1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/mobile/android/base/db/SharedBrowserDatabaseProvider.java Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,115 @@
1.4 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.5 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.6 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.7 +
1.8 +package org.mozilla.gecko.db;
1.9 +
1.10 +import org.mozilla.gecko.db.BrowserContract.CommonColumns;
1.11 +import org.mozilla.gecko.db.BrowserContract.SyncColumns;
1.12 +import org.mozilla.gecko.db.PerProfileDatabases.DatabaseHelperFactory;
1.13 +
1.14 +import android.content.Context;
1.15 +import android.database.Cursor;
1.16 +import android.database.sqlite.SQLiteDatabase;
1.17 +import android.net.Uri;
1.18 +import android.util.Log;
1.19 +
1.20 +/**
1.21 + * A ContentProvider subclass that provides per-profile browser.db access
1.22 + * that can be safely shared between multiple providers.
1.23 + *
1.24 + * If multiple ContentProvider classes wish to share a database, it's
1.25 + * vitally important that they use the same SQLiteOpenHelpers for access.
1.26 + *
1.27 + * Failure to do so can cause accidental concurrent writes, with the result
1.28 + * being unexpected SQLITE_BUSY errors.
1.29 + *
1.30 + * This class provides a static {@link PerProfileDatabases} instance, lazily
1.31 + * initialized within {@link SharedBrowserDatabaseProvider#onCreate()}.
1.32 + */
1.33 +public abstract class SharedBrowserDatabaseProvider extends AbstractPerProfileDatabaseProvider {
1.34 + private static final String LOGTAG = SharedBrowserDatabaseProvider.class.getSimpleName();
1.35 +
1.36 + private static PerProfileDatabases<BrowserDatabaseHelper> databases;
1.37 +
1.38 + @Override
1.39 + protected PerProfileDatabases<BrowserDatabaseHelper> getDatabases() {
1.40 + return databases;
1.41 + }
1.42 +
1.43 + @Override
1.44 + public boolean onCreate() {
1.45 + // If necessary, do the shared DB work.
1.46 + synchronized (SharedBrowserDatabaseProvider.class) {
1.47 + if (databases != null) {
1.48 + return true;
1.49 + }
1.50 +
1.51 + final DatabaseHelperFactory<BrowserDatabaseHelper> helperFactory = new DatabaseHelperFactory<BrowserDatabaseHelper>() {
1.52 + @Override
1.53 + public BrowserDatabaseHelper makeDatabaseHelper(Context context, String databasePath) {
1.54 + return new BrowserDatabaseHelper(context, databasePath);
1.55 + }
1.56 + };
1.57 +
1.58 + databases = new PerProfileDatabases<BrowserDatabaseHelper>(getContext(), BrowserDatabaseHelper.DATABASE_NAME, helperFactory);
1.59 + }
1.60 +
1.61 + return true;
1.62 + }
1.63 +
1.64 + /**
1.65 + * Clean up some deleted records from the specified table.
1.66 + *
1.67 + * If called in an existing transaction, it is the caller's responsibility
1.68 + * to ensure that the transaction is already upgraded to a writer, because
1.69 + * this method issues a read followed by a write, and thus is potentially
1.70 + * vulnerable to an unhandled SQLITE_BUSY failure during the upgrade.
1.71 + *
1.72 + * If not called in an existing transaction, no new explicit transaction
1.73 + * will be begun.
1.74 + */
1.75 + protected void cleanUpSomeDeletedRecords(Uri fromUri, String tableName) {
1.76 + Log.d(LOGTAG, "Cleaning up deleted records from " + tableName);
1.77 +
1.78 + // We clean up records marked as deleted that are older than a
1.79 + // predefined max age. It's important not be too greedy here and
1.80 + // remove only a few old deleted records at a time.
1.81 +
1.82 + // we cleanup records marked as deleted that are older than a
1.83 + // predefined max age. It's important not be too greedy here and
1.84 + // remove only a few old deleted records at a time.
1.85 +
1.86 + // Maximum age of deleted records to be cleaned up (20 days in ms)
1.87 + final long MAX_AGE_OF_DELETED_RECORDS = 86400000 * 20;
1.88 +
1.89 + // Number of records marked as deleted to be removed
1.90 + final long DELETED_RECORDS_PURGE_LIMIT = 5;
1.91 +
1.92 + // Android SQLite doesn't have LIMIT on DELETE. Instead, query for the
1.93 + // IDs of matching rows, then delete them in one go.
1.94 + final long now = System.currentTimeMillis();
1.95 + final String selection = SyncColumns.IS_DELETED + " = 1 AND " +
1.96 + SyncColumns.DATE_MODIFIED + " <= " +
1.97 + (now - MAX_AGE_OF_DELETED_RECORDS);
1.98 +
1.99 + final String profile = fromUri.getQueryParameter(BrowserContract.PARAM_PROFILE);
1.100 + final SQLiteDatabase db = getWritableDatabaseForProfile(profile, isTest(fromUri));
1.101 + final String[] ids;
1.102 + final String limit = Long.toString(DELETED_RECORDS_PURGE_LIMIT, 10);
1.103 + final Cursor cursor = db.query(tableName, new String[] { CommonColumns._ID }, selection, null, null, null, null, limit);
1.104 + try {
1.105 + ids = new String[cursor.getCount()];
1.106 + int i = 0;
1.107 + while (cursor.moveToNext()) {
1.108 + ids[i++] = Long.toString(cursor.getLong(0), 10);
1.109 + }
1.110 + } finally {
1.111 + cursor.close();
1.112 + }
1.113 +
1.114 + final String inClause = computeSQLInClause(ids.length,
1.115 + CommonColumns._ID);
1.116 + db.delete(tableName, inClause, ids);
1.117 + }
1.118 +}
