Auto-save plugin now works by periodically creating project backups in

user\.diylc\autoSave directory and maintains file history, keeping the
last X versions of the file. Maximum size for all backups is
configurable and pre-set to 64MB

diylc/diylc-swing/src/org/diylc/swing/plugins/autosave/AutoSavePlugin.java

@@ -22,85 +22,47 @@
 package org.diylc.swing.plugins.autosave;
 
 import java.io.File;
+import java.text.DateFormat;
+import java.text.SimpleDateFormat;
+import java.util.Arrays;
+import java.util.Comparator;
 import java.util.Date;
 import java.util.EnumSet;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 
-import javax.swing.SwingUtilities;
-
-import org.diylc.appframework.miscutils.ConfigurationManager;
+import org.apache.log4j.Logger;
 import org.diylc.appframework.miscutils.Utils;
 import org.diylc.common.EventType;
 import org.diylc.common.IPlugIn;
 import org.diylc.common.IPlugInPort;
 import org.diylc.core.IView;
-import org.diylc.presenter.Presenter;
-import org.diylc.swing.gui.DummyView;
 
 public class AutoSavePlugin implements IPlugIn {
 
-  private static final String AUTO_SAVE_FILE_NAME = Utils.getUserDataDirectory("diylc") + "autoSave.diy";
+  private static final String AUTO_SAVE_PATH = Utils.getUserDataDirectory("diylc") + "autoSave";
   
-  protected static final long autoSaveFrequency = 60 * 1000;
+  private static final Logger LOG = Logger.getLogger(AutoSavePlugin.class);
+
+  protected static final long autoSaveFrequencyMs = 60 * 1000;
+  protected static final int maxTotalSizeMb = 64;
 
   private ExecutorService executor;
 
   private IPlugInPort plugInPort;
-  private IView view;
   private long lastSave = 0;
 
   public AutoSavePlugin(IView view) {
-    this.view = view;
     executor = Executors.newSingleThreadExecutor();
   }
 
   @Override
   public void connect(IPlugInPort plugInPort) {
     this.plugInPort = plugInPort;
-    SwingUtilities.invokeLater(new Runnable() {
-
-      @Override
-      public void run() {
-        boolean wasAbnormal = ConfigurationManager.getInstance().readBoolean(IPlugInPort.ABNORMAL_EXIT_KEY, false);
-        Date lastHeartbeat = (Date) ConfigurationManager.getInstance().readObject(IPlugInPort.HEARTBEAT, new Date());
-        long msSinceHeartbeat = new Date().getTime() - lastHeartbeat.getTime();
-        File autoSaved = new File(AUTO_SAVE_FILE_NAME);
-        if (autoSaved.exists())
-          // try to figure out if another instance is running. Only pull auto-saved file if there's no recent heartbeat 
-          if (wasAbnormal && msSinceHeartbeat > autoSaveFrequency) {
-            IPlugInPort testPresenter = new Presenter(new DummyView());
-            testPresenter.loadProjectFromFile(AUTO_SAVE_FILE_NAME);
-            // Only prompt if there is something saved in the
-            // auto-saved file.
-            if (!testPresenter.getCurrentProject().getComponents().isEmpty()) {
-              int decision =
-                  view.showConfirmDialog(
-                      "It appears that application was not closed normally in the previous session. Do you want to open the last auto-saved file?",
-                      "Auto-Save", IView.YES_NO_OPTION, IView.QUESTION_MESSAGE);
-              if (decision == IView.YES_OPTION) {
-                AutoSavePlugin.this.plugInPort.loadProjectFromFile(AUTO_SAVE_FILE_NAME);
-              }
-            }
-          } else
-            autoSaved.delete();
-        // Set abnormal flag to true, GUI side of the app must flip to
-        // false when app closes regularly.
-        ConfigurationManager.getInstance().writeValue(IPlugInPort.ABNORMAL_EXIT_KEY, true);
-      }
-    });
-    // write heartbeat periodically
-    new Thread(new Runnable() {
-
-      @Override
-      public void run() {
-        try {
-          Thread.sleep(autoSaveFrequency);
-        } catch (InterruptedException e) {
-        }
-        ConfigurationManager.getInstance().writeValue(IPlugInPort.HEARTBEAT, new Date());
-      }
-    }).start();
+    // create the directory if needed
+    File dir = new File(AUTO_SAVE_PATH);
+    if (!dir.exists())
+      dir.mkdirs();
   }
 
