bundles/org.simantics/src/org/simantics/internal/FileServiceImpl.java

   1 package org.simantics.internal;\r
   2 \r
   3 import java.io.File;\r
   4 import java.io.FileFilter;\r
   5 import java.io.IOException;\r
   6 import java.util.ArrayDeque;\r
   7 import java.util.Collection;\r
   8 \r
   9 import org.eclipse.core.runtime.IProgressMonitor;\r
  10 import org.eclipse.core.runtime.IStatus;\r
  11 import org.eclipse.core.runtime.Status;\r
  12 import org.eclipse.core.runtime.jobs.Job;\r
  13 import org.simantics.utils.FileService;\r
  14 import org.simantics.utils.IOperation;\r
  15 import org.simantics.utils.IOperationListener;\r
  16 \r
  17 /**\r
  18  * @author Tuukka Lehtonen\r
  19  */\r
  20 public class FileServiceImpl implements FileService {\r
  21 \r
  22         private static final long DELETION_DELAY_MS = 10000;\r
  23         private static final long DELETION_ATTEMPT_INTERVAL_MS = 10000;\r
  24 \r
  25         private static abstract class Op<R, E extends Exception> implements IOperation<R, E> {\r
  26                 protected boolean done;\r
  27                 protected R result;\r
  28                 @SuppressWarnings("unused")\r
  29                 protected E lastException;\r
  30 \r
  31                 @Override\r
  32                 public R waitFor() throws E {\r
  33                         synchronized(this) {\r
  34                                 while (!isDone()) {\r
  35                                         try {\r
  36                                                 wait();\r
  37                                         } catch (InterruptedException e) {\r
  38                                         }\r
  39                                 }\r
  40                         }\r
  41                         return result;\r
  42                 }\r
  43 \r
  44                 @Override\r
  45                 public boolean isDone() {\r
  46                         return done;\r
  47                 }\r
  48 \r
  49                 @Override\r
  50                 public void addListener(IOperationListener<R, E> listener) {\r
  51                         throw new UnsupportedOperationException();\r
  52                 }\r
  53 \r
  54                 public abstract boolean tryExecute();\r
  55 \r
  56         }\r
  57 \r
  58         private static class Deletion extends Op<Boolean, IOException> {\r
  59 \r
  60                 File f;\r
  61 \r
  62                 EffortOption effort;\r
  63                 int tries;\r
  64 \r
  65                 public Deletion(File f, DeleteOption... options) {\r
  66                         this.f = f;\r
  67                         parseOptions(options);\r
  68                 }\r
  69 \r
  70                 private void parseOptions(DeleteOption[] options) {\r
  71                         for (DeleteOption opt : options) {\r
  72                                 if (opt instanceof EffortOption) {\r
  73                                         effort = (EffortOption) opt;\r
  74                                 }\r
  75                         }\r
  76                 }\r
  77 \r
  78                 @Override\r
  79                 public boolean tryExecute() {\r
  80                         if (effort != null) {\r
  81                                 if (tries > effort.maxTries) {\r
  82                                         // Give up.\r
  83                                         return true;\r
  84                                 }\r
  85                         }\r
  86                         try {\r
  87                                 deleteAll(f);\r
  88                                 lastException = null;\r
  89                                 result = true;\r
  90                                 return true;\r
  91                         } catch (IOException e) {\r
  92                                 ++tries;\r
  93                                 lastException = e;\r
  94                                 return false;\r
  95                         }\r
  96                 }\r
  97 \r
  98                 public void deleteAll(File dir) throws IOException {\r
  99                         if (dir.isFile()) {\r
 100                                 if (!dir.delete())\r
 101                                         throw new IOException("Could not delete file: " + dir.getAbsolutePath());\r
 102                                 return;\r
 103                         }\r
 104                         if (dir.isDirectory()) {\r
 105                                 File[] fs = dir.listFiles((FileFilter) null);\r
 106                                 if (fs == null)\r
 107                                         return;\r
 108 \r
 109                                 for (File f : fs) {\r
 110                                         if (f.isDirectory()) {\r
 111                                                 deleteAll(f);\r
 112                                         } else {\r
 113                                                 if (!f.delete()) {\r
 114                                                         throw new IOException("Could not delete file: " + f.getAbsolutePath());\r
 115                                                 }\r
 116                                         }\r
 117                                 }\r
 118 \r
 119                                 if (!dir.delete()) {\r
 120                                         throw new IOException("Could not delete directory: " + dir.getAbsolutePath());\r
 121                                 }\r
 122                         } else if (dir.exists()) {\r
 123                                 if (!dir.delete()) {\r
 124                                         throw new IOException("Could not delete file: " + dir.getAbsolutePath());\r
 125                                 }\r
 126                         }\r
 127                 }\r
 128 \r
 129         }\r
 130 \r
 131         private ArrayDeque<Deletion> deletionQueue = new ArrayDeque<Deletion>();\r
 132         private DeletionJob deletionJob = new DeletionJob();\r
 133 \r
 134         @Override\r
 135         public IOperation<Boolean, IOException> scheduleDeleteIfExists(File file, DeleteOption... options) {\r
 136                 if (!file.exists())\r
 137                         return null;\r
 138                 synchronized (deletionQueue) {\r
 139                         Deletion d = new Deletion(file, options);\r
 140                         if (deletionQueue.contains(d))\r
 141                                 return null;\r
 142                         deletionQueue.addLast(d);\r
 143                         deletionJob.schedule(DELETION_DELAY_MS);\r
 144                         return d;\r
 145                 }\r
 146         }\r
 147 \r
 148         class DeletionJob extends Job {\r
 149 \r
 150                 public DeletionJob() {\r
 151                         super("File background deletion");\r
 152                 }\r
 153 \r
 154                 @SuppressWarnings("unchecked")\r
 155                 private <O extends Op<?,?>> void process(Collection<O> ops) {\r
 156                         Object[] opa = ops.toArray();\r
 157                         for (int i = 0; i < opa.length; ++i) {\r
 158                                 O op = (O) opa[i];\r
 159                                 if (op.tryExecute()) {\r
 160                                         // Success. Will be removed from queue.\r
 161                                 } else {\r
 162                                         opa[i] = null;\r
 163                                 }\r
 164                         }\r
 165                         synchronized (ops) {\r
 166                                 for (int i = 0; i < opa.length; ++i) {\r
 167                                         if (opa[i] != null)\r
 168                                                 ops.remove(opa[i]);\r
 169                                 }\r
 170                         }\r
 171                 }\r
 172 \r
 173                 @Override\r
 174                 protected IStatus run(IProgressMonitor monitor) {\r
 175                         process(deletionQueue);\r
 176                         if (!deletionQueue.isEmpty())\r
 177                                 schedule(DELETION_ATTEMPT_INTERVAL_MS);\r
 178                         return Status.OK_STATUS;\r
 179                 }\r
 180 \r
 181         }\r
 182 \r
 183 }\r