X-Git-Url: https://git.opendaylight.org/gerrit/gitweb?a=blobdiff_plain;f=atomix-storage%2Fsrc%2Fmain%2Fjava%2Fio%2Fatomix%2Fstorage%2Fjournal%2FMappedJournalSegmentWriter.java;h=9f437b6125f4c68d8ea126434f1b805da5c9c478;hb=32bb8e8275884dd0e6dee40b02785c2e606a0914;hp=7ff58590d996729c51e7b8c2612f7a23e82deed5;hpb=b004038a282786fc29b4ba7fc9f8874debe21afd;p=controller.git

diff --git a/atomix-storage/src/main/java/io/atomix/storage/journal/MappedJournalSegmentWriter.java b/atomix-storage/src/main/java/io/atomix/storage/journal/MappedJournalSegmentWriter.java
index 7ff58590d9..9f437b6125 100644
--- a/atomix-storage/src/main/java/io/atomix/storage/journal/MappedJournalSegmentWriter.java
+++ b/atomix-storage/src/main/java/io/atomix/storage/journal/MappedJournalSegmentWriter.java
@@ -1,5 +1,6 @@
 /*
- * 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.
@@ -15,15 +16,17 @@
  */
 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.
@@ -40,187 +43,106 @@ import java.util.zip.CRC32;
  *
  * @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 JournalSegmentReader<E> reader;
   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,
-      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();
-    reset(0);
-  }
+  MappedJournalSegmentWriter(final FileChannel channel, final JournalSegment<E> segment, final int maxEntrySize,
+      final JournalIndex index, final JournalSerdes namespace) {
+    super(channel, segment, maxEntrySize, index, namespace);
 
-  /**
-   * Returns the mapped buffer underlying the segment writer.
-   *
-   * @return the mapped buffer underlying the segment writer
-   */
-  MappedByteBuffer buffer() {
-    return mappedBuffer;
+    mappedBuffer = mapBuffer(channel, maxSegmentSize);
+    buffer = mappedBuffer.slice();
+    reader = new JournalSegmentReader<>(segment, new MappedFileReader(segment.file().file().toPath(), mappedBuffer),
+        maxEntrySize, namespace);
+    reset(0);
   }
 
-  @Override
-  public void reset(long index) {
-    long nextIndex = firstIndex;
-
-    // Clear the buffer indexes.
-    buffer.position(JournalSegmentDescriptor.BYTES);
+  MappedJournalSegmentWriter(final JournalSegmentWriter<E> previous) {
+    super(previous);
 
-    // Record the current buffer position.
-    int position = buffer.position();
-
-    // Read the entry length.
-    buffer.mark();
+    mappedBuffer = mapBuffer(channel, maxSegmentSize);
+    buffer = mappedBuffer.slice();
+    reader = new JournalSegmentReader<>(segment, new MappedFileReader(segment.file().file().toPath(), mappedBuffer),
+        maxEntrySize, namespace);
+  }
 
+  private static @NonNull MappedByteBuffer mapBuffer(final FileChannel channel, final int maxSegmentSize) {
     try {
-      int length = buffer.getInt();
-
-      // If the length is non-zero, read the entry.
-      while (0 < length && length <= maxEntrySize && (index == 0 || nextIndex <= index)) {
-
-        // Read the checksum of the entry.
-        final long checksum = buffer.getInt() & 0xFFFFFFFFL;
-
-        // 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 does not equal the computed checksum, do not proceed further
-        if (checksum != crc32.getValue()) {
-          break;
-        }
-
-        slice.rewind();
-        final E entry = namespace.deserialize(slice);
-        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();
-      }
-
-      // Reset the buffer to the previous mark.
-      buffer.reset();
-    } catch (BufferUnderflowException e) {
-      buffer.reset();
+      return channel.map(FileChannel.MapMode.READ_WRITE, 0, maxSegmentSize);
+    } catch (IOException e) {
+      throw new StorageException(e);
     }
   }
 
   @Override
-  public long getLastIndex() {
-    return lastEntry != null ? lastEntry.index() : segment.index() - 1;
+  @NonNull MappedByteBuffer buffer() {
+    return mappedBuffer;
   }
 
