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1   /*
2    * Copyright (C) 2008-2011, Google Inc.
3    * and other copyright owners as documented in the project's IP log.
4    *
5    * This program and the accompanying materials are made available
6    * under the terms of the Eclipse Distribution License v1.0 which
7    * accompanies this distribution, is reproduced below, and is
8    * available at http://www.eclipse.org/org/documents/edl-v10.php
9    *
10   * All rights reserved.
11   *
12   * Redistribution and use in source and binary forms, with or
13   * without modification, are permitted provided that the following
14   * conditions are met:
15   *
16   * - Redistributions of source code must retain the above copyright
17   *   notice, this list of conditions and the following disclaimer.
18   *
19   * - Redistributions in binary form must reproduce the above
20   *   copyright notice, this list of conditions and the following
21   *   disclaimer in the documentation and/or other materials provided
22   *   with the distribution.
23   *
24   * - Neither the name of the Eclipse Foundation, Inc. nor the
25   *   names of its contributors may be used to endorse or promote
26   *   products derived from this software without specific prior
27   *   written permission.
28   *
29   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
30   * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
31   * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
32   * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
33   * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
34   * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
35   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
36   * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
37   * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
38   * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
39   * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
40   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
41   * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
42   */
43  
44  package org.eclipse.jgit.lib;
45  
46  import java.util.concurrent.Future;
47  import java.util.concurrent.TimeUnit;
48  
49  import org.eclipse.jgit.lib.internal.WorkQueue;
50  
51  /** ProgressMonitor that batches update events. */
52  public abstract class BatchingProgressMonitor implements ProgressMonitor {
53  	private long delayStartTime;
54  
55  	private TimeUnit delayStartUnit = TimeUnit.MILLISECONDS;
56  
57  	private Task task;
58  
59  	/**
60  	 * Set an optional delay before the first output.
61  	 *
62  	 * @param time
63  	 *            how long to wait before output. If 0 output begins on the
64  	 *            first {@link #update(int)} call.
65  	 * @param unit
66  	 *            time unit of {@code time}.
67  	 */
68  	public void setDelayStart(long time, TimeUnit unit) {
69  		delayStartTime = time;
70  		delayStartUnit = unit;
71  	}
72  
73  	@Override
74  	public void start(int totalTasks) {
75  		// Ignore the number of tasks.
76  	}
77  
78  	@Override
79  	public void beginTask(String title, int work) {
80  		endTask();
81  		task = new Task(title, work);
82  		if (delayStartTime != 0)
83  			task.delay(delayStartTime, delayStartUnit);
84  	}
85  
86  	@Override
87  	public void update(int completed) {
88  		if (task != null)
89  			task.update(this, completed);
90  	}
91  
92  	@Override
93  	public void endTask() {
94  		if (task != null) {
95  			task.end(this);
96  			task = null;
97  		}
98  	}
99  
100 	@Override
101 	public boolean isCancelled() {
102 		return false;
103 	}
104 
105 	/**
106 	 * Update the progress monitor if the total work isn't known,
107 	 *
108 	 * @param taskName
109 	 *            name of the task.
110 	 * @param workCurr
111 	 *            number of units already completed.
112 	 */
113 	protected abstract void onUpdate(String taskName, int workCurr);
114 
115 	/**
116 	 * Finish the progress monitor when the total wasn't known in advance.
117 	 *
118 	 * @param taskName
119 	 *            name of the task.
120 	 * @param workCurr
121 	 *            total number of units processed.
122 	 */
123 	protected abstract void onEndTask(String taskName, int workCurr);
124 
125 	/**
126 	 * Update the progress monitor when the total is known in advance.
127 	 *
128 	 * @param taskName
129 	 *            name of the task.
130 	 * @param workCurr
131 	 *            number of units already completed.
132 	 * @param workTotal
133 	 *            estimated number of units to process.
134 	 * @param percentDone
135 	 *            {@code workCurr * 100 / workTotal}.
136 	 */
137 	protected abstract void onUpdate(String taskName, int workCurr,
138 			int workTotal, int percentDone);
139 
140 	/**
141 	 * Finish the progress monitor when the total is known in advance.
142 	 *
143 	 * @param taskName
144 	 *            name of the task.
145 	 * @param workCurr
146 	 *            total number of units processed.
147 	 * @param workTotal
148 	 *            estimated number of units to process.
149 	 * @param percentDone
150 	 *            {@code workCurr * 100 / workTotal}.
151 	 */
152 	protected abstract void onEndTask(String taskName, int workCurr,
153 			int workTotal, int percentDone);
154 
155 	private static class Task implements Runnable {
156 		/** Title of the current task. */
157 		private final String taskName;
158 
159 		/** Number of work units, or {@link ProgressMonitor#UNKNOWN}. */
160 		private final int totalWork;
161 
162 		/** True when timer expires and output should occur on next update. */
163 		private volatile boolean display;
164 
165 		/** Scheduled timer, supporting cancellation if task ends early. */
166 		private Future<?> timerFuture;
167 
168 		/** True if the task has displayed anything. */
169 		private boolean output;
170 
171 		/** Number of work units already completed. */
172 		private int lastWork;
173 
174 		/** Percentage of {@link #totalWork} that is done. */
175 		private int lastPercent;
176 
177 		Task(String taskName, int totalWork) {
178 			this.taskName = taskName;
179 			this.totalWork = totalWork;
180 			this.display = true;
181 		}
182 
183 		void delay(long time, TimeUnit unit) {
184 			display = false;
185 			timerFuture = WorkQueue.getExecutor().schedule(this, time, unit);
186 		}
187 
188 		@Override
189 		public void run() {
190 			display = true;
191 		}
192 
193 		void update(BatchingProgressMonitor pm, int completed) {
194 			lastWork += completed;
195 
196 			if (totalWork == UNKNOWN) {
197 				// Only display once per second, as the alarm fires.
198 				if (display) {
199 					pm.onUpdate(taskName, lastWork);
200 					output = true;
201 					restartTimer();
202 				}
203 			} else {
204 				// Display once per second or when 1% is done.
205 				int currPercent = lastWork * 100 / totalWork;
206 				if (display) {
207 					pm.onUpdate(taskName, lastWork, totalWork, currPercent);
208 					output = true;
209 					restartTimer();
210 					lastPercent = currPercent;
211 				} else if (currPercent != lastPercent) {
212 					pm.onUpdate(taskName, lastWork, totalWork, currPercent);
213 					output = true;
214 					lastPercent = currPercent;
215 				}
216 			}
217 		}
218 
219 		private void restartTimer() {
220 			display = false;
221 			timerFuture = WorkQueue.getExecutor().schedule(this, 1,
222 					TimeUnit.SECONDS);
223 		}
224 
225 		void end(BatchingProgressMonitor pm) {
226 			if (output) {
227 				if (totalWork == UNKNOWN) {
228 					pm.onEndTask(taskName, lastWork);
229 				} else {
230 					int pDone = lastWork * 100 / totalWork;
231 					pm.onEndTask(taskName, lastWork, totalWork, pDone);
232 				}
233 			}
234 			if (timerFuture != null)
235 				timerFuture.cancel(false /* no interrupt */);
236 		}
237 	}
238 }