media-session: Add module to load/save default nodes

Nodes are stored with their (unique) name and restored with their
ID on the metadata.

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

@@ -0,0 +1,286 @@
+/* PipeWire
+ *
+ * Copyright © 2020 Wim Taymans
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+#include <string.h>
+#include <stdio.h>
+#include <errno.h>
+#include <math.h>
+#include <time.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+#include "config.h"
+
+#include <spa/utils/hook.h>
+#include <spa/utils/result.h>
+#include <spa/debug/pod.h>
+
+#include "pipewire/pipewire.h"
+#include "extensions/metadata.h"
+
+#include "media-session.h"
+
+#define NAME		"default-nodes"
+#define SESSION_KEY	"default-nodes"
+
+#define SAVE_INTERVAL	5
+
+struct impl {
+	struct timespec now;
+
+	struct sm_media_session *session;
+	struct spa_hook listener;
+
+	struct pw_context *context;
+	struct spa_source *idle_timeout;
+
+	struct spa_hook meta_listener;
+
+	uint32_t default_audio_source;
+	uint32_t default_audio_sink;
+	uint32_t default_video_source;
+
+	struct pw_properties *properties;
+};
+
+struct find_data {
+	struct impl *impl;
+	const char *name;
+	uint32_t id;
+};
+
+static int find_name(void *data, struct sm_object *object)
+{
+	struct find_data *d = data;
+	const char *str;
+
+	if (strcmp(object->type, PW_TYPE_INTERFACE_Node) == 0 &&
+	    object->props &&
+	    (str = pw_properties_get(object->props, PW_KEY_NODE_NAME)) != NULL &&
+	    strcmp(str, d->name) == 0) {
+		d->id = object->id;
+		return 1;
+	}
+	return 0;
+}
+
+#if 0
+static uint32_t find_id_for_name(struct impl *impl, const char *name)
+{
+	struct find_data d = { impl, name, SPA_ID_INVALID };
+	sm_media_session_for_each_object(impl->session, find_name, &d);
+	return d.id;
+}
+#endif
+
+static const char *find_name_for_id(struct impl *impl, uint32_t id)
+{
+	struct sm_object *obj;
+	const char *str;
+
+	if (id == SPA_ID_INVALID)
+		return NULL;
+
+	obj = sm_media_session_find_object(impl->session, id);
+	if (obj == NULL)
+		return NULL;
+
+	if (strcmp(obj->type, PW_TYPE_INTERFACE_Node) == 0 &&
+	    obj->props &&
+	    (str = pw_properties_get(obj->props, PW_KEY_NODE_NAME)) != NULL)
+		return str;
+	return NULL;
+}
+
+static int load_state(struct impl *impl)
+{
+	int res;
+
+	if ((res = sm_media_session_load_state(impl->session, SESSION_KEY, impl->properties)) < 0) {
+		pw_log_error("can't load "SESSION_KEY" state: %s", spa_strerror(res));
+		return res;
+	}
+	return res;
+}
+
+static int save_state(struct impl *impl)
+{
+	int res;
+
+	if ((res = sm_media_session_save_state(impl->session, SESSION_KEY, impl->properties)) < 0) {
+		pw_log_error("can't save "SESSION_KEY" state: %s", spa_strerror(res));
+		return res;
+	}
+	return res;
+}
+
+static void remove_idle_timeout(struct impl *impl)
+{
+	struct pw_loop *main_loop = pw_context_get_main_loop(impl->context);
+	if (impl->idle_timeout) {
+		pw_loop_destroy_source(main_loop, impl->idle_timeout);
+		impl->idle_timeout = NULL;
+	}
+}
+
+static void idle_timeout(void *data, uint64_t expirations)
+{
+	struct impl *impl = data;
+
+	pw_log_debug(NAME " %p: idle timeout", impl);
+	remove_idle_timeout(impl);
+	save_state(impl);
+}
+
+static void add_idle_timeout(struct impl *impl)
+{
+	struct timespec value;
+	struct pw_loop *main_loop = pw_context_get_main_loop(impl->context);
+
+	if (impl->idle_timeout == NULL)
+		impl->idle_timeout = pw_loop_add_timer(main_loop, idle_timeout, impl);
+
+	value.tv_sec = SAVE_INTERVAL;
+	value.tv_nsec = 0;
+	pw_loop_update_timer(main_loop, impl->idle_timeout, &value, NULL, false);
+}
+
+static int metadata_property(void *object, uint32_t subject,
+		const char *key, const char *type, const char *value)
+{
+	struct impl *impl = object;
+	uint32_t val;
+	bool changed = false;
+
+	if (key == NULL)
+		return 0;
+
+	if (subject == PW_ID_CORE) {
+		val = value ? (uint32_t)atoi(value) : SPA_ID_INVALID;
+
+		if (strcmp(key, "default.audio.sink") == 0) {
+			changed = val != impl->default_audio_sink;
+			impl->default_audio_sink = val;
+		} else if (strcmp(key, "default.audio.source") == 0) {
+			changed = val != impl->default_audio_source;
+			impl->default_audio_source = val;
+		} else if (strcmp(key, "default.video.source") == 0) {
+			changed = val != impl->default_video_source;
+			impl->default_video_source = val;
+		}
+	}
+	if (changed) {
+		const char *name = find_name_for_id(impl, val);
+		pw_properties_set(impl->properties, key, name);
+		add_idle_timeout(impl);
+	}
+	return 0;
+}
+
+static const struct pw_metadata_events metadata_events = {
+	PW_VERSION_METADATA_EVENTS,
+	.property = metadata_property,
+};
+
+static void session_destroy(void *data)
+{
+	struct impl *impl = data;
+	spa_hook_remove(&impl->listener);
+	pw_properties_free(impl->properties);
+	free(impl);
+}
+
+static void session_create(void *data, struct sm_object *object)
+{
+	struct impl *impl = data;
+	const struct spa_dict_item *it;
+
+	if (strcmp(object->type, PW_TYPE_INTERFACE_Node) != 0)
+		return;
+
+	spa_dict_for_each(it, &impl->properties->dict) {
+		struct find_data d = { impl, it->value, SPA_ID_INVALID };
+		if (find_name(&d, object)) {
+			char val[16];
+			snprintf(val, sizeof(val)-1, "%u", d.id);
+			pw_metadata_set_property(impl->session->metadata,
+				PW_ID_CORE, it->key, SPA_TYPE_INFO_BASE"Id", val);
+		}
+	}
+}
+
+static void session_remove(void *data, struct sm_object *object)
+{
+	struct impl *impl = data;
+
+	if (strcmp(object->type, PW_TYPE_INTERFACE_Node) != 0)
+		return;
+
+	if (impl->default_audio_sink == object->id)
+		impl->default_audio_sink = SPA_ID_INVALID;
+	if (impl->default_audio_source == object->id)
+		impl->default_audio_source = SPA_ID_INVALID;
+	if (impl->default_video_source == object->id)
+		impl->default_video_source = SPA_ID_INVALID;
+}
+
+static const struct sm_media_session_events session_events = {
+	SM_VERSION_MEDIA_SESSION_EVENTS,
+	.create = session_create,
+	.remove = session_remove,
+	.destroy = session_destroy,
+};
+
+int sm_default_nodes_start(struct sm_media_session *session)
+{
+	struct impl *impl;
+
+	impl = calloc(1, sizeof(struct impl));
+	if (impl == NULL)
+		return -errno;
+
+	impl->session = session;
+	impl->context = session->context;
+
+	impl->default_audio_sink = SPA_ID_INVALID;
+	impl->default_audio_source = SPA_ID_INVALID;
+	impl->default_video_source = SPA_ID_INVALID;
+
+	impl->properties = pw_properties_new(NULL, NULL);
+	if (impl->properties == NULL) {
+		free(impl);
+		return -ENOMEM;
+	}
+
+	load_state(impl);
+
+	sm_media_session_add_listener(impl->session, &impl->listener, &session_events, impl);
+
+	if (session->metadata) {
+		pw_metadata_add_listener(session->metadata,
+				&impl->meta_listener,
+				&metadata_events, impl);
+	}
+	return 0;
+}

