Add revert-metadata subcommand

Signed-off-by: Fabio Di Fabio <fabio.difabio@consensys.net>

Author: fab-10

besu/src/main/java/org/hyperledger/besu/cli/subcommands/storage/RevertMetadataSubCommand.java

@@ -0,0 +1,129 @@
+/*
+ * Copyright Hyperledger Besu Contributors.
+ *
+ * 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.subcommands.storage;
+
+import org.hyperledger.besu.cli.util.VersionProvider;
+import org.hyperledger.besu.plugin.services.storage.DataStorageFormat;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.file.Path;
+import java.util.OptionalInt;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.annotation.JsonSerialize;
+import com.fasterxml.jackson.datatype.jdk8.Jdk8Module;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import picocli.CommandLine;
+import picocli.CommandLine.Command;
+import picocli.CommandLine.ParentCommand;
+
+/** The revert metadata to v1 subcommand. */
+@Command(
+    name = "revert-metadata",
+    description = "Revert database metadata to previous format",
+    mixinStandardHelpOptions = true,
+    versionProvider = VersionProvider.class,
+    subcommands = RevertMetadataSubCommand.v2ToV1.class)
+public class RevertMetadataSubCommand implements Runnable {
+  private static final Logger LOG = LoggerFactory.getLogger(RevertMetadataSubCommand.class);
+  private static final String METADATA_FILENAME = "DATABASE_METADATA.json";
+  private static final ObjectMapper MAPPER = new ObjectMapper().registerModule(new Jdk8Module());
+
+  @SuppressWarnings("unused")
+  @ParentCommand
+  private StorageSubCommand parentCommand;
+
+  @SuppressWarnings("unused")
+  @CommandLine.Spec
+  private CommandLine.Model.CommandSpec spec;
+
+  @Override
+  public void run() {
+    spec.commandLine().usage(System.out);
+  }
+
+  @Command(
+      name = "v2-to-v1",
+      description = "Revert a database metadata v2 format to v1 format",
+      mixinStandardHelpOptions = true,
+      versionProvider = VersionProvider.class)
+  static class v2ToV1 implements Runnable {
+
+    @SuppressWarnings("unused")
+    @CommandLine.Spec
+    private CommandLine.Model.CommandSpec spec;
+
+    @SuppressWarnings("unused")
+    @ParentCommand
+    private RevertMetadataSubCommand parentCommand;
+
+    @Override
+    public void run() {
+
+      final Path dataDir = parentCommand.parentCommand.parentCommand.dataDir();
+
+      final File dbMetadata = dataDir.resolve(METADATA_FILENAME).toFile();
+      if (!dbMetadata.exists()) {
+        String errMsg =
+            String.format(
+                "Could not find database metadata file %s, check your data dir %s",
+                dbMetadata, dataDir);
+        LOG.error(errMsg);
+        throw new IllegalArgumentException(errMsg);
+      }
+      try {
+        final var root = MAPPER.readTree(dbMetadata);
+        if (!root.has("v2")) {
+          String errMsg =
+              String.format("Database metadata file %s is not in v2 format", dbMetadata);
+          LOG.error(errMsg);
+          throw new IllegalArgumentException(errMsg);
+        }
+
+        final var v2Obj = root.get("v2");
+        if (!v2Obj.has("format")) {
+          String errMsg =
+              String.format(
+                  "Database metadata file %s is malformed, \"format\" field not found", dbMetadata);
+          LOG.error(errMsg);
+          throw new IllegalArgumentException(errMsg);
+        }
+
+        final var formatField = v2Obj.get("format").asText();
+        final OptionalInt maybePrivacyVersion =
+            v2Obj.has("privacyVersion")
+                ? OptionalInt.of(v2Obj.get("privacyVersion").asInt())
+                : OptionalInt.empty();
+
+        final DataStorageFormat dataStorageFormat = DataStorageFormat.valueOf(formatField);
+        final int v1Version =
+            switch (dataStorageFormat) {
+              case FOREST -> 1;
+              case BONSAI -> 2;
+            };
+
+        @JsonSerialize
+        record V1(int version, OptionalInt privacyVersion) {}
+
+        MAPPER.writeValue(dbMetadata, new V1(v1Version, maybePrivacyVersion));
+        LOG.info("Successfully reverted database metadata from v2 to v1 in {}", dbMetadata);
+      } catch (IOException ioe) {
+        throw new RuntimeException(ioe);
+      }
+    }
+  }
+}

besu/src/main/java/org/hyperledger/besu/cli/subcommands/storage/StorageSubCommand.java

@@ -48,7 +48,8 @@
     subcommands = {
       StorageSubCommand.RevertVariablesStorage.class,
       RocksDbSubCommand.class,
-      TrieLogSubCommand.class
+      TrieLogSubCommand.class,
+      RevertMetadataSubCommand.class
     })
 public class StorageSubCommand implements Runnable {