content: /*
   * Copyright 2010 Proofpoint, Inc.
   *
   * 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 io.airlift.discovery.server;
  
  import com.google.common.base.Preconditions;
  import com.google.common.base.Supplier;
  import com.google.common.collect.ImmutableSet;
  import com.google.common.collect.Maps;
  import com.google.inject.Inject;
  import io.airlift.units.Duration;
  import org.joda.time.DateTime;
  
  import com.google.errorprone.annotations.ThreadSafe;
  
  import java.util.Iterator;
  import java.util.Map;
  import java.util.Set;
  
  import static com.google.common.base.Predicates.and;
  import static com.google.common.collect.Collections2.transform;
  import static com.google.common.collect.Iterables.filter;
  import static io.airlift.discovery.server.DynamicServiceAnnouncement.toServiceWith;
  import static io.airlift.discovery.server.Service.matchesPool;
  import static io.airlift.discovery.server.Service.matchesType;
  
  @ThreadSafe
  public class InMemoryDynamicStore
          implements DynamicStore
  {
      private final Map<Id<Node>, Entry> descriptors = Maps.newHashMap();
      private final Duration maxAge;
      private final Supplier<DateTime> currentTime;
  
      @Inject
      public InMemoryDynamicStore(DiscoveryConfig config, Supplier<DateTime> timeSource)
      {
          this.currentTime = timeSource;
          this.maxAge = config.getMaxAge();
      }
  
      @Override
      public synchronized void put(Id<Node> nodeId, DynamicAnnouncement announcement)
      {
          Preconditions.checkNotNull(nodeId, "nodeId is null");
          Preconditions.checkNotNull(announcement, "announcement is null");
  
          Set<Service> services = ImmutableSet.copyOf(transform(announcement.getServiceAnnouncements(), toServiceWith(nodeId, announcement.getLocation(), announcement.getPool())));
  
          DateTime expiration = currentTime.get().plusMillis((int) maxAge.toMillis());
          descriptors.put(nodeId, new Entry(expiration, services));
      }
  
      @Override
      public synchronized void delete(Id<Node> nodeId)
      {
          Preconditions.checkNotNull(nodeId, "nodeId is null");
  
          descriptors.remove(nodeId);
      }
  
      @Override
      public synchronized Set<Service> getAll()
      {
          removeExpired();
  
          ImmutableSet.Builder<Service> builder = ImmutableSet.builder();
          for (Entry entry : descriptors.values()) {
              builder.addAll(entry.getServices());
          }
          return builder.build();
      }
  
      @Override
      public synchronized Set<Service> get(String type)
      {
          Preconditions.checkNotNull(type, "type is null");
  
          return ImmutableSet.copyOf(filter(getAll(), matchesType(type)));
      }
  
      @Override
      public synchronized Set<Service> get(String type, String pool)
      {
          Preconditions.checkNotNull(type, "type is null");
          Preconditions.checkNotNull(pool, "pool is null");
  
          return ImmutableSet.copyOf(filter(getAll(), and(matchesType(type), matchesPool(pool))));
      }
  
      private synchronized void removeExpired()
      {
          Iterator<Entry> iterator = descriptors.values().iterator();
  
          DateTime now = currentTime.get();
          while (iterator.hasNext()) {
              Entry entry = iterator.next();
  
              if (now.isAfter(entry.getExpiration())) {
                  iterator.remove();
              }
          }
      }
  
      private static class Entry
      {
          private final Set<Service> services;
          private final DateTime expiration;
  
          public Entry(DateTime expiration, Set<Service> services)
          {
              this.expiration = expiration;
              this.services = ImmutableSet.copyOf(services);
          }
  
          public DateTime getExpiration()
          {
              return expiration;
          }
  
          public Set<Service> getServices()
          {
              return services;
          }
      }
  }
  