2362N/A * Copyright (c) 1997, 2001, Oracle and/or its affiliates. All rights reserved. 0N/A * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 0N/A * This code is free software; you can redistribute it and/or modify it 0N/A * under the terms of the GNU General Public License version 2 only, as 2362N/A * published by the Free Software Foundation. Oracle designates this 0N/A * particular file as subject to the "Classpath" exception as provided 2362N/A * by Oracle in the LICENSE file that accompanied this code. 0N/A * This code is distributed in the hope that it will be useful, but WITHOUT 0N/A * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 0N/A * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 0N/A * version 2 for more details (a copy is included in the LICENSE file that 0N/A * accompanied this code). 0N/A * You should have received a copy of the GNU General Public License version 0N/A * 2 along with this work; if not, write to the Free Software Foundation, 0N/A * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 2362N/A * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 2362N/A * or visit www.oracle.com if you need additional information or have any 0N/A * A LogHandler represents snapshots and update records as serializable 0N/A * This implementation does not know how to create an initial snaphot or 0N/A * apply an update to a snapshot. The client must specifiy these methods 0N/A * @author Ann Wollrath 0N/A * Creates a LogHandler for a ReliableLog. 0N/A * Creates and returns the initial state of data structure that needs 0N/A * to be stably stored. This method is called when a ReliableLog is 0N/A * @return the initial state 0N/A * @exception Exception can raise any exception 0N/A * Writes the snapshot object to a stream. This callback is 0N/A * invoked when the client calls the snaphot method of ReliableLog. 0N/A * @param out the output stream 0N/A * @param value the snapshot 0N/A * @exception Exception can raise any exception 0N/A * Read the snapshot object from a stream and returns the snapshot. 0N/A * This callback is invoked when the client calls the recover method 0N/A * @param in the input stream 0N/A * @return the state (snapshot) 0N/A * @exception Exception can raise any exception 0N/A * Writes the representation (a serializable object) of an update 0N/A * to a stream. This callback is invoked when the client calls the 0N/A * update method of ReliableLog. 0N/A * @param out the output stream 0N/A * @param value the snapshot 0N/A * @exception Exception can raise any exception 0N/A * Reads a stably logged update (a serializable object) from a 0N/A * stream. This callback is invoked during recovery, once for 0N/A * every record in the log. After reading the update, this method 0N/A * invokes the applyUpdate (abstract) method in order to obtain 0N/A * the new snapshot value. It then returns the new snapshot. 0N/A * @param in the input stream 0N/A * @param state the current state 0N/A * @return the new state 0N/A * @exception Exception can raise any exception 0N/A * Reads a stably logged update (a serializable object) from a stream. 0N/A * This callback is invoked during recovery, once for every record in the 0N/A * log. After reading the update, this method is invoked in order to 0N/A * obtain the new snapshot value. The method should apply the update 0N/A * object to the current state <code>state</code> and return the new 0N/A * state (the new snapshot value). 0N/A * @param update the update object 0N/A * @param state the current state 0N/A * @return the new state 0N/A * @exception Exception can raise any exception