lib: begin working on a library to allow implementing policy plugins

lib/meson.build

+subdir('wp')

lib/wp/error.c

+/* WirePlumber
+ *
+ * Copyright © 2019 Collabora Ltd.
+ *    @author George Kiagiadakis <george.kiagiadakis@collabora.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published
+ * by the Free Software Foundation, either version 2.1 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+*/
+
+#include "error.h"
+
+G_DEFINE_QUARK (wireplumber-library, wp_domain_library);

lib/wp/error.h

+/* WirePlumber
+ *
+ * Copyright © 2019 Collabora Ltd.
+ *    @author George Kiagiadakis <george.kiagiadakis@collabora.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published
+ * by the Free Software Foundation, either version 2.1 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+*/
+
+#ifndef __WP_ERROR_H__
+#define __WP_ERROR_H__
+
+#include <glib.h>
+
+G_BEGIN_DECLS
+
+GQuark wp_domain_library_quark (void);
+#define WP_DOMAIN_LIBRARY (wp_domain_library_quark ())
+
+typedef enum {
+  WP_LIBRARY_ERROR_INVARIANT,
+} WpLibraryErrorEnum;
+
+G_END_DECLS
+
+#endif

lib/wp/interface-impl.c

+/* WirePlumber
+ *
+ * Copyright © 2019 Collabora Ltd.
+ *    @author George Kiagiadakis <george.kiagiadakis@collabora.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published
+ * by the Free Software Foundation, either version 2.1 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+*/
+
+#include "interface-impl.h"
+#include "object.h"
+
+typedef struct {
+  GObject *object;
+} WpInterfaceImplPrivate;
+
+G_DEFINE_ABSTRACT_TYPE_WITH_PRIVATE (WpInterfaceImpl, wp_interface_impl, G_TYPE_OBJECT);
+
+static void
+wp_interface_impl_init (WpInterfaceImpl * self)
+{
+}
+
+static void
+wp_interface_impl_finalize (GObject * obj)
+{
+  WpInterfaceImpl *self = WP_INTERFACE_IMPL (obj);
+  WpInterfaceImplPrivate *priv = wp_interface_impl_get_instance_private (self);
+
+  g_clear_weak_pointer (&priv->object);
+
+  G_OBJECT_CLASS (wp_interface_impl_parent_class)->finalize (obj);
+}
+
+static void
+wp_interface_impl_class_init (WpInterfaceImplClass * klass)
+{
+  GObjectClass *object_class = (GObjectClass *) klass;
+  object_class->finalize = wp_interface_impl_finalize;
+}
+
+/**
+ * wp_interface_impl_set_object: (skip)
+ * @self: the interface implementation instance
+ * @object: (nullable) (transfer none): the implementor
+ */
+void
+wp_interface_impl_set_object (WpInterfaceImpl * self, GObject * object)
+{
+  WpInterfaceImplPrivate *priv = wp_interface_impl_get_instance_private (self);
+
+  g_return_if_fail (WP_IS_INTERFACE_IMPL (self));
+  g_return_if_fail (WP_IS_OBJECT (object));
+
+  g_set_weak_pointer (&priv->object, object);
+}
+
+/**
+ * wp_interface_impl_get_object: (method)
+ * @self: the interface implementation instance
+ *
+ * Returns: (nullable) (transfer none): the object implementing this interface
+ */
+GObject *
+wp_interface_impl_get_object (WpInterfaceImpl * self)
+{
+  WpInterfaceImplPrivate *priv = wp_interface_impl_get_instance_private (self);
+
+  g_return_val_if_fail (WP_IS_INTERFACE_IMPL (self), NULL);
+
+  return priv->object;
+}
+
+/**
+ * wp_interface_impl_get_sibling: (method)
+ * @self: the interface implementation instance
+ * @interface: an interface type
+ *
+ * Returns: (nullable) (transfer full): the object implementing @interface
+ */
+GObject *
+wp_interface_impl_get_sibling (WpInterfaceImpl * self, GType interface)
+{
+  WpInterfaceImplPrivate *priv = wp_interface_impl_get_instance_private (self);
+  GObject *iface = NULL;
+
+  g_return_val_if_fail (WP_IS_INTERFACE_IMPL (self), NULL);
+  g_return_val_if_fail (G_TYPE_IS_INTERFACE (interface), NULL);
+
+  if (g_type_is_a (G_TYPE_FROM_INSTANCE (self), interface)) {
+    iface = G_OBJECT (g_object_ref (self));
+  } else if (priv->object) {
+    iface = wp_object_get_interface (WP_OBJECT (priv->object), interface);
+  }
+
+  return iface;
+}
+
+/**
+ * wp_interface_impl_get_prerequisites: (virtual get_prerequisites)
+ * @self: the interface implementation instance
+ * @n_prerequisites: (out): the number of elements in the returned array
+ *
+ * Returns: (array length=n_prerequisites) (transfer none): the types that are
+ *   required by this interface implementation
+ */
+GType *
+wp_interface_impl_get_prerequisites (WpInterfaceImpl * self,
+    guint * n_prerequisites)
+{
+  WpInterfaceImplClass * klass = WP_INTERFACE_IMPL_GET_CLASS (self);
+
+  g_return_val_if_fail (WP_IS_INTERFACE_IMPL (self), NULL);
+  g_return_val_if_fail (n_prerequisites != NULL, NULL);
+
+  if (klass->get_prerequisites)
+    return klass->get_prerequisites (self, n_prerequisites);
+
+  *n_prerequisites = 0;
+  return NULL;
+}

