This may raise a few eyebrows.
Does this mean that all the things that were planned for API 3.0.0 are done?
Not at all. The plans laid out in December 2016 for API 3.0.0 were far too ambitious, and as a result the ALPHA series dragged out forever (18 months now). This is a break away from those plans, to bring development and release flow back to some sort of sanity.
Does this mean that my plugins will stop breaking all the time now?
No, it does not! Development isn't going to stop, although breaking changes will be confined only to major API releases. It's anticipated that the major API version will be bumped as nearly as often as the ALPHA version was during the last 18 months. The reason for this return to 3.0.0 is to allow us to fine-tune our release flow so that plugin developers can get advantage of newer, non-breaking API features without having to bump the API in a breaking way.
What are the criteria for the API versions now?
- Major: This will be bumped for breaking changes, changes which will break plugins. it's expected that we'll roll out new major versions regularly.
- Minor: This will be bumped when non-breaking feature additions are made, such that API 3.0.0 plugins would still load on 3.1.0. However, plugins requiring 3.1.0 will not run on 3.0.0.
- Patch: This will be bumped for bugfix updates. Plugins requiring 3.0.0 will work on 3.0.1, but not vice versa.
TL;DR: This insanity has gone on far too long.
This features a near-total rewrite of PluginLoaders and some code associated with them.
Highlights:
- PluginManager->registerInterface() does not return anything, and now accepts a PluginLoader instance instead of a string.
- PluginLoader itself is drastically simplified. getPluginFilters(), enablePlugin() and disablePlugin() are now removed. loadPlugin() responsibilities are now solely confined to doing whatever is necessary to make the plugin's classes visible by the server, and does not emit log messages or check for data directories.
- PluginBase->init() and PluginBase->isInitialized() have been removed.
- Plugin interface now declares a signature for the constructor which implementations must comply with.
- Plugin interface now declares setEnabled().
- Removed `Server->getScheduler()`. All plugins now have their own scheduler which is accessible using `Plugin->getScheduler()`. Aside from being syntactically more concise and pleasant, this also allows much more effective management of tasks when plugins are disabled.
- Removed `PluginTask` class. Before this PR it was necessary for plugin tasks to descend from `PluginTask` to ensure that the server could clean them up correctly on plugin disable. This is no longer necessary, so the `PluginTask` class has been removed. Plugins may now utilize the `Task` class as a base if they like.
- Added `Server->getAsyncPool()`. Since the global scheduler does not exist any more, it does not manage the server's `AsyncPool` any more. Additionally, `ServerScheduler` was previously bloated by a lot of `AsyncTask` related methods, which are now not necessary because direct access to `AsyncPool` is granted instead.
- `ServerScheduler`:
- `ServerScheduler` has been renamed to `TaskScheduler` since it is now a general-purpose task scheduler which is non-dependent on the user. This allows much greater flexibility and also makes it possible to unit-test.
- All `AsyncTask`/`AsyncPool` related methods have been removed - the task scheduler does not manage the async pool anymore.
- Calls to `Server->getScheduler()->scheduleAsyncTask()` should be replaced with `Server->getAsyncPool()->submitTask()`.
- Calls to `Server->getScheduler()->scheduleAsyncTaskToWorker()` should be replaced with and `Server->getAsyncPool()->submitTaskToWorker()`.
## Backwards compatibility
This poses significant backwards compatibility breaks for any plugins utilizing Tasks or AsyncTasks. These breaks are described above, along with basic upgrade steps. The upgrade process is quite straightforward.
## Follow-up
A large part of the goal with this pull request is to modularize these parts of the code so that they can be reused and also unit-tested. I would like to remove the existing test set from TesterPlugin at some stage when the AsyncPool can operate without a Server.
Because of the above, I am considering making further backwards incompatible changes directly to `AsyncTask` to remove the `Server` parameters from `onCompletion()` and `onProgressUpdate()`. These shouldn't be too difficult to upgrade from and can be prepared for in advance.
By default it starts 30 workers on Travis because there are 32 logical cores available. This is ridiculously excessive and pollutes the log with debug spam.
This change breaks pretty much all API pertaining to synchronous task scheduling.
Significant changes:
- Server->getScheduler() has been removed
- Plugin->getScheduler() has been added - every plugin now has its own scheduler
- Because schedulers are now per-plugin, it is now unnecessary for PluginTask to exist because stopping plugin tasks on plugin disable is as simple as destroying the plugin's scheduler. Therefore PluginTask has now been removed and it is expected for things to now use the base Task class instead.
For the most part, plugins will simply need to change Plugin->getServer()->getScheduler()->... to Plugin->getScheduler()->...
Another highlight is that plugin tasks now no longer have global IDs - they are unique to each scheduler.
This commit contains quite a few breaking changes with respect to how AsyncTasks are handled. This is necessary to allow separation of the ServerScheduler and the AsyncPool, because in the future the ServerScheduler may be removed and instead there will be isolated per-plugin sync-task schedulers - but we cannot have every plugin with its own worker pool for memory usage reasons if nothing else.
The following things have changed:
- ServerScheduler: scheduleAsyncTask(), scheduleAsyncTaskToWorker(), getAsyncTaskPoolSize(), increaseAsyncTaskPoolSize() and similar methods have all been removed. Additionally the static \$WORKERS field has been removed.
- Server: added API method getAsyncPool(). This grants you direct access to the server's AsyncPool. Calls to getScheduler()->scheduleAsyncTask() and scheduleAsyncTaskToWorker() should be replaced with getAsyncPool()->submitTask() and submitTaskToWorker() respectively.
Yes, I am not happy about this either. new-versioning has issues, and there hasn't been enough development and testing on it.
I didn't want to delay release to cram in a half-baked new versioning system, and it's ended up delayed anyway and new-versioning is still half-baked.
we're overdue a new release, so here it is.
These are never called accidentally, or at least it's highly unlikely to do so. It might be reasonable to throw exceptions for this, but for the meantime they are redundant - extra indentation for no good reason.
This also removes the $force parameter from BlockFactory::init().
Far too often I see people using IDEs which generate the constructors for them and then accidentally unintentionally store things in the object store. This parent constructor behaviour is unexpected. If a developer wants to store something, they should now do so explicitly by calling storeLocal().
