/*
- * Copyright 2017-present Open Networking Foundation
+ * Copyright 2017-2022 Open Networking Foundation and others. All rights reserved.
+ * Copyright (c) 2024 PANTHEON.tech, s.r.o.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
*/
package io.atomix.storage.journal;
+import static io.atomix.storage.journal.SegmentEntry.HEADER_BYTES;
+
import com.esotericsoftware.kryo.KryoException;
import io.atomix.storage.journal.index.JournalIndex;
-
import java.io.IOException;
import java.nio.BufferOverflowException;
import java.nio.BufferUnderflowException;
import java.nio.ByteBuffer;
import java.nio.MappedByteBuffer;
+import java.nio.channels.FileChannel;
import java.util.zip.CRC32;
+import org.eclipse.jdt.annotation.NonNull;
/**
* Segment writer.
*
* @author <a href="http://github.com/kuujo">Jordan Halterman</a>
*/
-class MappedJournalSegmentWriter<E> implements JournalWriter<E> {
- private final MappedByteBuffer mappedBuffer;
+final class MappedJournalSegmentWriter<E> extends JournalSegmentWriter<E> {
+ private final @NonNull MappedByteBuffer mappedBuffer;
private final ByteBuffer buffer;
- private final JournalSegment<E> segment;
- private final int maxEntrySize;
- private final JournalIndex index;
- private final JournalSerdes namespace;
- private final long firstIndex;
+
private Indexed<E> lastEntry;
MappedJournalSegmentWriter(
- MappedByteBuffer buffer,
+ FileChannel channel,
JournalSegment<E> segment,
int maxEntrySize,
JournalIndex index,
JournalSerdes namespace) {
- this.mappedBuffer = buffer;
- this.buffer = buffer.slice();
- this.segment = segment;
- this.maxEntrySize = maxEntrySize;
- this.index = index;
- this.namespace = namespace;
- this.firstIndex = segment.index();
+ super(channel, segment, maxEntrySize, index, namespace);
+ mappedBuffer = mapBuffer(channel, maxSegmentSize);
+ buffer = mappedBuffer.slice();
reset(0);
}
- /**
- * Returns the mapped buffer underlying the segment writer.
- *
- * @return the mapped buffer underlying the segment writer
- */
- MappedByteBuffer buffer() {
+ MappedJournalSegmentWriter(JournalSegmentWriter<E> previous, int position) {
+ super(previous);
+ mappedBuffer = mapBuffer(channel, maxSegmentSize);
+ buffer = mappedBuffer.slice().position(position);
+ lastEntry = previous.getLastEntry();
+ }
+
+ private static @NonNull MappedByteBuffer mapBuffer(FileChannel channel, int maxSegmentSize) {
+ try {
+ return channel.map(FileChannel.MapMode.READ_WRITE, 0, maxSegmentSize);
+ } catch (IOException e) {
+ throw new StorageException(e);
+ }
+ }
+
+ @Override
+ @NonNull MappedByteBuffer buffer() {
return mappedBuffer;
}
@Override
- public void reset(long index) {
+ MappedJournalSegmentWriter<E> toMapped() {
+ return this;
+ }
+
+ @Override
+ DiskJournalSegmentWriter<E> toFileChannel() {
+ final int position = buffer.position();
+ close();
+ return new DiskJournalSegmentWriter<>(this, position);
+ }
+
+ @Override
+ void reset(long index) {
long nextIndex = firstIndex;
// Clear the buffer indexes.
// Read the checksum of the entry.
final long checksum = buffer.getInt() & 0xFFFFFFFFL;
+ // Slice off the entry's bytes
+ final ByteBuffer entryBytes = buffer.slice();
+ entryBytes.limit(length);
+
// Compute the checksum for the entry bytes.
final CRC32 crc32 = new CRC32();
- ByteBuffer slice = buffer.slice();
- slice.limit(length);
- crc32.update(slice);
-
- // If the stored checksum equals the computed checksum, return the entry.
