franz1981 commented on a change in pull request #2522: ARTEMIS-2239 Zero-copy
NIO/MAPPED TimedBuffer
URL: https://github.com/apache/activemq-artemis/pull/2522#discussion_r251009673
##########
File path:
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);
Review comment:
It has been solved on the abstract seq file Local: ASYNCIO is doing is
exactly like before (with the copy), while NIO/MAPPED avoid the copy by using a
specialized class.
For ASYNCIO:
```java
@Override
public void flushBuffer(final ByteBuffer buffer, final boolean
requestedSync, final List<IOCallback> callbacks) { public void
flushBuffer(final ByteBuf byteBuf, final boolean requestedSync, final
List<IOCallback> callbacks) {
buffer.flip(); final int bytes =
byteBuf.readableBytes();
if (bytes > 0) {
if (buffer.limit() == 0) { final ByteBuffer buffer =
newBuffer(byteBuf.capacity(), bytes);
factory.releaseBuffer(buffer); buffer.limit(bytes);
} else { byteBuf.getBytes(byteBuf.readerIndex(),
buffer);
buffer.flip();
writeDirect(buffer, requestedSync, new
DelegateCallback(callbacks)); writeDirect(buffer,
requestedSync, new DelegateCallback(callbacks));
} else {
DelegateCallback.done(callbacks);
} }
} }
```
----------------------------------------------------------------
This is an automated message from the Apache Git Service.
To respond to the message, please log on GitHub and use the
URL above to go to the specific comment.
For queries about this service, please contact Infrastructure at:
us...@infra.apache.org
With regards,
Apache Git Services
