Migrated source code from Simantics SVN

[simantics/platform.git] / bundles / org.simantics.utils.datastructures / src / org / simantics / utils / datastructures / ContextLocal.java

diff --git a/bundles/org.simantics.utils.datastructures/src/org/simantics/utils/datastructures/ContextLocal.java b/bundles/org.simantics.utils.datastructures/src/org/simantics/utils/datastructures/ContextLocal.java
new file mode 100644 (file)
index 0000000..b417735
--- /dev/null
+++ b/bundles/org.simantics.utils.datastructures/src/org/simantics/utils/datastructures/ContextLocal.java
@@ -0,0 +1,90 @@
+/*******************************************************************************\r
+ * Copyright (c) 2007, 2010 Association for Decentralized Information Management\r
+ * in Industry THTH ry.\r
+ * All rights reserved. This program and the accompanying materials\r
+ * are made available under the terms of the Eclipse Public License v1.0\r
+ * which accompanies this distribution, and is available at\r
+ * http://www.eclipse.org/legal/epl-v10.html\r
+ *\r
+ * Contributors:\r
+ *     VTT Technical Research Centre of Finland - initial API and implementation\r
+ *******************************************************************************/\r
+package org.simantics.utils.datastructures;\r
+\r
+import java.util.concurrent.ConcurrentHashMap;\r
+\r
+import org.simantics.utils.datastructures.disposable.AbstractDisposable;\r
+\r
+/**\r
+ * This class provides context-local variables. There is a different value for \r
+ * each context. This class handles disposing of all values if optional\r
+ * disposer is provided.  \r
+ *\r
+ * @param <T>\r
+ */\r
+public class ContextLocal<T> extends AbstractDisposable {\r
+       \r
+       protected ConcurrentHashMap<Object, T> reg = new ConcurrentHashMap<Object, T>();\r
+       \r
+       public static interface Disposer<T> {\r
+               public void dispose(T object);\r
+       }\r
+       \r
+       Disposer<T> disposer;\r
+       \r
+       /**\r
+        * Creates context-local variable container.\r
+        */\r
+       public ContextLocal() \r
+       {               \r
+       }\r
+       \r
+       /**\r
+        * Create context-local variable container.\r
+        * Container created with this method takes ownership of its object.\r
+        * \r
+        * @param disposed\r
+        */\r
+       public ContextLocal(Disposer<T> disposer)\r
+       {\r
+               this.disposer = disposer;\r
+       }\r
+       \r
+       /**\r
+        * Gets the object associated in the specified context\r
+        * \r
+        * @param context\r
+        * @return associated Object or <code>null</code> if not found\r
+        */\r
+       public T get(Object context) {\r
+               return reg.get(context);\r
+       }\r
+\r
+       /**\r
+        * Associates the specified Object with the specified context.\r
+        * \r
+        * @param context\r
+        * @param monitor\r
+        */\r
+       public void replace(Object context, T value) {\r
+               T old = value != null ? reg.put(context, value) : reg.remove(context);\r
+               if (old!=null && disposer!=null)\r
+                       disposer.dispose(old);\r
+       }\r
+       \r
+       public void remove(Object context) {\r
+               replace(context, null);\r
+       }\r
+\r
+       @Override\r
+       protected void doDispose() {\r
+               if (disposer!=null)\r
+                       for (T lr : reg.values()) {\r
+                               disposer.dispose(lr);\r
+                       }\r
+               reg.clear();\r
+       }\r
+\r
+\r
+}\r
+\r