lib: implement WpSiFactory, a factory for session items

lib/wp/meson.build

@@ -17,6 +17,7 @@ wp_lib_sources = files(
   'proxy.c',
   'session.c',
   'session-item.c',
+  'si-factory.c',
   'si-interfaces.c',
   'spa-props.c',
   'transition.c',
@@ -43,6 +44,7 @@ wp_lib_headers = files(
   'session.h',
   'session-item.h',
   'si-interfaces.h',
+  'si-factory.h',
   'transition.h',
   'wp.h',
 )

lib/wp/session-item.c

@@ -8,6 +8,7 @@
 
 /**
  * SECTION: WpSessionItem
+ * @title: Session Items
  */
 
 #include "session-item.h"
@@ -27,6 +28,9 @@ enum {
 
 guint32 signals[N_SIGNALS] = {0};
 
+/**
+ * WpSessionItem:
+ */
 G_DEFINE_ABSTRACT_TYPE_WITH_PRIVATE (WpSessionItem, wp_session_item, G_TYPE_OBJECT)
 
 static void

lib/wp/si-factory.c

+/* WirePlumber
+ *
+ * Copyright © 2020 Collabora Ltd.
+ *    @author George Kiagiadakis <george.kiagiadakis@collabora.com>
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+/**
+ * SECTION: WpSiFactory
+ * @title: Session Items Factory
+ */
+
+#include "si-factory.h"
+#include "private.h"
+
+enum {
+  PROP_0,
+  PROP_NAME,
+};
+
+typedef struct _WpSiFactoryPrivate WpSiFactoryPrivate;
+struct _WpSiFactoryPrivate
+{
+  GQuark name_quark;
+};
+
+/**
+ * WpSiFactory:
+ *
+ * A factory for session items.
+ *
+ * The most simple way to register a new item implementation would be:
+ * |[
+ * GVariantBuilder b = G_VARIANT_BUILDER_INIT ("a(ssymv)");
+ * g_variant_builder_add (&b, ...);
+ * wp_si_factory_register (core, wp_si_factory_new_simple (
+ *    "foobar", FOO_TYPE_BAR, g_variant_builder_end (&b)));
+ * ]|
+ *
+ * And the most simple way to construct an item from a registered factory:
+ * |[
+ * item = wp_session_item_make (core, "foobar");
+ * ]|
+ */
+G_DEFINE_ABSTRACT_TYPE_WITH_PRIVATE (WpSiFactory, wp_si_factory, G_TYPE_OBJECT)
+
+static void
+wp_si_factory_init (WpSiFactory * self)
+{
+}
+
+static void
+wp_si_factory_set_property (GObject * object, guint property_id,
+    const GValue * value, GParamSpec * pspec)
+{
+  WpSiFactory *self = WP_SI_FACTORY (object);
+  WpSiFactoryPrivate *priv = wp_si_factory_get_instance_private (self);
+
+  switch (property_id) {
+  case PROP_NAME:
+    priv->name_quark = g_quark_from_string (g_value_get_string (value));
+    break;
+  default:
+    G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+    break;
+  }
+}
+
+static void
+wp_si_factory_get_property (GObject * object, guint property_id, GValue * value,
+    GParamSpec * pspec)
+{
+  WpSiFactory *self = WP_SI_FACTORY (object);
+  WpSiFactoryPrivate *priv = wp_si_factory_get_instance_private (self);
+
+  switch (property_id) {
+  case PROP_NAME:
+    g_value_set_string (value, g_quark_to_string (priv->name_quark));
+    break;
+  default:
+    G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+    break;
+  }
+}
+
+static void
+wp_si_factory_class_init (WpSiFactoryClass * klass)
+{
+  GObjectClass * object_class = (GObjectClass *) klass;
+
+  object_class->get_property = wp_si_factory_get_property;
+  object_class->set_property = wp_si_factory_set_property;
+
+  g_object_class_install_property (object_class, PROP_NAME,
+      g_param_spec_string ("name", "name", "The factory's name", "",
+          G_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY | G_PARAM_STATIC_STRINGS));
+}
+
+/**
+ * wp_si_factory_get_name:
+ * @self: the factory
+ *
+ * Returns: the factory name
+ */
+const gchar *
+wp_si_factory_get_name (WpSiFactory * self)
+{
+  g_return_val_if_fail (WP_IS_SI_FACTORY (self), NULL);
+
+  WpSiFactoryPrivate *priv = wp_si_factory_get_instance_private (self);
+  return g_quark_to_string (priv->name_quark);
+}
+
+/**
+ * wp_si_factory_construct:
+ * @self: the factory
+ *
+ * Creates a new instance of the session item that is constructed
+ * by this factory
+ *
+ * Returns: (transfer full): a new session item instance
+ */
+WpSessionItem *
+wp_si_factory_construct (WpSiFactory * self)
+{
+  g_return_val_if_fail (WP_IS_SI_FACTORY (self), NULL);
+  g_return_val_if_fail (WP_SI_FACTORY_GET_CLASS (self)->construct, NULL);
+
+  return WP_SI_FACTORY_GET_CLASS (self)->construct (self);
+}
+
+/**
+ * wp_si_factory_get_config_spec:
+ * @self: the factory
+ *
+ * Returns a description of all the configuration options that the constructed
+ * items of this factory have. Configuration options are a way for items to
+ * accept input from external sources that affects their behavior, or to
+ * provide output for other items to consume as their configuration.
+ *
+ * The returned GVariant has the a(ssymv) type. This is an array of tuples,
+ * where each tuple has the following values, in order:
+ *  * s (string): the name of the option
+ *  * s (string): a GVariant type string, describing the type of the data
+ *  * y (byte): a combination of #WpSiConfigOptionFlags
