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.internal.core;
  
  import com.datastax.oss.driver.api.core.ProtocolVersion;
  import com.datastax.oss.driver.api.core.UnsupportedProtocolVersionException;
  import com.datastax.oss.driver.api.core.config.DefaultDriverOption;
  import com.datastax.oss.driver.api.core.metadata.Node;
  import com.datastax.oss.driver.internal.core.metadata.TopologyMonitor;
  import java.util.Collection;
  import java.util.Optional;
  
  /** Defines which native protocol versions are supported by a driver instance. */
  public interface ProtocolVersionRegistry {
  
    /**
     * Look up a version by its {@link ProtocolVersion#name() name}. This is used when a version was
     * forced in the configuration.
     *
     * @throws IllegalArgumentException if there is no known version with this name.
     * @see DefaultDriverOption#PROTOCOL_VERSION
     */
    ProtocolVersion fromName(String name);
  
    /**
     * The highest, non-beta version supported by the driver. This is used as the starting point for
     * the negotiation process for the initial connection (if the version wasn't forced).
     */
    ProtocolVersion highestNonBeta();
  
    /**
     * Downgrade to a lower version if the current version is not supported by the server. This is
     * used during the negotiation process for the initial connection (if the version wasn't forced).
     *
     * @return empty if there is no version to downgrade to.
     */
    Optional<ProtocolVersion> downgrade(ProtocolVersion version);
  
    /**
     * Computes the highest common version supported by the given nodes. This is called after the
     * initial {@link TopologyMonitor#refreshNodeList()} node refresh} (provided that the version was
     * not forced), to ensure that we proceed with a version that will work with all the nodes.
     *
     * @throws UnsupportedProtocolVersionException if no such version exists (the nodes support
     *     non-intersecting ranges), or if there was an error during the computation. This will cause
     *     the driver initialization to fail.
     */
    ProtocolVersion highestCommon(Collection<Node> nodes);
  
    /** Whether a given version supports a given feature. */
    boolean supports(ProtocolVersion version, ProtocolFeature feature);
  }
  