ARTEMIS-2239 Zero-copy NIO/MAPPED TimedBuffer

NIO/MAPPED journal types can use directly the buffer of TimedBuffer
to perform file writes, avoiding an expensive copy + zeroing.

artemis-journal/src/main/java/org/apache/activemq/artemis/core/io/AbstractSequentialFile.java

@@ -25,6 +25,7 @@
 import java.util.concurrent.Executor;
 import java.util.concurrent.atomic.AtomicLong;
 
+import io.netty.buffer.ByteBuf;
 import org.apache.activemq.artemis.api.core.ActiveMQBuffer;
 import org.apache.activemq.artemis.api.core.ActiveMQBuffers;
 import org.apache.activemq.artemis.api.core.ActiveMQException;
@@ -58,7 +59,7 @@ public abstract class AbstractSequentialFile implements SequentialFile {
     * Instead of having AIOSequentialFile implementing the Observer, I have done it on an inner class.
     * This is the class returned to the factory when the file is being activated.
     */
-   protected final TimedBufferObserver timedBufferObserver = new LocalBufferObserver();
+   protected final TimedBufferObserver timedBufferObserver = createTimedBufferObserver();
 
    /**
     * @param file
@@ -74,6 +75,10 @@ public AbstractSequentialFile(final File directory,
       this.factory = factory;
    }
 
+   protected TimedBufferObserver createTimedBufferObserver() {
+      return new LocalBufferObserver();
+   }
+
    // Public --------------------------------------------------------
 
    @Override
@@ -252,43 +257,6 @@ protected File getFile() {
       return file;
    }
 
-   private static final class DelegateCallback implements IOCallback {
-
-      final List<IOCallback> delegates;
-
-      private DelegateCallback(final List<IOCallback> delegates) {
-         this.delegates = delegates;
-      }
-
-      @Override
-      public void done() {
-         final int size = delegates.size();
-         for (int i = 0; i < size; i++) {
-            try {
-               delegates.get(i).done();
-            } catch (Throwable e) {
-               ActiveMQJournalLogger.LOGGER.errorCompletingCallback(e);
-            }
-         }
-      }
-
-      @Override
-      public void onError(final int errorCode, final String errorMessage) {
-         if (logger.isTraceEnabled()) {
-            logger.trace("onError" + " code: " + errorCode + " message: " + errorMessage);
-         }
-
-         final int size = delegates.size();
-         for (int i = 0; i < size; i++) {
-            try {
-               delegates.get(i).onError(errorCode, errorMessage);
-            } catch (Throwable e) {
-               ActiveMQJournalLogger.LOGGER.errorCallingErrorCallback(e);
-            }
-         }
-      }
-   }
-
    protected ByteBuffer newBuffer(int size, int limit) {
       size = factory.calculateBlockSize(size);
       limit = factory.calculateBlockSize(limit);
@@ -301,21 +269,19 @@ protected ByteBuffer newBuffer(int size, int limit) {
    protected class LocalBufferObserver implements TimedBufferObserver {
 
       @Override
-      public void flushBuffer(final ByteBuffer buffer, final boolean requestedSync, final List<IOCallback> callbacks) {
-         buffer.flip();
-
-         if (buffer.limit() == 0) {
-            factory.releaseBuffer(buffer);
-         } else {
+      public void flushBuffer(final ByteBuf byteBuf, final boolean requestedSync, final List<IOCallback> callbacks) {
+         final int bytes = byteBuf.readableBytes();
+         if (bytes > 0) {
+            final ByteBuffer buffer = newBuffer(byteBuf.capacity(), bytes);
+            buffer.limit(bytes);
+            byteBuf.getBytes(byteBuf.readerIndex(), buffer);
+            buffer.flip();
             writeDirect(buffer, requestedSync, new DelegateCallback(callbacks));
+         } else {
+            IOCallback.done(callbacks);
          }
       }
 
-      @Override
-      public ByteBuffer newBuffer(final int size, final int limit) {
-         return AbstractSequentialFile.this.newBuffer(size, limit);
-      }
-
       @Override
       public int getRemainingBytes() {
          if (fileSize - position.get() > Integer.MAX_VALUE) {

artemis-journal/src/main/java/org/apache/activemq/artemis/core/io/DelegateCallback.java

