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 com.datastax.oss.driver.api.core.metadata.schema;
  
  import com.datastax.oss.driver.api.core.session.Session;
  import com.datastax.oss.driver.api.core.session.SessionBuilder;
  import com.datastax.oss.driver.api.core.type.UserDefinedType;
  import edu.umd.cs.findbugs.annotations.NonNull;
  
  /**
   * Tracks schema changes.
   *
   * <p>Implementations of this interface can be registered either via the configuration (see {@code
   * reference.conf} in the manual or core driver JAR), or programmatically via {@link
   * SessionBuilder#addSchemaChangeListener(SchemaChangeListener)}.
   *
   * <p>Note that the methods defined by this interface will be executed by internal driver threads,
   * and are therefore expected to have short execution times. If you need to perform long
   * computations or blocking calls in response to schema change events, it is strongly recommended to
   * schedule them asynchronously on a separate thread provided by your application code.
   *
   * <p>If you implement this interface but don't need to implement all the methods, extend {@link
   * SchemaChangeListenerBase}.
   */
  public interface SchemaChangeListener extends AutoCloseable {
  
    void onKeyspaceCreated(@NonNull KeyspaceMetadata keyspace);
  
    void onKeyspaceDropped(@NonNull KeyspaceMetadata keyspace);
  
    void onKeyspaceUpdated(@NonNull KeyspaceMetadata current, @NonNull KeyspaceMetadata previous);
  
    void onTableCreated(@NonNull TableMetadata table);
  
    void onTableDropped(@NonNull TableMetadata table);
  
    void onTableUpdated(@NonNull TableMetadata current, @NonNull TableMetadata previous);
  
    void onUserDefinedTypeCreated(@NonNull UserDefinedType type);
  
    void onUserDefinedTypeDropped(@NonNull UserDefinedType type);
  
    void onUserDefinedTypeUpdated(
        @NonNull UserDefinedType current, @NonNull UserDefinedType previous);
  
    void onFunctionCreated(@NonNull FunctionMetadata function);
  
    void onFunctionDropped(@NonNull FunctionMetadata function);
  
    void onFunctionUpdated(@NonNull FunctionMetadata current, @NonNull FunctionMetadata previous);
  
    void onAggregateCreated(@NonNull AggregateMetadata aggregate);
  
    void onAggregateDropped(@NonNull AggregateMetadata aggregate);
  
    void onAggregateUpdated(@NonNull AggregateMetadata current, @NonNull AggregateMetadata previous);
  
    void onViewCreated(@NonNull ViewMetadata view);
  
    void onViewDropped(@NonNull ViewMetadata view);
  
    void onViewUpdated(@NonNull ViewMetadata current, @NonNull ViewMetadata previous);
  
    /**
     * Invoked when the session is ready to process user requests.
     *
     * <p>This corresponds to the moment when {@link SessionBuilder#build()} returns, or the future
     * returned by {@link SessionBuilder#buildAsync()} completes. If the session initialization fails,
     * this method will not get called.
     *
     * <p>Listener methods are invoked from different threads; if you store the session in a field,
     * make it at least volatile to guarantee proper publication.
     *
     * <p>This method is guaranteed to be the first one invoked on this object.
     *
     * <p>The default implementation is empty.
     */
    default void onSessionReady(@NonNull Session session) {}
  }
  