Migrated source code from Simantics SVN

[simantics/platform.git] / bundles / org.simantics.scenegraph / src / org / simantics / scenegraph / LookupService.java

diff --git a/bundles/org.simantics.scenegraph/src/org/simantics/scenegraph/LookupService.java b/bundles/org.simantics.scenegraph/src/org/simantics/scenegraph/LookupService.java
new file mode 100644 (file)
index 0000000..548feca
--- /dev/null
+++ b/bundles/org.simantics.scenegraph/src/org/simantics/scenegraph/LookupService.java
@@ -0,0 +1,122 @@
+/*******************************************************************************\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.scenegraph;\r
+\r
+import java.util.HashMap;\r
+import java.util.Map;\r
+import java.util.logging.Level;\r
+import java.util.logging.Logger;\r
+\r
+/**\r
+ * A synchronized reference implementation of {@link ILookupService}.\r
+ * \r
+ * @author Tuukka Lehtonen\r
+ */\r
+public class LookupService implements ILookupService {\r
+\r
+    private final Object             lookupLock = new Object();\r
+    private final Map<String, INode> toNode     = new HashMap<String, INode>();\r
+    private final Map<INode, String> toId       = new HashMap<INode, String>();\r
+\r
+    Logger                     logger     = Logger.getLogger(getClass().getName());\r
+\r
+    @Override\r
+    public INode map(String id, INode node) {\r
+        if (id == null)\r
+            throw new NullPointerException("null id");\r
+        if (node == null)\r
+            throw new NullPointerException("null node");\r
+\r
+        INode oldNode;\r
+        String oldId;\r
+        synchronized (lookupLock) {\r
+            oldNode = toNode.put(id, node);\r
+            oldId = toId.put(node, id);\r
+\r
+            // Keep the mapping a consistent bijection:\r
+            // If ID => INode mapping is removed, the INode => ID mappings must\r
+            // removed also.\r
+\r
+            if (oldNode != null && !oldNode.equals(node)) {\r
+                String removedId = toId.remove(oldNode);\r
+                if (!id.equals(removedId))\r
+                    toNode.remove(removedId);\r
+            }\r
+            if (oldId != null && !oldId.equals(id)) {\r
+                INode removedNode = toNode.remove(oldId);\r
+                if (removedNode != node)\r
+                    toId.remove(removedNode);\r
+            }\r
+        }\r
+        if (logger.isLoggable(Level.FINE))\r
+            logger.fine("map(" + id + ", " + node + ")");\r
+        if (oldNode != null || oldId != null) {\r
+            if (logger.isLoggable(Level.INFO)) {\r
+                logger.info("replaced mappings for ID " + oldId + " and node " + oldNode);\r
+            }\r
+        }\r
+        return oldNode;\r
+    }\r
+\r
+    @Override\r
+    public INode unmap(String id) {\r
+        INode node;\r
+        String mappedId;\r
+        synchronized (lookupLock) {\r
+            node = toNode.remove(id);\r
+            if (node == null)\r
+                return null;\r
+            mappedId = toId.remove(node);\r
+        }\r
+        if (logger.isLoggable(Level.FINE))\r
+            logger.fine("unmap(" + id + "): " + node);\r
+        if (mappedId != null && !mappedId.equals(id)) {\r
+            if (logger.isLoggable(Level.WARNING))\r
+                logger.log(Level.WARNING, "mapping was out-of-sync: " + id + " => " + node + " & " + mappedId + " => " + node, new Exception("trace"));\r
+        }\r
+        return node;\r
+    }\r
+\r
+    @Override\r
+    public String unmap(INode node) {\r
+        String id;\r
+        INode mappedNode;\r
+        synchronized (lookupLock) {\r
+            id = toId.remove(node);\r
+            if (node == null)\r
+                return null;\r
+            mappedNode = toNode.remove(id);\r
+        }\r
+        if (logger.isLoggable(Level.FINE))\r
+            logger.fine("unmap(" + node + "): " + id);\r
+        if (mappedNode != null && node != mappedNode) {\r
+            if (logger.isLoggable(Level.WARNING))\r
+                logger.log(Level.WARNING, "mapping was out-of-sync: " + node + " => " + id + " & " + id + " => " + mappedNode, new Exception("trace"));\r
+        }\r
+        return id;\r
+    }\r
+\r
+    @Override\r
+    public INode lookupNode(String id) {\r
+        synchronized (lookupLock) {\r
+            return toNode.get(id);\r
+        }\r
+    }\r
+\r
+    @Override\r
+    public String lookupId(INode node) {\r
+        synchronized (lookupLock) {\r
+            return toId.get(node);\r
+        }\r
+    }\r
+\r
+}\r