+/*******************************************************************************\r
+ * Copyright (c) 2012 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
+ * Semantum Oy - initial API and implementation\r
+ *******************************************************************************/\r
+package org.simantics.event.writer;\r
+\r
+import java.util.ArrayList;\r
+import java.util.List;\r
+import java.util.concurrent.atomic.AtomicBoolean;\r
+\r
+import org.eclipse.core.runtime.IProgressMonitor;\r
+import org.eclipse.core.runtime.IStatus;\r
+import org.eclipse.core.runtime.Status;\r
+import org.simantics.DatabaseJob;\r
+import org.simantics.Simantics;\r
+import org.simantics.db.ReadGraph;\r
+import org.simantics.db.Resource;\r
+import org.simantics.db.Session;\r
+import org.simantics.db.VirtualGraph;\r
+import org.simantics.db.WriteOnlyGraph;\r
+import org.simantics.db.common.request.UniqueRead;\r
+import org.simantics.db.common.request.WriteOnlyRequest;\r
+import org.simantics.db.exception.CancelTransactionException;\r
+import org.simantics.db.exception.DatabaseException;\r
+import org.simantics.db.request.WriteOnly;\r
+import org.simantics.event.Activator;\r
+import org.simantics.event.util.EventUtils;\r
+import org.simantics.event.util.EventWriteData;\r
+\r
+/**\r
+ * A self-scheduling job that queues up {@link EventWriteTask} instances and\r
+ * periodically executes the queued up tasks in a single graph {@link WriteOnly}\r
+ * request.\r
+ * \r
+ * <p>\r
+ * Intended to be constructed and scheduled by experiment implementations.\r
+ * \r
+ * <p>\r
+ * Must be disposed when no longer used.\r
+ * \r
+ * @author Tuukka Lehtonen\r
+ * \r
+ * @see EventWriteTask\r
+ * @see EventSourceResolver\r
+ */\r
+public class EventWriterJob extends DatabaseJob {\r
+\r
+ private final boolean DEBUG = false;\r
+\r
+ private static final int WRITE_SCHEDULE_PERIOD = 1000;\r
+\r
+ private static final long MIN_QUEUE_QUIET_TIME = 1000L;\r
+\r
+ private static final long MIN_WRITE_QUIET_TIME = 1000L;\r
+\r
+ private static final int MAX_TASK_QUEUE_SIZE = 500;\r
+\r
+ private static final EventWriteTask[] NONE = {};\r
+\r
+ private List<EventWriteTask> tasks = new ArrayList<EventWriteTask>();\r
+\r
+ private VirtualGraph virtualGraph;\r
+ private Resource eventLog;\r
+ private EventSourceResolver resolver;\r
+\r
+ private AtomicBoolean scheduled = new AtomicBoolean(false);\r
+ private AtomicBoolean polling = new AtomicBoolean(true);\r
+\r
+ private long lastWriteTime = Long.MIN_VALUE;\r
+ private long lastQueueTime = Long.MIN_VALUE;\r
+\r
+ public EventWriterJob(VirtualGraph virtualGraph, Resource eventLog, EventSourceResolver resolver) {\r
+ super("Event Writer");\r
+ setPriority(DECORATE);\r
+ setUser(false);\r
+ setSystem(false);\r
+ this.virtualGraph = virtualGraph;\r
+ this.eventLog = eventLog;\r
+ this.resolver = resolver;\r
+ }\r
+\r
+ public void dispose() {\r
+ if (DEBUG)\r
+ System.out.println(this + ": DISPOSE");\r
+ polling.set(false);\r
+ }\r
+\r
+ public void queue(EventWriteTask task) {\r
+ synchronized (tasks) {\r
+ tasks.add(task);\r
+ this.lastQueueTime = System.currentTimeMillis();\r
+\r
+ if (scheduled.compareAndSet(false, true)) {\r
+ schedule(WRITE_SCHEDULE_PERIOD);\r
+ }\r
+ }\r
+ }\r
+\r
+ @Override\r
+ public boolean shouldRun() {\r
+ return polling.get() && Simantics.peekSession() != null;\r
+ }\r
+\r
+ @Override\r
+ protected IStatus run(final IProgressMonitor monitor) {\r
+ try {\r
+ Session session = Simantics.peekSession();\r
+ if (session == null)\r
