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Merged
erwan-serandour merged 1 commit into from
Jun 23, 2025
Merged

SONARJAVA-5612 Add performance benchmark table to S2864, S1643 and S4635 #5209

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101 changes: 101 additions & 0 deletions sonar-java-plugin/src/main/resources/org/sonar/l10n/java/rules/java/S1643.html
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Expand Up @@ -18,4 +18,105 @@ <h3>Compliant solution</h3>
}
String str = bld.toString();
</pre>
<table>
<colgroup>
<col style="width: 20%;">
<col style="width: 20%;">
<col style="width: 20%;">
<col style="width: 20%;">
<col style="width: 20%;">
</colgroup>
<thead>
<tr>
<th>Method</th>
<th>size</th>
<th>Runtime</th>
<th>Average time</th>
<th>Error margin</th>
</tr>
</thead>
<tbody>
<tr>
<td><p>plus</p></td>
<td><p>100</p></td>
<td><p>Temurin 21</p></td>
<td><p>4.19 µs/op</p></td>
<td><p>±0.34 µs/op</p></td>
</tr>
<tr>
<td><p>plus</p></td>
<td><p>1000</p></td>
<td><p>Temurin 21</p></td>
<td><p>377.08 µs/op</p></td>
<td><p>±17.36 µs/op</p></td>
</tr>
<tr>
<td><p>plus</p></td>
<td><p>10000</p></td>
<td><p>Temurin 21</p></td>
<td><p>40221.49 µs/op</p></td>
<td><p>±1342.76 µs/op</p></td>
</tr>
<tr>
<td><p>plus</p></td>
<td><p>100000</p></td>
<td><p>Temurin 21</p></td>
<td><p>5286840.53 µs/op</p></td>
<td><p>±185796.75 µs/op</p></td>
</tr>
<tr>
<td><p>stringBuilder</p></td>
<td><p>100</p></td>
<td><p>Temurin 21</p></td>
<td><p>0.97 µs/op</p></td>
<td><p>±0.03 µs/op</p></td>
</tr>
<tr>
<td><p>stringBuilder</p></td>
<td><p>1000</p></td>
<td><p>Temurin 21</p></td>
<td><p>10.25 µs/op</p></td>
<td><p>±1.64 µs/op</p></td>
</tr>
<tr>
<td><p>stringBuilder</p></td>
<td><p>10000</p></td>
<td><p>Temurin 21</p></td>
<td><p>93.27 µs/op</p></td>
<td><p>±16.05 µs/op</p></td>
</tr>
<tr>
<td><p>stringBuilder</p></td>
<td><p>100000</p></td>
<td><p>Temurin 21</p></td>
<td><p>1019.91 µs/op</p></td>
<td><p>±69.58 µs/op</p></td>
</tr>
</tbody>
</table>
<p><strong>Benchmarking code</strong></p>
<p>The results were generated by running the following snippet with <a href="https://github.com/openjdk/jmh">JMH</a>.</p>
<pre>
@Param({"100", "1000", "10000", "100000"})
int size;
private String word = "append";

@Benchmark
public String plus() {
String str = "";
for (int i = 0; i &lt; size; i++) {
str = str + word;
}
return str;
}

@Benchmark
public String stringBuilder() {
StringBuilder builder = new StringBuilder();
for (int i = 0; i &lt; size; i++) {
builder.append(word);
}
return builder.toString();
}
</pre>

103 changes: 103 additions & 0 deletions sonar-java-plugin/src/main/resources/org/sonar/l10n/java/rules/java/S2864.html
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Expand Up @@ -24,6 +24,109 @@ <h3>Compliant solution</h3>
}
}
</pre>
<h3>Benchmarks</h3>
<table>
<colgroup>
<col style="width: 20%;">
<col style="width: 20%;">
<col style="width: 20%;">
<col style="width: 20%;">
<col style="width: 20%;">
</colgroup>
<thead>
<tr>
<th>Method</th>
<th>size</th>
<th>Runtime</th>
<th>Average time</th>
<th>Error margin</th>
</tr>
</thead>
<tbody>
<tr>
<td><p>usingEntrySet</p></td>
<td><p>10</p></td>
<td><p>Temurin 21</p></td>
<td><p>27.48 ns/op</p></td>
<td><p>±6.22 ns/op</p></td>
</tr>
<tr>
<td><p>usingEntrySet</p></td>
<td><p>1000</p></td>
<td><p>Temurin 21</p></td>
<td><p>2480.26 ns/op</p></td>
<td><p>±899.05 ns/op</p></td>
</tr>
<tr>
<td><p>usingEntrySet</p></td>
<td><p>10000</p></td>
<td><p>Temurin 21</p></td>
<td><p>22745.78 ns/op</p></td>
<td><p>±10505.46 ns/op</p></td>
</tr>
<tr>
<td><p>usingKeySet</p></td>
<td><p>10</p></td>
<td><p>Temurin 21</p></td>
<td><p>49.70 ns/op</p></td>
<td><p>±3.78 ns/op</p></td>
</tr>
<tr>
<td><p>usingKeySet</p></td>
<td><p>1000</p></td>
<td><p>Temurin 21</p></td>
<td><p>5061.54 ns/op</p></td>
<td><p>±2056.60 ns/op</p></td>
</tr>
<tr>
<td><p>usingKeySet</p></td>
<td><p>10000</p></td>
<td><p>Temurin 21</p></td>
<td><p>46689.04 ns/op</p></td>
<td><p>±14509.97 ns/op</p></td>
</tr>
</tbody>
</table>
<p><strong>Benchmarking code</strong></p>
<p>The results were generated by running the following snippet with <a href="https://github.com/openjdk/jmh">JMH</a>.</p>
<pre>
@BenchmarkMode({Mode.AverageTime})
@OutputTimeUnit(TimeUnit.NANOSECONDS)
@State(Scope.Benchmark)
public class S2864 {
@Param({"10", "1000", "10000"})
int size;

