opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/entityownership/selectionstrategy/EntityOwnerSelectionStrategyConfig.java

   1 /*
   2  * Copyright (c) 2015 Cisco Systems, Inc. and others.  All rights reserved.
   3  *
   4  * This program and the accompanying materials are made available under the
   5  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
   6  * and is available at http://www.eclipse.org/legal/epl-v10.html
   7  */
   8
   9 package org.opendaylight.controller.cluster.datastore.entityownership.selectionstrategy;
  10
  11 import java.lang.reflect.InvocationTargetException;
  12 import java.util.HashMap;
  13 import java.util.Map;
  14 import org.slf4j.Logger;
  15 import org.slf4j.LoggerFactory;
  16
  17 public class EntityOwnerSelectionStrategyConfig {
  18     private static final Logger LOG = LoggerFactory.getLogger(EntityOwnerSelectionStrategyConfig.class);
  19     private final Map<String, StrategyInfo> entityTypeToStrategyInfo = new HashMap<>();
  20     private final Map<String, EntityOwnerSelectionStrategy> entityTypeToOwnerSelectionStrategy = new HashMap<>();
  21
  22     private EntityOwnerSelectionStrategyConfig(){
  23
  24     }
  25
  26     public boolean isStrategyConfigured(String entityType){
  27         return entityTypeToStrategyInfo.get(entityType) != null;
  28     }
  29
  30     public EntityOwnerSelectionStrategy createStrategy(String entityType){
  31         final EntityOwnerSelectionStrategy strategy;
  32         final EntityOwnerSelectionStrategy existingStrategy = entityTypeToOwnerSelectionStrategy.get(entityType);
  33         if(existingStrategy != null){
  34             strategy = existingStrategy;
  35         } else {
  36             EntityOwnerSelectionStrategyConfig.StrategyInfo strategyInfo = entityTypeToStrategyInfo.get(entityType);
  37             if(strategyInfo == null){
  38                 strategy = FirstCandidateSelectionStrategy.INSTANCE;
  39             } else {
  40                 strategy = strategyInfo.createStrategy();
  41             }
  42             entityTypeToOwnerSelectionStrategy.put(entityType, strategy);
  43         }
  44         return strategy;
  45
  46     }
  47
  48     private static final class StrategyInfo {
  49         private final Class<? extends EntityOwnerSelectionStrategy> strategyClass;
  50         private final long delay;
  51
  52         private StrategyInfo(Class<? extends EntityOwnerSelectionStrategy> strategyClass, long delay) {
  53             this.strategyClass = strategyClass;
  54             this.delay = delay;
  55         }
  56
  57         public EntityOwnerSelectionStrategy createStrategy(){
  58             try {
  59                 return strategyClass.getDeclaredConstructor(long.class).newInstance(delay);
  60             } catch (InstantiationException | IllegalAccessException | InvocationTargetException | NoSuchMethodException e) {
  61                 LOG.warn("could not create custom strategy", e);
  62             }
  63             return FirstCandidateSelectionStrategy.INSTANCE;
  64         }
  65     }
  66
  67     public static Builder newBuilder(){
  68         return new Builder(new EntityOwnerSelectionStrategyConfig());
  69     }
  70
  71     public static class Builder {
  72         private final EntityOwnerSelectionStrategyConfig config;
  73
  74         private Builder(EntityOwnerSelectionStrategyConfig config){
  75             this.config = config;
  76         }
  77
  78         public Builder addStrategy(String entityType, Class<? extends EntityOwnerSelectionStrategy> strategy, long delay){
  79             config.entityTypeToStrategyInfo.put(entityType, new StrategyInfo(strategy, delay));
  80             return this;
  81         }
  82
  83         public EntityOwnerSelectionStrategyConfig build(){
  84             return this.config;
  85         }
  86     }
  87
  88 }