C++ GST_IS_OBJECT函数代码示例

/**
 * gst_object_replace:
 * @oldobj: (inout) (transfer full): pointer to a place of a #GstObject to
 *     replace
 * @newobj: (transfer none): a new #GstObject
 *
 * Unrefs the #GstObject pointed to by @oldobj, refs @newobj and
 * puts @newobj in *@oldobj. Be carefull when calling this
 * function, it does not take any locks. You might want to lock
 * the object owning @oldobj pointer before calling this
 * function.
 *
 * Make sure not to LOCK @oldobj because it might be unreffed
 * which could cause a deadlock when it is disposed.
 *
 * Since 0.10.36, this function operates atomically.
 */
void
gst_object_replace (GstObject ** oldobj, GstObject * newobj)
{
  GstObject *oldptr;

  g_return_if_fail (oldobj != NULL);
  g_return_if_fail (*oldobj == NULL || GST_IS_OBJECT (*oldobj));
  g_return_if_fail (newobj == NULL || GST_IS_OBJECT (newobj));

#ifdef DEBUG_REFCOUNT
  GST_CAT_TRACE (GST_CAT_REFCOUNTING, "replace %p %s (%d) with %p %s (%d)",
      *oldobj, *oldobj ? GST_STR_NULL (GST_OBJECT_NAME (*oldobj)) : "(NONE)",
      *oldobj ? G_OBJECT (*oldobj)->ref_count : 0,
      newobj, newobj ? GST_STR_NULL (GST_OBJECT_NAME (newobj)) : "(NONE)",
      newobj ? G_OBJECT (newobj)->ref_count : 0);
#endif

  if (newobj)
    g_object_ref (newobj);
  do {
    oldptr = *oldobj;
  } while (!G_ATOMIC_POINTER_COMPARE_AND_EXCHANGE (oldobj, oldptr, newobj));
  if (oldptr)
    g_object_unref (oldptr);
}

EXPORT_C
#endif

void
gst_object_replace (GstObject ** oldobj, GstObject * newobj)
{
  g_return_if_fail (oldobj != NULL);
  g_return_if_fail (*oldobj == NULL || GST_IS_OBJECT (*oldobj));
  g_return_if_fail (newobj == NULL || GST_IS_OBJECT (newobj));

#ifdef DEBUG_REFCOUNT
  GST_CAT_LOG (GST_CAT_REFCOUNTING, "replace %p %s (%d) with %p %s (%d)",
      *oldobj, *oldobj ? GST_STR_NULL (GST_OBJECT_NAME (*oldobj)) : "(NONE)",
      *oldobj ? G_OBJECT (*oldobj)->ref_count : 0,
      newobj, newobj ? GST_STR_NULL (GST_OBJECT_NAME (newobj)) : "(NONE)",
      newobj ? G_OBJECT (newobj)->ref_count : 0);
#endif

  if (G_LIKELY (*oldobj != newobj)) {
    if (newobj)
      gst_object_ref (newobj);
    if (*oldobj)
      gst_object_unref (*oldobj);

    *oldobj = newobj;
  }
}

/**
 * gst_object_set_parent:
 * @object: a #GstObject
 * @parent: new parent of object
 *
 * Sets the parent of @object to @parent. The object's reference count will
 * be incremented, and any floating reference will be removed (see gst_object_ref_sink()).
 *
 * Returns: TRUE if @parent could be set or FALSE when @object
 * already had a parent or @object and @parent are the same.
 *
 * MT safe. Grabs and releases @object's LOCK.
 */
gboolean
gst_object_set_parent (GstObject * object, GstObject * parent)
{
  g_return_val_if_fail (GST_IS_OBJECT (object), FALSE);
  g_return_val_if_fail (GST_IS_OBJECT (parent), FALSE);
  g_return_val_if_fail (object != parent, FALSE);

  GST_CAT_DEBUG_OBJECT (GST_CAT_REFCOUNTING, object,
      "set parent (ref and sink)");

  GST_OBJECT_LOCK (object);
  if (G_UNLIKELY (object->parent != NULL))
    goto had_parent;

  object->parent = parent;
  gst_object_ref_sink (object);
  GST_OBJECT_UNLOCK (object);

  /* FIXME, this does not work, the deep notify takes the lock from the parent
   * object and deadlocks when the parent holds its lock when calling this
   * function (like _element_add_pad()) */
  /* g_object_notify_by_pspec ((GObject *)object, properties[PROP_PARENT]); */

  return TRUE;

  /* ERROR handling */
had_parent:
  {
    GST_CAT_DEBUG_OBJECT (GST_CAT_REFCOUNTING, object,
        "set parent failed, object already had a parent");
    GST_OBJECT_UNLOCK (object);
    return FALSE;
  }
}

