001// License: GPL. For details, see LICENSE file.
002package org.openstreetmap.josm.data;
003
004import static org.openstreetmap.josm.tools.I18n.tr;
005
006import java.io.BufferedReader;
007import java.io.File;
008import java.io.FileFilter;
009import java.io.IOException;
010import java.io.PrintStream;
011import java.lang.management.ManagementFactory;
012import java.nio.charset.StandardCharsets;
013import java.nio.file.Files;
014import java.util.ArrayList;
015import java.util.Date;
016import java.util.Deque;
017import java.util.HashSet;
018import java.util.Iterator;
019import java.util.LinkedList;
020import java.util.List;
021import java.util.Set;
022import java.util.Timer;
023import java.util.TimerTask;
024import java.util.regex.Pattern;
025
026import org.openstreetmap.josm.Main;
027import org.openstreetmap.josm.actions.OpenFileAction.OpenFileTask;
028import org.openstreetmap.josm.data.osm.DataSet;
029import org.openstreetmap.josm.data.osm.event.AbstractDatasetChangedEvent;
030import org.openstreetmap.josm.data.osm.event.DataSetListenerAdapter;
031import org.openstreetmap.josm.data.osm.event.DataSetListenerAdapter.Listener;
032import org.openstreetmap.josm.data.preferences.BooleanProperty;
033import org.openstreetmap.josm.data.preferences.IntegerProperty;
034import org.openstreetmap.josm.gui.MapView;
035import org.openstreetmap.josm.gui.MapView.LayerChangeListener;
036import org.openstreetmap.josm.gui.Notification;
037import org.openstreetmap.josm.gui.layer.Layer;
038import org.openstreetmap.josm.gui.layer.OsmDataLayer;
039import org.openstreetmap.josm.gui.util.GuiHelper;
040import org.openstreetmap.josm.io.OsmExporter;
041import org.openstreetmap.josm.io.OsmImporter;
042
043/**
044 * Saves data layers periodically so they can be recovered in case of a crash.
045 *
046 * There are 2 directories
047 *  - autosave dir: copies of the currently open data layers are saved here every
048 *      PROP_INTERVAL seconds. When a data layer is closed normally, the corresponding
049 *      files are removed. If this dir is non-empty on start, JOSM assumes
050 *      that it crashed last time.
051 *  - deleted layers dir: "secondary archive" - when autosaved layers are restored
052 *      they are copied to this directory. We cannot keep them in the autosave folder,
053 *      but just deleting it would be dangerous: Maybe a feature inside the file
054 *      caused JOSM to crash. If the data is valuable, the user can still try to
055 *      open with another versions of JOSM or fix the problem manually.
056 *
057 *      The deleted layers dir keeps at most PROP_DELETED_LAYERS files.
058 */
059public class AutosaveTask extends TimerTask implements LayerChangeListener, Listener {
060
061    private static final char[] ILLEGAL_CHARACTERS = { '/', '\n', '\r', '\t', '\0', '\f', '`', '?', '*', '\\', '<', '>', '|', '\"', ':' };
062    private static final String AUTOSAVE_DIR = "autosave";
063    private static final String DELETED_LAYERS_DIR = "autosave/deleted_layers";
064
065    public static final BooleanProperty PROP_AUTOSAVE_ENABLED = new BooleanProperty("autosave.enabled", true);
066    public static final IntegerProperty PROP_FILES_PER_LAYER = new IntegerProperty("autosave.filesPerLayer", 1);
067    public static final IntegerProperty PROP_DELETED_LAYERS = new IntegerProperty("autosave.deletedLayersBackupCount", 5);
068    public static final IntegerProperty PROP_INTERVAL = new IntegerProperty("autosave.interval", 5 * 60);
069    public static final IntegerProperty PROP_INDEX_LIMIT = new IntegerProperty("autosave.index-limit", 1000);
070    /** Defines if a notification should be displayed after each autosave */
071    public static final BooleanProperty PROP_NOTIFICATION = new BooleanProperty("autosave.notification", false);
072
073    private static class AutosaveLayerInfo {
074        OsmDataLayer layer;
075        String layerName;
076        String layerFileName;
077        final Deque<File> backupFiles = new LinkedList<>();
078    }
079
080    private final DataSetListenerAdapter datasetAdapter = new DataSetListenerAdapter(this);
081    private final Set<DataSet> changedDatasets = new HashSet<>();
