Mercurial > hg > blitz_condensed
comparison src/com/go/trove/log/IntervalLogStream.java @ 0:3dc0c5604566
Initial checkin of blitz 2.0 fcs - no installer yet.
author | Dan Creswell <dan.creswell@gmail.com> |
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date | Sat, 21 Mar 2009 11:00:06 +0000 |
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-1:000000000000 | 0:3dc0c5604566 |
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1 /* ==================================================================== | |
2 * Trove - Copyright (c) 1997-2000 Walt Disney Internet Group | |
3 * ==================================================================== | |
4 * The Tea Software License, Version 1.1 | |
5 * | |
6 * Copyright (c) 2000 Walt Disney Internet Group. All rights reserved. | |
7 * | |
8 * Redistribution and use in source and binary forms, with or without | |
9 * modification, are permitted provided that the following conditions | |
10 * are met: | |
11 * | |
12 * 1. Redistributions of source code must retain the above copyright | |
13 * notice, this list of conditions and the following disclaimer. | |
14 * | |
15 * 2. Redistributions in binary form must reproduce the above copyright | |
16 * notice, this list of conditions and the following disclaimer in | |
17 * the documentation and/or other materials provided with the | |
18 * distribution. | |
19 * | |
20 * 3. The end-user documentation included with the redistribution, | |
21 * if any, must include the following acknowledgment: | |
22 * "This product includes software developed by the | |
23 * Walt Disney Internet Group (http://opensource.go.com/)." | |
24 * Alternately, this acknowledgment may appear in the software itself, | |
25 * if and wherever such third-party acknowledgments normally appear. | |
26 * | |
27 * 4. The names "Tea", "TeaServlet", "Kettle", "Trove" and "BeanDoc" must | |
28 * not be used to endorse or promote products derived from this | |
29 * software without prior written permission. For written | |
30 * permission, please contact opensource@dig.com. | |
31 * | |
32 * 5. Products derived from this software may not be called "Tea", | |
33 * "TeaServlet", "Kettle" or "Trove", nor may "Tea", "TeaServlet", | |
34 * "Kettle", "Trove" or "BeanDoc" appear in their name, without prior | |
35 * written permission of the Walt Disney Internet Group. | |
36 * | |
37 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED | |
38 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES | |
39 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE | |
40 * DISCLAIMED. IN NO EVENT SHALL THE WALT DISNEY INTERNET GROUP OR ITS | |
41 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, | |
42 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, | |
43 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR | |
44 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY | |
45 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | |
46 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE | |
47 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
48 * ==================================================================== | |
49 * | |
50 * For more information about Tea, please see http://opensource.go.com/. | |
51 */ | |
52 | |
53 package com.go.trove.log; | |
54 | |
55 import java.lang.ref.WeakReference; | |
56 import java.io.*; | |
57 import java.util.*; | |
58 | |
59 /****************************************************************************** | |
60 * IntervalLogStream writes to an underlying OutputStream that is opened once | |
61 * per a specific time interval. This class forms the basis of a dated file | |
62 * logging mechanism. | |
63 * | |
64 * @author Brian S O'Neill | |
65 * @version | |
66 * <!--$$Revision: 1.1 $-->, <!--$$JustDate:--> 9/07/00 <!-- $--> | |
67 * @see DailyFileLogStream | |
68 */ | |
69 public abstract class IntervalLogStream extends OutputStream { | |
70 private static int cCounter; | |
71 | |
72 private static synchronized String nextName() { | |
73 return "IntervalLogStream Auto Rollover " + cCounter++; | |
74 } | |
75 | |
76 private Factory mFactory; | |
77 private OutputStream mOut; | |
78 private boolean mIsClosed; | |
79 | |
80 private Calendar mIntervalStart; | |
81 private Calendar mNextIntervalStart; | |
82 | |
83 private Thread mRolloverThread; | |
84 | |
85 public IntervalLogStream(Factory factory) { | |
86 mFactory = factory; | |
87 } | |
88 | |
89 /** | |
90 * Starts up a thread that automatically rolls the underlying OutputStream | |
91 * at the beginning of the interval, even if no output is written. | |
