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.
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.
This change completely refactors the way components are loaded in wireplumber:
- The module_init() function must return a GObject now. This object is either
a WpPlugin or a WpSiFactory in the current modules.
- When the component loader initializes a module, it automatically registers
the WpPlugin or WpSiFactory with their respective methods. There is no need
to register the WpPlugin or WpSiFactory in the module now.
- The wp_core_load_component() API has been refactored to be asynchronows. This
allows the component loader to automatically activate WpPlugin objects, and
therefore allows the application to directly get the WpPlugin without having
to find it. This simplifies a lot of things.
- The 'ifexists' and 'nofail' component flags now work even if the respective
WpPlugin could not be activated.
- The code that loads components in main.c has also been simplified a lot,
and the option to load dangling components has also been removed.
This module provides an API to get/set volume controls on nodes,
using the same logic as pipewire-pulse, which means it will use
the device Route props when a node is associated with a device
that has this capability
