chore: Simplified implementation of TransactionGenerator (#18785)

Signed-off-by: Michael Heinrichs <[email protected]>

Author: netopyr

platform-sdk/consensus-otter-tests/src/test/java/org/hiero/otter/test/BirthRoundMigrationTest.java

@@ -1,17 +1,13 @@
 // SPDX-License-Identifier: Apache-2.0
 package org.hiero.otter.test;
 
-import static org.hiero.otter.fixtures.TransactionGenerator.INFINITE;
-
 import java.time.Duration;
 import org.hiero.consensus.config.EventConfig_;
 import org.hiero.otter.fixtures.Network;
 import org.hiero.otter.fixtures.Node;
 import org.hiero.otter.fixtures.OtterTest;
 import org.hiero.otter.fixtures.TestEnvironment;
 import org.hiero.otter.fixtures.TimeManager;
-import org.hiero.otter.fixtures.TransactionGenerator.Distribution;
-import org.hiero.otter.fixtures.TransactionGenerator.Rate;
 
 class BirthRoundMigrationTest {
 
@@ -26,13 +22,13 @@ void testBirthRoundMigration(TestEnvironment env) throws InterruptedException {
         // Setup simulation
         network.addNodes(4);
         network.start(ONE_MINUTE);
-        env.generator().generateTransactions(INFINITE, Rate.fixedRateWithTps(1000), Distribution.UNIFORM);
+        env.generator().start();
 
         // Wait for 30 seconds
         timeManager.waitFor(THIRTY_SECONDS);
 
         // Initiate the migration
-        env.generator().pause();
+        env.generator().stop();
         network.prepareUpgrade(ONE_MINUTE);
 
         // update the configuration
@@ -42,7 +38,7 @@ void testBirthRoundMigration(TestEnvironment env) throws InterruptedException {
 
         // restart the network
         network.resume(ONE_MINUTE);
-        env.generator().resume();
+        env.generator().start();
 
         // Wait for 30 seconds
         timeManager.waitFor(THIRTY_SECONDS);

platform-sdk/consensus-otter-tests/src/test/java/org/hiero/otter/test/HappyPathTest.java

@@ -1,15 +1,11 @@
 // SPDX-License-Identifier: Apache-2.0
 package org.hiero.otter.test;
 
-import static org.hiero.otter.fixtures.TransactionGenerator.INFINITE;
-
 import java.time.Duration;
 import org.hiero.otter.fixtures.Network;
 import org.hiero.otter.fixtures.OtterTest;
 import org.hiero.otter.fixtures.TestEnvironment;
 import org.hiero.otter.fixtures.TimeManager;
-import org.hiero.otter.fixtures.TransactionGenerator.Distribution;
-import org.hiero.otter.fixtures.TransactionGenerator.Rate;
 import org.hiero.otter.fixtures.Validator.Profile;
 import org.hiero.otter.fixtures.turtle.TurtleNode;
 
@@ -23,7 +19,7 @@ void testHappyPath(TestEnvironment env) throws InterruptedException {
         // Setup simulation
         network.addNodes(4);
         network.start(Duration.ofMinutes(1L));
-        env.generator().generateTransactions(INFINITE, Rate.fixedRateWithTps(1000), Distribution.UNIFORM);
+        env.generator().start();
 
         // Wait for two minutes
         timeManager.waitFor(Duration.ofMinutes(2L));

platform-sdk/consensus-otter-tests/src/test/java/org/hiero/otter/test/SandboxTest.java

@@ -1,7 +1,6 @@
 // SPDX-License-Identifier: Apache-2.0
 package org.hiero.otter.test;
 
-import static org.hiero.otter.fixtures.TransactionGenerator.INFINITE;
 import static org.hiero.otter.fixtures.Validator.EventStreamConfig.ignoreNode;
 import static org.hiero.otter.fixtures.Validator.LogErrorConfig.ignoreMarkers;
 import static org.hiero.otter.fixtures.Validator.RatioConfig.within;
@@ -15,8 +14,6 @@
 import org.hiero.otter.fixtures.OtterTest;
 import org.hiero.otter.fixtures.TestEnvironment;
 import org.hiero.otter.fixtures.TimeManager;
-import org.hiero.otter.fixtures.TransactionGenerator.Distribution;
-import org.hiero.otter.fixtures.TransactionGenerator.Rate;
 import org.hiero.otter.fixtures.Validator.Profile;
 
 public class SandboxTest {
@@ -33,7 +30,7 @@ void testConsistencyNDReconnect(TestEnvironment env) throws InterruptedException
         // Setup simulation
         final List<Node> nodes = network.addNodes(4);
         network.start(ONE_MINUTE);
-        env.generator().generateTransactions(INFINITE, Rate.fixedRateWithTps(1000), Distribution.UNIFORM);
+        env.generator().start();
 