92 */ | |
93 public synchronized void startAutoRollover() { | |
94 // TODO: If java.util.Timer class is available, use it instead of | |
95 // creating a thread each time. | |
96 if (mRolloverThread == null) { | |
97 mRolloverThread = new Thread(new AutoRollover(this), nextName()); | |
98 mRolloverThread.setDaemon(true); | |
99 mRolloverThread.start(); | |
100 } | |
101 } | |
102 | |
103 /** | |
104 * If the auto-rollover thread was started, calling this method will | |
105 * stop it. | |
106 */ | |
107 public synchronized void stopAutoRollover() { | |
108 if (mRolloverThread != null) { | |
109 mRolloverThread.interrupt(); | |
110 mRolloverThread = null; | |
111 } | |
112 } | |
113 | |
114 /** | |
115 * Moves calendar to beginning of log interval. | |
116 */ | |
117 protected abstract void moveToIntervalStart(Calendar cal); | |
118 | |
119 /** | |
120 * Moves calendar to beginning of next log interval. | |
121 */ | |
122 protected abstract void moveToNextIntervalStart(Calendar cal); | |
123 | |
124 public synchronized void write(int b) throws IOException { | |
125 getOutputStream().write(b); | |
126 } | |
127 | |
128 public synchronized void write(byte[] array) throws IOException { | |
129 getOutputStream().write(array, 0, array.length); | |
130 } | |
131 | |
132 public synchronized void write(byte[] array, int off, int len) | |
133 throws IOException { | |
134 | |
135 getOutputStream().write(array, off, len); | |
136 } | |
137 | |
138 public synchronized void flush() throws IOException { | |
139 getOutputStream().flush(); | |
140 } | |
141 | |
142 /** | |
143 * Closes any underlying OutputStreams and stops the auto-rollover thread | |
144 * if it is running. | |
145 */ | |
146 public synchronized void close() throws IOException { | |
147 mIsClosed = true; | |
148 stopAutoRollover(); | |
149 | |
150 if (mOut != null) { | |
151 mOut.close(); | |
152 } | |
153 } | |
154 | |
155 protected synchronized void finalize() throws IOException { | |
156 close(); | |
157 } | |
158 | |
159 private synchronized OutputStream getOutputStream() throws IOException { | |
160 if (mIsClosed) { | |
161 throw new IOException("LogStream is closed"); | |
162 } | |
163 | |
164 Calendar cal = Calendar.getInstance(); | |
165 | |
166 if (mOut == null || | |
167 cal.before(mIntervalStart) || !cal.before(mNextIntervalStart)) { | |
168 | |
169 if (mOut != null) { | |
170 mOut.close(); | |
171 } | |
172 | |
173 mOut = new BufferedOutputStream | |
174 (mFactory.openOutputStream(cal.getTime())); | |
175 | |
176 setIntervalEndpoints(cal); | |
177 } | |
178 | |
179 return mOut; | |
180 } | |
181 | |
182 private void setIntervalEndpoints(Calendar cal) { | |
183 mIntervalStart = (Calendar)cal.clone(); | |
184 moveToIntervalStart(mIntervalStart); | |
185 | |
186 mNextIntervalStart = cal; | |
187 moveToNextIntervalStart(mNextIntervalStart); | |
188 } | |
189 | |
190 public static interface Factory { | |
191 public OutputStream openOutputStream(Date date) throws IOException; | |
192 } | |
193 | |
194 /** | |
195 * Thread that just wakes up at the proper time so that log stream | |
196 * rolls over even when there is no output. | |
197 */ | |
198 private static class AutoRollover implements Runnable { | |
199 // Refer to the log stream via a weak reference so that this thread | |
200 // doesn't prevent it from being garbage collected. | |
201 private WeakReference mLogStream; | |
202 | |
203 public AutoRollover(IntervalLogStream stream) { | |
204 mLogStream = new WeakReference(stream); | |
205 } | |
206 | |
207 public void run() { | |
208 try { | |
209 while (!Thread.interrupted()) { | |
210 IntervalLogStream stream = | |
211 (IntervalLogStream)mLogStream.get(); | |
212 | |
213 if (stream == null || stream.mIsClosed) { | |
214 break; | |
215 } | |
216 | |
217 try { | |
218 // Just requesting the stream forces a rollover. | |
219 stream.getOutputStream(); | |
220 } | |
221 catch (IOException e) { | |
222 } | |
223 | |
224 Calendar cal = Calendar.getInstance(); | |
225 stream.moveToNextIntervalStart(cal); | |
226 | |
227 // Clear reference to stream so that it isn't strongly | |
228 // reachable from this thread. | |
229 stream = null; | |
230 | |
231 long calTime = cal.getTime().getTime(); | |
232 long timeLeft = calTime - System.currentTimeMillis(); | |
233 | |
234 while (timeLeft > 0) { | |
235 // Sleep until next start interval. ZZZ... | |
236 Thread.sleep(timeLeft); | |
237 timeLeft = calTime - System.currentTimeMillis(); | |
238 } | |
239 } | |
240 } | |
241 catch (InterruptedException e) { | |
242 // Exit thread. | |
243 } | |
244 } | |
245 } | |
246 } |