   @Override
-  public Indexed<E> getLastEntry() {
-    return lastEntry;
+  MappedJournalSegmentWriter<E> toMapped() {
+    return this;
   }
 
   @Override
-  public long getNextIndex() {
-    if (lastEntry != null) {
-      return lastEntry.index() + 1;
-    } else {
-      return firstIndex;
-    }
+  DiskJournalSegmentWriter<E> toFileChannel() {
+    close();
+    return new DiskJournalSegmentWriter<>(this);
   }
 
   @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());
+  JournalSegmentReader<E> reader() {
+    return reader;
   }
 
   @Override
   @SuppressWarnings("unchecked")
-  public <T extends E> Indexed<T> append(T entry) {
+  <T extends E> Indexed<T> append(final 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()) {
+    final int bodyPosition = currentPosition + HEADER_BYTES;
+    final int avail = maxSegmentSize - bodyPosition;
+    if (avail < 0) {
       throw new BufferOverflowException();
     }
 
-    buffer.position(position + Integer.BYTES + Integer.BYTES);
-
+    final var entryBytes = buffer.slice(bodyPosition, Math.min(avail, maxEntrySize));
     try {
-      namespace.serialize(entry, buffer);
+      namespace.serialize(entry, entryBytes);
     } catch (KryoException e) {
-      throw new BufferOverflowException();
-    }
-
-    final int length = buffer.position() - (position + Integer.BYTES + Integer.BYTES);
+      if (entryBytes.capacity() != maxEntrySize) {
+        // We have not provided enough capacity, signal to roll to next segment
+        throw new BufferOverflowException();
+      }
 
-    // If the entry length exceeds the maximum entry size then throw an exception.
-    if (length > maxEntrySize) {
       // Just reset the buffer. There's no need to zero the bytes since we haven't written the length or checksum.
-      buffer.position(position);
-      throw new StorageException.TooLarge("Entry size " + length + " exceeds maximum allowed bytes (" + maxEntrySize + ")");
+      throw new StorageException.TooLarge("Entry size exceeds maximum allowed bytes (" + maxEntrySize + ")");
     }
 
+    final int length = entryBytes.position();
+
     // Compute the checksum for the entry.
-    final CRC32 crc32 = new CRC32();
-    buffer.position(position + Integer.BYTES + Integer.BYTES);
-    ByteBuffer slice = buffer.slice();
-    slice.limit(length);
-    crc32.update(slice);
-    final long checksum = crc32.getValue();
+    final var crc32 = new CRC32();
+    crc32.update(entryBytes.flip());
 
     // 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.putInt(currentPosition, length).putInt(currentPosition + Integer.BYTES, (int) crc32.getValue());
 
     // Update the last entry with the correct index/term/length.
     Indexed<E> indexedEntry = new Indexed<>(index, entry, length);
-    this.lastEntry = indexedEntry;
-    this.index.index(index, position);
-    return (Indexed<T>) indexedEntry;
-  }
-
-  @Override
-  public void commit(long index) {
+    lastEntry = indexedEntry;
+    this.index.index(index, currentPosition);
 
+    currentPosition = currentPosition + HEADER_BYTES + length;
+    return (Indexed<T>) indexedEntry;
   }
 
   @Override
-  public void truncate(long index) {
+  void truncate(final long index) {
     // If the index is greater than or equal to the last index, skip the truncate.
     if (index >= getLastIndex()) {
       return;
@@ -232,28 +154,26 @@ class MappedJournalSegmentWriter<E> implements JournalWriter<E> {
     // Truncate the index.
     this.index.truncate(index);
 
-    if (index < segment.index()) {
+    if (index < firstIndex) {
       // Reset the writer to the first entry.
-      buffer.position(JournalSegmentDescriptor.BYTES);
+      currentPosition = JournalSegmentDescriptor.BYTES;
     } else {
       // Reset the writer to the given index.
       reset(index);
     }
 
     // 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);
-    buffer.position(position);
+    buffer.putLong(currentPosition, 0L);
   }
 
   @Override
-  public void flush() {
+  void flush() {
     mappedBuffer.force();
   }
 
   @Override
-  public void close() {
+  void close() {
     flush();
     try {
       BufferCleaner.freeBuffer(mappedBuffer);