Method getBuilder

app/src/main/java/eu/faircode/email/DB.java:528–668

(Context context)

    }

    private static RoomDatabase.Builder<DB> getBuilder(Context context) {
        SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
        boolean wal = prefs.getBoolean("wal", true);
        Log.i("DB wal=" + wal);

        RoomDatabase.Builder<DB> builder = Room
                .databaseBuilder(context, DB.class, DB_NAME)
                //.openHelperFactory(new RequerySQLiteOpenHelperFactory())
                //.setQueryExecutor()
                .setTransactionExecutor(executor)
                .setJournalMode(wal ? JournalMode.WRITE_AHEAD_LOGGING : JournalMode.TRUNCATE) // using the latest sqlite
                .addCallback(new Callback() {
                    @Override
                    public void onCreate(@NonNull SupportSQLiteDatabase db) {
                        defaultSearches(db, context);
                    }

                    @Override
                    public void onOpen(@NonNull SupportSQLiteDatabase db) {
                        try {
                            Map<String, String> crumb = new HashMap<>();
                            crumb.put("version", Integer.toString(db.getVersion()));
                            crumb.put("WAL", Boolean.toString(db.isWriteAheadLoggingEnabled()));
                            Log.breadcrumb("Database", crumb);

                            // https://www.sqlite.org/pragma.html#pragma_auto_vacuum
                            // https://android.googlesource.com/platform/external/sqlite.git/+/6ab557bdc070f11db30ede0696888efd19800475%5E!/
                            boolean sqlite_auto_vacuum = prefs.getBoolean("sqlite_auto_vacuum", false);
                            String mode = (sqlite_auto_vacuum ? "FULL" : "INCREMENTAL");
                            Log.i("Set PRAGMA auto_vacuum=" + mode);
                            try (Cursor cursor = db.query("PRAGMA auto_vacuum=" + mode + ";")) {
                                cursor.moveToNext(); // required
                            }

                            // https://sqlite.org/pragma.html#pragma_synchronous
                            boolean sqlite_sync_extra = prefs.getBoolean("sqlite_sync_extra", true);
                            String sync = (sqlite_sync_extra ? "EXTRA" : "NORMAL");
                            Log.i("Set PRAGMA synchronous=" + sync);
                            try (Cursor cursor = db.query("PRAGMA synchronous=" + sync + ";")) {
                                cursor.moveToNext(); // required
                            }

                            // https://www.sqlite.org/pragma.html#pragma_journal_size_limit
                            Log.i("Set PRAGMA journal_size_limit=" + DB_JOURNAL_SIZE_LIMIT);
                            try (Cursor cursor = db.query("PRAGMA journal_size_limit=" + DB_JOURNAL_SIZE_LIMIT + ";")) {
                                cursor.moveToNext(); // required
                            }

                            // https://www.sqlite.org/pragma.html#pragma_cache_size
                            Integer cache_size = getCacheSizeKb(context);
                            if (cache_size != null) {
                                cache_size = -cache_size; // kibibytes
                                Log.i("Set PRAGMA cache_size=" + cache_size);
                                // TODO CASA PRAGMA does not support placeholders
                                try (Cursor cursor = db.query("PRAGMA cache_size=" + cache_size + ";")) {
                                    cursor.moveToNext(); // required
                                }
                            }