+ return Status.CANCEL_STATUS;\r
+\r
+ int taskCount = countTasks();\r
+ if (taskCount == 0)\r
+ return Status.CANCEL_STATUS;\r
+\r
+ long currentTime = System.currentTimeMillis();\r
+\r
+ // Must flush write at some point if no flush has been performed yet.\r
+ if (lastWriteTime == Long.MIN_VALUE)\r
+ lastWriteTime = currentTime;\r
+\r
+ long queueQuietTime = currentTime - lastQueueTime;\r
+ long writeQuietTime = currentTime - lastWriteTime;\r
+ boolean queueQuietTimePassed = queueQuietTime >= MIN_QUEUE_QUIET_TIME;\r
+ boolean writeQuietTimePassed = writeQuietTime >= MIN_WRITE_QUIET_TIME;\r
+ boolean taskCountExceeded = taskCount >= MAX_TASK_QUEUE_SIZE;\r
+\r
+ if (DEBUG) {\r
+ System.out.println("Queue quiet time: " + queueQuietTime);\r
+ System.out.println("Write quiet time: " + writeQuietTime);\r
+ System.out.println("Task count: " + taskCount);\r
+ }\r
+\r
+ if (!writeQuietTimePassed && !queueQuietTimePassed && !taskCountExceeded) {\r
+ return Status.CANCEL_STATUS;\r
+ }\r
+\r
+ if (DEBUG) {\r
+ if (queueQuietTimePassed)\r
+ System.out.println("Queue quiet time (" + MIN_QUEUE_QUIET_TIME + ") exceeded: " + queueQuietTime);\r
+ if (writeQuietTimePassed)\r
+ System.out.println("Write quiet time (" + MIN_WRITE_QUIET_TIME + ") exceeded: " + writeQuietTime);\r
+ if (taskCountExceeded)\r
+ System.out.println("Maximum queued task count (" + MAX_TASK_QUEUE_SIZE + ") exceeded: " + taskCount);\r
+ }\r
+\r
+ final EventWriteTask[] tasks = pruneTasks();\r
+ if (tasks.length == 0)\r
+ return Status.CANCEL_STATUS;\r
+\r
+ if (DEBUG)\r
+ System.out.println(this + ": about to write " + tasks.length + " events");\r
+ setThread(Thread.currentThread());\r
+\r
+ monitor.beginTask("Flush Events", tasks.length);\r
+ \r
+ try {\r
+ \r
+ final EventWriteData writeData = session.syncRequest(new UniqueRead<EventWriteData>() {\r
+\r
+ @Override\r
+ public EventWriteData perform(ReadGraph graph) throws DatabaseException {\r
+ return new EventWriteData(graph, eventLog, virtualGraph);\r
+ }\r
+ \r
+ }); \r
+\r
+ session.sync(new WriteOnlyRequest(virtualGraph) {\r
+ @Override\r
+ public void perform(WriteOnlyGraph graph) throws DatabaseException {\r
+ \r
+ setThread(Thread.currentThread());\r
+ List<Resource> events = new ArrayList<Resource>(tasks.length);\r
+ for (EventWriteTask task : tasks) {\r
+\r
+ writeData.prepareToWrite(graph);\r
+ \r
+ Resource event = task.write(graph, writeData.targetSlice, writeData.targetPos);\r
+ if (event != null) {\r
+ events.add(event);\r
+ writeData.written();\r
+ }\r
+ monitor.worked(1);\r
+ \r
+ }\r
+ \r
+ writeData.commit(graph);\r
+ \r
+ if (resolver != null) {\r
+ if (DEBUG)\r
+ System.out.println(EventWriterJob.this + ": queue " + events.size() + " for source resolution");\r
+ resolver.queueEvents(events);\r
+ }\r
+ }\r
+ });\r
+ lastWriteTime = System.currentTimeMillis();\r
+ } catch (CancelTransactionException e) {\r
+ polling.set(false);\r
+ return Status.CANCEL_STATUS;\r
+ } catch (DatabaseException e) {\r
+ return new Status(IStatus.ERROR, Activator.BUNDLE_ID, "Event writing failed", e);\r
+ }\r
+\r
+ return Status.OK_STATUS;\r
+ } finally {\r
+ monitor.done();\r
+ schedule(WRITE_SCHEDULE_PERIOD);\r
+ }\r
+ }\r
+\r
+ private int countTasks() {\r
+ synchronized (tasks) {\r
+ return tasks.size();\r
+ }\r
+ }\r
+\r
+ private EventWriteTask[] pruneTasks() {\r
+ synchronized (this.tasks) {\r
+ EventWriteTask[] tasks = this.tasks.toArray(NONE);\r
+ this.tasks.clear();\r
+ return tasks;\r
+ }\r
+ }\r
+\r
+}
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