encoder: fix subclassing process.

Fix the GstVaapiEncoderClass parent class type. Make sure to validate
subclass hooks as early as possible, i.e. in gst_vaapi_encoder_init(),
thus avoiding useless run-time checks. Also simplify the subclass
initialization process to be less error prone.

6 files changed, 63 insertions, 140 deletions

diff --git a/gst-libs/gst/vaapi/gstvaapiencoder.c b/gst-libs/gst/vaapi/gstvaapiencoder.c
index 61f063a6..adb5b2cd 100644
--- a/gst-libs/gst/vaapi/gstvaapiencoder.c
+++ b/gst-libs/gst/vaapi/gstvaapiencoder.c
@@ -261,9 +261,6 @@ gst_vaapi_encoder_put_frame (GstVaapiEncoder * encoder,
   GstVaapiCodedBufferProxy *coded_buf = NULL;
   GstVaapiEncoderSyncPic *sync_pic = NULL;
 
-  if (!klass->reordering || !klass->encode)
-    goto error;
-
 again:
   picture = NULL;
   sync_pic = NULL;
@@ -350,18 +347,9 @@ end:
 GstVaapiEncoderStatus
 gst_vaapi_encoder_flush (GstVaapiEncoder * encoder)
 {
-  GstVaapiEncoderStatus ret = GST_VAAPI_ENCODER_STATUS_SUCCESS;
   GstVaapiEncoderClass *const klass = GST_VAAPI_ENCODER_GET_CLASS (encoder);
 
-  if (!klass->flush)
-    goto error;
-
-  ret = klass->flush (encoder);
-  return ret;
-
-error:
-  GST_ERROR ("flush failed");
-  return GST_VAAPI_ENCODER_STATUS_FUNC_PTR_ERR;
+  return klass->flush (encoder);
 }
 
 GstVaapiEncoderStatus
@@ -390,9 +378,8 @@ gst_vaapi_encoder_ensure_context (GstVaapiEncoder * encoder)
     return TRUE;
 
   memset (&info, 0, sizeof (info));
-  if (!klass->get_context_info || !klass->get_context_info (encoder, &info)) {
+  if (!klass->get_context_info (encoder, &info))
     return FALSE;
-  }
 
   context = gst_vaapi_context_new_full (GST_VAAPI_ENCODER_DISPLAY (encoder),
       &info);
@@ -418,9 +405,6 @@ gst_vaapi_encoder_set_format (GstVaapiEncoder * encoder,
   }
   GST_VAAPI_ENCODER_VIDEO_INFO (encoder) = in_state->info;
 
-  if (!klass->set_format)
-    goto error;
-
   out_caps = klass->set_format (encoder, in_state, ref_caps);
   if (!out_caps)
     goto error;
@@ -460,19 +444,28 @@ error:
 static gboolean
 gst_vaapi_encoder_init (GstVaapiEncoder * encoder, GstVaapiDisplay * display)
 {
-  GstVaapiEncoderClass *kclass = GST_VAAPI_ENCODER_GET_CLASS (encoder);
+  GstVaapiEncoderClass *const klass = GST_VAAPI_ENCODER_GET_CLASS (encoder);
 
-  g_assert (kclass);
-  g_assert (display);
+  g_return_val_if_fail (display != NULL, FALSE);
 
-  g_return_val_if_fail (display, FALSE);
-  g_return_val_if_fail (encoder->display == NULL, FALSE);
+#define CHECK_VTABLE_HOOK(FUNC) do {            \
+    if (!klass->FUNC)                           \
+      goto error_invalid_vtable;                \
+  } while (0)
+
+  CHECK_VTABLE_HOOK (init);
+  CHECK_VTABLE_HOOK (finalize);
+  CHECK_VTABLE_HOOK (encode);
+  CHECK_VTABLE_HOOK (reordering);
+  CHECK_VTABLE_HOOK (flush);
+  CHECK_VTABLE_HOOK (get_context_info);
+  CHECK_VTABLE_HOOK (set_format);
+
+#undef CHECK_VTABLE_HOOK
 
   encoder->display = gst_vaapi_display_ref (display);
   encoder->va_display = gst_vaapi_display_get_display (display);
-  encoder->context = NULL;
   encoder->va_context = VA_INVALID_ID;
-  encoder->caps = NULL;
 
   gst_video_info_init (&encoder->video_info);
 
