wireplumber/lib/wp/endpoint-link.c

/* WirePlumber
 *
 * Copyright © 2020 Collabora Ltd.
 *    @author George Kiagiadakis <george.kiagiadakis@collabora.com>
 *
 * SPDX-License-Identifier: MIT
 */

/**
 * SECTION: endpoint-link
 * @title: PipeWire Endpoint Link
 */

#define G_LOG_DOMAIN "wp-endpoint-link"

#include "endpoint-link.h"
#include "debug.h"
#include "error.h"
#include "wpenums.h"
#include "private/impl-endpoint.h"
#include "private/pipewire-object-mixin.h"

#include <pipewire/extensions/session-manager.h>
#include <pipewire/extensions/session-manager/introspect-funcs.h>

enum {
  SIGNAL_STATE_CHANGED,
  N_SIGNALS,
};

static guint32 signals[N_SIGNALS] = {0};

static void wp_endpoint_link_pw_object_mixin_priv_interface_init (
    WpPwObjectMixinPrivInterface * iface);

/**
 * WpEndpointLink:
 *
 * The #WpEndpointLink class allows accessing the properties and methods of a
 * PipeWire endpoint link object (`struct pw_endpoint_link` from the
 * session-manager extension).
 *
 * A #WpEndpointLink is constructed internally when a new endpoint link appears
 * on the PipeWire registry and it is made available through the
 * #WpObjectManager API.
 */
G_DEFINE_TYPE_WITH_CODE (WpEndpointLink, wp_endpoint_link, WP_TYPE_GLOBAL_PROXY,
    G_IMPLEMENT_INTERFACE (WP_TYPE_PIPEWIRE_OBJECT,
        wp_pw_object_mixin_object_interface_init)
    G_IMPLEMENT_INTERFACE (WP_TYPE_PW_OBJECT_MIXIN_PRIV,
        wp_endpoint_link_pw_object_mixin_priv_interface_init));

static void
wp_endpoint_link_init (WpEndpointLink * self)
{
}

static void
wp_endpoint_link_activate_execute_step (WpObject * object,
    WpFeatureActivationTransition * transition, guint step,
    WpObjectFeatures missing)
{
  switch (step) {
  case WP_PW_OBJECT_MIXIN_STEP_BIND:
  case WP_TRANSITION_STEP_ERROR:
    /* base class can handle BIND and ERROR */
    WP_OBJECT_CLASS (wp_endpoint_link_parent_class)->
        activate_execute_step (object, transition, step, missing);
    break;
  case WP_PW_OBJECT_MIXIN_STEP_WAIT_INFO:
    /* just wait, info will be emitted anyway after binding */
    break;
  case WP_PW_OBJECT_MIXIN_STEP_CACHE_PARAMS:
    wp_pw_object_mixin_cache_params (object, missing);
    break;
  default:
    g_assert_not_reached ();
  }
}

static void
wp_endpoint_link_deactivate (WpObject * object, WpObjectFeatures features)
{
  wp_pw_object_mixin_deactivate (object, features);
  WP_OBJECT_CLASS (wp_endpoint_link_parent_class)->deactivate (object, features);
}

static const struct pw_endpoint_link_events endpoint_link_events = {
  PW_VERSION_ENDPOINT_LINK_EVENTS,
  .info = (HandleEventInfoFunc(endpoint_link)) wp_pw_object_mixin_handle_event_info,
  .param = wp_pw_object_mixin_handle_event_param,
};

static void
wp_endpoint_link_pw_proxy_created (WpProxy * proxy, struct pw_proxy * pw_proxy)
{
  wp_pw_object_mixin_handle_pw_proxy_created (proxy, pw_proxy,
      endpoint_link, &endpoint_link_events);
}

static void
wp_endpoint_link_class_init (WpEndpointLinkClass * klass)
{
  GObjectClass *object_class = (GObjectClass *) klass;
  WpObjectClass *wpobject_class = (WpObjectClass *) klass;
  WpProxyClass *proxy_class = (WpProxyClass *) klass;

  object_class->get_property = wp_pw_object_mixin_get_property;