@@ -0,0 +1,49 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You 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 org.apache.activemq.artemis.core.io;
+
+import java.util.Collection;
+import java.util.Objects;
+
+/**
+ * It is a utility class to allow several {@link IOCallback}s to be used as one.
+ */
+public final class DelegateCallback implements IOCallback {
+
+   private final Collection<? extends IOCallback> delegates;
+
+   /**
+    * It doesn't copy defensively the given {@code delegates}.
+    *
+    * @throws NullPointerException if {@code delegates} is {@code null}
+    */
+   public DelegateCallback(final Collection<? extends IOCallback> delegates) {
+      Objects.requireNonNull(delegates, "delegates cannot be null!");
+      this.delegates = delegates;
+   }
+
+   @Override
+   public void done() {
+      IOCallback.done(delegates);
+   }
+
+   @Override
+   public void onError(final int errorCode, final String errorMessage) {
+      IOCallback.onError(delegates, errorCode, errorMessage);
+   }
+
+}

artemis-journal/src/main/java/org/apache/activemq/artemis/core/io/IOCallback.java

@@ -16,6 +16,10 @@
  */
 package org.apache.activemq.artemis.core.io;
 
+import java.util.Collection;
+
+import org.apache.activemq.artemis.journal.ActiveMQJournalLogger;
+
 /**
  * The interface used for AIO Callbacks.
  */
@@ -32,4 +36,24 @@ public interface IOCallback {
     * Observation: The whole file will be probably failing if this happens. Like, if you delete the file, you will start to get errors for these operations
     */
    void onError(int errorCode, String errorMessage);
+
+   static void done(Collection<? extends IOCallback> delegates) {
+      delegates.forEach(callback -> {
+         try {
+            callback.done();
+         } catch (Throwable e) {
+            ActiveMQJournalLogger.LOGGER.errorCompletingCallback(e);
+         }
+      });
+   }
+
+   static void onError(Collection<? extends IOCallback> delegates, int errorCode, final String errorMessage) {
+      delegates.forEach(callback -> {
+         try {
+            callback.onError(errorCode, errorMessage);
+         } catch (Throwable e) {
+            ActiveMQJournalLogger.LOGGER.errorCallingErrorCallback(e);
+         }
+      });
+   }
 }

artemis-journal/src/main/java/org/apache/activemq/artemis/core/io/buffer/TimedBuffer.java

@@ -358,13 +358,7 @@ public boolean flushBatch() {
                   bytesFlushed.addAndGet(pos);
                }
 
-               final ByteBuffer bufferToFlush = bufferObserver.newBuffer(bufferSize, pos);
-               //bufferObserver::newBuffer doesn't necessary return a buffer with limit == pos or limit == bufferSize!!
-               bufferToFlush.limit(pos);
-               //perform memcpy under the hood due to the off heap buffer
-               buffer.getBytes(0, bufferToFlush);
-
-               bufferObserver.flushBuffer(bufferToFlush, pendingSync, callbacks);
+               bufferObserver.flushBuffer(buffer.byteBuf(), pendingSync, callbacks);
 
                stopSpin();
 

artemis-journal/src/main/java/org/apache/activemq/artemis/core/io/buffer/TimedBufferObserver.java

@@ -16,38 +16,22 @@
  */
 package org.apache.activemq.artemis.core.io.buffer;
 
-import java.nio.ByteBuffer;
 import java.util.List;
 
+import io.netty.buffer.ByteBuf;
 import org.apache.activemq.artemis.core.io.IOCallback;
 
 public interface TimedBufferObserver {
 
-   // Constants -----------------------------------------------------
-
-   // Attributes ----------------------------------------------------
-
-   // Static --------------------------------------------------------
-
-   // Constructors --------------------------------------------------
-
-   // Public --------------------------------------------------------
-
-   void flushBuffer(ByteBuffer buffer, boolean syncRequested, List<IOCallback> callbacks);
+   /**
+    * It flushes {@link ByteBuf#readableBytes()} of {@code buffer} without changing its reader/writer indexes.<br>
+    * It just use {@code buffer} temporary: it can be reused by the caller right after this call.
+    */
+   void flushBuffer(ByteBuf buffer, boolean syncRequested, List<IOCallback> callbacks);
 
    /**
     * Return the number of remaining bytes that still fit on the observer (file)
     */
    int getRemainingBytes();
 
-   ByteBuffer newBuffer(int size, int limit);
-
-   // Package protected ---------------------------------------------
-
-   // Protected -----------------------------------------------------
-
-   // Private -------------------------------------------------------
-
-   // Inner classes -------------------------------------------------
-
 }

artemis-journal/src/main/java/org/apache/activemq/artemis/core/io/mapped/TimedSequentialFile.java

@@ -22,8 +22,11 @@
 import java.nio.ByteBuffer;
 import java.util.List;
 