lib/wp/interface-impl.h

+/* WirePlumber
+ *
+ * Copyright © 2019 Collabora Ltd.
+ *    @author George Kiagiadakis <george.kiagiadakis@collabora.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published
+ * by the Free Software Foundation, either version 2.1 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+*/
+
+#ifndef __WP_INTERFACE_IMPL_H__
+#define __WP_INTERFACE_IMPL_H__
+
+#include <glib-object.h>
+
+G_BEGIN_DECLS
+
+G_DECLARE_DERIVABLE_TYPE (WpInterfaceImpl, wp_interface_impl, WP, INTERFACE_IMPL, GObject)
+
+struct _WpInterfaceImplClass
+{
+  GObjectClass parent_class;
+
+  /**
+   * get_prerequisites:
+   * @self: the interface implementation instance
+   * @n_prerequisites: (out): the number of elements in the returned array
+   *
+   * Returns: (array length=n_prerequisites) (transfer none): the types that are
+   *   required by this interface implementation
+   */
+  GType *(*get_prerequisites) (WpInterfaceImpl * self, guint * n_prerequisites);
+};
+
+void wp_interface_impl_set_object (WpInterfaceImpl * self, GObject * object);
+GObject * wp_interface_impl_get_object (WpInterfaceImpl * self);
+GObject * wp_interface_impl_get_sibling (WpInterfaceImpl * self,
+    GType interface);
+GType * wp_interface_impl_get_prerequisites (WpInterfaceImpl * self,
+    guint * n_prerequisites);
+
+G_END_DECLS
+
+#endif

lib/wp/meson.build

+wp_lib_sources = [
+  'error.c',
+  'interface-impl.c',
+  'object.c',
+]
+
+wp_lib_headers = [
+  'error.h',
+  'interface-impl.h',
+  'object.h',
+]
+
+enums = gnome.mkenums_simple('wpenums', sources: wp_lib_headers)
+
+wp_lib = library('wireplumber-' + wireplumber_api_version,
+  wp_lib_sources, enums,
+  c_args : [ '-D_GNU_SOURCE', '-DG_LOG_USE_STRUCTURED' ],
+  install: true,
+  dependencies : [gobject_dep, pipewire_dep],
+)
+
+gnome.generate_gir(wp_lib,
+  namespace: 'Wp',
+  nsversion: wireplumber_api_version,
+  sources: [wp_lib_sources, wp_lib_headers],
+  includes: ['GLib-2.0', 'GObject-2.0'],
+  install: true,
+)

