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Modify S3169: Add benchmarks (#4595)

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* Modify S3169: Add benchmarks

* Update rules/S3169/csharp/rule.adoc

Co-authored-by: Sebastien Marichal <sebastien.marichal@sonarsource.com>

* Update benchmark

* LAYC

* diff-id

---------

Co-authored-by: Sebastien Marichal <sebastien.marichal@sonarsource.com>
This commit is contained in:
Martin Strecker 2025-01-08 12:15:50 +01:00 committed by GitHub
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89
rules/S3169/csharp/rule.adoc
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@ -1,14 +1,16 @@
== Why is this an issue?
There's no point in chaining multiple ``++OrderBy++`` calls in a LINQ; only the last one will be reflected in the result because each subsequent call completely reorders the list. Thus, calling ``++OrderBy++`` multiple times is a performance issue as well, because all of the sorting will be executed, but only the result of the last sort will be kept.
There's no point in chaining multiple `OrderBy` calls in a LINQ; only the last one will be reflected in the result because each subsequent call completely reorders the list. Thus, calling `OrderBy` multiple times is a performance issue as well, because all of the sorting will be executed, but only the result of the last sort will be kept.
== How to fix it
Instead, use ``++ThenBy++`` for each call after the first.
Instead, use `ThenBy` for each call after the first.
=== Code examples
=== Noncompliant code example
==== Noncompliant code example
[source,csharp]
[source,csharp,diff-id=1,diff-type=noncompliant]
----
var x = personList
.OrderBy(person => person.Age)
@ -17,9 +19,9 @@ var x = personList
----
=== Compliant solution
==== Compliant solution
[source,csharp]
[source,csharp,diff-id=1,diff-type=compliant]
----
var x = personList
.OrderBy(person => person.Age)
@ -27,6 +29,79 @@ var x = personList
.ToList();
----
== Resources
=== Benchmarks
[options="header"]
|===
| Method | Runtime | Mean | StdDev | Allocated
| OrderByAge | .NET 9.0 | 12.84 ms | 0.804 ms | 1.53 MB
| OrderByAgeOrderBySize | .NET 9.0 | 24.08 ms | 0.267 ms | 3.05 MB
| OrderByAgeThenBySize | .NET 9.0 | 18.58 ms | 0.747 ms | 1.91 MB
| | | | |
| OrderByAge | .NET Framework 4.8.1 | 22.99 ms | 0.228 ms | 1.53 MB
| OrderByAgeOrderBySize | .NET Framework 4.8.1 | 44.90 ms | 0.581 ms | 4.3 MB
| OrderByAgeThenBySize | .NET Framework 4.8.1 | 31.72 ms | 0.402 ms | 1.91 MB
|===
==== Glossary
* https://en.wikipedia.org/wiki/Arithmetic_mean[Mean]
* https://en.wikipedia.org/wiki/Standard_deviation[Standard Deviation]
The results were generated by running the following snippet with https://github.com/dotnet/BenchmarkDotNet[BenchmarkDotNet]:
[source,csharp]
----
public class Person
{
public string Name { get; set; }
public int Age { get; set; }
public int Size { get; set; }
}
private Random random = new Random(1);
private Consumer consumer = new Consumer();
private Person[] array;
[Params(100_000)]
public int N { get; set; }
[GlobalSetup]
public void GlobalSetup()
{
array = Enumerable.Range(0, N).Select(x => new Person
{
Name = Path.GetRandomFileName(),
Age = random.Next(0, 100),
Size = random.Next(0, 200)
}).ToArray();
}
[Benchmark(Baseline = true)]
public void OrderByAge() =>
array.OrderBy(x => x.Age).Consume(consumer);
[Benchmark]
public void OrderByAgeOrderBySize() =>
array.OrderBy(x => x.Age).OrderBy(x => x.Size).Consume(consumer);
[Benchmark]
public void OrderByAgeThenBySize() =>
array.OrderBy(x => x.Age).ThenBy(x => x.Size).Consume(consumer);
----
Hardware configuration:
[source]
----
BenchmarkDotNet v0.14.0, Windows 10 (10.0.19045.5247/22H2/2022Update)
Intel Core Ultra 7 165H, 1 CPU, 22 logical and 16 physical cores
[Host] : .NET Framework 4.8.1 (4.8.9282.0), X64 RyuJIT VectorSize=256
.NET 9.0 : .NET 9.0.0 (9.0.24.52809), X64 RyuJIT AVX2
.NET Framework 4.8.1 : .NET Framework 4.8.1 (4.8.9282.0), X64 RyuJIT VectorSize=256
----
ifdef::env-github,rspecator-view[]
@ -56,7 +131,7 @@ I shuffled the text some, [~tamas.vajk]
\[~ann.campbell.2] Shouldn't this issue have some performance related label as well?
I simplified the message as the ordering might not happen by some property, but by some complex logic, and in this case we can't display the whole expression and ``++Comparer++`` in the message.
I simplified the message as the ordering might not happen by some property, but by some complex logic, and in this case we can't display the whole expression and `Comparer` in the message.
=== on 1 Jul 2015, 11:26:48 Ann Campbell wrote:
added [~tamas.vajk]

3
rules/S6961/csharp/metadata.json
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@ -7,8 +7,7 @@
"constantCost": "5min"
},
"tags": [
"asp.net",
"performance"
"asp.net"
],
"defaultSeverity": "Major",
"ruleSpecification": "RSPEC-6961",