OSM upload: Reuse export file if already exists

src/me/guillaumin/android/osmtracker/gpx/ExportToStorageTask.java

@@ -25,32 +25,21 @@ public ExportToStorageTask(Context context, long trackId) {
 		super(context, trackId);
 	}
 
+	/**
+	 * Calculate a track's export directory, and create if it doesn't exist already.
+	 * @param startDate  The track's starting date, from
+	 *   {@link me.guillaumin.android.osmtracker.db.TrackContentProvider.Schema#COL_START_DATE Schema.COL_START_DATE}
+	 * @return The export directory
+	 * @throws ExportTrackException if the directory can't be created
+	 * @see #getExportDirectory(Context, Date)
+	 */
 	@Override
 	protected File getExportDirectory(Date startDate) throws ExportTrackException {
 		File sdRoot = Environment.getExternalStorageDirectory();
-
-		// The location that the user has specified gpx files 
-		// and associated content to be written
-		SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
-		String userGPXExportDirectoryName = prefs.getString(
-				OSMTracker.Preferences.KEY_STORAGE_DIR,	OSMTracker.Preferences.VAL_STORAGE_DIR);
-
-		boolean directoryPerTrack = prefs.getBoolean(OSMTracker.Preferences.KEY_OUTPUT_DIR_PER_TRACK, 
-				OSMTracker.Preferences.VAL_OUTPUT_GPX_OUTPUT_DIR_PER_TRACK);
-
-		// Create the path to the directory to which we will be writing
-		// Trim the directory name, as additional spaces at the end will 
-		// not allow the directory to be created if required
-		String exportDirectoryPath = userGPXExportDirectoryName.trim();
-		String perTrackDirectory = "";
-		if (directoryPerTrack) {
-			// If the user wants a directory per track, then create a name for the destination directory
-			// based on the start date of the track
-			perTrackDirectory = File.separator + DataHelper.FILENAME_FORMATTER.format(startDate);
-		}
+		final String exportDirectoryPath = getExportDirectory(context, startDate);		
 
 		// Create a file based on the path we've generated above
-		File trackGPXExportDirectory = new File(sdRoot + exportDirectoryPath + perTrackDirectory);
+		File trackGPXExportDirectory = new File(sdRoot + exportDirectoryPath);
 
 		// Create track directory if needed
 		if (! trackGPXExportDirectory.exists()) {
@@ -63,7 +52,7 @@ protected File getExportDirectory(Date startDate) throws ExportTrackException {
 				// Specific hack for Google Nexus  S(See issue #168)
 				if (android.os.Build.MODEL.equals(OSMTracker.Devices.NEXUS_S)) {
 					// exportDirectoryPath always starts with "/"
-					trackGPXExportDirectory = new File(exportDirectoryPath + perTrackDirectory);
+					trackGPXExportDirectory = new File(exportDirectoryPath);
 					trackGPXExportDirectory.mkdirs();
 				}
 			}
@@ -86,4 +75,43 @@ protected boolean exportMediaFiles() {
 	protected boolean updateExportDate() {
 		return true;
 	}
+
+	/**
+	 *<p>Calculate a track's export directory path. Does not create the directory if missing.</p>
+	 *
+	 *<p>The returned directory is relative to <tt>sdRoot</tt> because of bug #168
+	 * mentioned in {@link #getExportDirectory(Date)}.  If you can't find the
+	 * returned directory at <tt>sdRoot + directory</tt>, try just <tt>directory</tt>.</p>
+	 *
+	 * @param context  Calling activity context, for {@link PreferenceManager#getDefaultSharedPreferences(Context)}
+	 * @param startDate  The track's starting date, from
+	 *   {@link me.guillaumin.android.osmtracker.db.TrackContentProvider.Schema#COL_START_DATE Schema.COL_START_DATE}
+	 * @return track export directory name within sdcard;
+	 *   The full path to dirname is {@link Environment#getExternalStorageDirectory()} + dirname
+	 * @see #getExportDirectory(Date)
+	 */
+	public static String getExportDirectory(Context context, Date startDate) {
+
+		// The location that the user has specified gpx files 
+		// and associated content to be written
+		SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
+		String userGPXExportDirectoryName = prefs.getString(
+				OSMTracker.Preferences.KEY_STORAGE_DIR,	OSMTracker.Preferences.VAL_STORAGE_DIR);
+
+		boolean directoryPerTrack = prefs.getBoolean(OSMTracker.Preferences.KEY_OUTPUT_DIR_PER_TRACK, 
+				OSMTracker.Preferences.VAL_OUTPUT_GPX_OUTPUT_DIR_PER_TRACK);
+
+		// Create the path to the directory to which we will be writing
+		// Trim the directory name, as additional spaces at the end will 
+		// not allow the directory to be created if required
+		String exportDirectoryPath = userGPXExportDirectoryName.trim();
+		String perTrackDirectory = "";
+		if (directoryPerTrack) {
+			// If the user wants a directory per track, then create a name for the destination directory
+			// based on the start date of the track
+			perTrackDirectory = File.separator + DataHelper.FILENAME_FORMATTER.format(startDate);
+		}
+
+		return exportDirectoryPath + perTrackDirectory;
+	}
 }

src/me/guillaumin/android/osmtracker/gpx/ExportToTempFileTask.java

@@ -4,25 +4,36 @@
 import java.io.IOException;
 import java.util.Date;
 
+import me.guillaumin.android.osmtracker.db.TrackContentProvider;
+import me.guillaumin.android.osmtracker.db.TrackContentProvider.Schema;
 import me.guillaumin.android.osmtracker.exception.ExportTrackException;
+import android.content.ContentUris;
 import android.content.Context;
 import android.database.Cursor;
+import android.os.Environment;
 import android.util.Log;
 
