7311: Add feature toggle for enabling use of the peertask system where available

Signed-off-by: Matilda Clerke <matilda.clerke@consensys.net>

besu/src/main/java/org/hyperledger/besu/cli/BesuCommand.java

@@ -40,6 +40,7 @@ import org.hyperledger.besu.cli.converter.MetricCategoryConverter;
 import org.hyperledger.besu.cli.converter.PercentageConverter;
 import org.hyperledger.besu.cli.converter.SubnetInfoConverter;
 import org.hyperledger.besu.cli.custom.JsonRPCAllowlistHostsProperty;
+import org.hyperledger.besu.cli.custom.PeerTaskFeatureToggle;
 import org.hyperledger.besu.cli.error.BesuExecutionExceptionHandler;
 import org.hyperledger.besu.cli.error.BesuParameterExceptionHandler;
 import org.hyperledger.besu.cli.options.MiningOptions;
@@ -842,6 +843,12 @@ public class BesuCommand implements DefaultCommandValues, Runnable {
       description = "Specifies the number of last blocks to cache  (default: ${DEFAULT-VALUE})")
   private final Integer numberOfblocksToCache = 0;
 
+  @Option(
+      names = {"--peertask-system-enabled"},
+      description =
+          "Temporary feature toggle to enable using the new peertask system (default: ${DEFAULT-VALUE})")
+  private final Boolean isPeerTaskSystemEnabled = false;
+
   @Mixin private P2PTLSConfigOptions p2pTLSConfigOptions;
 
   // Plugins Configuration Option Group
@@ -1784,6 +1791,9 @@ public class BesuCommand implements DefaultCommandValues, Runnable {
 
     instantiateSignatureAlgorithmFactory();
 
+    PeerTaskFeatureToggle.initialize(isPeerTaskSystemEnabled);
+    logger.info("PeerTask feature toggle is {}", PeerTaskFeatureToggle.usePeerTaskSystem() ? "enabled" : "disabled");
+
     logger.info(generateConfigurationOverview());
     logger.info("Security Module: {}", securityModuleName);
   }

besu/src/main/java/org/hyperledger/besu/cli/custom/PeerTaskFeatureToggle.java

@@ -0,0 +1,53 @@
+/*
+ * Copyright contributors to Hyperledger Besu.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
+ * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+package org.hyperledger.besu.cli.custom;
+
+/**
+ * Temporary class to allow easy access to the PeerTask feature toggle. This class can be removed
+ * once we've properly tested the PeerTask system and want to enable it permanently
+ */
+public class PeerTaskFeatureToggle {
+  private static Boolean USE_PEER_TASK_SYSTEM = null;
+
+  /**
+   * Initialize the PeerTaskFeatureToggle with the supplied usePeerTaskSystem Boolean.
+   * PeerTaskFeatureToggle may only be initialized once!
+   *
+   * @param usePeerTaskSystem Boolean indicating whether or not the PeerTask system should be used
+   * @throws IllegalStateException if PeerTaskFeatureToggle has already been initialized
+   */
+  public static void initialize(final Boolean usePeerTaskSystem) {
+    if (USE_PEER_TASK_SYSTEM != null) {
+      throw new IllegalStateException(
+          "PeerTaskFeatureToggle has already been initialized, and cannot be initialized again");
+    }
+    USE_PEER_TASK_SYSTEM = usePeerTaskSystem;
+  }
+
+  /**
+   * Indicates whether or not to use the PeerTask system. PeerTaskFeatureToggle must have been
+   * initialized before this method can be called!
+   *
+   * @return whether or not to use the PeerTask system
+   * @throws IllegalStateException if the PeerTaskFeatureToggle has not been initialized
+   */
+  public static Boolean usePeerTaskSystem() {
+    if (USE_PEER_TASK_SYSTEM == null) {
+      throw new IllegalStateException(
+          "PeerTaskFeatureToggle has not been initialized, but getUsePeerTaskSystem() has been called");
+    }
+    return USE_PEER_TASK_SYSTEM;
+  }
+}