💶 🕒 🔍 C ++ / Qt: est-il temps de blâmer?. 🐷 🤽🏻 🤶🏻

Si j'avais précédemment lancé un nouveau projet de longue durée dans lequel les fonctions principales sont associées à une grande quantité de calcul lors d'une sorte d'interaction avec l'utilisateur via une interface graphique, je n'hésiterais pas à utiliser C ++ / Qt. Cela a permis d'utiliser un framework / langage partout, quelle que soit la structure du projet et ses composants, sans difficultés supplémentaires avec le zoo des technologies et des dépendances.

Maintenant, à la lumière de ce qui se passe avec Qt, vous devez changer d'approche ...

Introduction lyrique

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PHP

<?php

$horse_name = htmlspecialchars($_GET['horse_name'], ENT_QUOTES, 'UTF-8');
$horse_hash = hash('sha256', $horse_name);

$database = new PDO("mysql:dbname=vacuum;host=127.0.0.1", 'user', 'password');
$database->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);

$query = "SELECT `horse_color` FROM `horses` WHERE `horse_hash`=:horse_hash";
$statement = $database->prepare($query);
$statement->bindParam('horse_hash', $horse_hash);
$statement->execute();
$result = $statement->fetch(PDO::FETCH_ASSOC);

if ($result)
  $horse_color = $result['horse_color'];
else
  $horse_color = 'unknown';

?>
<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="utf-8">
  <title>Horse Color</title>
</head>

<body>
  <p><?= $horse_name ?> color is <?= $horse_color ?>.</p>
</body>

</html>

QtWebApp

void HorseHandler::service(HttpRequest& request, HttpResponse& response)
{
    QSqlDatabase database = QSqlDatabase::addDatabase(
        "QMYSQL", QString::number(
                      reinterpret_cast<uint64_t>(QThread::currentThreadId())));

    database.setHostName("127.0.0.1");
    database.setPort(3306);
    database.setDatabaseName("vacuum");
    database.setUserName("user");
    database.setPassword("password");
    database.open();

    QString horseName =
        QString(request.getParameter("horse_name")).toHtmlEscaped();
    QByteArray horseHash =
        QCryptographicHash::hash(horseName.toUtf8(), QCryptographicHash::Sha256)
            .toHex();

    QString queryString(
        "SELECT `horse_color` FROM `horses` WHERE `horse_hash`=:horse_hash");
    QSqlQuery query(database);
    query.prepare(queryString);
    query.bindValue(":horse_hash", horseHash);
    query.exec();

    QString horseColor;
    if (query.next())
        horseColor = query.value("horse_color").toString();
    else
        horseColor = "unknown";

    QString templateString(R"RAW(<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="utf-8">
  <title>Horse Color</title>
</head>

<body>
  <p>{horse_name} color is {horse_color}.</p>
</body>

</html>)RAW");

    Template horseColorTemplate(templateString, "horseColor");
    horseColorTemplate.setVariable("horse_name", horseName);
    horseColorTemplate.setVariable("horse_color", horseColor);

    response.setHeader("Content-Type", "text/html; charset=UTF-8");
    response.write(horseColorTemplate.toUtf8(), true);
}

, PHP .

ab -c 1 PHP

root@horsesab:~# ab -n 1000 -c 1 http://x.x.x.x:8080/
This is ApacheBench, Version 2.3 <$Revision: 1843412 $>
Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/
Licensed to The Apache Software Foundation, http://www.apache.org/

Benchmarking x.x.x.x (be patient)
Completed 100 requests
Completed 200 requests
Completed 300 requests
Completed 400 requests
Completed 500 requests
Completed 600 requests
Completed 700 requests
Completed 800 requests
Completed 900 requests
Completed 1000 requests
Finished 1000 requests


Server Software:        nginx/1.17.10
Server Hostname:        x.x.x.x
Server Port:            8080

Document Path:          /
Document Length:        155 bytes

Concurrency Level:      1
Time taken for tests:   1.125 seconds
Complete requests:      1000
Failed requests:        0
Total transferred:      302000 bytes
HTML transferred:       155000 bytes
Requests per second:    888.77 [#/sec] (mean)
Time per request:       1.125 [ms] (mean)
Time per request:       1.125 [ms] (mean, across all concurrent requests)
Transfer rate:          262.12 [Kbytes/sec] received

Connection Times (ms)
              min  mean[+/-sd] median   max
Connect:        0    0   0.1      0       1
Processing:     1    1   0.2      1       6
Waiting:        1    1   0.2      1       6
Total:          1    1   0.2      1       6

Percentage of the requests served within a certain time (ms)
  50%      1
  66%      1
  75%      1
  80%      1
  90%      1
  95%      1
  98%      2
  99%      2
 100%      6 (longest request)
root@horsesab:~#

ab -c 1 QtWebApp

root@horsesab:~# ab -n 1000 -c 1 http://x.x.x.x:8081/
This is ApacheBench, Version 2.3 <$Revision: 1843412 $>
Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/
Licensed to The Apache Software Foundation, http://www.apache.org/

Benchmarking x.x.x.x (be patient)
Completed 100 requests
Completed 200 requests
Completed 300 requests
Completed 400 requests
Completed 500 requests
Completed 600 requests
Completed 700 requests
Completed 800 requests
Completed 900 requests
Completed 1000 requests
Finished 1000 requests