/**
 * gst_child_proxy_set_valist:
 * @object: the parent object
 * @first_property_name: name of the first property to set
 * @var_args: value for the first property, followed optionally by more name/value pairs, followed by NULL
 *
 * Sets properties of the parent object and its children.
 */
void
gst_child_proxy_set_valist (GstChildProxy * object,
    const gchar * first_property_name, va_list var_args)
{
  const gchar *name;
  gchar *error = NULL;
  GValue value = { 0, };
  GParamSpec *pspec;
  GObject *target;

  g_return_if_fail (GST_IS_CHILD_PROXY (object));

  name = first_property_name;

  /* iterate over pairs */
  while (name) {
    if (!gst_child_proxy_lookup (object, name, &target, &pspec))
      goto not_found;

    G_VALUE_COLLECT_INIT (&value, pspec->value_type, var_args,
        G_VALUE_NOCOPY_CONTENTS, &error);

    if (error)
      goto cant_copy;

    g_object_set_property (target, pspec->name, &value);
    g_object_unref (target);

    g_value_unset (&value);
    name = va_arg (var_args, gchar *);
  }
  return;

not_found:
  {
    g_warning ("no property %s in object %s", name,
        (GST_IS_OBJECT (object) ? GST_OBJECT_NAME (object) : ""));
    return;
  }
cant_copy:
  {
    g_warning ("error copying value %s in object %s: %s", pspec->name,
        (GST_IS_OBJECT (object) ? GST_OBJECT_NAME (object) : ""), error);
    g_value_unset (&value);
    g_object_unref (target);
    return;
  }
}

void
gst_debugserver_log_send_log (GstDebugserverLog * log,
    GstDebugserverTcp * tcp_server, GstDebugCategory * category,
    GstDebugLevel level, const gchar * file, const gchar * function, gint line,
    GObject * object, GstDebugMessage * message)
{
  GstDebugger__GStreamerData gst_data = GST_DEBUGGER__GSTREAMER_DATA__INIT;
  GstDebugger__LogInfo log_info = GST_DEBUGGER__LOG_INFO__INIT;

  log_info.level = (gint) level;
  log_info.category = (gchar *) gst_debug_category_get_name (category);
  log_info.file = (gchar *) file;
  log_info.function = (gchar *) function;
  log_info.line = line;

  if (GST_IS_OBJECT (object)) {
    log_info.object = GST_OBJECT_NAME (object);
  } else {
    log_info.object = (gchar *) G_OBJECT_TYPE_NAME (object);
  }

  log_info.message = (gchar *) gst_debug_message_get (message);

  gst_data.info_type_case = GST_DEBUGGER__GSTREAMER_DATA__INFO_TYPE_LOG_INFO;
  gst_data.log_info = &log_info;

  gst_debugserver_hooks_send_data (&log->hooks, tcp_server, &gst_data);
}

EXPORT_C
#endif

gboolean
gst_object_set_name (GstObject * object, const gchar * name)
{
  gboolean result;

  g_return_val_if_fail (GST_IS_OBJECT (object), FALSE);

  GST_OBJECT_LOCK (object);

  /* parented objects cannot be renamed */
  if (G_UNLIKELY (object->parent != NULL))
    goto had_parent;

  if (name != NULL) {
    g_free (object->name);
    object->name = g_strdup (name);
    GST_OBJECT_UNLOCK (object);
    result = TRUE;
  } else {
    GST_OBJECT_UNLOCK (object);
    result = gst_object_set_name_default (object);
  }
  return result;

  /* error */
had_parent:
  {
    GST_WARNING ("parented objects can't be renamed");
    GST_OBJECT_UNLOCK (object);
    return FALSE;
  }
}

EXPORT_C
#endif

void
gst_object_unparent (GstObject * object)
{
  GstObject *parent;

  g_return_if_fail (GST_IS_OBJECT (object));

