code: /*
   * Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements.  See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.
   * The ASF licenses this file to You 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 org.apache.skywalking.oap.server.core.storage.model;
  
  import lombok.RequiredArgsConstructor;
  import lombok.extern.slf4j.Slf4j;
  import org.apache.skywalking.oap.server.core.CoreModule;
  import org.apache.skywalking.oap.server.core.RunningMode;
  import org.apache.skywalking.oap.server.core.storage.StorageException;
  import org.apache.skywalking.oap.server.library.client.Client;
  import org.apache.skywalking.oap.server.library.module.ModuleManager;
  
  /**
   * The core module installation controller.
   */
  @RequiredArgsConstructor
  @Slf4j
  public abstract class ModelInstaller implements ModelCreator.CreatingListener {
      protected final Client client;
      protected final ModuleManager moduleManager;
  
      @Override
      public void whenCreating(Model model) throws StorageException {
          if (RunningMode.isNoInitMode()) {
              while (!isExists(model)) {
                  try {
                      log.info(
                          "table: {} does not exist. OAP is running in 'no-init' mode, waiting... retry 3s later.",
                          model.getName()
                      );
                      Thread.sleep(3000L);
                  } catch (InterruptedException e) {
                      log.error(e.getMessage());
                  }
              }
          } else {
              if (!isExists(model)) {
                  log.info("table: {} does not exist", model.getName());
                  createTable(model);
              }
          }
      }
  
      public void start() {
      }
  
      /**
       * Installer implementation could use this API to request a column name replacement. This method delegates for
       * {@link ModelManipulator}.
       */
      protected final void overrideColumnName(String columnName, String newName) {
          ModelManipulator modelOverride = moduleManager.find(CoreModule.NAME)
                                                        .provider()
                                                        .getService(ModelManipulator.class);
          modelOverride.overrideColumnName(columnName, newName);
      }
  
      /**
       * Check whether the storage entity exists. Need to implement based on the real storage.
       */
      public abstract boolean isExists(Model model) throws StorageException;
  
      /**
       * Create the storage entity. All creations should be after the {@link #isExists(Model)} check.
       */
      public abstract void createTable(Model model) throws StorageException;
  }
  