| 1 | package dk.deepthought.sidious.blackboard; |
| 2 | |
| 3 | import java.util.Collection; |
| 4 | |
| 5 | import org.apache.commons.logging.Log; |
| 6 | import org.apache.commons.logging.LogFactory; |
| 7 | |
| 8 | import dk.deepthought.sidious.goalhandler.Goal; |
| 9 | import dk.deepthought.sidious.planner.Plan; |
| 10 | import dk.deepthought.sidious.planner.PlannerEngine; |
| 11 | import dk.deepthought.sidious.supportsystem.Adjustable; |
| 12 | import dk.deepthought.sidious.supportsystem.PlanRequester; |
| 13 | import dk.deepthought.sidious.supportsystem.Repository; |
| 14 | import dk.deepthought.sidious.supportsystem.SuperLinkID; |
| 15 | import dk.deepthought.sidious.util.SidiousMap; |
| 16 | |
| 17 | /** |
| 18 | * This class acts as a blackboard. It facilitates the communication |
| 19 | * between the various components of the system. |
| 20 | * <p> |
| 21 | * The class is implemented as a Singleton. |
| 22 | * |
| 23 | * @author Deepthought |
| 24 | * |
| 25 | */ |
| 26 | public class BlackBoardEngine implements BlackBoard { |
| 27 | |
| 28 | /** |
| 29 | * Logger for this class. |
| 30 | */ |
| 31 | private static final Log logger = LogFactory.getLog(BlackBoardEngine.class); |
| 32 | |
| 33 | /** |
| 34 | * The instance of the blackboard; to facilitate singleton property. |
| 35 | */ |
| 36 | private static final BlackBoard INSTANCE = new BlackBoardEngine(); |
| 37 | |
| 38 | /** |
| 39 | * This maps the id of a plan requester to the actual reference. |
| 40 | */ |
| 41 | private final SidiousMap requesterMapping; |
| 42 | |
| 43 | /** |
| 44 | * Private constructor; to facilitate singleton property. |
| 45 | */ |
| 46 | private BlackBoardEngine() { |
| 47 | requesterMapping = new SidiousMap(); |
| 48 | if (logger.isDebugEnabled()) { |
| 49 | logger.debug("BlackBoardEngine() - initialized"); |
| 50 | } |
| 51 | } |
| 52 | |
| 53 | /** |
| 54 | * Returns a reference to the blackboard of the system. |
| 55 | * <p> |
| 56 | * Note that the blackboard is implemented as a Singleton. |
| 57 | * |
| 58 | * @return a reference to the blackboard |
| 59 | */ |
| 60 | public static BlackBoard getInstance() { |
| 61 | return INSTANCE; |
| 62 | } |
| 63 | |
| 64 | /** |
| 65 | * TESTING purposes ONLY!! |
| 66 | */ |
| 67 | public void addToMapping(PlanRequester requester) { |
| 68 | SuperLinkID id = requester.getID(); |
| 69 | synchronized (requesterMapping) { |
| 70 | PlanRequester put = requesterMapping.put(id, requester); |
| 71 | if (put != null) { |
| 72 | logger.warn("requestPlan(PlanRequester requester=" + requester |
| 73 | + ") - requester already in map"); |
| 74 | } |
| 75 | } |
| 76 | } |
| 77 | |
| 78 | /* (non-Javadoc) |
| 79 | * @see dk.deepthought.sidious.blackboard.BlackBoard#requestPlan(dk.deepthought.sidious.supportsystem.PlanRequester) |
| 80 | */ |
| 81 | public void requestPlan(PlanRequester requester) { |
| 82 | if (requester == null) { |
| 83 | logger |
| 84 | .error("requestPlan(PlanRequester requester=null) - requester was null"); |
| 85 | throw new IllegalArgumentException("requester was null"); |
| 86 | } |
| 87 | SuperLinkID id = requester.getID(); |
| 88 | synchronized (requesterMapping) { |
| 89 | PlanRequester put = requesterMapping.put(id, requester); |
| 90 | if (put != null) { |
| 91 | logger.warn("requestPlan(PlanRequester requester=" + requester |
| 92 | + ") - requester already in map"); |
| 93 | } |
| 94 | } |
| 95 | |
| 96 | Repository.getGoalHandler().request(id); |
| 97 | if (logger.isDebugEnabled()) { |
| 98 | logger.debug("requestPlan(PlanRequester requester=" + requester |
| 99 | + ") - requested a plan"); |
| 100 | } |
| 101 | } |
| 102 | |
| 103 | /** |
| 104 | * Returns a reference to the plan requester associated with the specified |
| 105 | * <code>id</code>. |
| 106 | * <p> |
| 107 | * If no requester is associated with the specified id, planning for the |
| 108 | * specified id is stopped in the PlannerEngine, and <code>null</code> is |
| 109 | * returned. |
