content: /*
   * 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.cassandra.sidecar.db;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import com.datastax.driver.core.ResultSet;
  import com.datastax.driver.core.Session;
  import com.datastax.driver.core.Statement;
  import org.apache.cassandra.sidecar.common.server.CQLSessionProvider;
  import org.apache.cassandra.sidecar.db.schema.TableSchema;
  import org.jetbrains.annotations.NotNull;
  
  /**
   * Encapsulates the database operations (i.e. CRUD) of objects.
   * @param <T> TableSchema
   *
   */
  public abstract class DatabaseAccessor<T extends TableSchema>
  {
      public final CQLSessionProvider cqlSessionProvider;
      protected final T tableSchema;
  
      protected final Logger logger = LoggerFactory.getLogger(this.getClass());
  
      protected DatabaseAccessor(T tableSchema,
                                 CQLSessionProvider sessionProvider)
      {
          this.tableSchema = tableSchema;
          this.cqlSessionProvider = sessionProvider;
      }
  
      @NotNull
      public Session session()
      {
          return cqlSessionProvider.get();
      }
  
      /**
       * @return whether DatabaseAccessor is available to access database
       */
      public boolean isAvailable()
      {
          return tableSchema.isInitialized();
      }
  
      protected ResultSet execute(Statement statement)
      {
          return session().execute(statement);
      }
  }
  