1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache license, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the license for the specific language governing permissions and
15 * limitations under the license.
16 */
17 package org.apache.logging.log4j.core.async;
18
19 import com.lmax.disruptor.Sequence;
20 import com.lmax.disruptor.SequenceReportingEventHandler;
21
22 /**
23 * This event handler gets passed messages from the RingBuffer as they become
24 * available. Processing of these messages is done in a separate thread,
25 * controlled by the {@code Executor} passed to the {@code Disruptor}
26 * constructor.
27 */
28 public class RingBufferLogEventHandler implements
29 SequenceReportingEventHandler<RingBufferLogEvent> {
30
31 private static final int NOTIFY_PROGRESS_THRESHOLD = 50;
32 private Sequence sequenceCallback;
33 private int counter;
34
35 @Override
36 public void setSequenceCallback(final Sequence sequenceCallback) {
37 this.sequenceCallback = sequenceCallback;
38 }
39
40 @Override
41 public void onEvent(final RingBufferLogEvent event, final long sequence,
42 final boolean endOfBatch) throws Exception {
43 event.execute(endOfBatch);
44 event.clear();
45
46 // notify the BatchEventProcessor that the sequence has progressed.
47 // Without this callback the sequence would not be progressed
48 // until the batch has completely finished.
49 if (++counter > NOTIFY_PROGRESS_THRESHOLD) {
50 sequenceCallback.set(sequence);
51 counter = 0;
52 }
53 }
54
55 }