extensions: implement new session manager extension

This extension, implemented in module-session-manager, implements
a set of objects that are useful for session managers.

src/modules/module-session-manager/session.c

@@ -0,0 +1,341 @@
+/* PipeWire
+ *
+ * Copyright © 2019 Collabora Ltd.
+ *   @author George Kiagiadakis <george.kiagiadakis@collabora.com>
+ *
+ * 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 <stdbool.h>
+#include <string.h>
+
+#include <pipewire/pipewire.h>
+#include <extensions/session-manager.h>
+
+#include <spa/pod/filter.h>
+
+#include "session.h"
+#include "client-session.h"
+
+#include <pipewire/private.h>
+
+#define NAME "session"
+
+struct resource_data {
+	struct session *session;
+	struct spa_hook resource_listener;
+	struct spa_hook object_listener;
+	uint32_t n_subscribe_ids;
+	uint32_t subscribe_ids[32];
+};
+
+#define pw_session_resource(r,m,v,...)	\
+	pw_resource_call(r,struct pw_session_proxy_events,m,v,__VA_ARGS__)
+#define pw_session_resource_info(r,...)	\
+	pw_session_resource(r,info,0,__VA_ARGS__)
+#define pw_session_resource_param(r,...)	\
+	pw_session_resource(r,param,0,__VA_ARGS__)
+
+static int session_enum_params (void *object, int seq,
+				uint32_t id, uint32_t start, uint32_t num,
+				const struct spa_pod *filter)
+{
+	struct pw_resource *resource = object;
+	struct resource_data *data = pw_resource_get_user_data(resource);
+	struct session *this = data->session;
+	struct spa_pod *result;
+	struct spa_pod *param;
+	uint8_t buffer[1024];
+	struct spa_pod_builder b = { 0 };
+	uint32_t index;
+	uint32_t next = start;
+	uint32_t count = 0;
+
+	while (true) {
+		index = next++;
+		if (index >= this->n_params)
+			break;
+
+		param = this->params[index];
+
+		if (param == NULL || !spa_pod_is_object_id(param, id))
+			continue;
+
+		spa_pod_builder_init(&b, buffer, sizeof(buffer));
+		if (spa_pod_filter(&b, &result, param, filter) != 0)
+			continue;
+
+		pw_log_debug(NAME" %p: %d param %u", this, seq, index);
+
+		pw_session_resource_param(resource, seq, id, index, next, result);
+
+		if (++count == num)
+			break;
+	}
+	return 0;
+}
+
+static int session_subscribe_params (void *object, uint32_t *ids, uint32_t n_ids)
+{
+	struct pw_resource *resource = object;
+	struct resource_data *data = pw_resource_get_user_data(resource);
+	uint32_t i;
+
+	n_ids = SPA_MIN(n_ids, SPA_N_ELEMENTS(data->subscribe_ids));
+	data->n_subscribe_ids = n_ids;
+
+	for (i = 0; i < n_ids; i++) {
+		data->subscribe_ids[i] = ids[i];
+		pw_log_debug(NAME" %p: resource %d subscribe param %u",
+			data->session, resource->id, ids[i]);
+		session_enum_params(resource, 1, ids[i], 0, UINT32_MAX, NULL);
+	}
+	return 0;
+}
+
+static int session_set_param (void *object, uint32_t id, uint32_t flags,
+				const struct spa_pod *param)
+{
+	struct pw_resource *resource = object;
+	struct resource_data *data = pw_resource_get_user_data(resource);
+	struct session *this = data->session;
+
+	pw_client_session_resource_set_param(this->client_sess->resource,
+						id, flags, param);
+
+	return 0;
+}
+
+static int session_create_link(void *object, const struct spa_dict *props)
+{
+	struct pw_resource *resource = object;
+	struct resource_data *data = pw_resource_get_user_data(resource);
+	struct session *this = data->session;
+
+	pw_client_session_resource_create_link(this->client_sess->resource,
+						props);
+
+	return 0;
+}
+
+static const struct pw_session_proxy_methods methods = {
+	PW_VERSION_SESSION_PROXY_METHODS,
+	.subscribe_params = session_subscribe_params,
+	.enum_params = session_enum_params,
+	.set_param = session_set_param,
+	.create_link = session_create_link,
+};
+
+static void session_notify_subscribed(struct session *this,
+					uint32_t index, uint32_t next)
+{
+	struct pw_global *global = this->global;
+	struct pw_resource *resource;
+	struct resource_data *data;
+	struct spa_pod *param = this->params[index];
+	uint32_t id;
+	uint32_t i;
+
+	if (!param || !spa_pod_is_object (param))
+		return;
+
+	id = SPA_POD_OBJECT_ID (param);
+
+	spa_list_for_each(resource, &global->resource_list, link) {
+		data = pw_resource_get_user_data(resource);
+		for (i = 0; i < data->n_subscribe_ids; i++) {
+			if (data->subscribe_ids[i] == id) {
+				pw_session_resource_param(resource, 1, id,
+					index, next, param);
+			}
+		}
+	}
+}
+
+int session_update(struct session *this,
+			uint32_t change_mask,
+			uint32_t n_params,