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

@@ -77,6 +77,7 @@
 int sm_access_flatpak_start(struct sm_media_session *sess);
 int sm_access_portal_start(struct sm_media_session *sess);
 int sm_metadata_start(struct sm_media_session *sess);
+int sm_default_nodes_start(struct sm_media_session *sess);
 int sm_alsa_midi_start(struct sm_media_session *sess);
 int sm_v4l2_monitor_start(struct sm_media_session *sess);
 int sm_libcamera_monitor_start(struct sm_media_session *sess);
@@ -1988,7 +1989,7 @@ static void do_quit(void *data, int signal_number)
 	pw_main_loop_quit(impl->loop);
 }
 
-#define DEFAULT_ENABLED		"flatpak,portal,metadata,alsa-acp,alsa-seq,v4l2,bluez5,suspend-node,policy-node"
+#define DEFAULT_ENABLED		"flatpak,portal,metadata,default-nodes,alsa-acp,alsa-seq,v4l2,bluez5,suspend-node,policy-node"
 #define DEFAULT_DISABLED	""
 
 static const struct {
@@ -2001,6 +2002,7 @@ static const struct {
 	{ "flatpak", "manage flatpak access", sm_access_flatpak_start, NULL },
 	{ "portal", "manage portal permissions", sm_access_portal_start, NULL },
 	{ "metadata", "export metadata API", sm_metadata_start, NULL },
+	{ "default-nodes", "restore default nodes", sm_default_nodes_start, NULL },
 	{ "alsa-seq", "alsa seq midi support", sm_alsa_midi_start, NULL },
 	{ "alsa-pcm", "alsa pcm udev detection", sm_alsa_monitor_start, NULL },
 	{ "alsa-acp", "alsa card profile udev detection", sm_alsa_monitor_start, "alsa.use-acp=true" },

src/examples/meson.build

@@ -74,6 +74,7 @@ if alsa_dep.found()
     'media-session/alsa-endpoint.c',
     'media-session/bluez-monitor.c',
     'media-session/bluez-endpoint.c',
+    'media-session/default-nodes.c',
     'media-session/media-session.c',
     'media-session/session-manager.c',
     'media-session/metadata.c',