lib/wp/object.c

+/* WirePlumber
+ *
+ * Copyright © 2019 Collabora Ltd.
+ *    @author George Kiagiadakis <george.kiagiadakis@collabora.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published
+ * by the Free Software Foundation, either version 2.1 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+*/
+
+#include "object.h"
+#include "error.h"
+
+typedef struct {
+  GArray *iface_objects;
+  GArray *iface_types;
+} WpObjectPrivate;
+
+G_DEFINE_TYPE_WITH_PRIVATE (WpObject, wp_object, G_TYPE_OBJECT);
+
+static void
+wp_object_init (WpObject * self)
+{
+  WpObjectPrivate *priv = wp_object_get_instance_private (self);
+
+  priv->iface_objects = g_array_new (FALSE, FALSE, sizeof (gpointer));
+  priv->iface_types = g_array_new (FALSE, FALSE, sizeof (GType));
+}
+
+static void
+wp_object_finalize (GObject * obj)
+{
+  WpObject *self = WP_OBJECT (obj);
+  WpObjectPrivate *priv = wp_object_get_instance_private (self);
+  guint i;
+
+  for (i = 0; i < priv->iface_objects->len; i++) {
+    GObject *obj = g_array_index (priv->iface_objects, GObject*, i);
+    wp_interface_impl_set_object (WP_INTERFACE_IMPL (obj), NULL);
+    g_object_unref (obj);
+  }
+
+  g_array_free (priv->iface_objects, TRUE);
+  g_array_free (priv->iface_types, TRUE);
+
+  G_OBJECT_CLASS (wp_object_parent_class)->finalize (obj);
+}
+
+static void
+wp_object_class_init (WpObjectClass * klass)
+{
+  GObjectClass *object_class = (GObjectClass *) klass;
+  object_class->finalize = wp_object_finalize;
+}
+
+/**
+ * wp_object_implements_interface: (method)
+ * @self: the object
+ * @interface: an interface type
+ *
+ * Returns: whether the interface is implemented in this object or not
+ */
+gboolean
+wp_object_implements_interface (WpObject * self, GType interface)
+{
+  WpObjectPrivate *priv = wp_object_get_instance_private (self);
+  guint i;
+
+  g_return_val_if_fail (WP_IS_OBJECT (self), FALSE);
+
+  for (i = 0; i < priv->iface_types->len; i++) {
+    GType t = g_array_index (priv->iface_types, GType, i);
+    if (t == interface)
+      return TRUE;
+  }
+
+  return FALSE;
+}
+
+/**
+ * wp_object_get_interface: (method)
+ * @self: the object
+ * @interface: an interface type
+ *
+ * Returns: (nullable) (transfer full): the object implementing @interface
+ */
+GObject *
+wp_object_get_interface (WpObject * self, GType interface)
+{
+  WpObjectPrivate *priv = wp_object_get_instance_private (self);
+  guint i;
+
+  g_return_val_if_fail (WP_IS_OBJECT (self), FALSE);
+
+  for (i = 0; i < priv->iface_objects->len; i++) {
+    GObject *obj = g_array_index (priv->iface_objects, GObject*, i);
+    if (g_type_is_a (G_TYPE_FROM_INSTANCE (obj), interface))
+      return g_object_ref (obj);
+  }
+
+  return NULL;
+}
+
+/**
+ * wp_object_list_interfaces: (method)
+ * @self: the object
+ * @n_interfaces: (out): the number of elements in the returned array
+ *
+ * Returns: (array length=n_interfaces) (transfer none): the interface types
+ *   that are implemented in this object
+ */
+GType *
+wp_object_list_interfaces (WpObject * self, guint * n_interfaces)
+{
+  WpObjectPrivate *priv = wp_object_get_instance_private (self);
+
+  g_return_val_if_fail (WP_IS_OBJECT (self), NULL);
+
+  *n_interfaces = priv->iface_types->len;
+  return (GType *) priv->iface_types->data;
+}
+
+/**
+ * wp_object_attach_interface_impl: (method)
+ * @self: the object
+ * @impl: (transfer none): the interface implementation
+ * @error: (out caller-allocates): a GError to return on failure
+ *
+ * Returns: TRUE one success, FALSE on error
+ */
+gboolean
+wp_object_attach_interface_impl (WpObject * self, WpInterfaceImpl * impl,
+    GError ** error)
+{
+  WpObjectPrivate *priv = wp_object_get_instance_private (self);
+  GType *new_ifaces;
+  GType *prerequisites;
+  guint n_new_ifaces;
+  guint n_prerequisites, n_satisfied = 0;
+  guint i, j;
+
+  g_return_val_if_fail (WP_IS_OBJECT (self), FALSE);
+  g_return_val_if_fail (WP_IS_INTERFACE_IMPL (impl), FALSE);
+
+  new_ifaces = g_type_interfaces (G_TYPE_FROM_INSTANCE (impl),
+      &n_new_ifaces);
+  prerequisites = wp_interface_impl_get_prerequisites (impl, &n_prerequisites);
+
+  for (i = 0; i < priv->iface_types->len; i++) {
+    GType t = g_array_index (priv->iface_types, GType, i);
+
+    for (j = 0; j < n_prerequisites; j++) {
+      if (prerequisites[j] == t)
+        n_satisfied++;
+    }
+
+    for (j = 0; j < n_new_ifaces; j++) {
+      if (new_ifaces[j] == t) {
+        g_set_error (error, WP_DOMAIN_LIBRARY, WP_LIBRARY_ERROR_INVARIANT,
+            "Interface %s is already provided on object %p",
+            g_type_name (t), self);
+        return FALSE;
+      }
+    }
+  }
+
+  if (n_satisfied != n_prerequisites) {
+    g_set_error (error, WP_DOMAIN_LIBRARY, WP_LIBRARY_ERROR_INVARIANT,
+        "Interface implementation %p has unsatisfied requirements", impl);
+    return FALSE;
+  }
+
+  g_object_ref (impl);
+  g_array_append_val (priv->iface_objects, impl);
+  g_array_append_vals (priv->iface_types, new_ifaces, n_new_ifaces);
+  wp_interface_impl_set_object (impl, G_OBJECT (self));
+  return TRUE;
+}