+ *  * mv (optional variant): optionally, an additional variant
+ *    This is provided to allow extensions.
+ *
+ * Returns: (transfer full): the configuration description
+ */
+GVariant *
+wp_si_factory_get_config_spec (WpSiFactory * self)
+{
+  g_return_val_if_fail (WP_IS_SI_FACTORY (self), NULL);
+  g_return_val_if_fail (WP_SI_FACTORY_GET_CLASS (self)->get_config_spec, NULL);
+
+  return WP_SI_FACTORY_GET_CLASS (self)->get_config_spec (self);
+}
+
+/**
+ * wp_si_factory_register:
+ * @core: the core
+ * @factory: (transfer full): the factory to register
+ *
+ * Registers the @factory on the @core.
+ */
+void
+wp_si_factory_register (WpCore * core, WpSiFactory * factory)
+{
+  g_return_if_fail (WP_IS_CORE (core));
+  g_return_if_fail (WP_IS_SI_FACTORY (factory));
+
+  wp_registry_register_object (wp_core_get_registry (core), factory);
+}
+
+static gboolean
+find_factory_func (gpointer factory, gpointer name_quark)
+{
+  if (!WP_IS_SI_FACTORY (factory))
+    return FALSE;
+
+  WpSiFactoryPrivate *priv =
+      wp_si_factory_get_instance_private ((WpSiFactory *) factory);
+  return priv->name_quark == GPOINTER_TO_UINT (name_quark);
+}
+
+/**
+ * wp_si_factory_find:
+ * @core: the core
+ * @factory_name: the lookup name
+ *
+ * Returns: (transfer full) (nullable): the factory matching the lookup name
+ */
+WpSiFactory *
+wp_si_factory_find (WpCore * core, const gchar * factory_name)
+{
+  g_return_val_if_fail (WP_IS_CORE (core), NULL);
+
+  GQuark q = g_quark_try_string (factory_name);
+  if (q == 0)
+    return NULL;
+  GObject *f = wp_registry_find_object (wp_core_get_registry (core),
+      (GEqualFunc) find_factory_func, GUINT_TO_POINTER (q));
+  return f ? WP_SI_FACTORY (f) : NULL;
+}
+
+/**
+ * wp_session_item_make:
+ * @core: the #WpCore
+ * @factory_name: the name of the factory to be used for constructing the object
+ *
+ * Finds the factory associated with the given @name from the @core and
+ * uses it to construct a new #WpSessionItem.
+ *
+ * Returns: (transfer full) (nullable): the new session item
+ */
+WpSessionItem *
+wp_session_item_make (WpCore * core, const gchar * factory_name)
+{
+  g_autoptr (WpSiFactory) f = wp_si_factory_find (core, factory_name);
+  return f ? wp_si_factory_construct (f) : NULL;
+}
+
+struct _WpSimpleSiFactory
+{
+  WpSiFactory parent;
+  GType si_type;
+  GVariant *config_spec;
+};
+
+G_DECLARE_FINAL_TYPE (WpSimpleSiFactory, wp_simple_si_factory,
+                      WP, SIMPLE_SI_FACTORY, WpSiFactory)
+G_DEFINE_TYPE (WpSimpleSiFactory, wp_simple_si_factory, WP_TYPE_SI_FACTORY)
+
+static void
+wp_simple_si_factory_init (WpSimpleSiFactory * self)
+{
+}
+
+static void
+wp_simple_si_factory_finalize (GObject * object)
+{
+  WpSimpleSiFactory * self = WP_SIMPLE_SI_FACTORY (object);
+
+  g_clear_pointer (&self->config_spec, g_variant_unref);
+
+  G_OBJECT_CLASS (wp_simple_si_factory_parent_class)->finalize (object);
+}
+
+static WpSessionItem *
+wp_simple_si_factory_construct (WpSiFactory * self)
+{
+  return g_object_new (WP_SIMPLE_SI_FACTORY (self)->si_type, NULL);
+}
+
+static GVariant *
+wp_simple_si_factory_get_config_spec (WpSiFactory * self)
+{
+  return g_variant_ref (WP_SIMPLE_SI_FACTORY (self)->config_spec);
+}
+
+static void
+wp_simple_si_factory_class_init (WpSimpleSiFactoryClass * klass)
+{
+  GObjectClass * object_class = (GObjectClass *) klass;
+  WpSiFactoryClass * factory_class = (WpSiFactoryClass *) klass;
+
+  object_class->finalize = wp_simple_si_factory_finalize;
+
+  factory_class->construct = wp_simple_si_factory_construct;
+  factory_class->get_config_spec = wp_simple_si_factory_get_config_spec;
+}
+
+/**
+ * wp_si_factory_new_simple:
+ * @factory_name: the factory name; must be a static string!
+ * @si_type: the #WpSessionItem subclass type to instantiate for
+ *    constructing items
+ * @config_spec: (transfer floating): the config spec that will be returned
+ *    by wp_si_factory_get_config_spec()
+ *
+ * Returns: (transfer full): the new factory
+ */
+WpSiFactory *
+wp_si_factory_new_simple (const gchar * factory_name,
+    GType si_type, GVariant * config_spec)
+{
+  g_return_val_if_fail (factory_name != NULL, NULL);
+  g_return_val_if_fail (g_type_is_a (si_type, WP_TYPE_SESSION_ITEM), NULL);
+  g_return_val_if_fail (
+      g_variant_is_of_type (config_spec, G_VARIANT_TYPE ("a{sv}")), NULL);
+
+  WpSimpleSiFactory *self = g_object_new (
+      wp_simple_si_factory_get_type (), NULL);
+
+  /* assign the quark directly to use g_quark_from_static_string */
+  WpSiFactoryPrivate *priv =
+      wp_si_factory_get_instance_private (WP_SI_FACTORY (self));
+  priv->name_quark = g_quark_from_static_string (factory_name);
+
+  self->si_type = si_type;
+  self->config_spec = g_variant_ref_sink (config_spec);
+
+  return WP_SI_FACTORY (self);
+}

