/**
 * 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.hadoop.hbase.client;

import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.classification.InterfaceAudience;
import org.apache.hadoop.hbase.ipc.HBaseRpcController;

/**
 * Implementations make an rpc call against a RegionService via a protobuf Service.
 * Implement #rpcCall(RpcController) and then call {@link #call(int)} to
 * trigger the rpc. The {@link #call(int)} eventually invokes your
 * #rpcCall(RpcController) meanwhile saving you having to write a bunch of
 * boilerplate. The {@link #call(int)} implementation is from {@link RpcRetryingCaller} so rpcs are
 * retried on fail.
 *
 * <p>TODO: this class is actually tied to one region, because most of the paths make use of
 *       the regioninfo part of location when building requests. The only reason it works for
 *       multi-region requests (e.g. batch) is that they happen to not use the region parts.
 *       This could be done cleaner (e.g. having a generic parameter and 2 derived classes,
 *       RegionCallable and actual RegionServerCallable with ServerName.
 * @param <T> the class that the ServerCallable handles
 */
@InterfaceAudience.Private
public abstract class NoncedRegionServerCallable<T> extends ClientServiceCallable<T> {
  private final long nonce;

  /**
   * @param connection Connection to use.
   * @param tableName Table name to which <code>row</code> belongs.
   * @param row The row we want in <code>tableName</code>.
   */
  public NoncedRegionServerCallable(Connection connection, TableName tableName, byte [] row,
      HBaseRpcController rpcController) {
    super(connection, tableName, row, rpcController);
    this.nonce = getConnection().getNonceGenerator().newNonce();
  }

  long getNonceGroup() {
    return getConnection().getNonceGenerator().getNonceGroup();
  }

  long getNonce() {
    return this.nonce;
  }
}