  wpobject_class->get_supported_features =
      wp_pw_object_mixin_get_supported_features;
  wpobject_class->activate_get_next_step =
      wp_pw_object_mixin_activate_get_next_step;
  wpobject_class->activate_execute_step =
      wp_endpoint_link_activate_execute_step;
  wpobject_class->deactivate = wp_endpoint_link_deactivate;

  proxy_class->pw_iface_type = PW_TYPE_INTERFACE_EndpointLink;
  proxy_class->pw_iface_version = PW_VERSION_ENDPOINT_LINK;
  proxy_class->pw_proxy_created = wp_endpoint_link_pw_proxy_created;
  proxy_class->pw_proxy_destroyed =
      wp_pw_object_mixin_handle_pw_proxy_destroyed;

  wp_pw_object_mixin_class_override_properties (object_class);

  /**
   * WpEndpointLink::state-changed:
   * @self: the endpoint link
   * @old_state: the old state of the link
   * @new_state: the new state of the link
   * @error: (nullable): the error string if the new state is
   *   %WP_ENDPOINT_LINK_STATE_ERROR
   *
   * Emitted when an endpoint link changes state
   */
  signals[SIGNAL_STATE_CHANGED] = g_signal_new (
      "state-changed", G_TYPE_FROM_CLASS (klass),
      G_SIGNAL_RUN_LAST, 0, NULL, NULL, NULL, G_TYPE_NONE, 3,
      WP_TYPE_ENDPOINT_LINK_STATE, WP_TYPE_ENDPOINT_LINK_STATE, G_TYPE_STRING);
}

static void
wp_endpoint_link_process_info (gpointer instance, gpointer old_info, gpointer i)
{
  const struct pw_endpoint_link_info *info = i;

  if (info->change_mask & PW_ENDPOINT_LINK_CHANGE_MASK_STATE) {
    WpEndpointLinkState old_state = old_info ?
        (WpEndpointLinkState) ((struct pw_endpoint_link_info *) old_info)->state
        : WP_ENDPOINT_LINK_STATE_ERROR;
    g_signal_emit (instance, signals[SIGNAL_STATE_CHANGED], 0,
        old_state, info->state, info->error);
  }
}

static gint
wp_endpoint_link_enum_params (gpointer instance, guint32 id,
    guint32 start, guint32 num, WpSpaPod *filter)
{
  WpPwObjectMixinData *d = wp_pw_object_mixin_get_data (instance);
  return pw_endpoint_link_enum_params (d->iface, 0, id, start, num,
      filter ? wp_spa_pod_get_spa_pod (filter) : NULL);
}

static gint
wp_endpoint_link_set_param (gpointer instance, guint32 id, guint32 flags,
    WpSpaPod * param)
{
  WpPwObjectMixinData *d = wp_pw_object_mixin_get_data (instance);
  return pw_endpoint_link_set_param (d->iface, id, flags,
      wp_spa_pod_get_spa_pod (param));
}

static void
wp_endpoint_link_pw_object_mixin_priv_interface_init (
    WpPwObjectMixinPrivInterface * iface)
{
  wp_pw_object_mixin_priv_interface_info_init (iface,
      endpoint_link, ENDPOINT_LINK);
  iface->process_info = wp_endpoint_link_process_info;
  iface->enum_params = wp_endpoint_link_enum_params;
  iface->set_param = wp_endpoint_link_set_param;
}

/**
 * wp_endpoint_link_get_linked_object_ids:
 * @self: the endpoint link
 * @output_endpoint: (out) (optional): the bound id of the output (source)
 *    endpoint
 * @output_stream: (out) (optional): the bound id of the output (source)
 *    endpoint's stream
 * @input_endpoint: (out) (optional): the bound id of the input (sink)
 *    endpoint
 * @input_stream: (out) (optional): the bound id of the input (sink)
 *    endpoint's stream
 *
 * Retrieves the ids of the objects that are linked by this endpoint link
 *
 * Note: Using this method requires %WP_PIPEWIRE_OBJECT_FEATURE_INFO
 */
void
wp_endpoint_link_get_linked_object_ids (WpEndpointLink * self,
    guint32 * output_endpoint, guint32 * output_stream,
    guint32 * input_endpoint, guint32 * input_stream)
{
  g_return_if_fail (WP_IS_ENDPOINT_LINK (self));

