Dispatching and listening to events is non-trivial. The apparent
triviality is in implementing a list of listeners and calling them. The
non-triviality is in the nature of what happens to a system when it has
multiple different interfaces to register listeners and publish events.
This commit adds TopicsFeature, which allows any class extending
AdvancedBase to declare topics. A topic is a simple pub/sub channel.
TopicsFeature will manage the state of listeners so the class doesn't
need to. A GC-friendly mechanism for detaching listeners is also provided.
The ServiceManager will replace manual management of services within
initgui, and will also be used within puter.js. Eventually Puter's
backend might use this instead of the existing Container class, although
this will be a large change that needs to be done incrementally.
The difference between ServiceManager and Container is the logic behind
when initialization occurs. Rather than have all services initialized at
once when Container's init() method is called, services are initialized
as soon as their dependencies have been initialized.
Adds CachedFilesystem layer to client filesystem chain. Currently only
stat is implemented. The stat implementation will hold onto an entry for
3 seconds as per hardcoded configuration. Eventually, once invalidation
via websockets is working, this TTL should be extended.
Support for trait method overrides will make it possible to use putility
traits with the decorator pattern while using a proxy class to avoid
redundant re-implementation of proxy methods.
Use of the pattern described above will occur in the implementation of
client-side filesystem caching.
- de-coupled xhr callback passing from the interface of the underlying
filesystem implementation.
- This makes the interface to delegate calls more suitable for use with
the decorator pattern.
- The decorator pattern will be used to manage the complexity of the
caching layer by separating the concerns of different caching methods.
This hides database entries with empty types from the list of suggested
apps for files that have no extension. These entries should also be
removed from the database and the bug causing them should be fixed in
dev center.
