add db dump option

app/src/main/java/ch/blinkenlights/android/medialibrary/MediaLibrary.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2016-2017 Adrian Ulrich <adrian@blinkenlights.ch>
+ * Copyright (C) 2016-2018 Adrian Ulrich <adrian@blinkenlights.ch>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -33,6 +33,10 @@ import java.io.ObjectInputStream;
 import java.io.Serializable;
 
 import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileOutputStream;
+import java.io.InputStream;
+import java.io.OutputStream;
 
 public class MediaLibrary  {
 
@@ -264,6 +268,28 @@ public class MediaLibrary  {
 		return sScanner.describeScanProgress();
 	}
 
+	/**
+	 * Dumps a copy of the media database to a specified path.
+	 *
+	 * @param context the context to use.
+	 * @param dst the destination path of the db dump.
+	 */
+	public static void createDebugDump(Context context, String dst) {
+		final String src = context.getDatabasePath(MediaLibraryBackend.DATABASE_NAME).getPath();
+		try {
+			try (InputStream in = new FileInputStream(src)) {
+				try (OutputStream out = new FileOutputStream(dst)) {
+					byte[] buffer = new byte[4096];
+					int len = 0;
+					while ((len = in.read(buffer)) > 0) {
+						out.write(buffer, 0, len);
+					}
+				}
+			}
+		} catch (Exception e) {
+			Log.v("VanillaMusic", "Debug dump failed: "+e);
+		}
+	}
 
 	/**
 	 * Registers a new content observer for the media library

app/src/main/java/ch/blinkenlights/android/medialibrary/MediaLibraryBackend.java

@@ -39,7 +39,7 @@ public class MediaLibraryBackend extends SQLiteOpenHelper {
 	/**
 	 * on-disk file to store the database
 	 */
-	private static final String DATABASE_NAME = "media-library.db";
+	static final String DATABASE_NAME = "media-library.db";
 	/**
 	 * The magic mtime to use for songs which are in PENDING_DELETION state.
 	 * This is NOT 0 as the mtime is always expected to be > 0 for existing rows

app/src/main/java/ch/blinkenlights/android/vanilla/PreferencesMediaLibrary.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2017 Adrian Ulrich <adrian@blinkenlights.ch>
+ * Copyright (C) 2017-2018 Adrian Ulrich <adrian@blinkenlights.ch>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -26,12 +26,17 @@ import android.content.DialogInterface;
 import android.content.Intent;
 import android.database.Cursor;
 import android.os.Bundle;
+import android.os.Environment;
 import android.view.LayoutInflater;
+import android.view.Menu;
+import android.view.MenuInflater;
+import android.view.MenuItem;
 import android.view.View;
 import android.view.ViewGroup;
 import android.widget.CheckBox;
 import android.widget.ProgressBar;
 import android.widget.TextView;
+import android.widget.Toast;
 
 import java.util.Timer;
 import java.util.TimerTask;
@@ -136,6 +141,8 @@ public class PreferencesMediaLibrary extends Fragment implements View.OnClickLis
 		mEditButton.setOnClickListener(this);
 		mGroupAlbumsCheck.setOnClickListener(this);
 		mForceBastpCheck.setOnClickListener(this);
+		// Enable options menu.
+		setHasOptionsMenu(true);
 	}
 
 	@Override
@@ -206,6 +213,29 @@ public class PreferencesMediaLibrary extends Fragment implements View.OnClickLis
 		}
 	}
 
+	private static final int MENU_DUMP_DB = 1;
+	@Override
+	public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
+		super.onCreateOptionsMenu(menu, inflater);
+		menu.add(0, MENU_DUMP_DB, 30, R.string.dump_database);
+	}
+
+	@Override
+	public boolean onOptionsItemSelected(MenuItem item) {
+		switch (item.getItemId()) {
+		case MENU_DUMP_DB:
+			final Context context = getActivity();
+			final String path = Environment.getExternalStorageDirectory().getPath() + "/dbdump-" + context.getPackageName() + ".sqlite";
+			final String msg = getString(R.string.dump_database_result, path);
+
+			MediaLibrary.createDebugDump(context, path);
+			Toast.makeText(context, msg, Toast.LENGTH_SHORT).show();
+			break;
+		default:
+			return super.onOptionsItemSelected(item);
+		}
+		return true;
+	}
 	/**
 	 * Wrapper for updatePreferences() which warns the user about
 	 * possible consequences.

app/src/main/res/values/translatable.xml

@@ -337,6 +337,8 @@ THE SOFTWARE.
 	<string name="sendto">Send to…</string>
 	<string name="no_receiving_apps">No receiving apps found for this media type!</string>
 	<string name="duration">Duration</string>
+	<string name="dump_database">Dump database</string>
+	<string name="dump_database_result">Database dumped to \'%s\'</string>
 
 	<string name="media_library">Media library</string>
 	<string name="media_folders_header">Indexed directories</string>