStateException.class, IllegalArgumentException.class)).getResult(batchRequest::execute);
         } catch(JsonRpcBatchException e) {
             if(failOnError) {
                 throw new ElectrumServerRpcException("Failed to retrieve mempool transactions for paths: " + getScriptHashesAbbreviation((Collection<String>)e.getErrors().keySet()), e);
@@ -139,7 +139,7 @@ public class BatchedElectrumServerRpc implements ElectrumServerRpc {
         }
 
         try {
-            return new RetryLogic<Map<String, String>>(MAX_RETRIES, RETRY_DELAY, IllegalStateException.class).getResult(batchRequest::execute);
+            return new RetryLogic<Map<String, String>>(MAX_RETRIES, RETRY_DELAY, List.of(IllegalStateException.class, IllegalArgumentException.class)).getResult(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 ElectrumServerRpcException("Failed to subscribe to paths: " + getScriptHashesAbbreviation((Collection<String>)e.getErrors().keySet()), e);

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

@@ -37,6 +37,8 @@ public class ElectrumServer {
 
     private static final String[] SUPPORTED_VERSIONS = new String[]{"1.3", "1.4.2"};
 
+    private static final Version ELECTRS_MIN_BATCHING_VERSION = new Version("0.9.0");
+
     private static final int MINIMUM_BROADCASTS = 2;
 
     public static final BlockTransaction UNFETCHABLE_BLOCK_TRANSACTION = new BlockTransaction(Sha256Hash.ZERO_HASH, 0, null, null, null);
@@ -839,7 +841,26 @@ public class ElectrumServer {
     }
 
     public static boolean supportsBatching(List<String> serverVersion) {
-        return serverVersion.size() > 0 && serverVersion.get(0).toLowerCase().contains("electrumx");
+        if(serverVersion.size() > 0) {
+            String server = serverVersion.get(0).toLowerCase();
+            if(server.contains("electrumx")) {
+                return true;
+            }
+
+            if(server.startsWith("electrs/")) {
+                String electrsVersion = server.substring("electrs/".length());
+                try {
+                    Version version = new Version(electrsVersion);
+                    if(version.compareTo(ELECTRS_MIN_BATCHING_VERSION) >= 0) {
+                        return true;
+                    }
+                } catch(Exception e) {
+                    //ignore
+                }
+            }
+        }
+
+        return false;
     }
 
     public static class ServerVersionService extends Service<List<String>> {

src/main/java/com/sparrowwallet/sparrow/net/RetryLogic.java

@@ -1,6 +1,7 @@
 package com.sparrowwallet.sparrow.net;
 
 import java.util.List;
+import java.util.Random;
 
 /**
  * Generic retry logic. Delegate must throw the specified exception type to trigger the retry logic.
@@ -21,7 +22,7 @@ public class RetryLogic<T> {
 
     public RetryLogic(int maxAttempts, int retryWaitSeconds, @SuppressWarnings("rawtypes") List<Class> retryExceptionTypes) {
         this.maxAttempts = maxAttempts;
-        this.retryWaitSeconds = retryWaitSeconds;
+        this.retryWaitSeconds = Math.max(retryWaitSeconds, 1);
         this.retryExceptionTypes = retryExceptionTypes;
     }
 
@@ -37,7 +38,8 @@ public class RetryLogic<T> {
                         throw new ServerException("Retries exhausted", e);
                     } else {
                         try {
-                            Thread.sleep((1000 * retryWaitSeconds));
+                            //Sleep with a +/- 2 seconds random wait time to avoid simultaneous retries
+                            Thread.sleep((1000L * (retryWaitSeconds - 1)) + new Random().nextInt(2000));
                         } catch(InterruptedException ie) {
                             //ignore
                         }

src/main/java/com/sparrowwallet/sparrow/net/TcpTransport.java

@@ -2,6 +2,7 @@ package com.sparrowwallet.sparrow.net;
 
 import com.github.arteam.simplejsonrpc.client.Transport;
 import com.github.arteam.simplejsonrpc.server.JsonRpcServer;
+import com.google.common.base.Splitter;
 import com.google.common.net.HostAndPort;
 import com.google.gson.Gson;
 import com.sparrowwallet.sparrow.io.Config;
@@ -24,7 +25,8 @@ public class TcpTransport implements Transport, Closeable {
     private static final Logger log = LoggerFactory.getLogger(TcpTransport.class);
 
     public static final int DEFAULT_PORT = 50001;
-    private static final int[] READ_TIMEOUT_SECS = {3, 8, 16, 34};
+    private static final int[] BASE_READ_TIMEOUT_SECS = {3, 8, 16, 34};
+    public static final long PER_REQUEST_READ_TIMEOUT_MILLIS = 50;
     public static final int SOCKET_READ_TIMEOUT_MILLIS = 5000;
 
     protected final HostAndPort server;
@@ -42,6 +44,7 @@ public class TcpTransport implements Transport, Closeable {
     private volatile boolean reading = true;
     private boolean firstRead = true;
     private int readTimeoutIndex;
+    private int requestIdCount = 1;
 
     private final JsonRpcServer jsonRpcServer = new JsonRpcServer();
     private final SubscriptionService subscriptionService = new SubscriptionService();
@@ -66,6 +69,8 @@ public class TcpTransport implements Transport, Closeable {
             Rpc recvRpc;
             String recv;
 
