File D:\maven-qcr-plugin-testsunitaires\qcr4java\jenkins-master\target\site\qc\core\src\main\java\hudson\util\RingBufferLogHandler.java.html

1 /*
2 * The MIT License
3 *
4 * Copyright (c) 2004-2009, Sun Microsystems, Inc., Kohsuke Kawaguchi
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a copy
7 * of this software and associated documentation files (the "Software"), to deal
8 * in the Software without restriction, including without limitation the rights
9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10 * copies of the Software, and to permit persons to whom the Software is
11 * furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
19 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22 * THE SOFTWARE.
23 */
24 package hudson.util;
25
26 import java.util.AbstractList;
27 import java.util.List;
28 import java.util.logging.Handler;
29 import java.util.logging.LogRecord;
30
31 /**
32 * Log {@link Handler} that stores the log records into a ring buffer.
33 *
34 * @author Kohsuke Kawaguchi
35 */
36 public class RingBufferLogHandler extends Handler {
37
38 private int start = 0;
39 private final LogRecord[] records;
40 private volatile int size = 0;
41
42 public RingBufferLogHandler() {
43 this(256);
44 }
45
46 public RingBufferLogHandler(int ringSize) {
47 records = new LogRecord[ringSize];
48 }
49
50 public synchronized void publish(LogRecord record) {
51 int len = records.length;
52 records[(start+size)%len]=record;
53 if(size==len) {
54 start++;
55 } else {
56 size++;
57 }
58 }
59
60 /**
61 * Returns the list view of {@link LogRecord}s in the ring buffer.
62 *
63 * <p>
64 * New records are always placed early in the list.
65 */
66 public List<LogRecord> getView() {
67 return new AbstractList<LogRecord>() {
68 public LogRecord get(int index) {
69 // flip the order
70 synchronized (RingBufferLogHandler.this) {
71 return records[(start+(size-(index+1)))%records.length];
72 }
73 }
74
75 public int size() {
76 return size;
77 }
78 };
79 }
80
81 // noop
82 public void flush() {}
83 public void close() throws SecurityException {}
84 }
85