pipewire/src/modules/module-spa-device-factory.c

/* PipeWire */
/* SPDX-FileCopyrightText: Copyright © 2018 Wim Taymans */
/* SPDX-License-Identifier: MIT */

#include <string.h>
#include <stdio.h>
#include <errno.h>
#include <dlfcn.h>

#include "config.h"

#include <spa/utils/result.h>

#include "pipewire/impl.h"

#include "spa/spa-device.h"

/** \page page_module_spa_device_factory SPA Device factory
 *
 * Provide a factory to create SPA devices.
 */
#define NAME "spa-device-factory"

PW_LOG_TOPIC_STATIC(mod_topic, "mod." NAME);
#define PW_LOG_TOPIC_DEFAULT mod_topic

#define FACTORY_USAGE	SPA_KEY_FACTORY_NAME"=<factory-name> " \
			"["SPA_KEY_LIBRARY_NAME"=<library-name>]"

static const struct spa_dict_item module_props[] = {
	{ PW_KEY_MODULE_AUTHOR, "Wim Taymans <wim.taymans@gmail.com>" },
	{ PW_KEY_MODULE_DESCRIPTION, "Provide a factory to make SPA devices" },
	{ PW_KEY_MODULE_VERSION, PACKAGE_VERSION },
};

struct factory_data {
	struct pw_context *context;

	struct pw_impl_module *module;
	struct spa_hook module_listener;

	struct pw_impl_factory *factory;
	struct spa_hook factory_listener;

	struct spa_list device_list;
};

struct device_data {
	struct spa_list link;
	struct pw_impl_device *device;
	struct spa_hook device_listener;
	struct spa_hook resource_listener;
};

static void resource_destroy(void *data)
{
	struct device_data *nd = data;
	pw_log_debug("device %p", nd);
	spa_hook_remove(&nd->resource_listener);
	if (nd->device)
		pw_impl_device_destroy(nd->device);
}

static const struct pw_resource_events resource_events = {
	PW_VERSION_RESOURCE_EVENTS,
	.destroy = resource_destroy
};

static void device_destroy(void *data)
{
	struct device_data *nd = data;
	spa_list_remove(&nd->link);
	spa_hook_remove(&nd->device_listener);
	nd->device = NULL;
}

static const struct pw_impl_device_events device_events = {
	PW_VERSION_IMPL_DEVICE_EVENTS,
	.destroy = device_destroy,
};

static void *create_object(void *_data,
			   struct pw_resource *resource,
			   const char *type,
			   uint32_t version,
			   struct pw_properties *properties,
			   uint32_t new_id)
{
	struct factory_data *data = _data;
	struct pw_context *context = data->context;
	struct pw_impl_device *device;
	const char *str;
	char *factory_name = NULL;
	struct device_data *nd;
	struct pw_impl_client *client;
	int res;

	if (properties == NULL)
		goto error_properties;

	if ((str = pw_properties_get(properties, SPA_KEY_FACTORY_NAME)) == NULL)
		goto error_properties;

	if ((factory_name = strdup(str)) == NULL)
		goto error_properties;

	pw_properties_setf(properties, PW_KEY_FACTORY_ID, "%d",
			pw_global_get_id(pw_impl_factory_get_global(data->factory)));

	client = resource ? pw_resource_get_client(resource) : NULL;

	if (client) {
		pw_properties_setf(properties, PW_KEY_CLIENT_ID, "%d",
			pw_global_get_id(pw_impl_client_get_global(client)));
	}

	device = pw_spa_device_load(context,
				factory_name,
				0,
				properties,
				sizeof(struct device_data));
	if (device == NULL) {
		res = -errno;
		goto error_device;
	}

	nd = pw_spa_device_get_user_data(device);
	nd->device = device;
	spa_list_append(&data->device_list, &nd->link);

	pw_impl_device_add_listener(device, &nd->device_listener, &device_events, nd);

	if (client) {
		struct pw_resource *bound_resource;