+            //Count number of requests in batched query to increase read timeout appropriately
+            requestIdCount = Splitter.on("\"id\"").splitToList(request).size() - 1;
             writeRequest(request);
             do {
                 recv = readResponse();
@@ -86,16 +91,16 @@ public class TcpTransport implements Transport, Closeable {
 
     private String readResponse() throws IOException {
         try {
-            if(!readLock.tryLock(READ_TIMEOUT_SECS[readTimeoutIndex], TimeUnit.SECONDS)) {
+            if(!readLock.tryLock((BASE_READ_TIMEOUT_SECS[readTimeoutIndex] * 1000) + (requestIdCount * PER_REQUEST_READ_TIMEOUT_MILLIS), TimeUnit.MILLISECONDS)) {
-                readTimeoutIndex = Math.min(readTimeoutIndex + 1, READ_TIMEOUT_SECS.length - 1);
+                readTimeoutIndex = Math.min(readTimeoutIndex + 1, BASE_READ_TIMEOUT_SECS.length - 1);
-                log.debug("No response from server, setting read timeout to " + READ_TIMEOUT_SECS[readTimeoutIndex] + " secs");
+                log.info("No response from server, setting read timeout to " + BASE_READ_TIMEOUT_SECS[readTimeoutIndex] + " secs");
                 throw new IOException("No response from server");
             }
         } catch(InterruptedException e) {
             throw new IOException("Read thread interrupted");
         }
 
-        if(readTimeoutIndex == READ_TIMEOUT_SECS.length - 1) {
+        if(readTimeoutIndex == BASE_READ_TIMEOUT_SECS.length - 1) {
             readTimeoutIndex--;
         }
 

src/main/java/com/sparrowwallet/sparrow/net/Version.java

@@ -0,0 +1,54 @@
+package com.sparrowwallet.sparrow.net;
+
+public class Version implements Comparable<Version> {
+    private final String version;
+
+    public final String get() {
+        return this.version;
+    }
+
+    public Version(String version) {
+        if(version == null) {
+            throw new IllegalArgumentException("Version can not be null");
+        }
+        if(!version.matches("[0-9]+(\\.[0-9]+)*")) {
+            throw new IllegalArgumentException("Invalid version format");
+        }
+        this.version = version;
+    }
+
+    @Override
+    public int compareTo(Version that) {
+        if(that == null) {
+            return 1;
+        }
+        String[] thisParts = this.get().split("\\.");
+        String[] thatParts = that.get().split("\\.");
+        int length = Math.max(thisParts.length, thatParts.length);
+        for(int i = 0; i < length; i++) {
+            int thisPart = i < thisParts.length ? Integer.parseInt(thisParts[i]) : 0;
+            int thatPart = i < thatParts.length ? Integer.parseInt(thatParts[i]) : 0;
+            if(thisPart < thatPart) {
+                return -1;
+            }
+            if(thisPart > thatPart) {
+                return 1;
+            }
+        }
+        return 0;
+    }
+
+    @Override
+    public boolean equals(Object that) {
+        if(this == that) {
+            return true;
+        }
+        if(that == null) {
+            return false;
+        }
+        if(this.getClass() != that.getClass()) {
+            return false;
+        }
+        return this.compareTo((Version) that) == 0;
+    }
+}

src/main/java/com/sparrowwallet/sparrow/net/VersionCheckService.java

@@ -100,56 +100,4 @@ public class VersionCheckService extends ScheduledService<VersionUpdatedEvent> {
         public Map<String, String> signatures;
     }
 
-    public static class Version implements Comparable<Version> {
-        private final String version;
-
-        public final String get() {
-            return this.version;
-        }
-
-        public Version(String version) {
-            if(version == null) {
-                throw new IllegalArgumentException("Version can not be null");
-            }
-            if(!version.matches("[0-9]+(\\.[0-9]+)*")) {
-                throw new IllegalArgumentException("Invalid version format");
-            }
-            this.version = version;
-        }
-
-        @Override
-        public int compareTo(Version that) {
-            if(that == null) {
-                return 1;
-            }
-            String[] thisParts = this.get().split("\\.");
-            String[] thatParts = that.get().split("\\.");
-            int length = Math.max(thisParts.length, thatParts.length);
-            for(int i = 0; i < length; i++) {
-                int thisPart = i < thisParts.length ? Integer.parseInt(thisParts[i]) : 0;
-                int thatPart = i < thatParts.length ? Integer.parseInt(thatParts[i]) : 0;
-                if(thisPart < thatPart) {
-                    return -1;
-                }
-                if(thisPart > thatPart) {
-                    return 1;
-                }
-            }
-            return 0;
-        }
-
-        @Override
-        public boolean equals(Object that) {
-            if(this == that) {
-                return true;
-            }
-            if(that == null) {
-                return false;
-            }
-            if(this.getClass() != that.getClass()) {
-                return false;
-            }
-            return this.compareTo((Version)that) == 0;
-        }
-    }
 }