/*
* Janino - An embedded Java[TM] compiler
*
* Copyright (c) 2001-2007, Arno Unkrig
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials
* provided with the distribution.
* 3. The name of the author may not be used to endorse or promote
* products derived from this software without specific prior
* written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
* GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
* IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
* IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package org.codehaus.janino.util;
import java.util.*;
/**
* Implements a scheme for benchmarking, i.e. for determining and/or reporting the time elapsed
* between the beginning and the end of an activity.
* <p>
* The measurement is done by invoking {@link #begin()} and later calling {@link #end()} whichs
* returns the time elapsed since the call to {@link #begin()}.
* <p>
* Notice that calls to {@link #begin()} and {@link #end()} can be nested, and each call to
* {@link #end()} refers to the matching {@link #begin()} call. To ensure that all calls match,
* the preferred way to write a benchmark is
* <pre>
* ...
* Benchmark b = new Benchmark();
* ...
* b.begin();
* try {
* ....
* } finally {
* long ms = b.end();
* }
* </pre>
* This code layout also makes it visually easy to write correct pairs of {@link #begin()} /
* {@link #end()} pairs.
* <p>
* The pair {@link #beginReporting()} and {@link #endReporting()} do basically the same, but
* report the benchmarking information through an internal {@link Reporter} object. The default
* {@link Reporter} prints its messages by <code>System.out.println()</code>.
* <p>
* Reporting is only enabled if the Benchmark object was created through {@link #Benchmark(boolean)}
* with a <code>true</code> argument.
*/
public class Benchmark {
private final Stack beginTimes = new Stack(); // Long
public Benchmark() {
this.reportingEnabled = false;
this.reporter = null;
}
/**
* @see Benchmark
*/
public void begin() {
this.beginTimes.push(new Long(System.currentTimeMillis()));
}
/**
* @see Benchmark
*/
public long end() {
return System.currentTimeMillis() - ((Long) this.beginTimes.pop()).longValue();
}
// Reporting-related methods and fields.
/**
* Set up a {@link Benchmark} with a default {@link Reporter} that reports to
* <code>System.out</code>.
*/
public Benchmark(boolean reportingEnabled) {
this.reportingEnabled = reportingEnabled;
this.reporter = new Reporter() {
public void report(String message) { System.out.println(message); }
};
}
/**
* Set up a {@link Benchmark} with a custom {@link Reporter}.
*/
public Benchmark(
boolean reportingEnabled,
Reporter reporter
) {
this.reportingEnabled = reportingEnabled;
this.reporter = reporter;
}
private final boolean reportingEnabled;
private final Reporter reporter;
/**
* Interface used to report messages.
*/
public interface Reporter {
void report(String message);
}
/**
* Begin a benchmark (see {@link #begin()}) and report the fact.
*/
public void beginReporting() {
if (!this.reportingEnabled) return;
this.reportIndented("Beginning...");
this.begin();
}
/**
* Begin a benchmark (see {@link #begin()}) and report the fact.
*/
public void beginReporting(String message) {
if (!this.reportingEnabled) return;
this.reportIndented(message + "...");
this.begin();
}
/**
* End a benchmark (see {@link #end()}) and report the fact.
*/
public void endReporting() {
if (!this.reportingEnabled) return;
this.reportIndented("... took " + this.end() + " ms");
}
/**
* End a benchmark (see {@link #begin()}) and report the fact.
*/
public void endReporting(String message) {
if (!this.reportingEnabled) return;
this.reportIndented("... took " + this.end() + " ms: " + message);
}
/**
* Report the given message.
*/
public void report(String message) {
if (!this.reportingEnabled) return;
this.reportIndented(message);
}
/**
* Report the <code>title</code>, a colon, a space, and the pretty-printed
* {@link Object}.
* @param optionalTitle
* @param o
*/
public void report(String optionalTitle, Object o) {
if (!this.reportingEnabled) return;
String prefix = optionalTitle == null ? "" : (
optionalTitle
+ ": "
+ (optionalTitle.length() < Benchmark.PAD.length() ? Benchmark.PAD.substring(optionalTitle.length()) : "")
);
if (o == null) {
this.reportIndented(prefix + "(undefined)");
} else
if (o.getClass().isArray()) {
Object[] oa = (Object[]) o;
if (oa.length == 0) {
this.reportIndented(prefix + "(empty)");
} else
if (oa.length == 1) {
this.reportIndented(prefix + oa[0].toString());
} else {
this.reportIndented(optionalTitle == null ? "Array:" : optionalTitle + ':');
this.begin();
try {
for (int i = 0; i < oa.length; ++i) this.report(null, oa[i]);
} finally {
this.end();
}
}
} else
{
this.reportIndented(prefix + o.toString());
}
}
private static final String PAD = " ";
/**
* Report a message through {@link #reporter}, indent by N spaces where N is the current
* benchmark stack depth.
*/
private void reportIndented(String message) {
StringBuffer sb = new StringBuffer();
for (int i = this.beginTimes.size(); i > 0; --i) sb.append(" ");
sb.append(message);
this.reporter.report(sb.toString());
}
}
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