gecko-dev/mobile/android/base/db/DBUtils.java

/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this file,
 * You can obtain one at http://mozilla.org/MPL/2.0/. */

package org.mozilla.gecko.db;

import org.mozilla.gecko.GeckoAppShell;
import org.mozilla.gecko.sync.Utils;

import android.content.ContentValues;
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.os.Build;
import android.text.TextUtils;
import android.util.Base64;
import android.util.Log;
import java.util.UUID;

import java.util.Random;

public class DBUtils {
    private static final String LOGTAG = "GeckoDBUtils";

    public static final String qualifyColumn(String table, String column) {
        return table + "." + column;
    }

    // This is available in Android >= 11. Implemented locally to be
    // compatible with older versions.
    public static String concatenateWhere(String a, String b) {
        if (TextUtils.isEmpty(a)) {
            return b;
        }

        if (TextUtils.isEmpty(b)) {
            return a;
        }

        return "(" + a + ") AND (" + b + ")";
    }

    // This is available in Android >= 11. Implemented locally to be
    // compatible with older versions.
    public static String[] appendSelectionArgs(String[] originalValues, String[] newValues) {
        if (originalValues == null || originalValues.length == 0) {
            return newValues;
        }

        if (newValues == null || newValues.length == 0) {
            return originalValues;
        }

        String[] result = new String[originalValues.length + newValues.length];
        System.arraycopy(originalValues, 0, result, 0, originalValues.length);
        System.arraycopy(newValues, 0, result, originalValues.length, newValues.length);

        return result;
    }

    public static void replaceKey(ContentValues aValues, String aOriginalKey,
                                  String aNewKey, String aDefault) {
        String value = aDefault;
        if (aOriginalKey != null && aValues.containsKey(aOriginalKey)) {
            value = aValues.get(aOriginalKey).toString();
            aValues.remove(aOriginalKey);
        }

        if (!aValues.containsKey(aNewKey)) {
            aValues.put(aNewKey, value);
        }
    }

    public static void ensureDatabaseIsNotLocked(SQLiteOpenHelper dbHelper, String databasePath) {
        SQLiteDatabase db = dbHelper.getWritableDatabase();

        // The returned writable database is read-only, this probably means that the
        // database is permanently locked due to a crash or a non-clean quit in Fennec.
        // We can assume it's safe to forcefully unlock the database file in this case
        // as all database access happens through this content provider (see bug 741718).
        if (db.isReadOnly()) {
            // Close read-only connection, we don't want to use it
            dbHelper.close();

            Log.d(LOGTAG, "Database is in read-only mode, trying to forcefully unlock the database file: " + databasePath);

            // Forcefully unlock the database file
            GeckoAppShell.unlockDatabaseFile(databasePath);

            // TODO: maybe check if the connection is still read-only and let the
            // user know that the device needs rebooting?
        }
    }
}