082    private final List<AutosaveLayerInfo> layersInfo = new ArrayList<>();
083    private Timer timer;
084    private final Object layersLock = new Object();
085    private final Deque<File> deletedLayers = new LinkedList<>();
086
087    private final File autosaveDir = new File(Main.pref.getPreferencesDir() + AUTOSAVE_DIR);
088    private final File deletedLayersDir = new File(Main.pref.getPreferencesDir() + DELETED_LAYERS_DIR);
089
090    public void schedule() {
091        if (PROP_INTERVAL.get() > 0) {
092
093            if (!autosaveDir.exists() && !autosaveDir.mkdirs()) {
094                Main.warn(tr("Unable to create directory {0}, autosave will be disabled", autosaveDir.getAbsolutePath()));
095                return;
096            }
097            if (!deletedLayersDir.exists() && !deletedLayersDir.mkdirs()) {
098                Main.warn(tr("Unable to create directory {0}, autosave will be disabled", deletedLayersDir.getAbsolutePath()));
099                return;
100            }
101
102            for (File f: deletedLayersDir.listFiles()) {
103                deletedLayers.add(f); // FIXME: sort by mtime
104            }
105
106            timer = new Timer(true);
107            timer.schedule(this, 1000, PROP_INTERVAL.get() * 1000);
108            MapView.addLayerChangeListener(this);
109            if (Main.isDisplayingMapView()) {
110                for (OsmDataLayer l: Main.map.mapView.getLayersOfType(OsmDataLayer.class)) {
111                    registerNewlayer(l);
112                }
113            }
114        }
115    }
116
117    private String getFileName(String layerName, int index) {
118        String result = layerName;
119        for (char illegalCharacter : ILLEGAL_CHARACTERS) {
120            result = result.replaceAll(Pattern.quote(String.valueOf(illegalCharacter)),
121                    '&' + String.valueOf((int) illegalCharacter) + ';');
122        }
123        if (index != 0) {
124            result = result + '_' + index;
125        }
126        return result;
127    }
128
129    private void setLayerFileName(AutosaveLayerInfo layer) {
130        int index = 0;
131        while (true) {
132            String filename = getFileName(layer.layer.getName(), index);
133            boolean foundTheSame = false;
134            for (AutosaveLayerInfo info: layersInfo) {
135                if (info != layer && filename.equals(info.layerFileName)) {
136                    foundTheSame = true;
137                    break;
138                }
139            }
140
141            if (!foundTheSame) {
142                layer.layerFileName = filename;
143                return;
144            }
145
146            index++;
147        }
148    }
149
150    private File getNewLayerFile(AutosaveLayerInfo layer) {
151        int index = 0;
152        Date now = new Date();
153        while (true) {
154            String filename = String.format("%1$s_%2$tY%2$tm%2$td_%2$tH%2$tM%2$tS%2$tL%3$s", layer.layerFileName, now, index == 0?"":"_" + index);
155            File result = new File(autosaveDir, filename+".osm");
156            try {
157                if (result.createNewFile()) {
158                    File pidFile = new File(autosaveDir, filename+".pid");
159                    try (PrintStream ps = new PrintStream(pidFile, "UTF-8")) {
160                        ps.println(ManagementFactory.getRuntimeMXBean().getName());
161                    } catch (Throwable t) {
162                        Main.error(t);
163                    }
164                    return result;
165                } else {
166                    Main.warn(tr("Unable to create file {0}, other filename will be used", result.getAbsolutePath()));
167                    if (index > PROP_INDEX_LIMIT.get())
168                        throw new IOException("index limit exceeded");
169                }
170            } catch (IOException e) {
171                Main.error(tr("IOError while creating file, autosave will be skipped: {0}", e.getMessage()));
172                return null;
173            }
174            index++;
175        }
176    }
177
178    private void savelayer(AutosaveLayerInfo info) {