@@ -482,18 +475,22 @@ gst_vaapi_encoder_init (GstVaapiEncoder * encoder, GstVaapiDisplay * display)
   g_queue_init (&encoder->sync_pictures);
   g_cond_init (&encoder->sync_ready);
 
-  if (kclass->init)
-    return kclass->init (encoder);
-  return TRUE;
+  return klass->init (encoder);
+
+  /* ERRORS */
+error_invalid_vtable:
+  {
+    GST_ERROR ("invalid subclass hook (internal error)");
+    return FALSE;
+  }
 }
 
-static void
-gst_vaapi_encoder_destroy (GstVaapiEncoder * encoder)
+void
+gst_vaapi_encoder_finalize (GstVaapiEncoder * encoder)
 {
   GstVaapiEncoderClass *const klass = GST_VAAPI_ENCODER_GET_CLASS (encoder);
 
-  if (klass->destroy)
-    klass->destroy (encoder);
+  klass->finalize (encoder);
 
   gst_vaapi_encoder_free_sync_pictures (encoder);
   gst_vaapi_video_pool_replace (&encoder->codedbuf_pool, NULL);
@@ -508,22 +505,6 @@ gst_vaapi_encoder_destroy (GstVaapiEncoder * encoder)
   g_cond_clear (&encoder->sync_ready);
 }
 
-void
-gst_vaapi_encoder_finalize (GstVaapiEncoder * encoder)
-{
-  gst_vaapi_encoder_destroy (encoder);
-}
-
-void
-gst_vaapi_encoder_class_init (GstVaapiEncoderClass * klass)
-{
-  GstVaapiMiniObjectClass *const object_class =
-      GST_VAAPI_MINI_OBJECT_CLASS (klass);
-
-  object_class->size = sizeof (GstVaapiEncoder);
-  object_class->finalize = (GDestroyNotify) gst_vaapi_encoder_finalize;
-}
-
 GstVaapiEncoder *
 gst_vaapi_encoder_new (const GstVaapiEncoderClass * klass,
     GstVaapiDisplay * display)
diff --git a/gst-libs/gst/vaapi/gstvaapiencoder_h264.c b/gst-libs/gst/vaapi/gstvaapiencoder_h264.c
index a7fa921c..01546daf 100644
--- a/gst-libs/gst/vaapi/gstvaapiencoder_h264.c
+++ b/gst-libs/gst/vaapi/gstvaapiencoder_h264.c
@@ -1711,10 +1711,10 @@ gst_vaapi_encoder_h264_init (GstVaapiEncoder * base)
 }
 
 static void
-gst_vaapi_encoder_h264_destroy (GstVaapiEncoder * base)
+gst_vaapi_encoder_h264_finalize (GstVaapiEncoder * base)
 {
   /*free private buffers */
-  GstVaapiEncoderH264 *encoder = GST_VAAPI_ENCODER_H264 (base);
+  GstVaapiEncoderH264 *const encoder = GST_VAAPI_ENCODER_H264 (base);
   GstVaapiEncPicture *pic;
   GstVaapiEncoderH264Ref *ref;
 
@@ -1736,38 +1736,14 @@ gst_vaapi_encoder_h264_destroy (GstVaapiEncoder * base)
 
