2 * Copyright 2017-present Open Networking Foundation
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
16 package io.atomix.storage.journal;
21 * @author <a href="http://github.com/kuujo">Jordan Halterman</a>
23 public interface JournalWriter<E> {
25 * Returns the last written index.
27 * @return The last written index.
32 * Returns the last entry written.
34 * @return The last entry written.
36 Indexed<E> getLastEntry();
39 * Returns the next index to be written.
41 * @return The next index to be written.
46 * Appends an entry to the journal.
48 * @param entry The entry to append.
49 * @return The appended indexed entry.
51 <T extends E> Indexed<T> append(T entry);
54 * Commits entries up to the given index.
56 * @param index The index up to which to commit entries.
58 void commit(long index);
61 * Resets the head of the journal to the given index.
63 * @param index the index to which to reset the head of the journal
65 void reset(long index);
68 * Truncates the log to the given index.
70 * @param index The index to which to truncate the log.
72 void truncate(long index);
75 * Flushes written entries to disk.