179        if (!info.layer.getName().equals(info.layerName)) {
180            setLayerFileName(info);
181            info.layerName = info.layer.getName();
182        }
183        if (changedDatasets.remove(info.layer.data)) {
184            File file = getNewLayerFile(info);
185            if (file != null) {
186                info.backupFiles.add(file);
187                new OsmExporter().exportData(file, info.layer, true /* no backup with appended ~ */);
188            }
189        }
190        while (info.backupFiles.size() > PROP_FILES_PER_LAYER.get()) {
191            File oldFile = info.backupFiles.remove();
192            if (!oldFile.delete()) {
193                Main.warn(tr("Unable to delete old backup file {0}", oldFile.getAbsolutePath()));
194            } else {
195                getPidFile(oldFile).delete();
196            }
197        }
198    }
199
200    @Override
201    public void run() {
202        synchronized (layersLock) {
203            try {
204                for (AutosaveLayerInfo info: layersInfo) {
205                    savelayer(info);
206                }
207                changedDatasets.clear();
208                if (PROP_NOTIFICATION.get() && !layersInfo.isEmpty()) {
209                    displayNotification();
210                }
211            } catch (Throwable t) {
212                // Don't let exception stop time thread
213                Main.error("Autosave failed:");
214                Main.error(t);
215            }
216        }
217    }
218
219    protected void displayNotification() {
220        GuiHelper.runInEDT(new Runnable() {
221            @Override
222            public void run() {
223                new Notification(tr("Your work has been saved automatically."))
224                .setDuration(Notification.TIME_SHORT)
225                .show();
226            }
227        });
228    }
229
230    @Override
231    public void activeLayerChange(Layer oldLayer, Layer newLayer) {
232        // Do nothing
233    }
234
235    private void registerNewlayer(OsmDataLayer layer) {
236        synchronized (layersLock) {
237            layer.data.addDataSetListener(datasetAdapter);
238            AutosaveLayerInfo info = new AutosaveLayerInfo();
239            info.layer = layer;
240            layersInfo.add(info);
241        }
242    }
243
244    @Override
245    public void layerAdded(Layer newLayer) {
246        if (newLayer instanceof OsmDataLayer) {
247            registerNewlayer((OsmDataLayer) newLayer);
248        }
249    }
250
251    @Override
252    public void layerRemoved(Layer oldLayer) {
253        if (oldLayer instanceof OsmDataLayer) {
254            synchronized (layersLock) {
255                OsmDataLayer osmLayer = (OsmDataLayer) oldLayer;
256                osmLayer.data.removeDataSetListener(datasetAdapter);
257                Iterator<AutosaveLayerInfo> it = layersInfo.iterator();
258                while (it.hasNext()) {
259                    AutosaveLayerInfo info = it.next();
260                    if (info.layer == osmLayer) {
261
262                        savelayer(info);
263                        File lastFile = info.backupFiles.pollLast();
264                        if (lastFile != null) {
265                            moveToDeletedLayersFolder(lastFile);
266                        }
267                        for (File file: info.backupFiles) {
268                            if (file.delete()) {
269                                getPidFile(file).delete();
270                            }
271                        }
272
273                        it.remove();
274                    }
275                }
276            }
277        }
278    }
279
280    @Override
281    public void processDatasetEvent(AbstractDatasetChangedEvent event) {
282        changedDatasets.add(event.getDataset());
283    }
284
285    private final File getPidFile(File osmFile) {
286        return new File(autosaveDir, osmFile.getName().replaceFirst("[.][^.]+$", ".pid"));
287    }
288
289    /**
290     * Replies the list of .osm files still present in autosave dir, that are not currently managed by another instance of JOSM.
