The Tor Browser: mobile/android/base/db/SharedBrowserDatabaseProvider.java@6474c204b198 (annotated)

mobile/android/base/db/SharedBrowserDatabaseProvider.java@6474c204b198 (annotated)

mobile/android/base/db/SharedBrowserDatabaseProvider.java

Wed, 31 Dec 2014 06:09:35 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 06:09:35 +0100
changeset 0: 6474c204b198
permissions: -rw-r--r--

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

 /* 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.db.BrowserContract.CommonColumns;
 import org.mozilla.gecko.db.BrowserContract.SyncColumns;
 import org.mozilla.gecko.db.PerProfileDatabases.DatabaseHelperFactory;
 import android.content.Context;
 import android.database.Cursor;
 import android.database.sqlite.SQLiteDatabase;
 import android.net.Uri;
 import android.util.Log;
 /**
  * A ContentProvider subclass that provides per-profile browser.db access
  * that can be safely shared between multiple providers.
  *
  * If multiple ContentProvider classes wish to share a database, it's
  * vitally important that they use the same SQLiteOpenHelpers for access.
  *
  * Failure to do so can cause accidental concurrent writes, with the result
  * being unexpected SQLITE_BUSY errors.
  *
  * This class provides a static {@link PerProfileDatabases} instance, lazily
  * initialized within {@link SharedBrowserDatabaseProvider#onCreate()}.
  */
 public abstract class SharedBrowserDatabaseProvider extends AbstractPerProfileDatabaseProvider {
     private static final String LOGTAG = SharedBrowserDatabaseProvider.class.getSimpleName();
     private static PerProfileDatabases<BrowserDatabaseHelper> databases;
     @Override
     protected PerProfileDatabases<BrowserDatabaseHelper> getDatabases() {
         return databases;
     }
     @Override
     public boolean onCreate() {
         // If necessary, do the shared DB work.
         synchronized (SharedBrowserDatabaseProvider.class) {
             if (databases != null) {
                 return true;
             }
             final DatabaseHelperFactory<BrowserDatabaseHelper> helperFactory = new DatabaseHelperFactory<BrowserDatabaseHelper>() {
                 @Override
                 public BrowserDatabaseHelper makeDatabaseHelper(Context context, String databasePath) {
                     return new BrowserDatabaseHelper(context, databasePath);
                 }
             };
             databases = new PerProfileDatabases<BrowserDatabaseHelper>(getContext(), BrowserDatabaseHelper.DATABASE_NAME, helperFactory);
         }
         return true;
     }
     /**
      * Clean up some deleted records from the specified table.
      *
      * If called in an existing transaction, it is the caller's responsibility
      * to ensure that the transaction is already upgraded to a writer, because
      * this method issues a read followed by a write, and thus is potentially
      * vulnerable to an unhandled SQLITE_BUSY failure during the upgrade.
      *
      * If not called in an existing transaction, no new explicit transaction
      * will be begun.
      */
     protected void cleanUpSomeDeletedRecords(Uri fromUri, String tableName) {
         Log.d(LOGTAG, "Cleaning up deleted records from " + tableName);
         // We clean up records marked as deleted that are older than a
         // predefined max age. It's important not be too greedy here and
         // remove only a few old deleted records at a time.
         // we cleanup records marked as deleted that are older than a
         // predefined max age. It's important not be too greedy here and
         // remove only a few old deleted records at a time.
         // Maximum age of deleted records to be cleaned up (20 days in ms)
         final long MAX_AGE_OF_DELETED_RECORDS = 86400000 * 20;
         // Number of records marked as deleted to be removed
         final long DELETED_RECORDS_PURGE_LIMIT = 5;
         // Android SQLite doesn't have LIMIT on DELETE. Instead, query for the
         // IDs of matching rows, then delete them in one go.
         final long now = System.currentTimeMillis();
         final String selection = SyncColumns.IS_DELETED + " = 1 AND " +
                 SyncColumns.DATE_MODIFIED + " <= " +
                 (now - MAX_AGE_OF_DELETED_RECORDS);
         final String profile = fromUri.getQueryParameter(BrowserContract.PARAM_PROFILE);
         final SQLiteDatabase db = getWritableDatabaseForProfile(profile, isTest(fromUri));
         final String[] ids;
         final String limit = Long.toString(DELETED_RECORDS_PURGE_LIMIT, 10);
         final Cursor cursor = db.query(tableName, new String[] { CommonColumns._ID }, selection, null, null, null, null, limit);
         try {
             ids = new String[cursor.getCount()];
             int i = 0;
             while (cursor.moveToNext()) {
                 ids[i++] = Long.toString(cursor.getLong(0), 10);
             }
         } finally {
             cursor.close();
         }
         final String inClause = computeSQLInClause(ids.length,
                 CommonColumns._ID);
         db.delete(tableName, inClause, ids);
     }
 }

The Tor Browser / annotate

mobile/android/base/db/SharedBrowserDatabaseProvider.java@6474c204b198 (annotated)

mobile/android/base/db/SharedBrowserDatabaseProvider.java