Each component can now list required and optional dependencies,
using the component feature names to match other components.
In addition, each component feature can be declared as required, optional
or disabled, making optional components easier to deal with.
The component flags (ifexists, nofail) have been removed.
Using virtual components, this system also allows easier customization
of which components should be loaded for a specific configuration,
without requiring the user to copy the list of components and edit it.
Also bump the required glib version to 2.68 for g_assert_cmpstrv()
This allows registering arbitrary objects on the core's registry and
finding them later, without having to add API for each and every object.
I think this is useful enough to have it public, even though it's
probably not going to be used that much... The rationale here is to
allow registering custom component loaders without having to make them
subclass WpPlugin or to create custom API for registering component
loaders specifically.
Also, remove the wp_plugin_register() and wp_si_factory_register()
functions, since they are not going to be used much in the future.
The idea is to let the component loader do the registration under the
scenes, as the component is getting loaded.
Each component can optionally "provide" a feature, which is basically
a string that describes the feature (ex. "support.dbus"). If the
component loads successfully, the feature is marked as provided and
can be tested for its presence with wp_core_test_feature()
Now that we have proper module load order, we can have this shared
dbus connection in a module instead of the library. The module has
to be loaded before any other modules that need it, obviously.
There is no reason to return the component object... all components
are supposed to be long-lived objects that are referenced by the
registry and there is API to find them. The caller is only interested
in the success or failure of the operation.
Do this in wp_core_load_component() and let the component loaders worry
only about creating the object.
Also run the main loop in tests while loading components, to ensure
that the async operation finishes before continuing execution. GTask
makes sure to make the operation async always, by emitting the callback
from an idle GSource.
Regarding the core parameter, the case used to be that WpComponentLoader
was a WpPlugin, so it had a reference to the core internally, but since
this is no longer a requirement, we need to pass this explicitly
converting a spa log level to a native log level is not trivial, it seems;
when we want to print a message, we should map 2 (WARN) to W, but when we
want to translate WIREPLUMBER_DEBUG=2 to a log level, we should map 2 to N
Syslog calls this level "notice" and I prefer it because we use it
to display significant messages that are not warnings, but they
are not really "standard", as GLib wants them to be. There is nothing
"standard" about log messages in general.
Also, make these notice messages be enabled at debug level 2, together
with warnings. The default log.level is 2 and it is a good idea to show
notices by default too.
Finally, show them in the log with "N" and also change criticals to be
shown with "E", meaning "error"... Then promote G_LOG_LEVEL_ERROR
messages to be shown with "F", meaning "fatal", because in fact these
messages are always fatal and always call abort(). Still, keep the term
"critical" in the functions to make sure that whoever uses them is aware
that this level is only for critical conditions and not suitable to
display any kind of error.
This topic contains traces to debug the pipewire socket protocol.
Adding this pattern allows WIREPLUMBER_DEBUG=5 to show everything
except this trace by default, which is a more reasonable amount
of trace. To enable it, it must be explicitly specified in the
WIREPLUMBER_DEBUG env variable.
* initialize all log-related features in a new wp_log_init() function
* remove the ability to change the log patterns later, as the log
topics are not referenced by the log system and there is no way to
re-initialize them with different levels (we can still implement this
in the future, if necessary, though)
* introduce the notion of a "global log level", referenced by all topics,
and make the topics know if they have a custom level or not, like in
pipewire; this is necessary to be able to set the level in the config
file, which is read later by pw_context / WpCore.
This allows lua scripts to work with log topics. A topic must be
opened at the top of the file, in global scope, and subsequently
all log commands should be executed on the returned object instead
of the Log global table
The intention is to make checks for enabled log topics faster.
Every topic has its own structure that is statically defined in the file
where the logs are printed from. The structure is initialized transparently
when it is first used and it contains all the log level flags for the levels
that this topic should print messages. It is then checked on the wp_log()
macro before printing the message.
Topics from SPA/PipeWire are also handled natively, so messages are printed
directly without checking if the topic is enabled, since the PipeWire and SPA
macros do the checking themselves.
Messages coming from GLib are checked inside the handler.
An internal WpLogFields object is used to manage the state of each log
message, populating all the fields appropriately from the place they
are coming from (wp_log, spa_log, glib log), formatting the message and
then printing it. For printing to the journald, we still use the glib
message handler, converting all the needed fields to GLogField on demand.
That message handler does not do any checks for the topic or the level, so
we can just call it to send the message.
Previously we were mapping SPA ERROR to GLib WARNING and
SPA WARN to GLib MESSAGE, which has been causing some confusion.
After some careful consideration, it makes sense to change that and
leave the GLib MESSAGE level as something to be avoided. With that
change, WIREPLUMBER_DEBUG=M will still enable the MESSAGE level,
but WIREPLUMBER_DEBUG=2 will only enable the WARN level and it will
take WIREPLUMBER_DEBUG=3 to enable both the INFO and MESSAGE levels.
This keeps the original head pointer intact, so that we can effectively
free the list later. If we use the head pointer to iterate, then at the
end we are not freeing anything because the pointer is NULL