 /**
  * Exports to a temporary file. Will not export associated
  * media, only the GPX file.
+ * If this track has already been exported, tries to find and re-use that file.
  *
  */
 public abstract class ExportToTempFileTask extends ExportTrackTask {
 
 	private static final String TAG = ExportToTempFileTask.class.getSimpleName();
 
-	private final File tmpFile;
+	/** Temp file created in constructor, or actual export file if found */
+	private File tmpFile;
 	private String filename;
+	/** True if a previous export file was found */
+	private boolean reusedRealExport = false;
 
 	public ExportToTempFileTask(Context context, long trackId) {
 		super(context, trackId);
+		tmpFile = checkForExportFile();
+		if (tmpFile != null)
+			return;
 		try {
 			tmpFile = File.createTempFile("osm-upload", ".gpx", context.getCacheDir());
 			Log.d(TAG, "Temporary file: " + tmpFile.getAbsolutePath());
@@ -32,15 +43,76 @@ public ExportToTempFileTask(Context context, long trackId) {
 		}
 	}
 
-
+	/**
+	 * Checks whether this file's already been exported, based on the track
+	 * db and our naming conventions. If so, we can reuse that GPX file,
+	 * instead of creating a new temporary one.
+	 * Sets {@link #reusedRealExport} but does not set {@link #tmpFile}.
+	 * @return  Export file if it exists
+	 */
+	private File checkForExportFile() {
+		reusedRealExport = false;
+
+		// Query the track columns needed by this method and buildGPXFilename
+		final String[] pro = { Schema.COL_EXPORT_DATE, Schema.COL_START_DATE,  Schema.COL_NAME };
+		Cursor c = context.getContentResolver().query(ContentUris.withAppendedId(
+				TrackContentProvider.CONTENT_URI_TRACK, trackId), pro, null,
+				null, null);
+		if (null == c)
+			return null;  // <--- Early return: could not query ---
+
+		// Get the exportDate and startDate of this track
+		Date exportDate = null, startDate = null;
+		if (1 <= c.getCount()) {
+			c.moveToFirst();
+			final int eidx = c.getColumnIndex(Schema.COL_EXPORT_DATE);
+			if (! c.isNull(eidx))
+			{
+				exportDate = new Date();
+				exportDate.setTime(c.getLong(eidx));
+				startDate = new Date();
+				startDate.setTime(c.getLong(c.getColumnIndex(Schema.COL_START_DATE)));
+			}
+		}
+
+		if (exportDate == null) {
+			c.close();
+			return null;  // <--- Early return: Not exported ---
+		}
+
+		final String exportDirectoryPath = ExportToStorageTask.getExportDirectory(context, startDate);
+		final File sdRoot = Environment.getExternalStorageDirectory();
+		File expDir = new File(sdRoot + exportDirectoryPath);
+		if (! expDir.exists())
+			expDir = new File(exportDirectoryPath); // Specific hack for Google Nexus S (See issue #168)
+		if (! expDir.exists()) {
+			c.close();
+			return null;  // <--- Early return: Export dir doesn't exist ---
+		}
+
+		// Export dir exists. Does the GPX file exist with the expected name?
+		final String filenameBase = super.buildGPXFilename(c);
+		c.close();
+		File f = new File(expDir, filenameBase);
+		if (f.exists()) {
+			reusedRealExport = true;
+			return f;
+		} else {
+			return null;
+		}
+	}
+
 	@Override
 	protected File getExportDirectory(Date startDate) throws ExportTrackException {
 		return tmpFile.getParentFile();
 	}
 
 	@Override
 	protected String buildGPXFilename(Cursor c) {
-		filename = super.buildGPXFilename(c);
+		if (reusedRealExport)
+			filename = tmpFile.getName();
+		else
+			filename = super.buildGPXFilename(c);
 		return tmpFile.getName();
 	}
 
@@ -62,6 +134,16 @@ public String getFilename() {
 		return filename;
 	}
 
+	@Override
+	protected Boolean doInBackground(Void... params) {
+		if (reusedRealExport) {
+			trackFile = tmpFile;
+			return true;
+		} else {
+			return super.doInBackground(params);
+		}
+	}
+
 	@Override
 	protected void onPostExecute(Boolean success) {
 		super.onPostExecute(success);

src/me/guillaumin/android/osmtracker/gpx/ExportTrackTask.java

@@ -88,7 +88,7 @@ public abstract class ExportTrackTask  extends AsyncTask<Void, Integer, Boolean>
 	/**
 	 * Path to the exported GPX file
 	 */
-	private File trackFile;
+	protected File trackFile;
 
 	/**
 	 * Dialog to display while exporting
@@ -138,7 +138,11 @@ protected void onPreExecute() {
 		dialog.show();
 	}
 
-
+	/**
+	 * Export the track to a new GPX file.
+	 * Calls {@link #exportTrackAsGpx(long)} which sets {@link #trackFile} to the file.
+	 * If any error occurs, sets {@link #errorMsg}.
+	 */
 	@Override
 	protected Boolean doInBackground(Void... params) {
 		try {
@@ -180,6 +184,11 @@ public void onClick(DialogInterface dialog, int which) {
 		}
 	}
 
+	/**
+	 * Export the track to a new GPX file.  Sets {@link #trackFile} to the file.
+	 * @param trackId  Track ID
+	 * @throws ExportTrackException  if any error occurs during export
+	 */
 	private void exportTrackAsGpx(long trackId) throws ExportTrackException {
 		File sdRoot = Environment.getExternalStorageDirectory();