Coverage Report - com.allanbank.mongodb.client.state.LatencyServerSelector
 
Classes in this File Line Coverage Branch Coverage Complexity
LatencyServerSelector
100%
12/12
100%
4/4
2.5
 
 1  
 /*
 2  
  * #%L
 3  
  * LatencyServerSelector.java - mongodb-async-driver - Allanbank Consulting, Inc.
 4  
  * %%
 5  
  * Copyright (C) 2011 - 2014 Allanbank Consulting, Inc.
 6  
  * %%
 7  
  * Licensed under the Apache License, Version 2.0 (the "License");
 8  
  * you may not use this file except in compliance with the License.
 9  
  * You may obtain a copy of the License at
 10  
  * 
 11  
  *      http://www.apache.org/licenses/LICENSE-2.0
 12  
  * 
 13  
  * Unless required by applicable law or agreed to in writing, software
 14  
  * distributed under the License is distributed on an "AS IS" BASIS,
 15  
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 16  
  * See the License for the specific language governing permissions and
 17  
  * limitations under the License.
 18  
  * #L%
 19  
  */
 20  
 package com.allanbank.mongodb.client.state;
 21  
 
 22  
 import java.util.ArrayList;
 23  
 import java.util.Collections;
 24  
 import java.util.List;
 25  
 
 26  
 /**
 27  
  * LatencyServerSelector provides an implementation of the server selector that
 28  
  * uses the server latencies to determine the server to select.
 29  
  * 
 30  
  * @api.no This class is <b>NOT</b> part of the drivers API. This class may be
 31  
  *         mutated in incompatible ways between any two releases of the driver.
 32  
  * @copyright 2012-2013, Allanbank Consulting, Inc., All Rights Reserved
 33  
  */
 34  
 public class LatencyServerSelector implements ServerSelector {
 35  
 
 36  
     /** The cluster to choose from. */
 37  
     private final Cluster myCluster;
 38  
 
 39  
     /** If true then only writable servers should be selected. */
 40  
     private final boolean myWritableOnly;
 41  
 
 42  
     /**
 43  
      * Creates a new LatencyServerSelector.
 44  
      * 
 45  
      * @param cluster
 46  
      *            The cluster to choose from.
 47  
      * @param writableOnly
 48  
      *            If true then only writable servers should be selected. If
 49  
      *            false then any server (writable and not writable) may be
 50  
      *            selected.
 51  
      */
 52  
     public LatencyServerSelector(final Cluster cluster,
 53  79
             final boolean writableOnly) {
 54  79
         myCluster = cluster;
 55  79
         myWritableOnly = writableOnly;
 56  79
     }
 57  
 
 58  
     /**
 59  
      * {@inheritDoc}
 60  
      * <p>
 61  
      * Overridden to order the servers with the lowest latency first.
 62  
      * </p>
 63  
      */
 64  
     @Override
 65  
     public List<Server> pickServers() {
 66  
         List<Server> servers;
 67  8
         if (myWritableOnly) {
 68  7
             servers = myCluster.getWritableServers();
 69  
         }
 70  
         else {
 71  1
             servers = myCluster.getServers();
 72  
         }
 73  
 
 74  
         // If there are no servers then there is no one to pick.
 75  8
         if (servers.isEmpty()) {
 76  3
             return Collections.emptyList();
 77  
         }
 78  
 
 79  
         // Copy to a list we know we can modify and sort.
 80  5
         servers = new ArrayList<Server>(servers);
 81  5
         Collections.sort(servers, ServerLatencyComparator.COMPARATOR);
 82  
 
 83  5
         return servers;
 84  
     }
 85  
 }