1 files changed, 84 insertions, 0 deletions
diff --git a/src/main/java/com/c2kernel/utils/DescriptionObjectCache.java b/src/main/java/com/c2kernel/utils/DescriptionObjectCache.java
new file mode 100644
index 0000000..a8cd197
--- /dev/null
+++ b/src/main/java/com/c2kernel/utils/DescriptionObjectCache.java
@@ -0,0 +1,84 @@
+/**
+ *
+ */
+package com.c2kernel.utils;
+
+import com.c2kernel.common.InvalidDataException;
+import com.c2kernel.common.ObjectNotFoundException;
+import com.c2kernel.entity.proxy.EntityProxyObserver;
+import com.c2kernel.entity.proxy.ItemProxy;
+import com.c2kernel.entity.proxy.MemberSubscription;
+import com.c2kernel.persistency.ClusterStorage;
+import com.c2kernel.persistency.outcome.Viewpoint;
+
+public abstract class DescriptionObjectCache<D extends DescriptionObject> {
+
+	SoftCache<String, CacheEntry<D>> cache = new SoftCache<String, CacheEntry<D>>();
+
+	public D get(String name, String version) throws ObjectNotFoundException, InvalidDataException {
+		D thisDef;
+		synchronized(cache) {
+			CacheEntry<D> thisDefEntry = cache.get(name+"_"+version);
+			if (thisDefEntry == null) {
+				Logger.msg(6, name+" v"+version+" not found in cache. Retrieving.");
+		        ItemProxy defItem = LocalObjectLoader.loadLocalObjectDef(getDefRoot(), name);
+		        thisDef = loadObject(name, version, defItem);
+		        cache.put(name+"_"+version, new CacheEntry<D>(thisDef, defItem, this));
+			}
+			else {
+				Logger.msg(6, name+" v"+version+" found in cache.");
+				thisDef = thisDefEntry.def;
+			}
+		}
+        return thisDef;
+	}
+	
+	public abstract String getDefRoot();
+	
+	public abstract D loadObject(String name, String version, ItemProxy proxy) throws ObjectNotFoundException, InvalidDataException;
+
+	public void removeAct(String id) {
+		synchronized(cache) {
+		if (cache.keySet().contains(id)) {
+			Logger.msg(7, "ActDefCache: Removing activity def "+id+" from cache");
+			cache.remove(id);
+			}
+		}
+	}
+
+	public class CacheEntry<E extends DescriptionObject> implements EntityProxyObserver<Viewpoint> {
+		public String id;
+		public ItemProxy proxy;
+		public E def;
+		public DescriptionObjectCache<E> parent;
+		public CacheEntry(E def, ItemProxy proxy, DescriptionObjectCache<E> parent) {
+			this.id = def.getName()+"_"+def.getVersion();
+			this.def = def;
+			this.parent = parent;
+			this.proxy = proxy;
+			proxy.subscribe(new MemberSubscription<Viewpoint>(this, ClusterStorage.VIEWPOINT, false));
+		}
+		@Override
+		public void finalize() {
+			parent.removeAct(id);
+			proxy.unsubscribe(this);
+		}
+		@Override
+		public void add(Viewpoint contents) {
+			parent.removeAct(id);
+		}
+
+		@Override
+		public void remove(String oldId) {
+			parent.removeAct(oldId);
+		}
+
+		@Override
+		public String toString() {
+			return "Cache entry: "+id;
+		}
+		@Override
+		public void control(String control, String msg) {
+		}
+	}
+}
+\ No newline at end of file