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.bifromq.basekv.client.scheduler;
  
  import static org.apache.bifromq.basekv.client.KVRangeRouterUtil.findByKey;
  
  import com.google.protobuf.ByteString;
  import java.util.Optional;
  import org.apache.bifromq.basekv.client.IBaseKVStoreClient;
  import org.apache.bifromq.basekv.client.KVRangeSetting;
  import org.apache.bifromq.basescheduler.BatchCallScheduler;
  
  /**
   * The abstract class for base-kv query call scheduler.
   *
   * @param <ReqT> the type of the request
   * @param <RespT> the type of the response
   * @param <BatchCallT> the type of the batch call
   */
  public abstract class QueryCallScheduler<ReqT, RespT, BatchCallT extends BatchQueryCall<ReqT, RespT>>
      extends BatchCallScheduler<ReqT, RespT, QueryCallBatcherKey> {
      protected final IBaseKVStoreClient storeClient;
  
      public QueryCallScheduler(IBatchQueryCallBuilder<ReqT, RespT, BatchCallT> batchCallBuilder,
                                long maxBurstLatency,
                                IBaseKVStoreClient storeClient) {
          super(new BatchQueryCallBuilderFactory<>(storeClient, batchCallBuilder), maxBurstLatency);
          this.storeClient = storeClient;
      }
  
      protected String selectStore(KVRangeSetting setting, ReqT request) {
          return setting.leader();
      }
  
      protected abstract int selectQueue(ReqT request);
  
      protected abstract boolean isLinearizable(ReqT request);
  
      protected abstract ByteString rangeKey(ReqT request);
  
      @Override
      protected final Optional<QueryCallBatcherKey> find(ReqT req) {
          return findByKey(rangeKey(req), storeClient.latestEffectiveRouter())
              .map(range -> new QueryCallBatcherKey(range.id(), selectStore(range, req),
                  selectQueue(req), range.ver(), isLinearizable(req)));
      }
  }
  