[Issue] compiled interceptors module

[m2-assistant]

This issue is automatically created based on existing pull request: #22826: compiled interceptors module

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Description (*)

At Creatuity we have developed a module that generates Interceptors code using app config instead of a boilerplate that reads config at runtime.

https://github.com/creatuity/magento2-interceptors

We believe it changes performance and debugging magento significantly and it is worth to consider making it a part of the core witch this pull request does.

Any comments welcome.

Manual testing scenarios (*)

to use in developer mode in app/etc/di.xml replace:

<item name="interceptor" xsi:type="string">\Magento\Framework\Interception\Code\Generator\Interceptor</item>

with:

<item name="interceptor" xsi:type="string">\Magento\Framework\CompiledInterception\Generator\CompiledInterceptor</item>

clear generated files and cache:

rm -rf generated/* && rm -rf var/cache/* && bin/magento cache:clean

generated interceptors instead of boilerplate that reads plugins config at runtime like this:

public function methodX($arg) {
    $pluginInfo = $this->pluginList->getNext($this->subjectType, 'methodX');
    if (!$pluginInfo) {
        return parent::methodX($arg);
    } else {
        return $this->___callPlugins('methodX', func_get_args(), $pluginInfo);
    }
}

should have a code built using config like:

public function methodX($arg) {
    switch(getCurrentScope()){
        case 'frontend':
            $this->_get_example_plugin()->beforeMethodX($this, $arg);
            $this->_get_another_plugin()->beforeMethodX($this, $arg);
            $result = $this->_get_around_plugin()->aroundMethodX($this, function($arg){
                return parent::methodX($arg);
            });
            return $this->_get_after_plugin()->afterMethodX($this, $result);
        case 'adminhtml':
            // ...
        default:
            return parent::methodX($arg);
    }
}

Contribution checklist (*)

• [*] Pull request has a meaningful description of its purpose
• [*] All commits are accompanied by meaningful commit messages
• [*] All new or changed code is covered with unit/integration tests (if applicable)
• All automated tests passed successfully (all builds on Travis CI are green)