  WpPwObjectMixinData *d = wp_pw_object_mixin_get_data (self);
  struct pw_endpoint_link_info *info = d->info;
  g_return_if_fail (info);

  if (output_endpoint)
    *output_endpoint = info->output_endpoint_id;
  if (output_stream)
    *output_stream = info->output_stream_id;
  if (input_endpoint)
    *input_endpoint = info->input_endpoint_id;
  if (input_stream)
    *input_stream = info->input_stream_id;
}

/**
 * wp_endpoint_link_get_state:
 * @self: the endpoint link
 * @error: (out) (optional) (transfer none): the error string if the state is
 *   %WP_ENDPOINT_LINK_STATE_ERROR
 *
 * Retrieves the current state of the link
 *
 * Note: Using this method requires %WP_PIPEWIRE_OBJECT_FEATURE_INFO
 * Returns: the current state of the link
 */
WpEndpointLinkState
wp_endpoint_link_get_state (WpEndpointLink * self, const gchar ** error)
{
  g_return_val_if_fail (WP_IS_ENDPOINT_LINK (self), WP_ENDPOINT_LINK_STATE_ERROR);

  WpPwObjectMixinData *d = wp_pw_object_mixin_get_data (self);
  struct pw_endpoint_link_info *info = d->info;
  g_return_val_if_fail (info, WP_ENDPOINT_LINK_STATE_ERROR);

  if (error)
    *error = info->error;
  return (WpEndpointLinkState) info->state;
}

/**
 * wp_endpoint_link_request_state:
 * @self: the endpoint link
 * @target: the desired target state of the link
 *
 * Requests a state change on the link
 *
 * Note: Using this method requires %WP_PROXY_FEATURE_BOUND
 */
void
wp_endpoint_link_request_state (WpEndpointLink * self,
    WpEndpointLinkState target)
{
  g_return_if_fail (WP_IS_ENDPOINT_LINK (self));

  WpPwObjectMixinData *d = wp_pw_object_mixin_get_data (self);
  g_return_if_fail (d->iface);

  pw_endpoint_link_request_state (d->iface,
      (enum pw_endpoint_link_state) target);
}

/* WpImplEndpointLink */

enum {
  IMPL_PROP_0,
  IMPL_PROP_ITEM,
};

struct _WpImplEndpointLink
{
  WpEndpointLink parent;

  struct spa_interface iface;
  struct pw_endpoint_link_info info;
  WpProperties *immutable_props;

  WpSiLink *item;
};

static void wp_endpoint_link_impl_pw_object_mixin_priv_interface_init (
    WpPwObjectMixinPrivInterface * iface);

G_DEFINE_TYPE_WITH_CODE (WpImplEndpointLink, wp_impl_endpoint_link, WP_TYPE_ENDPOINT_LINK,
    G_IMPLEMENT_INTERFACE (WP_TYPE_PW_OBJECT_MIXIN_PRIV,
        wp_endpoint_link_impl_pw_object_mixin_priv_interface_init))

static void
on_item_activated (WpSessionItem * item, GAsyncResult * res, gpointer data)
{
  WpImplEndpointLink *self = WP_IMPL_ENDPOINT_LINK (data);
  g_autoptr (GError) error = NULL;

  if (!wp_session_item_activate_finish (item, res, &error)) {
    wp_message_object (self, "failed to activate link: %s", error->message);
    self->info.error = g_strdup (error->message);
    /* on_si_link_flags_changed() will be called right after we return,
       taking care of the rest... */
  }
}

static int
impl_request_state (void *object, enum pw_endpoint_link_state state)
{
  WpImplEndpointLink *self = WP_IMPL_ENDPOINT_LINK (object);
  int ret = 0;

  if (state == self->info.state)
    return ret;