Map&lt;Integer,Integer&gt; map;

@Setup(Level.Trial)
public void setup() {
Random random = new Random();
map = new HashMap&lt;&gt;();
for (int i = 0; i &lt; size; i++) {
map.put(i, random.nextInt());
}
}

@Benchmark
public int usingKeySet() {
int sumKeysValues = 0;
for (Integer key : map.keySet()) {
sumKeysValues += key + map.get(key);
}
return sumKeysValues;
}

@Benchmark
public int usingEntrySet() {
int sumKeysValues = 0;
for (Map.Entry&lt;Integer, Integer&gt; entry : map.entrySet()) {
sumKeysValues += entry.getKey() + entry.getValue();
}
return sumKeysValues;
}
}
</pre>
<h2>Resources</h2>
<h3>Documentation</h3>
<ul>
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110 changes: 110 additions & 0 deletions sonar-java-plugin/src/main/resources/org/sonar/l10n/java/rules/java/S4635.html
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Expand Up @@ -21,4 +21,114 @@ <h3>Compliant solution</h3>
<pre>
str.indexOf(char1, beginIndex) - beginIndex; // index for char1 not found is (-1-beginIndex)
</pre>
<h2>Resources</h2>
<h3>Benchmarks</h3>
<table>
<colgroup>
<col style="width: 20%;">
<col style="width: 20%;">
<col style="width: 20%;">
<col style="width: 20%;">
<col style="width: 20%;">
</colgroup>
<thead>
<tr>
<th>Method</th>
<th>stringSize</th>
<th>Runtime</th>
<th>Average time</th>
<th>Error margin</th>
</tr>
</thead>
<tbody>
<tr>
<td><p>indexOfOnly</p></td>
<td><p>10</p></td>
<td><p>Temurin 21</p></td>
<td><p>1.55 ns/op</p></td>
<td><p>±0.12 ns/op</p></td>
</tr>
<tr>
<td><p>indexOfOnly</p></td>
<td><p>100</p></td>
<td><p>Temurin 21</p></td>
<td><p>1.78 ns/op</p></td>
<td><p>±0.05 ns/op</p></td>
</tr>
<tr>
<td><p>indexOfOnly</p></td>
<td><p>1000</p></td>
<td><p>Temurin 21</p></td>
<td><p>1.82 ns/op</p></td>
<td><p>±0.18 ns/op</p></td>
</tr>
<tr>
<td><p>indexOfOnly</p></td>
<td><p>10000</p></td>
<td><p>Temurin 21</p></td>
<td><p>1.77 ns/op</p></td>
<td><p>±0.08 ns/op</p></td>
</tr>
<tr>
<td><p>substringThenIndexOf</p></td>
<td><p>10</p></td>
<td><p>Temurin 21</p></td>
<td><p>4.85 ns/op</p></td>
<td><p>±0.41 ns/op</p></td>
</tr>
<tr>
<td><p>substringThenIndexOf</p></td>
<td><p>100</p></td>
<td><p>Temurin 21</p></td>
<td><p>6.22 ns/op</p></td>
<td><p>±0.40 ns/op</p></td>
</tr>
<tr>
<td><p>substringThenIndexOf</p></td>
<td><p>1000</p></td>
<td><p>Temurin 21</p></td>
<td><p>14.22 ns/op</p></td>
<td><p>±1.66 ns/op</p></td>
</tr>
<tr>
<td><p>substringThenIndexOf</p></td>
<td><p>10000</p></td>
<td><p>Temurin 21</p></td>
<td><p>275.00 ns/op</p></td>
<td><p>±20.49 ns/op</p></td>
</tr>
</tbody>
</table>
<p><strong>Benchmarking code</strong></p>
<p>The results were generated by running the following snippet with <a href="https://github.com/openjdk/jmh">JMH</a>.</p>
<pre>
@BenchmarkMode({Mode.AverageTime})
@OutputTimeUnit(TimeUnit.NANOSECONDS)
@State(Scope.Benchmark)
public class S4635 {
@Param({"10", "100", "1000", "10000"})
int stringSize;

String input;

@Setup
public void setup() {
StringBuilder builder = new StringBuilder();
for (int i = 0; i &lt; stringSize; i++) {
builder.append('a');
}
input = builder.toString();
}

@Benchmark
public int substringThenIndexOf() {
return stringSize / 2 + input.substring(stringSize / 2).indexOf('a');
}

@Benchmark
public int indexOfOnly() {
return input.indexOf('a', stringSize / 2);
}
}
</pre>

2 changes: 1 addition & 1 deletion sonarpedia.json
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Expand Up @@ -3,7 +3,7 @@
"languages": [
"JAVA"
],
"latest-update": "2025-05-28T09:17:51.640344029Z",
"latest-update": "2025-06-23T12:44:09.599349313Z",
"options": {
"no-language-in-filenames": true,
"preserve-filenames": false
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