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 accord.maelstrom;
  
  import accord.api.Data;
  import accord.api.Key;
  import accord.api.Read;
  import accord.local.SafeCommandStore;
  import accord.primitives.Keys;
  import accord.primitives.Participants;
  import accord.primitives.Ranges;
  import accord.primitives.Seekable;
  import accord.primitives.Timestamp;
  import accord.utils.async.AsyncChain;
  import accord.utils.async.AsyncChains;
  
  public class MaelstromRead implements Read
  {
      final Keys readKeys;
      final Keys keys;
  
      public MaelstromRead(Keys readKeys, Keys keys)
      {
          this.readKeys = readKeys;
          this.keys = keys;
      }
  
      @Override
      public Keys keys()
      {
          return keys;
      }
  
      @Override
      public AsyncChain<Data> read(SafeCommandStore safeStore, Seekable key, Timestamp executeAt)
      {
          if (key == null)
              return AsyncChains.success(new MaelstromData());
  
          MaelstromStore s = (MaelstromStore)safeStore.dataStore();
          MaelstromData result = new MaelstromData();
          result.put((Key)key, s.get((Key)key));
          return AsyncChains.success(result);
      }
  
      @Override
      public Read slice(Ranges ranges)
      {
          return new MaelstromRead(readKeys.slice(ranges), keys.slice(ranges));
      }
  
      @Override
      public Read intersecting(Participants<?> participants)
      {
          return new MaelstromRead(readKeys.intersecting(participants), keys.intersecting(participants));
      }
  
      @Override
      public Read merge(Read other)
      {
          MaelstromRead that = (MaelstromRead) other;
          Keys readKeys = this.readKeys.with(that.readKeys);
          Keys keys = this.keys.with(that.keys);
          if (readKeys == this.readKeys && keys == this.keys)
              return this;
          if (readKeys == that.readKeys && keys == that.keys)
              return that;
          return new MaelstromRead(readKeys.with(that.readKeys), keys.with(that.keys));
      }
  }
  