  switch (state) {
  case PW_ENDPOINT_LINK_STATE_ACTIVE:
    wp_session_item_activate (WP_SESSION_ITEM (self->item),
        (GAsyncReadyCallback) on_item_activated, self);
    break;
  case PW_ENDPOINT_LINK_STATE_INACTIVE:
    wp_session_item_deactivate (WP_SESSION_ITEM (self->item));
    break;
  default:
    ret = -EINVAL;
    break;
  }

  return ret;
}

static const struct pw_endpoint_link_methods impl_endpoint_link = {
  PW_VERSION_ENDPOINT_LINK_METHODS,
  .add_listener =
      (ImplAddListenerFunc(endpoint_link)) wp_pw_object_mixin_impl_add_listener,
  .subscribe_params = wp_pw_object_mixin_impl_subscribe_params,
  .enum_params = wp_pw_object_mixin_impl_enum_params,
  .set_param = wp_pw_object_mixin_impl_set_param,
  .request_state = impl_request_state,
};

static void
wp_impl_endpoint_link_init (WpImplEndpointLink * self)
{
  WpPwObjectMixinData *d = wp_pw_object_mixin_get_data (self);

  self->iface = SPA_INTERFACE_INIT (
      PW_TYPE_INTERFACE_EndpointLink,
      PW_VERSION_ENDPOINT_LINK,
      &impl_endpoint_link, self);

  d->info = &self->info;
  d->iface = &self->iface;
}

static void
populate_properties (WpImplEndpointLink * self)
{
  WpPwObjectMixinData *d = wp_pw_object_mixin_get_data (self);

  g_clear_pointer (&d->properties, wp_properties_unref);
  d->properties = wp_si_link_get_properties (self->item);
  if (!d->properties)
    d->properties = wp_properties_new_empty ();
  d->properties = wp_properties_ensure_unique_owner (d->properties);
  wp_properties_update (d->properties, self->immutable_props);

  self->info.props = (struct spa_dict *) wp_properties_peek_dict (d->properties);
}

static void
on_si_link_properties_changed (WpSiLink * item, WpImplEndpointLink * self)
{
  populate_properties (self);
  wp_pw_object_mixin_notify_info (self, PW_ENDPOINT_LINK_CHANGE_MASK_PROPS);
}

static void
on_si_link_flags_changed (WpSiLink * item, WpSiFlags flags,
    WpImplEndpointLink * self)
{
  enum pw_endpoint_link_state old_state = self->info.state;

  if (flags & WP_SI_FLAG_ACTIVATE_ERROR)
    self->info.state = PW_ENDPOINT_LINK_STATE_ERROR;
  else if (flags & WP_SI_FLAG_ACTIVE)
    self->info.state = PW_ENDPOINT_LINK_STATE_ACTIVE;
  else if (flags & WP_SI_FLAG_ACTIVATING)
    self->info.state = PW_ENDPOINT_LINK_STATE_PREPARING;
  else
    self->info.state = PW_ENDPOINT_LINK_STATE_INACTIVE;

  if (self->info.state != PW_ENDPOINT_LINK_STATE_ERROR)
    g_clear_pointer (&self->info.error, g_free);

  if (old_state != self->info.state) {
    wp_pw_object_mixin_notify_info (self, PW_ENDPOINT_LINK_CHANGE_MASK_STATE);
    g_signal_emit (self, signals[SIGNAL_STATE_CHANGED], 0,
        old_state, self->info.state, self->info.error);
  }
}

static void
wp_impl_endpoint_link_constructed (GObject * object)
{
  WpImplEndpointLink *self = WP_IMPL_ENDPOINT_LINK (object);
  g_autoptr (GVariant) info = NULL;
  g_autoptr (GVariantIter) immutable_props = NULL;
  const gchar *key, *value;
  WpSiStream *stream;

  self->info.version = PW_VERSION_ENDPOINT_LINK_INFO;
  self->info.error = NULL;
  self->info.params = NULL;
  self->info.n_params = 0;

  /* get info from the interface */
  info = wp_si_link_get_registration_info (self->item);
  g_variant_get (info, "a{ss}", &immutable_props);