		res = pw_global_bind(pw_impl_device_get_global(device),
				client,
				PW_PERM_ALL, version,
				new_id);
		if (res < 0)
			goto error_bind;

		if ((bound_resource = pw_impl_client_find_resource(client, new_id)) == NULL)
			goto error_bind;

		pw_resource_add_listener(bound_resource, &nd->resource_listener, &resource_events, nd);
	}
	free(factory_name);
	return device;

error_properties:
	res = -EINVAL;
	pw_resource_errorf_id(resource, new_id, res, "usage: "FACTORY_USAGE);
	goto error_exit_cleanup;
error_device:
	pw_resource_errorf_id(resource, new_id, res,
				"can't create device %s: %s", factory_name,
				spa_strerror(res));
	goto error_exit;
error_bind:
	pw_resource_errorf_id(resource, new_id, res, "can't bind device");
	pw_impl_device_destroy(device);
	goto error_exit;

error_exit_cleanup:
	pw_properties_free(properties);
error_exit:
	free(factory_name);
	errno = -res;
	return NULL;
}

static const struct pw_impl_factory_implementation factory_impl = {
	PW_VERSION_IMPL_FACTORY_IMPLEMENTATION,
	.create_object = create_object,
};

static void factory_destroy(void *data)
{
	struct factory_data *d = data;
	struct device_data *nd;

	spa_hook_remove(&d->factory_listener);

	spa_list_consume(nd, &d->device_list, link)
		pw_impl_device_destroy(nd->device);

	d->factory = NULL;
	if (d->module)
		pw_impl_module_destroy(d->module);
}

static const struct pw_impl_factory_events factory_events = {
	PW_VERSION_IMPL_FACTORY_EVENTS,
	.destroy = factory_destroy,
};

static void module_destroy(void *data)
{
	struct factory_data *d = data;

	spa_hook_remove(&d->module_listener);
	d->module = NULL;
	if (d->factory)
		pw_impl_factory_destroy(d->factory);
}

static void module_registered(void *data)
{
	struct factory_data *d = data;
	struct pw_impl_module *module = d->module;
	struct pw_impl_factory *factory = d->factory;
	struct spa_dict_item items[1];
	char id[16];
	int res;

	snprintf(id, sizeof(id), "%d", pw_global_get_id(pw_impl_module_get_global(module)));
	items[0] = SPA_DICT_ITEM_INIT(PW_KEY_MODULE_ID, id);
	pw_impl_factory_update_properties(factory, &SPA_DICT_INIT(items, 1));

	if ((res = pw_impl_factory_register(factory, NULL)) < 0) {
		pw_log_error("%p: can't register factory: %s", factory, spa_strerror(res));
	}
}

static const struct pw_impl_module_events module_events = {
	PW_VERSION_IMPL_MODULE_EVENTS,
	.destroy = module_destroy,
	.registered = module_registered,
};

SPA_EXPORT
int pipewire__module_init(struct pw_impl_module *module, const char *args)
{
	struct pw_context *context = pw_impl_module_get_context(module);
	struct pw_impl_factory *factory;
	struct factory_data *data;

	PW_LOG_TOPIC_INIT(mod_topic);

	factory = pw_context_create_factory(context,
				 "spa-device-factory",
				 PW_TYPE_INTERFACE_Device,
				 PW_VERSION_DEVICE,
				 NULL,
				 sizeof(*data));
	if (factory == NULL)
		return -errno;

	data = pw_impl_factory_get_user_data(factory);
	data->factory = factory;
	data->module = module;
	data->context = context;
	spa_list_init(&data->device_list);

	pw_impl_factory_add_listener(factory, &data->factory_listener, &factory_events, data);
	pw_impl_factory_set_implementation(factory, &factory_impl, data);

	pw_log_debug("module %p: new", module);
	pw_impl_module_update_properties(module, &SPA_DICT_INIT_ARRAY(module_props));

	pw_impl_module_add_listener(module, &data->module_listener, &module_events, data);

	return 0;
}