Changes:
- Configuration files are no longer located by libpipewire,
which allows us to control the paths that are being looked up.
This is a requirement for installations where pipewire and
wireplumber are built using different prefixes, in which case
the configuration files of wireplumber end up being installed in
a place that libpipewire doesn't look into...
- The location of conf files is now again $prefix/share/wireplumber,
/etc/wireplumber and $XDG_CONFIG_HOME/wireplumber, instead of using
the pipewire directories. Also, since the previous commits, we now
also support $XDG_CONFIG_DIRS/wireplumber (typically /etc/xdg/wireplumber)
and $XDG_DATA_DIRS/wireplumber for system-wide configuration.
- Since libpipewire doesn't expose the parser, we now also do the
parsing of sections ourselves. This has the advantage that we can
optimize it a bit for our use case.
- The WpConf API has changed to not be a singleton and it is a
property of WpCore instead. The configuration is now expected
to be opened before the core is created, which allows the caller
to identify configuration errors in advance. By not being a singleton,
we can also reuse the WpConf API to open other SPA-JSON files.
- WpConf also now has a lazy loading mechanism. The configuration
files are mmap'ed and the various sections are located in advance,
but not parsed until they are actually requested. Also, the sections
are not copied in memory, unlike what happens in libpipewire. They
are only copied when merging is needed.
- WpCore now disables loading of a configuration file in pw_context,
if a WpConf is provided. This is to have complete control here.
The 'context.spa-libs' and 'context.modules' sections are still
loaded, but we load them in WpConf and pass them down to pw_context
for parsing. If a WpConf is not provided, pw_context is left to load
the default configuration file (client.conf normally).
The previous naming convention was confusing because it did not make
it explicit that the string is not being copied. We had this wrong already
in the Lua bindings and thanks to some miracle it hasn't backfired so far
(it was using the "wrap" behaviour with a string that doesn't stay alive).
In some places we actually need the "copy" behaviour and in some other
places we need the "wrap" behaviour, so let's have both variants available.
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.
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.