  /* get the current state */
  self->info.state =
      (wp_session_item_get_flags (WP_SESSION_ITEM (self->item))
          & WP_SI_FLAG_ACTIVE)
      ? PW_ENDPOINT_LINK_STATE_ACTIVE
      : PW_ENDPOINT_LINK_STATE_INACTIVE;

  /* associate with the session, the endpoints and the streams */
  self->info.session_id = wp_session_item_get_associated_proxy_id (
      WP_SESSION_ITEM (self->item), WP_TYPE_SESSION);

  stream = wp_si_link_get_out_stream (self->item);
  self->info.output_endpoint_id = wp_session_item_get_associated_proxy_id (
      WP_SESSION_ITEM (stream), WP_TYPE_ENDPOINT);
  self->info.output_stream_id = wp_session_item_get_associated_proxy_id (
      WP_SESSION_ITEM (stream), WP_TYPE_ENDPOINT_STREAM);

  stream = wp_si_link_get_in_stream (self->item);
  self->info.input_endpoint_id = wp_session_item_get_associated_proxy_id (
      WP_SESSION_ITEM (stream), WP_TYPE_ENDPOINT);
  self->info.input_stream_id = wp_session_item_get_associated_proxy_id (
      WP_SESSION_ITEM (stream), WP_TYPE_ENDPOINT_STREAM);

  /* construct export properties (these will come back through
      the registry and appear in wp_proxy_get_global_properties) */
  self->immutable_props = wp_properties_new_empty ();
  wp_properties_setf (self->immutable_props,
      PW_KEY_SESSION_ID, "%d", self->info.session_id);
  wp_properties_setf (self->immutable_props,
      PW_KEY_ENDPOINT_LINK_OUTPUT_ENDPOINT, "%d", self->info.output_endpoint_id);
  wp_properties_setf (self->immutable_props,
      PW_KEY_ENDPOINT_LINK_OUTPUT_STREAM, "%d", self->info.output_stream_id);
  wp_properties_setf (self->immutable_props,
      PW_KEY_ENDPOINT_LINK_INPUT_ENDPOINT, "%d", self->info.input_endpoint_id);
  wp_properties_setf (self->immutable_props,
      PW_KEY_ENDPOINT_LINK_INPUT_STREAM, "%d", self->info.input_stream_id);

  /* populate immutable (global) properties */
  while (g_variant_iter_next (immutable_props, "{&s&s}", &key, &value))
    wp_properties_set (self->immutable_props, key, value);

  /* populate standard properties */
  populate_properties (self);

  /* subscribe to changes */
  g_signal_connect_object (self->item, "link-properties-changed",
      G_CALLBACK (on_si_link_properties_changed), self, 0);
  g_signal_connect_object (self->item, "flags-changed",
      G_CALLBACK (on_si_link_flags_changed), self, 0);

  wp_object_update_features (WP_OBJECT (self),
      WP_PIPEWIRE_OBJECT_FEATURE_INFO, 0);

  G_OBJECT_CLASS (wp_impl_endpoint_link_parent_class)->constructed (object);
}

static void
wp_impl_endpoint_link_dispose (GObject * object)
{
  WpImplEndpointLink *self = WP_IMPL_ENDPOINT_LINK (object);

  g_clear_pointer (&self->immutable_props, wp_properties_unref);
  g_clear_pointer (&self->info.error, g_free);

  wp_object_update_features (WP_OBJECT (self), 0,
      WP_PIPEWIRE_OBJECT_FEATURE_INFO);

  G_OBJECT_CLASS (wp_impl_endpoint_link_parent_class)->dispose (object);
}

static void
wp_impl_endpoint_link_set_property (GObject * object, guint property_id,
    const GValue * value, GParamSpec * pspec)
{
  WpImplEndpointLink *self = WP_IMPL_ENDPOINT_LINK (object);

  switch (property_id) {
  case IMPL_PROP_ITEM:
    self->item = g_value_get_object (value);
    break;
  default:
    G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
    break;
  }
}

static void
wp_impl_endpoint_link_get_property (GObject * object, guint property_id,
    GValue * value, GParamSpec * pspec)
{
  WpImplEndpointLink *self = WP_IMPL_ENDPOINT_LINK (object);