 }
 
-static void
-gst_vaapi_encoder_h264_class_init (GstVaapiEncoderH264Class * klass)
-{
-  GstVaapiMiniObjectClass *const object_class =
-      GST_VAAPI_MINI_OBJECT_CLASS (klass);
-  GstVaapiEncoderClass *const encoder_class = GST_VAAPI_ENCODER_CLASS (klass);
-
-  gst_vaapi_encoder_class_init (encoder_class);
-
-  object_class->size = sizeof (GstVaapiEncoderH264);
-
-  encoder_class->init = gst_vaapi_encoder_h264_init;
-  encoder_class->destroy = gst_vaapi_encoder_h264_destroy;
-  encoder_class->set_format = gst_vaapi_encoder_h264_set_format;
-  encoder_class->get_context_info = gst_vaapi_encoder_h264_get_context_info;
-  encoder_class->reordering = gst_vaapi_encoder_h264_reordering;
-  encoder_class->encode = gst_vaapi_encoder_h264_encode;
-  encoder_class->get_codec_data = gst_vaapi_encoder_h264_get_codec_data;
-  encoder_class->flush = gst_vaapi_encoder_h264_flush;
-}
-
 static inline const GstVaapiEncoderClass *
 gst_vaapi_encoder_h264_class ()
 {
-  static GstVaapiEncoderH264Class g_class;
-  static gsize g_class_init = FALSE;
-
-  if (g_once_init_enter (&g_class_init)) {
-    gst_vaapi_encoder_h264_class_init (&g_class);
-    g_once_init_leave (&g_class_init, TRUE);
-  }
-  return GST_VAAPI_ENCODER_CLASS (&g_class);
+  static const GstVaapiEncoderClass GstVaapiEncoderH264Class = {
+    GST_VAAPI_ENCODER_CLASS_INIT (H264, h264),
+    .get_codec_data = gst_vaapi_encoder_h264_get_codec_data
+  };
+  return &GstVaapiEncoderH264Class;
 }
 
 GstVaapiEncoder *
diff --git a/gst-libs/gst/vaapi/gstvaapiencoder_h264_priv.h b/gst-libs/gst/vaapi/gstvaapiencoder_h264_priv.h
index a7027ae9..3a60a6fc 100644
--- a/gst-libs/gst/vaapi/gstvaapiencoder_h264_priv.h
+++ b/gst-libs/gst/vaapi/gstvaapiencoder_h264_priv.h
@@ -33,14 +33,6 @@ G_BEGIN_DECLS
     ((GstVaapiEncoderH264 *)(encoder))
 #define GST_VAAPI_ENCODER_H264_CAST(encoder) \
     ((GstVaapiEncoderH264 *)(encoder))
-#define GST_VAAPI_ENCODER_H264_CLASS(klass) \
-    ((GstVaapiEncoderH264Class *)(klass))
-#define GST_IS_VAAPI_ENCODER_H264_CLASS(klass) \
-    ((klass) != NULL)
-#define GST_VAAPI_ENCODER_H264_GET_CLASS(obj) \
-    GST_VAAPI_ENCODER_H264_CLASS(GST_VAAPI_MINI_OBJECT_GET_CLASS(obj))
-
-typedef struct _GstVaapiEncoderH264Class GstVaapiEncoderH264Class;
 
 typedef enum
 {
@@ -115,12 +107,6 @@ struct _GstVaapiEncoderH264
 
 };
 
-struct _GstVaapiEncoderH264Class
-{
-  /*< private > */
-  GstVaapiEncoderClass parent_class;
-};
-
 G_END_DECLS
 