+import io.netty.buffer.ByteBuf;
 import org.apache.activemq.artemis.api.core.ActiveMQBuffer;
 import org.apache.activemq.artemis.api.core.ActiveMQException;
+import org.apache.activemq.artemis.api.core.ActiveMQExceptionType;
+import org.apache.activemq.artemis.api.core.ActiveMQIOErrorException;
 import org.apache.activemq.artemis.core.io.DummyCallback;
 import org.apache.activemq.artemis.core.io.IOCallback;
 import org.apache.activemq.artemis.core.io.SequentialFile;
@@ -32,7 +35,6 @@
 import org.apache.activemq.artemis.core.io.buffer.TimedBufferObserver;
 import org.apache.activemq.artemis.core.journal.EncodingSupport;
 import org.apache.activemq.artemis.core.journal.impl.SimpleWaitIOCallback;
-import org.apache.activemq.artemis.journal.ActiveMQJournalLogger;
 
 final class TimedSequentialFile implements SequentialFile {
 
@@ -239,88 +241,44 @@ public File getJavaFile() {
       return this.sequentialFile.getJavaFile();
    }
 
-   private static void invokeDoneOn(List<? extends IOCallback> callbacks) {
-      final int size = callbacks.size();
-      for (int i = 0; i < size; i++) {
-         try {
-            final IOCallback callback = callbacks.get(i);
-            callback.done();
-         } catch (Throwable e) {
-            ActiveMQJournalLogger.LOGGER.errorCompletingCallback(e);
-         }
-      }
-   }
-
-   private static void invokeOnErrorOn(final int errorCode,
-                                       final String errorMessage,
-                                       List<? extends IOCallback> callbacks) {
-      final int size = callbacks.size();
-      for (int i = 0; i < size; i++) {
-         try {
-            final IOCallback callback = callbacks.get(i);
-            callback.onError(errorCode, errorMessage);
-         } catch (Throwable e) {
-            ActiveMQJournalLogger.LOGGER.errorCallingErrorCallback(e);
-         }
-      }
-   }
-
-   private static final class DelegateCallback implements IOCallback {
-
-      List<IOCallback> delegates;
-
-      private DelegateCallback() {
-         this.delegates = null;
-      }
-
-      @Override
-      public void done() {
-         invokeDoneOn(delegates);
-      }
-
-      @Override
-      public void onError(final int errorCode, final String errorMessage) {
-         invokeOnErrorOn(errorCode, errorMessage, delegates);
-      }
-   }
-
    private final class LocalBufferObserver implements TimedBufferObserver {
 
-      private final DelegateCallback delegateCallback = new DelegateCallback();
-
       @Override
-      public void flushBuffer(final ByteBuffer buffer, final boolean requestedSync, final List<IOCallback> callbacks) {
-         buffer.flip();
-
-         if (buffer.limit() == 0) {
-            try {
-               invokeDoneOn(callbacks);
-            } finally {
-               factory.releaseBuffer(buffer);
-            }
-         } else {
-            if (callbacks.isEmpty()) {
-               try {
-                  sequentialFile.writeDirect(buffer, requestedSync);
-               } catch (Exception e) {
-                  throw new IllegalStateException(e);
-               }
+      public void flushBuffer(final ByteBuf byteBuf, final boolean requestedSync, final List<IOCallback> callbacks) {
+         final int bytes = byteBuf.readableBytes();
+         if (bytes > 0) {
+            final boolean releaseBuffer;
+            final ByteBuffer buffer;
+            if (byteBuf.nioBufferCount() == 1) {
+               //any ByteBuffer is fine with the MAPPED journal
+               releaseBuffer = false;
+               buffer = byteBuf.internalNioBuffer(byteBuf.readerIndex(), bytes);
             } else {
-               delegateCallback.delegates = callbacks;
-               try {
-                  sequentialFile.writeDirect(buffer, requestedSync, delegateCallback);
-               } finally {
-                  delegateCallback.delegates = null;
+               //perform the copy on buffer
+               releaseBuffer = true;
+               buffer = factory.newBuffer(byteBuf.capacity());
+               buffer.limit(bytes);
+               byteBuf.getBytes(byteBuf.readerIndex(), buffer);
+               buffer.flip();
+            }
+            try {
+               blockingWriteDirect(buffer, requestedSync, releaseBuffer);
+               IOCallback.done(callbacks);
+            } catch (Throwable t) {
+               final int code;
+               if (t instanceof IOException) {
+                  code = ActiveMQExceptionType.IO_ERROR.getCode();
+                  factory.onIOError(new ActiveMQIOErrorException(t.getMessage(), t), t.getMessage(), TimedSequentialFile.this.sequentialFile);
+               } else {
+                  code = ActiveMQExceptionType.GENERIC_EXCEPTION.getCode();
                }
+               IOCallback.onError(callbacks, code, t.getMessage());
             }
+         } else {
+            IOCallback.done(callbacks);
          }
       }
 
-      @Override
-      public ByteBuffer newBuffer(final int size, final int limit) {
-         return factory.newBuffer(limit);
-      }
-
       @Override
       public int getRemainingBytes() {
          try {