2 * Copyright 2017-2022 Open Networking Foundation and others. All rights reserved.
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;
18 import org.eclipse.jdt.annotation.NonNull;
23 * @author <a href="http://github.com/kuujo">Jordan Halterman</a>
25 public interface JournalWriter<E> {
27 * Returns the last written index.
29 * @return The last written index.
34 * Returns the last entry written.
36 * @return The last entry written.
38 Indexed<E> getLastEntry();
41 * Returns the next index to be written.
43 * @return The next index to be written.
48 * Appends an entry to the journal.
50 * @param entry The entry to append.
51 * @return The appended indexed entry.
53 <T extends E> @NonNull Indexed<T> append(T entry);
56 * Commits entries up to the given index.
58 * @param index The index up to which to commit entries.
60 void commit(long index);
63 * Resets the head of the journal to the given index.
65 * @param index the index to which to reset the head of the journal
67 void reset(long index);
70 * Truncates the log to the given index.
72 * @param index The index to which to truncate the log.
74 void truncate(long index);
77 * Flushes written entries to disk.