context: add object store

Add method to set and get typed objects from the context. This can
be used to pass around context objects between modules without having
to register them.

src/examples/media-session/media-session.c

@@ -1639,6 +1639,8 @@ int main(int argc, char *argv[])
 	pw_context_add_spa_lib(impl.this.context, "api.alsa.*", "alsa/libspa-alsa");
 	pw_context_add_spa_lib(impl.this.context, "api.v4l2.*", "v4l2/libspa-v4l2");
 
+	pw_context_set_object(impl.this.context, SM_TYPE_MEDIA_SESSION, &impl);
+
 	pw_map_init(&impl.globals, 64, 64);
 	spa_list_init(&impl.global_list);
 	pw_map_init(&impl.endpoint_links, 64, 64);

src/examples/media-session/media-session.h

@@ -32,6 +32,8 @@
 extern "C" {
 #endif
 
+#define SM_TYPE_MEDIA_SESSION	PW_TYPE_INFO_OBJECT_BASE "SessionManager"
+
 struct sm_media_session;
 
 struct sm_object_events {

src/pipewire/context.c

@@ -203,6 +203,7 @@ struct pw_context *pw_context_new(struct pw_loop *main_loop,
 	this->n_support = n_support;
 
 	pw_array_init(&this->factory_lib, 32);
+	pw_array_init(&this->objects, 32);
 	pw_map_init(&this->globals, 128, 32);
 
 	spa_list_init(&this->core_impl_list);
@@ -317,6 +318,8 @@ void pw_context_destroy(struct pw_context *context)
 	}
 	pw_array_clear(&context->factory_lib);
 
+	pw_array_clear(&context->objects);
+
 	pw_map_clear(&context->globals);
 
 	free(context);
@@ -889,3 +892,51 @@ const struct pw_export_type *pw_context_find_export_type(struct pw_context *cont
 	}
 	return NULL;
 }
+
+struct object_entry {
+	const char *type;
+	void *value;
+};
+
+static struct object_entry *find_object(struct pw_context *context, const char *type)
+{
+	struct object_entry *entry;
+	pw_array_for_each(entry, &context->objects) {
+		if (strcmp(entry->type, type) == 0)
+			return entry;
+	}
+	return NULL;
+}
+
+SPA_EXPORT
+int pw_context_set_object(struct pw_context *context, const char *type, void *value)
+{
+	struct object_entry *entry;
+
+	entry = find_object(context, type);
+
+	if (value == NULL) {
+		if (entry)
+			pw_array_remove(&context->objects, entry);
+	} else {
+		if (entry == NULL) {
+			entry = pw_array_add(&context->objects, sizeof(*entry));
+			if (entry == NULL)
+				return -errno;
+			entry->type = type;
+		}
+		entry->value = value;
+	}
+	return 0;
+}
+
+SPA_EXPORT
+void *pw_context_get_object(struct pw_context *context, const char *type)
+{
+	struct object_entry *entry;
+
+	if ((entry = find_object(context, type)) != NULL)
+		return entry->value;
+
+	return NULL;
+}

src/pipewire/context.h

@@ -160,6 +160,11 @@ int pw_context_register_export_type(struct pw_context *context, struct pw_export
 /** find information about registered export type */
 const struct pw_export_type *pw_context_find_export_type(struct pw_context *context, uint32_t type);
 
+/** add an object to the context */
+int pw_context_set_object(struct pw_context *context, const char *type, void *value);
+/** get an object from the context */
+void *pw_context_get_object(struct pw_context *context, const char *type);
+
 #ifdef __cplusplus
 }
 #endif

src/pipewire/private.h

@@ -258,6 +258,8 @@ struct pw_context {
 	uint32_t n_support;		/**< number of support items */
 	struct pw_array factory_lib;	/**< mapping of factory_name regexp to library */
 
+	struct pw_array objects;	/**< objects */
+
 	struct pw_impl_client *current_client;	/**< client currently executing code in mainloop */
 
 	long sc_pagesize;