  GST_OBJECT_LOCK (object);
  parent = object->parent;

  if (G_LIKELY (parent != NULL)) {
    GST_CAT_LOG_OBJECT (GST_CAT_REFCOUNTING, object, "unparent");
    object->parent = NULL;
    GST_OBJECT_UNLOCK (object);

    g_signal_emit (object, gst_object_signals[PARENT_UNSET], 0, parent);

    gst_object_unref (object);
  } else {
    GST_OBJECT_UNLOCK (object);
  }
}

/**
 * gst_child_proxy_set_property:
 * @object: the parent object
 * @name: name of the property to set
 * @value: new #GValue for the property
 *
 * Sets a single property using the GstChildProxy mechanism.
 */
void
gst_child_proxy_set_property (GstChildProxy * object, const gchar * name,
    const GValue * value)
{
  GParamSpec *pspec;
  GObject *target;

  g_return_if_fail (GST_IS_CHILD_PROXY (object));
  g_return_if_fail (name != NULL);
  g_return_if_fail (G_IS_VALUE (value));

  if (!gst_child_proxy_lookup (object, name, &target, &pspec))
    goto not_found;

  g_object_set_property (target, pspec->name, value);
  g_object_unref (target);
  return;

not_found:
  {
    g_warning ("cannot set property %s on object %s", name,
        (GST_IS_OBJECT (object) ? GST_OBJECT_NAME (object) : ""));
    return;
  }
}

static void gst_log_android_handler(GstDebugCategory *category,
                 GstDebugLevel level,
                 const gchar *file,
                 const gchar *function,
                 gint line,
                 GObject *object,
                 GstDebugMessage *message,
                 gpointer data)
{
    gchar *obj = NULL;

    OWR_UNUSED(data);

    if (level > gst_debug_category_get_threshold(category))
      return;

    if (GST_IS_PAD(object) && GST_OBJECT_NAME(object)) {
      obj = g_strdup_printf("<%s:%s>", GST_DEBUG_PAD_NAME(object));
    } else if (GST_IS_OBJECT(object)) {
      obj = g_strdup_printf("<%s>", GST_OBJECT_NAME(object));
    }

    __android_log_print(ANDROID_LOG_INFO, "gst_log", "%p %s %s %s:%d:%s:%s %s\n",
            (void *)g_thread_self(),
            gst_debug_level_get_name(level), gst_debug_category_get_name(category),
            file, line, function, obj ? obj : "", gst_debug_message_get(message));

    g_free(obj);
}

/**
 * gst_index_get_writer_id:
 * @index: the index to get a unique write id for
 * @writer: the GstObject to allocate an id for
 * @id: a pointer to a gint to hold the id
 *
 * Before entries can be added to the index, a writer
 * should obtain a unique id. The methods to add new entries
 * to the index require this id as an argument.
 *
 * The application can implement a custom function to map the writer object
 * to a string. That string will be used to register or look up an id
 * in the index.
 *
 * <note>
 * The caller must not hold @writer's #GST_OBJECT_LOCK, as the default
 * resolver may call functions that take the object lock as well, and
 * the lock is not recursive.
 * </note>
 *
 * Returns: TRUE if the writer would be mapped to an id.
 */
gboolean
gst_index_get_writer_id (GstIndex * index, GstObject * writer, gint * id)
{
  gchar *writer_string = NULL;
  GstIndexEntry *entry;
  GstIndexClass *iclass;
  gboolean success = FALSE;

  g_return_val_if_fail (GST_IS_INDEX (index), FALSE);
  g_return_val_if_fail (GST_IS_OBJECT (writer), FALSE);
  g_return_val_if_fail (id, FALSE);

  *id = -1;

  /* first try to get a previously cached id */
  entry = g_hash_table_lookup (index->writers, writer);
  if (entry == NULL) {

    iclass = GST_INDEX_GET_CLASS (index);

    /* let the app make a string */
    if (index->resolver) {
      gboolean res;

      res =
          index->resolver (index, writer, &writer_string,
          index->resolver_user_data);
      if (!res)
        return FALSE;
    } else {
      g_warning ("no resolver found");
      return FALSE;
    }

    /* if the index has a resolver, make it map this string to an id */
    if (iclass->get_writer_id) {
      success = iclass->get_writer_id (index, id, writer_string);
    }
    /* if the index could not resolve, we allocate one ourselves */
    if (!success) {
      *id = ++index->last_id;
    }

    entry = gst_index_add_id (index, *id, writer_string);
    if (!entry) {
      /* index is probably not writable, make an entry anyway
       * to keep it in our cache */
      entry = g_slice_new (GstIndexEntry);
      entry->type = GST_INDEX_ENTRY_ID;
      entry->id = *id;
      entry->data.id.description = writer_string;
    }
    g_hash_table_insert (index->writers, writer, entry);
  } else {
    *id = entry->id;
  }

  return TRUE;
}

static void
gst_object_real_restore_thyself (GstObject * object, xmlNodePtr self)
{
  g_return_if_fail (GST_IS_OBJECT (object));
  g_return_if_fail (self != NULL);

  gst_class_signal_emit_by_name (object, "object_loaded", self);
}

EXPORT_C
#endif

gboolean
gst_object_set_parent (GstObject * object, GstObject * parent)
{
  g_return_val_if_fail (GST_IS_OBJECT (object), FALSE);
  g_return_val_if_fail (GST_IS_OBJECT (parent), FALSE);
  g_return_val_if_fail (object != parent, FALSE);