+			const struct spa_pod **params,
+			const struct pw_session_info *info)
+{
+	if (change_mask & PW_CLIENT_SESSION_UPDATE_PARAMS) {
+		uint32_t i;
+		size_t size = n_params * sizeof(struct spa_pod *);
+
+		pw_log_debug(NAME" %p: update %d params", this, n_params);
+
+		for (i = 0; i < this->n_params; i++)
+			free(this->params[i]);
+		this->params = realloc(this->params, size);
+		if (size > 0 && !this->params) {
+			this->n_params = 0;
+			goto no_mem;
+		}
+		this->n_params = n_params;
+
+		for (i = 0; i < this->n_params; i++) {
+			this->params[i] = params[i] ? spa_pod_copy(params[i]) : NULL;
+			session_notify_subscribed(this, i, i+1);
+		}
+	}
+
+	if (change_mask & PW_CLIENT_SESSION_UPDATE_INFO) {
+		struct pw_resource *resource;
+
+		if (info->change_mask & PW_SESSION_CHANGE_MASK_PROPS)
+			pw_properties_update(this->props, info->props);
+
+		if (info->change_mask & PW_SESSION_CHANGE_MASK_PARAMS) {
+			size_t size = info->n_params * sizeof(struct spa_param_info);
+
+			this->info.params = realloc(this->info.params, size);
+			if (size > 0 && !this->info.params) {
+				this->info.n_params = 0;
+				goto no_mem;
+			}
+			this->info.n_params = info->n_params;
+
+			memcpy(this->info.params, info->params, size);
+		}
+
+		this->info.change_mask = info->change_mask;
+		spa_list_for_each(resource, &this->global->resource_list, link) {
+			pw_session_resource_info(resource, &this->info);
+		}
+		this->info.change_mask = 0;
+	}
+
+	return 0;
+
+      no_mem:
+	pw_log_error(NAME" can't update: no memory");
+	pw_resource_error(this->client_sess->resource, -ENOMEM,
+			NAME" can't update: no memory");
+	return -ENOMEM;
+}
+
+static void session_unbind(void *data)
+{
+	struct pw_resource *resource = data;
+	spa_list_remove(&resource->link);
+}
+
+static const struct pw_resource_events resource_events = {
+	PW_VERSION_RESOURCE_EVENTS,
+	.destroy = session_unbind,
+};
+
+static int session_bind(void *_data, struct pw_client *client,
+			uint32_t permissions, uint32_t version, uint32_t id)
+{
+	struct session *this = _data;
+	struct pw_global *global = this->global;
+	struct pw_resource *resource;
+	struct resource_data *data;
+
+	resource = pw_resource_new(client, id, permissions, global->type, version, sizeof(*data));
+	if (resource == NULL)
+		goto no_mem;
+
+	data = pw_resource_get_user_data(resource);
+	data->session = this;
+	pw_resource_add_listener(resource, &data->resource_listener,
+				&resource_events, resource);
+	pw_resource_add_object_listener(resource, &data->object_listener,
+					&methods, resource);
+
+	pw_log_debug(NAME" %p: bound to %d", this, resource->id);
+
+	spa_list_append(&global->resource_list, &resource->link);
+
+	this->info.change_mask = PW_SESSION_CHANGE_MASK_ALL;
+	pw_session_resource_info(resource, &this->info);
+	this->info.change_mask = 0;
+
+	return 0;
+
+      no_mem:
+	pw_log_error(NAME" can't create resource: no memory");
+	pw_resource_error(this->client_sess->resource, -ENOMEM,
+			NAME" can't create resource: no memory");
+	return -ENOMEM;
+}
+
+int session_init(struct session *this,
+		struct client_session *client_sess,
+		struct pw_core *core,
+		struct pw_properties *properties)
+{
+	const char *keys[] = {
+		PW_KEY_FACTORY_ID,
+		PW_KEY_CLIENT_ID,
+		NULL
+	};
+
+	pw_log_debug(NAME" %p: new", this);
+
+	this->client_sess = client_sess;
+	this->props = properties;
+
+	properties = pw_properties_new(NULL, NULL);
+	if (!properties)
+		goto no_mem;
+
+	pw_properties_copy_keys(this->props, properties, keys);
+
+	this->global = pw_global_new (core,
+			PW_TYPE_INTERFACE_Session,
+			PW_VERSION_SESSION_PROXY,
+			properties, session_bind, this);
+	if (!this->global)
+		goto no_mem;
+
+	pw_properties_setf(this->props, PW_KEY_SESSION_ID, "%u", this->global->id);
+
+	this->info.version = PW_VERSION_SESSION_INFO;
+	this->info.id = this->global->id;
+	this->info.props = &this->props->dict;
+
+	pw_client_session_resource_set_id(client_sess->resource, this->global->id);
+
+	return pw_global_register(this->global);
+
+      no_mem:
+	pw_log_error(NAME" - can't create - out of memory");
+	return -ENOMEM;
+}
+
+void session_clear(struct session *this)
+{
+	uint32_t i;
+
+	pw_log_debug(NAME" %p: destroy", this);
+
+	pw_global_destroy(this->global);
+
+	for (i = 0; i < this->n_params; i++)
+		free(this->params[i]);
+	free(this->params);
+
+	free(this->info.params);
+
+	if (this->props)
+		pw_properties_free(this->props);
+}