content: /*
   * Licensed 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.bookkeeper.clients.impl.internal;
  
  import com.google.common.annotations.VisibleForTesting;
  import com.google.common.collect.Maps;
  import java.util.concurrent.CompletableFuture;
  import java.util.concurrent.ConcurrentMap;
  import org.apache.bookkeeper.clients.impl.internal.api.RootRangeClient;
  import org.apache.bookkeeper.common.concurrent.FutureUtils;
  import org.apache.bookkeeper.stream.proto.StreamProperties;
  
  /**
   * Build the stream metadata cache.
   */
  public class StreamMetadataCache {
  
      private final RootRangeClient scClient;
      private final ConcurrentMap<Long, StreamProperties> streams;
  
      public StreamMetadataCache(RootRangeClient scClient) {
          this.scClient = scClient;
          this.streams = Maps.newConcurrentMap();
      }
  
      @VisibleForTesting
      ConcurrentMap<Long, StreamProperties> getStreams() {
          return streams;
      }
  
      CompletableFuture<StreamProperties> getStreamProperties(long streamId) {
          StreamProperties props = streams.get(streamId);
          if (null != props) {
              return FutureUtils.value(props);
          }
  
          return scClient.getStream(streamId).thenApply(propsReturned -> {
              streams.put(streamId, propsReturned);
              return propsReturned;
          });
      }
  
      boolean putStreamProperties(long streamId, StreamProperties props) {
          return null == streams.putIfAbsent(streamId, props);
      }
  
  }
  