content: /*
   * Copyright 1999-2018 Alibaba Group Holding Ltd.
   *
   * 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.
   */
  
  package com.alibaba.nacos.core.distributed.raft;
  
  import com.alibaba.nacos.common.utils.JacksonUtils;
  import com.alibaba.nacos.consistency.snapshot.LocalFileMeta;
  import com.alipay.sofa.jraft.Closure;
  import com.alipay.sofa.jraft.entity.LocalFileMetaOutter;
  import com.alipay.sofa.jraft.storage.snapshot.SnapshotReader;
  import com.alipay.sofa.jraft.storage.snapshot.SnapshotWriter;
  import com.google.protobuf.ZeroByteStringHelper;
  
  /**
   * JRaft snapshot operation.
   *
   * @author <a href="mailto:liaochuntao@live.com">liaochuntao</a>
   */
  @SuppressWarnings("PMD.ClassNamingShouldBeCamelRule")
  interface JSnapshotOperation {
      
      /**
       * do snapshot save operation.
       *
       * @param writer {@link SnapshotWriter}
       * @param done   {@link Closure}
       */
      void onSnapshotSave(SnapshotWriter writer, Closure done);
      
      /**
       * do snapshot load operation.
       *
       * @param reader {@link SnapshotReader}
       * @return operation label
       */
      boolean onSnapshotLoad(SnapshotReader reader);
      
      /**
       * return actually snapshot executor.
       *
       * @return name
       */
      String info();
      
      /**
       * Metadata information for snapshot files.
       *
       * @param metadata meta data
       * @return {@link LocalFileMetaOutter.LocalFileMeta}
       * @throws Exception Exception
       */
      default LocalFileMetaOutter.LocalFileMeta buildMetadata(final LocalFileMeta metadata) throws Exception {
          return metadata == null ? null : LocalFileMetaOutter.LocalFileMeta.newBuilder()
                  .setUserMeta(ZeroByteStringHelper.wrap(JacksonUtils.toJsonBytes(metadata))).build();
      }
      
  }
  