bundles/org.simantics.utils.datastructures/src/org/simantics/utils/datastructures/context/Context.java

   1 /*******************************************************************************
   2  * Copyright (c) 2007, 2010 Association for Decentralized Information Management
   3  * in Industry THTH ry.
   4  * All rights reserved. This program and the accompanying materials
   5  * are made available under the terms of the Eclipse Public License v1.0
   6  * which accompanies this distribution, and is available at
   7  * http://www.eclipse.org/legal/epl-v10.html
   8  *
   9  * Contributors:
  10  *     VTT Technical Research Centre of Finland - initial API and implementation
  11  *******************************************************************************/
  12 /*
  13  *
  14  * @author Toni Kalajainen
  15  */
  16 package org.simantics.utils.datastructures.context;
  17
  18 import java.lang.reflect.Array;
  19 import java.lang.reflect.Method;
  20 import java.util.ArrayList;
  21 import java.util.Collection;
  22 import java.util.HashMap;
  23 import java.util.HashSet;
  24 import java.util.Iterator;
  25 import java.util.Map;
  26 import java.util.Set;
  27
  28 import org.simantics.utils.datastructures.disposable.AbstractDisposable;
  29 import org.simantics.utils.strings.EString;
  30 import org.simantics.utils.threads.Executable;
  31 import org.simantics.utils.threads.IThreadWorkQueue;
  32 import org.simantics.utils.threads.SyncListenerList;
  33 import org.simantics.utils.threads.ThreadUtils;
  34
  35 /**
  36  *
  37  * TODO Optimize getItemsByClass queries (Create optimizing structures after 1st query)
  38  * TODO Optimize getSingleItem query
  39  *
  40  * @param <E>
  41  */
  42 public class Context<E> extends AbstractDisposable implements IContext<E> {
  43
  44         protected Set<E> set = new HashSet<E>();
  45         @SuppressWarnings({ "rawtypes" })
  46     protected SyncListenerList<IContextListener> listeners =
  47                 new SyncListenerList<IContextListener>(IContextListener.class);
  48
  49         final Class<E> clazz;
  50
  51         private E[] snapshotArray;
  52         private Map<Class<? extends E>, Collection<? extends E>> classQueryResultCache =
  53                 new HashMap<Class<? extends E>, Collection<? extends E>>();
  54
  55         public Context(Class<E> clazz) {
  56                 this.clazz = clazz;
  57                 snapshotArray = createArray(clazz, 0);
  58         }
  59
  60         @Override
  61         public void add(E item) {
  62             assertNotDisposed();
  63                 Executable executables[];
  64                 synchronized(this) {
  65                         if (set.contains(item))
  66                                 throw new IllegalArgumentException("Context already contains item "+item);
  67
  68                         set.add(item);
  69                         snapshotArray = createSnapshot(set);
  70
  71                         executables = listeners.getExecutables(itemAdded, this, item);
  72
  73                         Iterator<Class<? extends E>> i = classQueryResultCache.keySet().iterator();
  74                         while (i.hasNext()) {
  75                                 Class<? extends E> c = i.next();
  76                                 if (c.isInstance(item))
  77                                         i.remove();
  78                         }
  79                 }
  80                 ThreadUtils.multiSyncExec(executables);
  81         }
  82
  83         @Override
  84         public boolean remove(E item) {
  85         assertNotDisposed();
  86                 Executable executables[];
  87                 synchronized(this) {
  88                         if (!set.remove(item))
  89                                 return false;
  90                         snapshotArray = createSnapshot(set);
  91                         executables = listeners.getExecutables(itemRemoved, this, item);
  92
  93                         Iterator<Class<? extends E>> i = classQueryResultCache.keySet().iterator();
  94                         while (i.hasNext()) {
  95                                 Class<? extends E> c = i.next();
  96                                 if (c.isInstance(item))
  97                                         i.remove();
  98                         }
  99                 }
 100                 ThreadUtils.multiSyncExec(executables);
 101                 return true;
 102         }
 103
 104         @Override
 105         public synchronized boolean contains(E item) {
 106         assertNotDisposed();
 107                 return set.contains(item);
 108         }
 109
 110     @Override
 111     public void clear() {
 112         assertNotDisposed();
 113         classQueryResultCache.clear();
 114         ArrayList<Executable> executables = new ArrayList<Executable>();
 115         synchronized(this) {
 116                 if (set.isEmpty())
 117                         return;
 118
 119                 for (E item : snapshotArray)
