Import atomix/{storage,utils}

[controller.git] / third-party / atomix / storage / src / main / java / io / atomix / storage / journal / MappableJournalSegmentWriter.java

diff --git a/third-party/atomix/storage/src/main/java/io/atomix/storage/journal/MappableJournalSegmentWriter.java b/third-party/atomix/storage/src/main/java/io/atomix/storage/journal/MappableJournalSegmentWriter.java
new file mode 100644 (file)
index 0000000..1ca8924
--- /dev/null
+++ b/third-party/atomix/storage/src/main/java/io/atomix/storage/journal/MappableJournalSegmentWriter.java
@@ -0,0 +1,167 @@
+/*
+ * Copyright 2018-present Open Networking Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package io.atomix.storage.journal;
+
+import io.atomix.storage.StorageException;
+import io.atomix.storage.journal.index.JournalIndex;
+import io.atomix.utils.serializer.Namespace;
+
+import java.io.IOException;
+import java.nio.MappedByteBuffer;
+import java.nio.channels.FileChannel;
+
+/**
+ * Mappable log segment writer.
+ */
+class MappableJournalSegmentWriter<E> implements JournalWriter<E> {
+  private final FileChannel channel;
+  private final JournalSegment<E> segment;
+  private final int maxEntrySize;
+  private final JournalIndex index;
+  private final Namespace namespace;
+  private JournalWriter<E> writer;
+
+  MappableJournalSegmentWriter(
+      FileChannel channel,
+      JournalSegment<E> segment,
+      int maxEntrySize,
+      JournalIndex index,
+      Namespace namespace) {
+    this.channel = channel;
+    this.segment = segment;
+    this.maxEntrySize = maxEntrySize;
+    this.index = index;
+    this.namespace = namespace;
+    this.writer = new FileChannelJournalSegmentWriter<>(channel, segment, maxEntrySize, index, namespace);
+  }
+
+  /**
+   * Maps the segment writer into memory, returning the mapped buffer.
+   *
+   * @return the buffer that was mapped into memory
+   */
+  MappedByteBuffer map() {
+    if (writer instanceof MappedJournalSegmentWriter) {
+      return ((MappedJournalSegmentWriter<E>) writer).buffer();
+    }
+
+    try {
+      JournalWriter<E> writer = this.writer;
+      MappedByteBuffer buffer = channel.map(FileChannel.MapMode.READ_WRITE, 0, segment.descriptor().maxSegmentSize());
+      this.writer = new MappedJournalSegmentWriter<>(buffer, segment, maxEntrySize, index, namespace);
+      writer.close();
+      return buffer;
+    } catch (IOException e) {
+      throw new StorageException(e);
+    }
+  }
+
+  /**
+   * Unmaps the mapped buffer.
+   */
+  void unmap() {
+    if (writer instanceof MappedJournalSegmentWriter) {
+      JournalWriter<E> writer = this.writer;
+      this.writer = new FileChannelJournalSegmentWriter<>(channel, segment, maxEntrySize, index, namespace);
+      writer.close();
+    }
+  }
+
+  MappedByteBuffer buffer() {
+    JournalWriter<E> writer = this.writer;
+    if (writer instanceof MappedJournalSegmentWriter) {
+      return ((MappedJournalSegmentWriter<E>) writer).buffer();
+    }
+    return null;
+  }
+
+  /**
+   * Returns the writer's first index.
+   *
+   * @return the writer's first index
+   */
+  public long firstIndex() {
+    return segment.index();
+  }
+
+  /**
+   * Returns the size of the segment.
+   *
+   * @return the size of the segment
+   */
+  public int size() {
+    try {
+      return (int) channel.size();
+    } catch (IOException e) {
+      throw new StorageException(e);
+    }
+  }
+
+  @Override
+  public long getLastIndex() {
+    return writer.getLastIndex();
+  }
+
+  @Override
+  public Indexed<E> getLastEntry() {
+    return writer.getLastEntry();
+  }
+
+  @Override
+  public long getNextIndex() {
+    return writer.getNextIndex();
+  }
+
+  @Override
+  public <T extends E> Indexed<T> append(T entry) {
+    return writer.append(entry);
+  }
+
+  @Override
+  public void append(Indexed<E> entry) {
+    writer.append(entry);
+  }
+
+  @Override
+  public void commit(long index) {
+    writer.commit(index);
+  }
+
+  @Override
+  public void reset(long index) {
+    writer.reset(index);
+  }
+
+  @Override
+  public void truncate(long index) {
+    writer.truncate(index);
+  }
+
+  @Override
+  public void flush() {
+    writer.flush();
+  }
+
+  @Override
+  public void close() {
+    writer.close();
+    try {
+      channel.close();
+    } catch (IOException e) {
+      throw new StorageException(e);
+    }
+  }
+}