loadbefore operates by injecting self into the target plugin's soft-dependencies. The problem is that these soft-dependency lists are overwritten if the target plugin's soft-dependencies are resolved after the loadbefore of the origin plugin.
On most filesystems, plugins are loaded in lexical order because that's how the filesystem gives the files to us. This is a problem because it can hide bugs with dependency resolution on specific platforms with this behaviour, while inexplicably breaking on other platforms where the load order is different or undefined.
This change prevents plugins depending on any file yield order by randomizing the order in which plugin files are checked for loadability.
Warning for plugin developers: This is a silent BC break. It won't raise any errors.
This alters the default behaviour of event handlers to **not** receive cancelled events by default.
It is now required to opt into receiving cancelled events by using the @handleCancelled directive (or the handleCancelled parameter where it's appropriate).
The ambiguous @ignoreCancelled directive is now ignored.
Ramifications:
- The majority of handlers with `if($event->isCancelled()) return;` no longer need such checks.
- Handlers with `@ignoreCancelled true` or `@ignoreCancelled` annotations can have them removed.
- Handlers which want to receive cancelled events need to use `@handleCancelled`.
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.