  GST_CAT_DEBUG_OBJECT (GST_CAT_REFCOUNTING, object,
      "set parent (ref and sink)");

  GST_OBJECT_LOCK (object);
  if (G_UNLIKELY (object->parent != NULL))
    goto had_parent;

  /* sink object, we don't call our own function because we don't
   * need to release/acquire the lock needlessly or touch the refcount
   * in the floating case. */
  object->parent = parent;
  if (G_LIKELY (GST_OBJECT_IS_FLOATING (object))) {
    GST_CAT_LOG_OBJECT (GST_CAT_REFCOUNTING, object, "unsetting floating flag");
    GST_OBJECT_FLAG_UNSET (object, GST_OBJECT_FLOATING);
    GST_OBJECT_UNLOCK (object);
  } else {
    GST_OBJECT_UNLOCK (object);
    gst_object_ref (object);
  }

  g_signal_emit (object, gst_object_signals[PARENT_SET], 0, parent);

  return TRUE;

  /* ERROR handling */
had_parent:
  {
    GST_CAT_DEBUG_OBJECT (GST_CAT_REFCOUNTING, object,
        "set parent failed, object already had a parent");
    GST_OBJECT_UNLOCK (object);
    return FALSE;
  }
}

void
gst_object_set_name_prefix (GstObject * object, const gchar * name_prefix)
{
  g_return_if_fail (GST_IS_OBJECT (object));

  GST_OBJECT_LOCK (object);
  g_free (object->name_prefix);
  object->name_prefix = g_strdup (name_prefix); /* NULL gives NULL */
  GST_OBJECT_UNLOCK (object);
}

/**
 * gst_child_proxy_lookup:
 * @childproxy: child proxy object to lookup the property in
 * @name: name of the property to look up
 * @target: (out) (allow-none) (transfer full): pointer to a #GObject that
 *     takes the real object to set property on
 * @pspec: (out) (allow-none) (transfer none): pointer to take the #GParamSpec
 *     describing the property
 *
 * Looks up which object and #GParamSpec would be effected by the given @name.
 *
 * MT safe.
 *
 * Returns: TRUE if @target and @pspec could be found. FALSE otherwise. In that
 * case the values for @pspec and @target are not modified. Unref @target after
 * usage. For plain GObjects @target is the same as @object.
 */
gboolean
gst_child_proxy_lookup (GstChildProxy * childproxy, const gchar * name,
    GObject ** target, GParamSpec ** pspec)
{
  GObject *object;
  gboolean res = FALSE;
  gchar **names, **current;

  g_return_val_if_fail (GST_IS_CHILD_PROXY (childproxy), FALSE);
  g_return_val_if_fail (name != NULL, FALSE);

  object = g_object_ref (childproxy);

  current = names = g_strsplit (name, "::", -1);
  /* find the owner of the property */
  while (current[1]) {
    GObject *next;

    if (!GST_IS_CHILD_PROXY (object)) {
      GST_INFO
          ("object %s is not a parent, so you cannot request a child by name %s",
          (GST_IS_OBJECT (object) ? GST_OBJECT_NAME (object) : ""), current[0]);
      break;
    }
    next = gst_child_proxy_get_child_by_name (GST_CHILD_PROXY (object),
        current[0]);
    if (!next) {
      GST_INFO ("no such object %s", current[0]);
      break;
    }
    g_object_unref (object);
    object = next;
    current++;
  }

  /* look for psec */
  if (current[1] == NULL) {
    GParamSpec *spec =
        g_object_class_find_property (G_OBJECT_GET_CLASS (object), current[0]);
    if (spec == NULL) {
      GST_INFO ("no param spec named %s", current[0]);
    } else {
      if (pspec)
        *pspec = spec;
      if (target) {
        g_object_ref (object);
        *target = object;
      }
      res = TRUE;
    }
  }
  g_object_unref (object);
  g_strfreev (names);
  return res;
}

GstCaps *
gst_type_find_helper (GstPad * src, guint64 size)
{
  GstTypeFindHelperGetRangeFunction func;

  g_return_val_if_fail (GST_IS_OBJECT (src), NULL);
  g_return_val_if_fail (GST_PAD_GETRANGEFUNC (src) != NULL, NULL);

  func = (GstTypeFindHelperGetRangeFunction) (GST_PAD_GETRANGEFUNC (src));

  return gst_type_find_helper_get_range (GST_OBJECT (src), func, size, NULL);
}