  switch (property_id) {
  case IMPL_PROP_ITEM:
    g_value_set_object (value, self->item);
    break;
  default:
    G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
    break;
  }
}

static void
wp_impl_endpoint_link_activate_execute_step (WpObject * object,
    WpFeatureActivationTransition * transition, guint step,
    WpObjectFeatures missing)
{
  WpImplEndpointLink *self = WP_IMPL_ENDPOINT_LINK (object);

  switch (step) {
  case WP_PW_OBJECT_MIXIN_STEP_BIND: {
    g_autoptr (WpCore) core = wp_object_get_core (object);
    struct pw_core *pw_core = wp_core_get_pw_core (core);

    /* no pw_core -> we are not connected */
    if (!pw_core) {
      wp_transition_return_error (WP_TRANSITION (transition), g_error_new (
              WP_DOMAIN_LIBRARY, WP_LIBRARY_ERROR_OPERATION_FAILED,
              "The WirePlumber core is not connected; "
              "object cannot be exported to PipeWire"));
      return;
    }

    /* bind */
    wp_proxy_set_pw_proxy (WP_PROXY (self), pw_core_export (pw_core,
            PW_TYPE_INTERFACE_EndpointLink,
            wp_properties_peek_dict (self->immutable_props),
            &self->iface, 0));
    break;
  }
  default:
    WP_OBJECT_CLASS (wp_impl_endpoint_link_parent_class)->
        activate_execute_step (object, transition, step, missing);
    break;
  }
}

static void
wp_impl_endpoint_link_class_init (WpImplEndpointLinkClass * klass)
{
  GObjectClass *object_class = (GObjectClass *) klass;
  WpObjectClass *wpobject_class = (WpObjectClass *) klass;
  WpProxyClass *proxy_class = (WpProxyClass *) klass;

  object_class->constructed = wp_impl_endpoint_link_constructed;
  object_class->dispose = wp_impl_endpoint_link_dispose;
  object_class->set_property = wp_impl_endpoint_link_set_property;
  object_class->get_property = wp_impl_endpoint_link_get_property;

  wpobject_class->activate_execute_step =
      wp_impl_endpoint_link_activate_execute_step;

  proxy_class->pw_proxy_created = NULL;
  proxy_class->pw_proxy_destroyed = NULL;

  g_object_class_install_property (object_class, IMPL_PROP_ITEM,
      g_param_spec_object ("item", "item", "item", WP_TYPE_SI_LINK,
          G_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY | G_PARAM_STATIC_STRINGS));
}

#define pw_endpoint_link_emit(hooks,method,version,...) \
    spa_hook_list_call_simple(hooks, struct pw_endpoint_link_events, \
        method, version, ##__VA_ARGS__)

static void
wp_impl_endpoint_link_emit_info (struct spa_hook_list * hooks, gconstpointer info)
{
  pw_endpoint_link_emit (hooks, info, 0, info);
}

static void
wp_impl_endpoint_link_emit_param (struct spa_hook_list * hooks, int seq,
      guint32 id, guint32 index, guint32 next, const struct spa_pod *param)
{
  pw_endpoint_link_emit (hooks, param, 0, seq, id, index, next, param);
}

static void
wp_endpoint_link_impl_pw_object_mixin_priv_interface_init (
    WpPwObjectMixinPrivInterface * iface)
{
  iface->flags |= WP_PW_OBJECT_MIXIN_PRIV_NO_PARAM_CACHE;
  iface->enum_params = NULL;
  iface->set_param = NULL;
  iface->emit_info = wp_impl_endpoint_link_emit_info;
  iface->emit_param = wp_impl_endpoint_link_emit_param;
}

WpImplEndpointLink *
wp_impl_endpoint_link_new (WpCore * core, WpSiLink * item)
{
  g_return_val_if_fail (WP_IS_CORE (core), NULL);

  return g_object_new (WP_TYPE_IMPL_ENDPOINT_LINK,
      "core", core,
      "item", item,
      NULL);
}