Autopsy  4.15.0
Graphical digital forensics platform for The Sleuth Kit and other tools.
RefreshThrottler.java
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1 /*
2  * Autopsy Forensic Browser
3  *
4  * Copyright 2011-2020 Basis Technology Corp.
5  * Contact: carrier <at> sleuthkit <dot> org
6  *
7  * Licensed under the Apache License, Version 2.0 (the "License");
8  * you may not use this file except in compliance with the License.
9  * You may obtain a copy of the License at
10  *
11  * http://www.apache.org/licenses/LICENSE-2.0
12  *
13  * Unless required by applicable law or agreed to in writing, software
14  * distributed under the License is distributed on an "AS IS" BASIS,
15  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16  * See the License for the specific language governing permissions and
17  * limitations under the License.
18  */
19 package org.sleuthkit.autopsy.datamodel;
20 
21 import com.google.common.util.concurrent.ThreadFactoryBuilder;
22 import java.beans.PropertyChangeEvent;
23 import java.beans.PropertyChangeListener;
24 import java.util.EnumSet;
25 import java.util.Set;
26 import java.util.concurrent.ScheduledThreadPoolExecutor;
27 import java.util.concurrent.TimeUnit;
28 import java.util.concurrent.atomic.AtomicReference;
30 
36 class RefreshThrottler {
37 
42  interface Refresher {
43 
48  void refresh();
49 
57  boolean isRefreshRequired(PropertyChangeEvent evt);
58  }
59 
60  static ScheduledThreadPoolExecutor refreshExecutor = new ScheduledThreadPoolExecutor(1, new ThreadFactoryBuilder().setNameFormat("Node Refresh Thread").build());
61  // Keep a thread safe reference to the current refresh task (if any)
62  private final AtomicReference<RefreshTask> refreshTaskRef;
63 
64  // The factory instance that will be called when a refresh is due.
65  private final Refresher refresher;
66 
67  private static final long MIN_SECONDS_BETWEEN_REFRESH = 5;
68 
69  private static final Set<IngestManager.IngestModuleEvent> INGEST_MODULE_EVENTS_OF_INTEREST = EnumSet.of(IngestManager.IngestModuleEvent.DATA_ADDED, IngestManager.IngestModuleEvent.CONTENT_CHANGED);
70 
75  private final class RefreshTask implements Runnable {
76 
77  @Override
78  public void run() {
79  // Call refresh on the factory
80  refresher.refresh();
81  // Clear the refresh task reference
82  refreshTaskRef.set(null);
83  }
84  }
85 
90  private final PropertyChangeListener pcl;
91 
92  RefreshThrottler(Refresher r) {
93  this.refreshTaskRef = new AtomicReference<>(null);
94  refresher = r;
95 
96  pcl = (PropertyChangeEvent evt) -> {
97  String eventType = evt.getPropertyName();
98  if (eventType.equals(IngestManager.IngestModuleEvent.DATA_ADDED.toString())
99  || eventType.equals(IngestManager.IngestModuleEvent.CONTENT_CHANGED.toString())) {
100  if (!refresher.isRefreshRequired(evt)) {
101  return;
102  }
103 
104  RefreshTask task = new RefreshTask();
105  if (refreshTaskRef.compareAndSet(null, task)) {
106  refreshExecutor.schedule(task, MIN_SECONDS_BETWEEN_REFRESH, TimeUnit.SECONDS);
107  }
108  }
109  };
110  }
111 
115  void registerForIngestModuleEvents() {
116  IngestManager.getInstance().addIngestModuleEventListener(INGEST_MODULE_EVENTS_OF_INTEREST, pcl);
117  }
118 
122  void unregisterEventListener() {
123  IngestManager.getInstance().removeIngestModuleEventListener(pcl);
124  }
125 }

Copyright © 2012-2020 Basis Technology. Generated on: Mon Jul 6 2020
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