         // Wait for two minutes
         timeManager.waitFor(TWO_MINUTES);
@@ -70,7 +67,7 @@ void testBranching(TestEnvironment env) throws InterruptedException {
         network.addNodes(3);
         final InstrumentedNode nodeX = network.addInstrumentedNode();
         network.start(ONE_MINUTE);
-        env.generator().generateTransactions(INFINITE, Rate.fixedRateWithTps(1000), Distribution.UNIFORM);
+        env.generator().start();
 
         // Wait for one minute
         timeManager.waitFor(TEN_SECONDS);

platform-sdk/consensus-otter-tests/src/testFixtures/java/module-info.java

@@ -7,6 +7,7 @@
     requires com.swirlds.common.test.fixtures;
     requires com.swirlds.platform.core.test.fixtures;
     requires com.swirlds.platform.core;
+    requires org.hiero.base.utility;
     requires org.hiero.consensus.model;
     requires com.github.spotbugs.annotations;
     requires org.apache.logging.log4j;

platform-sdk/consensus-otter-tests/src/testFixtures/java/org/hiero/otter/fixtures/TransactionGenerator.java

@@ -1,79 +1,25 @@
 // SPDX-License-Identifier: Apache-2.0
 package org.hiero.otter.fixtures;
 
-import edu.umd.cs.findbugs.annotations.NonNull;
-import java.time.Instant;
-import org.hiero.otter.fixtures.internal.FixedRate;
-
 /**
  * Interface representing a transaction generator.
  *
- * <p>This interface provides methods to generate random transactions and send them to the nodes.
+ * <p>A {@link TransactionGenerator} generates a steady flow of transaction to all nodes in the
+ * network. The generator sends 100 transactions to each node per second, which ensures there is
+ * always at least one transaction waiting to be processed by the event creator.
  */
 public interface TransactionGenerator {
 
-    /**
-     * Constant representing an infinite number of transactions.
-     */
-    int INFINITE = -1;
+    int TPS = 100;
 
     /**
-     * Generate a specified number of transactions with a given rate and distribution.
-     *
-     * @param count the number of transactions to generate
-     * @param rate the rate at which to generate transactions
-     * @param distribution the distribution of transactions across the nodes
+     * Start the generation of transactions with the default transaction factory that uses
+     * random {@code int} values.
      */
-    void generateTransactions(int count, @NonNull Rate rate, @NonNull Distribution distribution);
+    void start();
 
     /**
      * Stop the transaction generation.
      */
     void stop();
-
-    /**
-     * Pause the transaction generation. Once paused, the transaction generation can be resumed by calling {@link #resume()}.
-     */
-    void pause();
-
-    /**
-     * Resume the transaction generation after it has been paused.
-     */
-    void resume();
-
-    /**
-     * The {@code Rate} class represents the rate at which transactions are generated.
-     */
-    interface Rate {
-
-        /**
-         * Creates a rate that generates transactions at a fixed frequency.
-         *
-         * @param tps the number of transactions per second
-         * @return a {@code Rate} object representing the specified rate
-         */
-        @NonNull
-        static Rate fixedRateWithTps(final int tps) {
-            return new FixedRate(tps);
-        }
-
-        /**
-         * Returns the duration until when the next transaction should be generated in nanoseconds.
-         *
-         * @param start the start time of the transaction generation
-         * @param now the current time
-         * @return the duration until when the next transaction should be generated
-         */
-        long nextDelayNS(@NonNull Instant start, @NonNull Instant now);
-    }
-
-    /**
-     * The {@code Distribution} enum represents the distribution of transactions across the nodes.
-     */
-    enum Distribution {
-        /**
-         * Transactions are distributed uniformly across the nodes.
-         */
-        UNIFORM
-    }
 }

platform-sdk/consensus-otter-tests/src/testFixtures/java/org/hiero/otter/fixtures/internal/Distributor.java

@@ -163,6 +163,10 @@ public void resume(@NonNull Duration duration) throws InterruptedException {
      */
     @Override
     public void tick(@NonNull final Instant now) {
+        if (state != State.RUNNING) {
+            return;
+        }
+
         simulatedNetwork.tick(now);
 
         // Iteration order over nodes does not need to be deterministic -- nodes are not permitted to communicate with