impl-node: add node.rules and device.rules

To be able to modify properties of nodes and devices. This is
interesting in the minimal config to give the nodes better defaults.

src/daemon/minimal.conf.in

@@ -191,10 +191,12 @@ context.objects = [
     }
 
     # This creates a ALSA udev device that will enumerate all
-    # ALSA devices. Because it is using ACP and has the audio-profile
+    # ALSA devices. Because it is using ACP and has the auto-profile
     # property set, this will enable a profile and create associated
     # nodes, which will be automatically configured to their best
-    # configuration.
+    # configuration with the auto-port-config settings.
+    # Extra node and device params can be given with node.param and
+    # device.param prefixes.
     { factory = spa-device-factory
         args = {
             factory.name           = api.alsa.enum.udev
@@ -411,3 +413,38 @@ context.exec = [
     #
     #@pulse_comment@{ path = "@pipewire_path@" args = "-c pipewire-pulse.conf" }
 ]
+
+node.rules = [
+    {   matches = [
+            {
+                # all keys must match the value. ! negates. ~ starts regex.
+                #alsa.card_name = "ICUSBAUDIO7D"
+                #api.alsa.pcm.stream = "playback"
+            }
+        ]
+        actions = {
+            update-props = {
+                #node.name = "alsa_playback.ICUSBAUDIO7D"
+            }
+        }
+    }
+]
+device.rules = [
+    {   matches = [
+            {
+                #alsa.card_name = "ICUSBAUDIO7D"
+            }
+        ]
+        actions = {
+            update-props = {
+                #device.name = "alsa_card.ICUSBAUDIO7D"
+                #api.acp.auto-profile = false
+                #api.acp.auto-port = false
+                #device.param.Profile    = {
+                #    #idx = 0
+                #    name = off
+                #}
+            }
+        }
+    }
+]

src/pipewire/impl-device.c

@@ -117,9 +117,33 @@ static void object_register(struct object_data *od, uint32_t device_id)
 	}
 }
 
+struct match {
+	struct pw_impl_device *device;
+	int count;
+};
+#define MATCH_INIT(n) ((struct match){ .device = (n) })
+
+static int execute_match(void *data, const char *location, const char *action,
+		const char *val, size_t len)
+{
+	struct match *match = data;
+	struct pw_impl_device *this = match->device;
+	if (spa_streq(action, "update-props")) {
+		match->count += pw_properties_update_string(this->properties, val, len);
+		this->info.props = &this->properties->dict;
+	}
+	return 1;
+}
+
 static void check_properties(struct pw_impl_device *device)
 {
+	struct pw_context *context = device->context;
 	const char *str;
+	struct match match;
+
+	match = MATCH_INIT(device);
+	pw_context_conf_section_match_rules(context, "device.rules",
+			&device->properties->dict, execute_match, &match);
 
 	if ((str = pw_properties_get(device->properties, PW_KEY_DEVICE_NAME)) &&
 	    (device->name == NULL || !spa_streq(str, device->name))) {
@@ -668,11 +692,10 @@ static int update_properties(struct pw_impl_device *device, const struct spa_dic
 
 	pw_log_debug("%p: updated %d properties", device, changed);
 
-	if (!changed)
-		return 0;
-
-	device->info.change_mask |= PW_DEVICE_CHANGE_MASK_PROPS;
-
+	if (changed) {
+		check_properties(device);
+		device->info.change_mask |= PW_DEVICE_CHANGE_MASK_PROPS;
+	}
 	return changed;
 }
 
@@ -961,6 +984,8 @@ int pw_impl_device_set_implementation(struct pw_impl_device *device, struct spa_
 		return -EEXIST;
 	}
 	device->device = spa_device;
+	res = spa_device_add_listener(device->device,
+			&device->listener, &device_events, device);
 
 again:
 	spa_dict_for_each(it, &device->properties->dict) {
@@ -971,8 +996,6 @@ again:
 			goto again;
 		}
 	}
-	res = spa_device_add_listener(device->device,
-			&device->listener, &device_events, device);
 	return res;
 }
 

src/pipewire/impl-node.c

@@ -913,6 +913,24 @@ int pw_impl_node_set_driver(struct pw_impl_node *node, struct pw_impl_node *driv
 	return 0;
 }
 
+struct match {
+	struct pw_impl_node *node;
+	int count;
+};
+#define MATCH_INIT(n) ((struct match){ .node = (n) })
+
+static int execute_match(void *data, const char *location, const char *action,
+		const char *val, size_t len)
+{
+	struct match *match = data;
+	struct pw_impl_node *this = match->node;
+	if (spa_streq(action, "update-props")) {
+		match->count += pw_properties_update_string(this->properties, val, len);
+		this->info.props = &this->properties->dict;
+	}
+	return 1;
+}
+
 static void check_properties(struct pw_impl_node *node)
 {
 	struct impl *impl = SPA_CONTAINER_OF(node, struct impl, this);
@@ -921,8 +939,11 @@ static void check_properties(struct pw_impl_node *node)
 	struct spa_fraction frac;
 	uint32_t value;
 	bool driver, trigger;
+	struct match match;
 
-
+	match = MATCH_INIT(node);
+	pw_context_conf_section_match_rules(context, "node.rules",
+			&node->properties->dict, execute_match, &match);
 
 	if ((str = pw_properties_get(node->properties, PW_KEY_PRIORITY_DRIVER))) {
 		value = pw_properties_parse_int(str);
@@ -1980,6 +2001,7 @@ int pw_impl_node_set_implementation(struct pw_impl_node *node,
 
 	node->node = spa_node;
 	spa_node_set_callbacks(node->node, &node_callbacks, node);
+	res = spa_node_add_listener(node->node, &node->listener, &node_events, node);
 
 again:
 	spa_dict_for_each(it, &node->properties->dict) {
@@ -1991,8 +2013,6 @@ again:
 		}
 	}
 
-	res = spa_node_add_listener(node->node, &node->listener, &node_events, node);
-
 	if (node->registered)
 		update_io(node);