| 110 | * |
| 111 | * @see PlannerEngine |
| 112 | * |
| 113 | * @param id |
| 114 | * the id of the requested requester |
| 115 | * @return a reference to the specified plan requester, or <code>null</code> |
| 116 | * if requester does not exist |
| 117 | */ |
| 118 | public PlanRequester getRequester(SuperLinkID id) { |
| 119 | if (id == null) { |
| 120 | logger.error("getRequester(SuperLinkID id=null) - not valid id"); |
| 121 | throw new IllegalArgumentException("null not valid id"); |
| 122 | } |
| 123 | PlanRequester returnPlanRequester = null; |
| 124 | synchronized (requesterMapping) { |
| 125 | returnPlanRequester = requesterMapping.get(id); |
| 126 | } |
| 127 | if (returnPlanRequester == null) { |
| 128 | logger.error("getRequester(SuperLinkID id=" + id |
| 129 | + ") - missing requester"); |
| 130 | Repository.getPlanner().stop(id); |
| 131 | return null; |
| 132 | } |
| 133 | if (logger.isDebugEnabled()) { |
| 134 | logger.debug("getRequester(SuperLinkID id=" + id |
| 135 | + ") - return value=" + returnPlanRequester); |
| 136 | } |
| 137 | return returnPlanRequester; |
| 138 | } |
| 139 | |
| 140 | /* |
| 141 | * (non-Javadoc) |
| 142 | * |
| 143 | * @see dk.deepthought.sidious.blackboard.BlackBoard#getAdjustableSetting(dk.deepthought.sidious.supportsystem.SuperLinkID, |
| 144 | * dk.deepthought.sidious.supportsystem.SuperLinkID) |
| 145 | */ |
| 146 | public double getAdjustableSetting(SuperLinkID requesterID, |
| 147 | SuperLinkID adjustableID) { |
| 148 | if (logger.isDebugEnabled()) { |
| 149 | logger.debug("getAdjustableSetting(SuperLinkID requesterID=" |
| 150 | + requesterID + ", SuperLinkID adjustableID=" |
| 151 | + adjustableID + ") - start"); |
| 152 | } |
| 153 | if (adjustableID == null) { |
| 154 | logger |
| 155 | .error("getAdjustableSetting(SuperLinkID requesterID=" |
| 156 | + requesterID |
| 157 | + ", SuperLinkID adjustableID=null) - not valid adjustableID"); |
| 158 | |
| 159 | throw new IllegalArgumentException("null not valid adjustableID"); |
| 160 | |
| 161 | } |
| 162 | PlanRequester requester = getRequester(requesterID); |
| 163 | if (requester == null) { |
| 164 | return 0; |
| 165 | } |
| 166 | Collection<Adjustable> adjustables = requester.getAdjustables(); |
| 167 | double returnValue = 0; |
| 168 | for (Adjustable adjustable : adjustables) { |
| 169 | if (adjustable.getID().equals(adjustableID)) { |
| 170 | returnValue = adjustable.getSetting(); |
| 171 | } |
| 172 | } |
| 173 | |
| 174 | if (logger.isDebugEnabled()) { |
| 175 | logger.debug("getAdjustableSetting(SuperLinkID requesterID=" |
| 176 | + requesterID + ", SuperLinkID adjustableID=" |
| 177 | + adjustableID + ") - end - return value=" + returnValue); |
| 178 | } |
| 179 | return returnValue; |
| 180 | } |
| 181 | |
| 182 | /** |
| 183 | * Adds a goal to |
| 184 | * @param goal the goal to be added |
| 185 | */ |
| 186 | public void addGoal(Goal goal) { |
| 187 | Repository.getPlanner().requestPlan(goal); |
| 188 | } |
| 189 | |
| 190 | /** |
| 191 | * Adds a plan to the blackboard. |
| 192 | * <p> |
| 193 | * The requester of the plan is notified that the plan is ready; and is |
| 194 | * removed from the queue. |
| 195 | * |
| 196 | * @param plan |
| 197 | * the devised plan |
| 198 | */ |
| 199 | public void addPlan(Plan plan) { |
| 200 | SuperLinkID id = plan.getId(); |
| 201 | synchronized (requesterMapping) { |
| 202 | PlanRequester requester = getRequester(id); |
| 203 | requester.setPlan(plan); |
| 204 | requesterMapping.remove(id); |
| 205 | } |
| 206 | } |
| 207 | |
| 208 | /* (non-Javadoc) |
| 209 | * @see dk.deepthought.sidious.blackboard.BlackBoard#deliverResult(java.lang.Object) |
| 210 | */ |
| 211 | public void deliverResult(Object result) { |
| 212 | if (result instanceof Plan) { |
| 213 | Plan plan = (Plan) result; |
| 214 | addPlan(plan); |
| 215 | } else if (result instanceof Goal) { |
| 216 | Goal goal = (Goal) result; |
| 217 | addGoal(goal); |
| 218 | } |
| 219 | } |
| 220 | |
| 221 | } |