Server Software:        nginx/1.17.10
Server Hostname:        x.x.x.x
Server Port:            8081

Document Path:          /
Document Length:        155 bytes

Concurrency Level:      1
Time taken for tests:   1.848 seconds
Complete requests:      1000
Failed requests:        0
Total transferred:      323000 bytes
HTML transferred:       155000 bytes
Requests per second:    541.26 [#/sec] (mean)
Time per request:       1.848 [ms] (mean)
Time per request:       1.848 [ms] (mean, across all concurrent requests)
Transfer rate:          170.73 [Kbytes/sec] received

Connection Times (ms)
              min  mean[+/-sd] median   max
Connect:        0    0   0.1      0       4
Processing:     1    2   0.3      2       7
Waiting:        1    2   0.3      1       7
Total:          1    2   0.4      2       7
ERROR: The median and mean for the waiting time are more than twice the standard
       deviation apart. These results are NOT reliable.

Percentage of the requests served within a certain time (ms)
  50%      2
  66%      2
  75%      2
  80%      2
  90%      2
  95%      2
  98%      2
  99%      2
 100%      7 (longest request)
root@horsesab:~#

ab -c 20 PHP

root@horsesab:~# ab -n 1000 -c 20 http://x.x.x.x:8080/
This is ApacheBench, Version 2.3 <$Revision: 1843412 $>
Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/
Licensed to The Apache Software Foundation, http://www.apache.org/

Benchmarking x.x.x.x (be patient)
Completed 100 requests
Completed 200 requests
Completed 300 requests
Completed 400 requests
Completed 500 requests
Completed 600 requests
Completed 700 requests
Completed 800 requests
Completed 900 requests
Completed 1000 requests
Finished 1000 requests


Server Software:        nginx/1.17.10
Server Hostname:        x.x.x.x
Server Port:            8080

Document Path:          /
Document Length:        155 bytes

Concurrency Level:      20
Time taken for tests:   0.664 seconds
Complete requests:      1000
Failed requests:        0
Total transferred:      302000 bytes
HTML transferred:       155000 bytes
Requests per second:    1505.59 [#/sec] (mean)
Time per request:       13.284 [ms] (mean)
Time per request:       0.664 [ms] (mean, across all concurrent requests)
Transfer rate:          444.03 [Kbytes/sec] received

Connection Times (ms)
              min  mean[+/-sd] median   max
Connect:        0    0   0.2      0       6
Processing:     2   13   1.2     13      18
Waiting:        1   13   1.3     13      18
Total:          3   13   1.2     13      18

Percentage of the requests served within a certain time (ms)
  50%     13
  66%     13
  75%     14
  80%     14
  90%     14
  95%     15
  98%     15
  99%     16
 100%     18 (longest request)
root@horsesab:~#

ab -c 20 QtWebApp

root@horsesab:~# ab -n 1000 -c 20 http://x.x.x.x:8081/
This is ApacheBench, Version 2.3 <$Revision: 1843412 $>
Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/
Licensed to The Apache Software Foundation, http://www.apache.org/

Benchmarking x.x.x.x (be patient)
Completed 100 requests
Completed 200 requests
Completed 300 requests
Completed 400 requests
Completed 500 requests
Completed 600 requests
Completed 700 requests
Completed 800 requests
Completed 900 requests
Completed 1000 requests
Finished 1000 requests


Server Software:        nginx/1.17.10
Server Hostname:        x.x.x.x
Server Port:            8081

Document Path:          /
Document Length:        155 bytes

Concurrency Level:      20
Time taken for tests:   1.716 seconds
Complete requests:      1000
Failed requests:        0
Total transferred:      323000 bytes
HTML transferred:       155000 bytes
Requests per second:    582.77 [#/sec] (mean)
Time per request:       34.319 [ms] (mean)
Time per request:       1.716 [ms] (mean, across all concurrent requests)
Transfer rate:          183.82 [Kbytes/sec] received

Connection Times (ms)
              min  mean[+/-sd] median   max
Connect:        0    0   0.2      0       2
Processing:     4   34  13.3     34     188
Waiting:        2   34  13.3     34     188
Total:          4   34  13.3     34     188

Percentage of the requests served within a certain time (ms)
  50%     34
  66%     39
  75%     41
  80%     44
  90%     49
  95%     54
  98%     60
  99%     69
 100%    188 (longest request)
root@horsesab:~#

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Le message principal est que dans une énorme couche d'applications, il n'y a pas de raison particulière de continuer à utiliser Qt, mais quelque part maintenant il y a des contre-indications. Et beaucoup de ce qui est nécessaire pour le remplacement, et en quantités beaucoup plus importantes, se trouve déjà dans les technologies Web, de la mise en page de l'interface à la sortie de graphiques et de modèles tridimensionnels.
Et ces technologies ont désormais un visage humain de tous les côtés: pour le propriétaire de l'entreprise, pour l'utilisateur, pour le programmeur et lors de la communication avec du code natif rapide. Nous serons amis avec eux. Mais allons-nous manquer Qt - je ne sais pas ...

C ++ / Qt: est-il temps de blâmer?.

Introduction lyrique

, , Qt?..

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