291     * These files are hence unsaved layers from an old instance of JOSM that crashed and may be recovered by this instance.
292     * @return The list of .osm files still present in autosave dir, that are not currently managed by another instance of JOSM
293     */
294    public List<File> getUnsavedLayersFiles() {
295        List<File> result = new ArrayList<>();
296        File[] files = autosaveDir.listFiles(OsmImporter.FILE_FILTER);
297        if (files == null)
298            return result;
299        for (File file: files) {
300            if (file.isFile()) {
301                boolean skipFile = false;
302                File pidFile = getPidFile(file);
303                if (pidFile.exists()) {
304                    try (BufferedReader reader = Files.newBufferedReader(pidFile.toPath(), StandardCharsets.UTF_8)) {
305                        String jvmId = reader.readLine();
306                        if (jvmId != null) {
307                            String pid = jvmId.split("@")[0];
308                            skipFile = jvmPerfDataFileExists(pid);
309                        }
310                    } catch (Throwable t) {
311                        Main.error(t);
312                    }
313                }
314                if (!skipFile) {
315                    result.add(file);
316                }
317            }
318        }
319        return result;
320    }
321
322    private boolean jvmPerfDataFileExists(final String jvmId) {
323        File jvmDir = new File(System.getProperty("java.io.tmpdir") + File.separator + "hsperfdata_" + System.getProperty("user.name"));
324        if (jvmDir.exists() && jvmDir.canRead()) {
325            File[] files = jvmDir.listFiles(new FileFilter() {
326                @Override
327                public boolean accept(File file) {
328                    return file.getName().equals(jvmId) && file.isFile();
329                }
330            });
331            return files != null && files.length == 1;
332        }
333        return false;
334    }
335
336    public void recoverUnsavedLayers() {
337        List<File> files = getUnsavedLayersFiles();
338        final OpenFileTask openFileTsk = new OpenFileTask(files, null, tr("Restoring files"));
339        Main.worker.submit(openFileTsk);
340        Main.worker.submit(new Runnable() {
341            @Override
342            public void run() {
343                for (File f: openFileTsk.getSuccessfullyOpenedFiles()) {
344                    moveToDeletedLayersFolder(f);
345                }
346            }
347        });
348    }
349
350    /**
351     * Move file to the deleted layers directory.
352     * If moving does not work, it will try to delete the file directly.
353     * Afterwards, if the number of deleted layers gets larger than PROP_DELETED_LAYERS,
354     * some files in the deleted layers directory will be removed.
355     *
356     * @param f the file, usually from the autosave dir
357     */
358    private void moveToDeletedLayersFolder(File f) {
359        File backupFile = new File(deletedLayersDir, f.getName());
360        File pidFile = getPidFile(f);
361
362        if (backupFile.exists()) {
363            deletedLayers.remove(backupFile);
364            if (!backupFile.delete()) {
365                Main.warn(String.format("Could not delete old backup file %s", backupFile));
366            }
367        }
368        if (f.renameTo(backupFile)) {
369            deletedLayers.add(backupFile);
370            pidFile.delete();
371        } else {
372            Main.warn(String.format("Could not move autosaved file %s to %s folder", f.getName(), deletedLayersDir.getName()));
373            // we cannot move to deleted folder, so just try to delete it directly
374            if (!f.delete()) {
375                Main.warn(String.format("Could not delete backup file %s", f));
376            } else {
377                pidFile.delete();
378            }
379        }
380        while (deletedLayers.size() > PROP_DELETED_LAYERS.get()) {
381            File next = deletedLayers.remove();
382            if (next == null) {
383                break;
384            }
385            if (!next.delete()) {
386                Main.warn(String.format("Could not delete archived backup file %s", next));
387            }
388        }
389    }
390
391    public void discardUnsavedLayers() {
392        for (File f: getUnsavedLayersFiles()) {
393            moveToDeletedLayersFolder(f);
394        }
395    }
396}