   @Override
@@ -111,7 +73,7 @@ public class AutoSavePlugin implements IPlugIn {
   @Override
   public void processMessage(EventType eventType, Object... params) {
     if (eventType == EventType.PROJECT_MODIFIED) {
-      if (System.currentTimeMillis() - lastSave > autoSaveFrequency) {
+      if (System.currentTimeMillis() - lastSave > autoSaveFrequencyMs) {
         executor.execute(new Runnable() {
 
           @Override
@@ -119,10 +81,59 @@ public class AutoSavePlugin implements IPlugIn {
             Thread.currentThread().setPriority(Thread.MIN_PRIORITY);
 
             lastSave = System.currentTimeMillis();
-            plugInPort.saveProjectToFile(AUTO_SAVE_FILE_NAME, true);
+            String fileName = generateBackupFileName(plugInPort.getCurrentFileName());
+            LOG.info("Creating backup file: " + fileName);
+            plugInPort.saveProjectToFile(fileName, true);
+            cleanupExtra();
           }
         });
       }
     }
   }
+  
+  private String generateBackupFileName(String baseFileName) {
+    if (baseFileName == null)
+      baseFileName = "Untitled";
+    File file = new File(baseFileName);
+    String name = file.getName();
+    
+    // remove extension
+    if (name.toLowerCase().endsWith(".diy"))
+      name = name.substring(name.length() - 4);
+    
+    // append date and time
+    Date date = new Date(); 
+    DateFormat dateFormat = new SimpleDateFormat("yyyyMMdd-HHmmss");
+    file = new File(AUTO_SAVE_PATH + File.separator + name + "." + dateFormat.format(date) + ".diy");
+    // make sure that it doesn't already exist
+    int i = 2;
+    while (file.exists()) {
+      file = new File(AUTO_SAVE_PATH + File.separator + name + "." + dateFormat.format(date) + "-" + i + ".diy");
+      i++;
+    }
+    return file.getAbsolutePath();
+  }
+  
+  private void cleanupExtra() {
+    File[] files = new File(AUTO_SAVE_PATH).listFiles();
+    // sort files by date
+    Arrays.sort(files, new Comparator<File>() {
+
+      @Override
+      public int compare(File o1, File o2) {       
+        return new Long(o1.lastModified()).compareTo(o2.lastModified());
+      }      
+    });
+    long totalSize = 0;
+    long maxTotalSize = maxTotalSizeMb * 1024 * 1024;
+    for (File f : files)
+      totalSize += f.length();
+    int i = 0;
+    while (i < files.length && totalSize > maxTotalSize) {
+      totalSize -= files[i].length();
+      LOG.info("Deleteting old backup file: " + files[i].getName());
+      files[i].delete();
+      i++;
+    }
+  }
 }

diylc/diylc-swing/update.xml

@@ -2634,6 +2634,10 @@
 					<changeType>NEW_FEATURE</changeType>
 					<description>Added an optional third control point to leaded components and some schematic symbols that can be used to set component label position. This feature is off by default to keep things backwards compatible and is driven by "Movable Label" property</description>
 				</org.diylc.appframework.update.Change>
+				<org.diylc.appframework.update.Change>
+					<changeType>NEW_FEATURE</changeType>
+					<description>Auto-save plugin now works by periodically creating project backups in user\.diylc\autoSave directory and maintains file history, keeping the last X versions of the file. Maximum size for all backups is configurable and pre-set to 64MB</description>
+				</org.diylc.appframework.update.Change>						
 				<org.diylc.appframework.update.Change>
 					<changeType>IMPROVEMENT</changeType>
 					<description>Ability to show labels for standing components and control the position</description>