lib/wp/object.h

+/* WirePlumber
+ *
+ * Copyright © 2019 Collabora Ltd.
+ *    @author George Kiagiadakis <george.kiagiadakis@collabora.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published
+ * by the Free Software Foundation, either version 2.1 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+*/
+
+#ifndef __WP_OBJECT_H__
+#define __WP_OBJECT_H__
+
+#include "interface-impl.h"
+
+G_BEGIN_DECLS
+
+G_DECLARE_DERIVABLE_TYPE (WpObject, wp_object, WP, OBJECT, GObject)
+
+struct _WpObjectClass
+{
+  GObjectClass parent_class;
+};
+
+gboolean wp_object_implements_interface (WpObject * self, GType interface);
+GObject * wp_object_get_interface (WpObject * self, GType interface);
+GType * wp_object_list_interfaces (WpObject * self, guint * n_interfaces);
+
+gboolean wp_object_attach_interface_impl (WpObject * self,
+    WpInterfaceImpl * impl, GError ** error);
+
+G_END_DECLS
+
+#endif

meson.build

@@ -8,7 +8,12 @@ project('wireplumber', ['c'],
   ]
 )
 
-glib_dep = dependency('gobject-2.0')
+wireplumber_api_version = '0.1'
+
+gobject_dep = dependency('gobject-2.0')
 pipewire_dep = dependency('libpipewire-0.3')
 
+gnome = import('gnome')
+
+subdir('lib')
 subdir('src')

src/meson.build

@@ -9,5 +9,5 @@ executable('wireplumber',
   wp_sources,
   c_args : [ '-D_GNU_SOURCE', '-DG_LOG_USE_STRUCTURED' ],
   install: true,
-  dependencies : [glib_dep, pipewire_dep],
+  dependencies : [gobject_dep, pipewire_dep],
 )