This is better for performance because these then don't need to be reevaluated every time they are called.
When encountering an unqualified function or constant reference, PHP will first try to locate a symbol in the current namespace by that name, and then fall back to the global namespace.
This short-circuits the check, which has substantial performance effects in some cases - in particular, ord(), chr() and strlen() show ~1500x faster calls when they are fully qualified.
However, this doesn't mean that PM is getting a massive amount faster. In real world terms, this translates to about 10-15% performance improvement.
But before anyone gets excited, you should know that the CodeOptimizer in the PreProcessor repo has been applying fully-qualified symbol optimizations to Jenkins builds for years, which is one of the reasons why Jenkins builds have better performance than home-built or source installations.
We're choosing to do this for the sake of future SafePHP integration and also to be able to get rid of the buggy CodeOptimizer, so that phar and source are more consistent.
This cleans up some cargo-cult code poorly copied from Bukkit, which has negative performance effects and also makes internal event handling more complex than necessary.
## API changes
- Removed `EventExecutor` and `MethodEventExecutor`.
- A listener is no longer required for an event handler to be registered. Closure objects can now be used directly provided that they meet the conditions for registration.
- `PluginManager->registerEvent()` signature has changed: the `Listener` and `EventExecutor` parameters have been removed and a `\Closure $handler` has been added in its place.
- `RegisteredListener` now requires a `Closure` parameter instead of `Listener, EventExecutor`.
## Behavioural changes
These changes reduce the execution complexity involved with calling an event handler. Since event calls can happen in hot paths, this may have visible positive effects on performance.
Initial testing reveals a performance improvement of ~15% per event handler call compared to the old method.
This removes the need for custom Plugin implementations to implement onCommand().
In the future it's planned to remove plugin.yml commands completely and have them registered similarly to how events are handled.
This is intended to break API in order to jerk the rug out from underneath plugin developers who have been misusing this without noticing the side effects.
Use of this by plugins will produce a lot of undefined behaviour, such as event handlers not being unregistered, scheduled tasks not being removed, and registered permissions causing memory leaks.
This has the triple bonus effect of a) making a lot of code easier to read, b) reducing Server::getInstance() usages, and c) removing a whole bunch of Server dependencies.
The network and block namespaces are untouched by this commit due to potential for merge conflicts. These should be dealt with separately on master.
This is dependent on the changes made in b1e0f82cbf2f585ed729245a6883d713effd1793. This now makes it possible to call events without fetching a Server reference, allowing to eliminate a vast array of Server dependencies.
The basic principle here is "if you're not expecting it, don't catch it".
Event handlers are **never** supposed to throw exceptions. If they do throw exceptions, it's usually going to one of two things;
1. Broken code producing an error
2. Code triggering (and not catching) a runtime error
Both 1) and 2) boil down to defective code on the part of the event handler, and thus should not be caught by the caller, but instead allowed to crash the server and produce a crashdump.
It's also undesirable to catch unexpected errors here for a few other reasons
- It leaves the owner of the event handler in an unknown, potentially unstable state
- It allows broken code to cause event handlers to spam the logger in events that happen frequently (for example movement handlers)
- It allows the process to continue down a train of further undefined behaviour, which may lead to more errors or ultimately a crash, so it makes no sense to hold off the inevitable.
This has a few advantages that are not merely inverted disadvantages:
- Crash dumps will now be created and automatically submitted for defective event handlers, allowing quicker issue location, debugging and fixing in plugins without manual user interaction
- Event calling now isn't dependent on Server to work.
This came to light after observing cfb6856634f91930f6e013e7b98edb638dea15d9 in a fresh light. I noticed that this fix should not have been necessary because clearPermissions() should have dealt with it. Unfortunately, permissions can be set without being set in PermissibleBase->permissions, so this misses things.
