Migrated source code from Simantics SVN

[simantics/platform.git] / bundles / org.simantics.db.common / src / org / simantics / db / common / processor / MergingWriteOnlyProcessor.java

diff --git a/bundles/org.simantics.db.common/src/org/simantics/db/common/processor/MergingWriteOnlyProcessor.java b/bundles/org.simantics.db.common/src/org/simantics/db/common/processor/MergingWriteOnlyProcessor.java
new file mode 100644 (file)
index 0000000..6c6883d
--- /dev/null
+++ b/bundles/org.simantics.db.common/src/org/simantics/db/common/processor/MergingWriteOnlyProcessor.java
@@ -0,0 +1,107 @@
+/*******************************************************************************\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.db.common.processor;\r
+\r
+import java.util.concurrent.ConcurrentLinkedQueue;\r
+\r
+import org.simantics.db.AsyncRequestProcessor;\r
+import org.simantics.db.VirtualGraph;\r
+import org.simantics.db.WriteOnlyGraph;\r
+import org.simantics.db.common.request.WriteOnlyRequest;\r
+import org.simantics.db.common.utils.Logger;\r
+import org.simantics.db.exception.DatabaseException;\r
+import org.simantics.db.request.WriteOnly;\r
+\r
+final public class MergingWriteOnlyProcessor extends ProcessorBase {\r
+\r
+    final long transactionKeepalivePeriod;\r
+    final ConcurrentLinkedQueue<WriteOnly> queue = new ConcurrentLinkedQueue<WriteOnly>(); \r
+    final private AsyncRequestProcessor processor;\r
+    final private VirtualGraph vg;\r
+\r
+    boolean hasAlreadyRequest = false;\r
+\r
+    public MergingWriteOnlyProcessor(AsyncRequestProcessor processor, VirtualGraph vg, long transactionKeepalivePeriod) {\r
+        this.processor = processor;\r
+        this.vg = vg;\r
+        this.transactionKeepalivePeriod = transactionKeepalivePeriod;\r
+    }\r
+\r
+    class MergedWrite extends WriteOnlyRequest {\r
+\r
+       public MergedWrite(VirtualGraph vg) {\r
+               super(vg);\r
+               }\r
+       \r
+        @Override\r
+        public void perform(WriteOnlyGraph graph) throws DatabaseException {\r
+\r
+//            System.out.println("MergedWrite begins");\r
+\r
+            while (true) {\r
+                \r
+                WriteOnly next = queue.poll();\r
+                if(next == null) {\r
+                    synchronized (MergingWriteOnlyProcessor.this) {\r
+                        if (transactionKeepalivePeriod > 0) {\r
+                            try {\r
+                                MergingWriteOnlyProcessor.this.wait(transactionKeepalivePeriod);\r
+                            } catch (InterruptedException e) {\r
+                                       Logger.defaultLogError(e);\r
+                            }\r
+                            next = queue.poll();\r
+                        }\r
+                        if(next == null) {\r
+                            hasAlreadyRequest = false;\r
+//                            System.out.println("MergedWrite ends");\r
+                            return;\r
+                        }\r
+                    }\r
+                }\r
+\r
+//                System.out.println("MergedWrite executes " + next);\r
+                try {\r
+                       next.perform(graph);\r
+                } catch(Throwable t) {\r
+                       Logger.defaultLogError(t);\r
+                }\r
+\r
+            }\r
+\r
+        }\r
+\r
+    }\r
+\r
+    @Override\r
+    public void asyncRequest(WriteOnly request) {\r
+        \r
+        queue.add(request);\r
+\r
+        synchronized (this) {\r
+        \r
+          if (!hasAlreadyRequest) {\r
+              processor.asyncRequest(new MergedWrite(vg));\r
+              hasAlreadyRequest = true;\r
+          } else {\r
+              notify();\r
+          }\r
+          \r
+        }\r
+\r
+    }\r
+\r
+    @Override\r
+    public String toString() {\r
+        return "MergingWriteOnlyProcessor@" + System.identityHashCode(this) + " (based on " + processor + ")";\r
+    }\r
+\r
+}\r