 120                         listeners.addExecutables(executables, itemRemoved, this, item);
 121
 122                 set.clear();
 123                 this.snapshotArray = createSnapshot(set);
 124         }
 125         ThreadUtils.multiSyncExec(executables);
 126     }
 127
 128         @SuppressWarnings("unchecked")
 129     @Override
 130         public synchronized <R extends E> Collection<R> getItemsByClass(Class<R> clazz) {
 131         assertNotDisposed();
 132                 Collection<R> result = (Collection<R>) classQueryResultCache.get(clazz);
 133                 if (result!=null)
 134                         return result;
 135                 result = new ArrayList<R>();
 136                 for (E i : set)
 137                         if (clazz.isAssignableFrom(i.getClass()))
 138                                 result.add((R)i);
 139                 classQueryResultCache.put(clazz, result);
 140                 return result;
 141         }
 142
 143         @SuppressWarnings("unchecked")
 144         @Override
 145         public synchronized <R> boolean containsItemByClass(Class<R> clazz) {
 146         assertNotDisposed();
 147                 Collection<R> result = (Collection<R>) classQueryResultCache.get(clazz);
 148                 if (result!=null) return !result.isEmpty();
 149                 for (E i : set)
 150                         if (clazz.isAssignableFrom(i.getClass()))
 151                                 return true;
 152                 return false;
 153         }
 154
 155     @SuppressWarnings({ "unchecked" })
 156     private <R extends E> R[] createArray(Class<R> clazz, int length)
 157     {
 158         return (R[]) Array.newInstance(clazz, length);
 159     }
 160
 161         E[] createSnapshot(Set<E> set) {
 162                 E[] result = createArray(clazz, set.size());
 163                 int index = 0;
 164                 for (E i : set)
 165                         result[index++] = i;
 166                 return result;
 167         }
 168
 169         public synchronized <R extends E> R getSingleItem(Class<R> clazz)
 170         {
 171         assertNotDisposed();
 172                 Collection<R> result = getItemsByClass(clazz);
 173                 if (result.size()==1)
 174                         return result.iterator().next();
 175                 throw new RuntimeException("one "+clazz.getName()+" expected in Context, got "+result.size());
 176         }
 177
 178         @Override
 179         public E[] toArray() {
 180         assertNotDisposed();
 181                 return snapshotArray;
 182         }
 183
 184         @Override
 185         public void addContextListener(IContextListener<E> listener) {
 186         assertNotDisposed();
 187                 listeners.add(listener);
 188         }
 189
 190         @Override
 191         public void removeContextListener(IContextListener<E> listener) {
 192         assertNotDisposed();
 193                 listeners.remove(listener);
 194         }
 195
 196         @Override
 197         public void addContextListener(IThreadWorkQueue thread,
 198                         IContextListener<E> listener) {
 199         assertNotDisposed();
 200                 listeners.add(thread, listener);
 201         }
 202
 203         @Override
 204         public void removeContextListener(IThreadWorkQueue thread,
 205                         IContextListener<E> listener) {
 206         assertNotDisposed();
 207                 listeners.remove(thread, listener);
 208         }
 209
 210         private static Method itemAdded = SyncListenerList.getMethod(IContextListener.class, "itemAdded");
 211         private static Method itemRemoved = SyncListenerList.getMethod(IContextListener.class, "itemRemoved");
 212
 213 //      private void fireItemAdded(E item)
 214 //      {
 215 //              listeners.fireEventSync(itemAdded, this, item);
 216 //      }
 217 //
 218 //      private void fireItemRemoved(E item)
 219 //      {
 220 //              listeners.fireEventSync(itemRemoved, this, item);
 221 //      }
 222
 223         @SuppressWarnings("unchecked")
 224     @Override
 225         public <R extends E> R getAtMostOneItemOfClass(Class<R> clazz) {
 226         assertNotDisposed();
 227             int count = 0;
 228             R r = null;
 229         for (E i : set) {
 230             if (clazz.isAssignableFrom(i.getClass())) {
 231                 ++count;
 232                 r = (R) i;
 233             }
 234         }
 235         if (count==0) return null;
 236         if (count>1)
 237                         throw new RuntimeException("one "+clazz.getName()+" expected in Context, got "+count);
 238                 return r;
 239         }
 240
 241         @Override
 242         protected void doDispose() {
 243         }
 244
 245         @Override
 246         public String toString() {
 247             String s = EString.implode(snapshotArray, "\n");
 248             return s != null ? s : "";
 249         }
 250
 251 }