src/edu/berkeley/fleet/loops/ShipPool.java

   1 package edu.berkeley.fleet.loops;
   2 import java.util.*;
   3 import edu.berkeley.fleet.api.*;
   4 import static edu.berkeley.fleet.util.BitManipulations.*;
   5
   6 /**
   7  *  A ShipPool keeps track of ships which have been "allocated" and
   8  *  are in use.  ShipPools may be arranged in a hierarchy; allocating
   9  *  a ship in one pool will allocate it in all ancestors.
  10  */
  11 public class ShipPool implements Iterable<Ship> {
  12
  13     public final Fleet fleet;
  14     public final ShipPool ancestor;
  15
  16     private HashSet<Ship> allocatedShips = new HashSet<Ship>();
  17
  18     public ShipPool(Fleet fleet) { this(fleet, null); }
  19     public ShipPool(Fleet fleet, ShipPool ancestor) {
  20         this.fleet = fleet;
  21         this.ancestor = ancestor;
  22     }
  23
  24     public Iterator<Ship> iterator() { return allocatedShips.iterator(); }
  25
  26     /** allocate a ship */
  27     public Ship allocateShip(String type) {
  28         Ship ship = null;
  29         if (ancestor != null) {
  30             ship = ancestor.allocateShip(type);
  31         } else {
  32             for(int i=0; ; i++) {
  33                 ship = fleet.getShip(type, i);
  34                 if (ship==null)
  35                     throw new RuntimeException("no more ships of type " + type);
  36                 if (!allocatedShips.contains(ship)) break;
  37             }
  38         }
  39         allocatedShips.add(ship);
  40         return ship;
  41     }
  42
  43     /** release an allocated ship */
  44     public void releaseShip(Ship ship) {
  45         if (!allocatedShips.contains(ship))
  46             throw new RuntimeException("ship " + ship + " released but was not allocated");
  47         allocatedShips.remove(ship);
  48         if (ancestor != null) ancestor.releaseShip(ship);
  49     }
  50
  51 }