2 * Copyright (c) 2024 PANTHEON.tech, s.r.o. 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 io.netty.buffer.ByteBuf;
19 import org.eclipse.jdt.annotation.NonNullByDefault;
20 import org.eclipse.jdt.annotation.Nullable;
23 * A reader of {@link ByteBufJournal} entries.
26 public interface ByteBufReader extends AutoCloseable {
28 * A journal entry processor. Responsible for transforming bytes into their internal representation.
30 * @param <T> Internal representation type
33 interface EntryMapper<T> {
37 * @param index entry index
38 * @param bytes entry bytes
39 * @return resulting internal representation
41 T mapEntry(long index, ByteBuf bytes);
45 * Returns the first index in the journal.
47 * @return The first index in the journal
52 * Returns the next reader index.
54 * @return The next reader index
59 * Try to move to the next binary data block.
61 * @param entryMapper callback to be invoked on binary data
62 * @return processed binary data, or {@code null}
64 <T> @Nullable T tryNext(EntryMapper<T> entryMapper);
67 * Resets the reader to the start.
72 * Resets the reader to the given index.
74 * @param index the next index to read
76 void reset(long index);