lib/wp/si-factory.h

+/* WirePlumber
+ *
+ * Copyright © 2020 Collabora Ltd.
+ *    @author George Kiagiadakis <george.kiagiadakis@collabora.com>
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#ifndef __WIREPLUMBER_SI_FACTORY_H__
+#define __WIREPLUMBER_SI_FACTORY_H__
+
+#include "core.h"
+#include "session-item.h"
+
+G_BEGIN_DECLS
+
+/**
+ * WP_TYPE_SI_FACTORY:
+ *
+ * The #WpSiFactory #GType
+ */
+#define WP_TYPE_SI_FACTORY (wp_si_factory_get_type ())
+WP_API
+G_DECLARE_DERIVABLE_TYPE (WpSiFactory, wp_si_factory, WP, SI_FACTORY, GObject)
+
+struct _WpSiFactoryClass
+{
+  GObjectClass parent_class;
+
+  WpSessionItem * (*construct) (WpSiFactory * self);
+  GVariant * (*get_config_spec) (WpSiFactory * self);
+};
+
+WP_API
+WpSiFactory * wp_si_factory_new_simple (const gchar * factory_name,
+    GType si_type, GVariant * config_spec);
+
+WP_API
+const gchar * wp_si_factory_get_name (WpSiFactory * self);
+
+WP_API
+WpSessionItem * wp_si_factory_construct (WpSiFactory * self);
+
+WP_API
+GVariant * wp_si_factory_get_config_spec (WpSiFactory * self);
+
+WP_API
+void wp_si_factory_register (WpCore * core, WpSiFactory * factory);
+
+WP_API
+WpSiFactory * wp_si_factory_find (WpCore * core, const gchar * factory_name);
+
+WP_API
+WpSessionItem * wp_session_item_make (WpCore * core, const gchar * factory_name);
+
+G_END_DECLS
+
+#endif

lib/wp/wp.h

@@ -25,5 +25,6 @@
 #include "session.h"
 #include "session-item.h"
 #include "si-interfaces.h"
+#include "si-factory.h"
 #include "transition.h"
 #include "wpenums.h"