- if (checksum == crc32.getValue()) {
- slice.rewind();
- final E entry = namespace.deserialize(slice);
- lastEntry = new Indexed<>(nextIndex, entry, length);
- this.index.index(nextIndex, position);
- nextIndex++;
- } else {
+ crc32.update(entryBytes);
+
+ // If the stored checksum does not equal the computed checksum, do not proceed further
+ if (checksum != crc32.getValue()) {
break;
}
+ entryBytes.rewind();
+ final E entry = namespace.deserialize(entryBytes);
+ lastEntry = new Indexed<>(nextIndex, entry, length);
+ this.index.index(nextIndex, position);
+ nextIndex++;
+
// Update the current position for indexing.
position = buffer.position() + length;
buffer.position(position);
- buffer.mark();
- length = buffer.getInt();
+ length = buffer.mark().getInt();
}
// Reset the buffer to the previous mark.
}
@Override
- public long getLastIndex() {
- return lastEntry != null ? lastEntry.index() : segment.index() - 1;
- }
-
- @Override
- public Indexed<E> getLastEntry() {
+ Indexed<E> getLastEntry() {
return lastEntry;
}
- @Override
- public long getNextIndex() {
- if (lastEntry != null) {
- return lastEntry.index() + 1;
- } else {
- return firstIndex;
- }
- }
-
- @Override
- public void append(Indexed<E> entry) {
- final long nextIndex = getNextIndex();
-
- // If the entry's index is greater than the next index in the segment, skip some entries.
- if (entry.index() > nextIndex) {
- throw new IndexOutOfBoundsException("Entry index is not sequential");
- }
-
- // If the entry's index is less than the next index, truncate the segment.
- if (entry.index() < nextIndex) {
- truncate(entry.index() - 1);
- }
- append(entry.entry());
- }
-
@Override
@SuppressWarnings("unchecked")
- public <T extends E> Indexed<T> append(T entry) {
+ <T extends E> Indexed<T> append(T entry) {
// Store the entry index.
final long index = getNextIndex();
// Serialize the entry.
int position = buffer.position();
- if (position + Integer.BYTES + Integer.BYTES > buffer.limit()) {
+ if (position + HEADER_BYTES > buffer.limit()) {
throw new BufferOverflowException();
}
- buffer.position(position + Integer.BYTES + Integer.BYTES);
+ buffer.position(position + HEADER_BYTES);
try {
namespace.serialize(entry, buffer);
throw new BufferOverflowException();
}
- final int length = buffer.position() - (position + Integer.BYTES + Integer.BYTES);
+ final int length = buffer.position() - (position + HEADER_BYTES);
// If the entry length exceeds the maximum entry size then throw an exception.
if (length > maxEntrySize) {
// Compute the checksum for the entry.
final CRC32 crc32 = new CRC32();
- buffer.position(position + Integer.BYTES + Integer.BYTES);
+ buffer.position(position + HEADER_BYTES);
ByteBuffer slice = buffer.slice();
slice.limit(length);
crc32.update(slice);
final long checksum = crc32.getValue();
// Create a single byte[] in memory for the entire entry and write it as a batch to the underlying buffer.
- buffer.position(position);
- buffer.putInt(length);
- buffer.putInt((int) checksum);
- buffer.position(position + Integer.BYTES + Integer.BYTES + length);
+ buffer.position(position).putInt(length).putInt((int) checksum).position(position + HEADER_BYTES + length);
// Update the last entry with the correct index/term/length.
Indexed<E> indexedEntry = new Indexed<>(index, entry, length);
}
@Override
- public void commit(long index) {
-
- }
-
- @Override
- public void truncate(long index) {
+ void truncate(long index) {
// If the index is greater than or equal to the last index, skip the truncate.
if (index >= getLastIndex()) {
return;
// Truncate the index.
this.index.truncate(index);
- if (index < segment.index()) {
- buffer.position(JournalSegmentDescriptor.BYTES);
- buffer.putInt(0);
- buffer.putInt(0);
+ if (index < firstIndex) {
+ // Reset the writer to the first entry.
buffer.position(JournalSegmentDescriptor.BYTES);
} else {
// Reset the writer to the given index.
reset(index);
-
- // Zero entries after the given index.
- int position = buffer.position();
- buffer.putInt(0);
- buffer.putInt(0);
- buffer.position(position);
}
+
+ // Zero the entry header at current buffer position.
+ int position = buffer.position();
+ // Note: we issue a single putLong() instead of two putInt()s.
+ buffer.putLong(0).position(position);
}
@Override
- public void flush() {
+ void flush() {
mappedBuffer.force();
}
@Override
- public void close() {
+ void close() {
flush();
try {
BufferCleaner.freeBuffer(mappedBuffer);
Code Review / controller.git / blobdiff