core: add method to add and find spa factory libraries

Make a method to add a mapping between a factory name regex
and the library it is in.
Add a method to find the library for a given factory name.

src/pipewire/core.c

@@ -25,6 +25,7 @@
 #include <unistd.h>
 #include <time.h>
 #include <stdio.h>
+#include <regex.h>
 
 #include <pipewire/log.h>
 
@@ -57,6 +58,11 @@ struct resource_data {
 	struct spa_hook object_listener;
 };
 
+struct factory_entry {
+	regex_t regex;
+	char *lib;
+};
+
 /** \endcond */
 static void * registry_bind(void *object, uint32_t id,
 		uint32_t type, uint32_t version, size_t user_data_size)
@@ -466,6 +472,7 @@ struct pw_core *pw_core_new(struct pw_loop *main_loop,
 	this->data_loop = pw_data_loop_get_loop(this->data_loop_impl);
 	this->main_loop = main_loop;
 
+	pw_array_init(&this->factory_lib, 32);
 	pw_map_init(&this->globals, 128, 32);
 
 	this->support[0] = SPA_SUPPORT_INIT(SPA_TYPE_INTERFACE_DataLoop, this->data_loop->loop);
@@ -562,6 +569,7 @@ void pw_core_destroy(struct pw_core *core)
 	struct pw_remote *remote;
 	struct pw_resource *resource;
 	struct pw_node *node;
+	struct factory_entry *entry;
 
 	pw_log_debug("core %p: destroy", core);
 	pw_core_emit_destroy(core);
@@ -596,6 +604,12 @@ void pw_core_destroy(struct pw_core *core)
 	if (impl->dbus_handle)
 		pw_unload_spa_handle(impl->dbus_handle);
 
+	pw_array_for_each(entry, &core->factory_lib) {
+		regfree(&entry->regex);
+		free(entry->lib);
+	}
+	pw_array_clear(&core->factory_lib);
+
 	pw_map_clear(&core->globals);
 
 	free(core);
@@ -1050,3 +1064,42 @@ int pw_core_recalc_graph(struct pw_core *core)
 	}
 	return 0;
 }
+
+SPA_EXPORT
+int pw_core_add_spa_lib(struct pw_core *core,
+		const char *factory_regexp, const char *lib)
+{
+	struct factory_entry *entry;
+	int err;
+
+	entry = pw_array_add(&core->factory_lib, sizeof(*entry));
+	if (entry == NULL)
+		return -ENOMEM;
+
+	if ((err = regcomp(&entry->regex, factory_regexp, REG_EXTENDED | REG_NOSUB)) != 0) {
+		char errbuf[1024];
+		regerror(err, &entry->regex, errbuf, sizeof(errbuf));
+		pw_log_error("can compile regex: %s", errbuf);
+
+		pw_array_remove(&core->factory_lib, entry);
+		return -EINVAL;
+	}
+
+	entry->lib = strdup(lib);
+	pw_log_debug("core %p: map factory regex '%s' to '%s", core,
+			factory_regexp, lib);
+
+	return 0;
+}
+
+SPA_EXPORT
+const char *pw_core_find_spa_lib(struct pw_core *core, const char *factory_name)
+{
+	struct factory_entry *entry;
+
+	pw_array_for_each(entry, &core->factory_lib) {
+		if (regexec(&entry->regex, factory_name, 0, NULL, 0) == 0)
+			return entry->lib;
+	}
+	return NULL;
+}

src/pipewire/core.h

@@ -147,6 +147,12 @@ struct pw_factory *
 pw_core_find_factory(struct pw_core *core	/**< the core */,
 		     const char *name		/**< the factory name */);
 
+/** add a spa library for the given factory_name regex */
+int pw_core_add_spa_lib(struct pw_core *core, const char *factory_regex, const char *lib);
+
+/** find the library name for a spa factory */
+const char * pw_core_find_spa_lib(struct pw_core *core, const char *factory_name);
+
 #ifdef __cplusplus
 }
 #endif

src/pipewire/private.h

@@ -235,6 +235,7 @@ struct pw_core {
 
 	struct spa_support support[16];	/**< support for spa plugins */
 	uint32_t n_support;		/**< number of support items */
+	struct pw_array factory_lib;	/**< mapping of factory_name regexp to library */
 
 	struct pw_client *current_client;	/**< client currently executing code in mainloop */