 #endif /*GST_VAAPI_ENCODER_H264_PRIV_H */
diff --git a/gst-libs/gst/vaapi/gstvaapiencoder_mpeg2.c b/gst-libs/gst/vaapi/gstvaapiencoder_mpeg2.c
index 70decdb3..10de5875 100644
--- a/gst-libs/gst/vaapi/gstvaapiencoder_mpeg2.c
+++ b/gst-libs/gst/vaapi/gstvaapiencoder_mpeg2.c
@@ -741,7 +741,7 @@ push_reference (GstVaapiEncoderMpeg2 * encoder, GstVaapiSurfaceProxy * ref)
 }
 
 static void
-gst_vaapi_encoder_mpeg2_destroy (GstVaapiEncoder * base)
+gst_vaapi_encoder_mpeg2_finalize (GstVaapiEncoder * base)
 {
   /*free private buffers */
   GstVaapiEncoderMpeg2 *encoder = GST_VAAPI_ENCODER_MPEG2 (base);
@@ -756,37 +756,13 @@ gst_vaapi_encoder_mpeg2_destroy (GstVaapiEncoder * base)
   g_queue_clear (&encoder->b_frames);
 }
 
-static void
-gst_vaapi_encoder_mpeg2_class_init (GstVaapiEncoderMpeg2Class * klass)
-{
-  GstVaapiMiniObjectClass *const object_class =
-      GST_VAAPI_MINI_OBJECT_CLASS (klass);
-  GstVaapiEncoderClass *const encoder_class = GST_VAAPI_ENCODER_CLASS (klass);
-
-  gst_vaapi_encoder_class_init (encoder_class);
-
-  object_class->size = sizeof (GstVaapiEncoderMpeg2);
-
-  encoder_class->init = gst_vaapi_encoder_mpeg2_init;
-  encoder_class->destroy = gst_vaapi_encoder_mpeg2_destroy;
-  encoder_class->set_format = gst_vaapi_encoder_mpeg2_set_format;
-  encoder_class->get_context_info = gst_vaapi_encoder_mpeg2_get_context_info;
-  encoder_class->reordering = gst_vaapi_encoder_mpeg2_reordering;
-  encoder_class->encode = gst_vaapi_encoder_mpeg2_encode;
-  encoder_class->flush = gst_vaapi_encoder_mpeg2_flush;
-}
-
 static inline const GstVaapiEncoderClass *
 gst_vaapi_encoder_mpeg2_class ()
 {
-  static GstVaapiEncoderMpeg2Class g_class;
-  static gsize g_class_init = FALSE;
-
-  if (g_once_init_enter (&g_class_init)) {
-    gst_vaapi_encoder_mpeg2_class_init (&g_class);
-    g_once_init_leave (&g_class_init, TRUE);
-  }
-  return GST_VAAPI_ENCODER_CLASS (&g_class);
+  static const GstVaapiEncoderClass GstVaapiEncoderMpeg2Class = {
+    GST_VAAPI_ENCODER_CLASS_INIT (Mpeg2, mpeg2),
+  };
+  return &GstVaapiEncoderMpeg2Class;
 }
 
 GstVaapiEncoder *
diff --git a/gst-libs/gst/vaapi/gstvaapiencoder_mpeg2_priv.h b/gst-libs/gst/vaapi/gstvaapiencoder_mpeg2_priv.h
index c5da350e..ff20dbe5 100644
--- a/gst-libs/gst/vaapi/gstvaapiencoder_mpeg2_priv.h
+++ b/gst-libs/gst/vaapi/gstvaapiencoder_mpeg2_priv.h
@@ -32,14 +32,6 @@ G_BEGIN_DECLS
         ((GstVaapiEncoderMpeg2 *)(encoder))
 #define GST_VAAPI_ENCODER_MPEG2_CAST(encoder) \
         ((GstVaapiEncoderMpeg2 *)(encoder))
-#define GST_VAAPI_ENCODER_MPEG2_CLASS(klass) \
-    ((GstVaapiEncoderMpeg2Class *)(klass))
-#define GST_IS_VAAPI_ENCODER_MPEG2_CLASS(klass) \
-    ((klass) != NULL)
-#define GST_VAAPI_ENCODER_MPEG2_GET_CLASS(obj) \
-    GST_VAAPI_ENCODER_MPEG2_CLASS(GST_VAAPI_MINI_OBJECT_GET_CLASS(obj))
-
-typedef struct _GstVaapiEncoderMpeg2Class GstVaapiEncoderMpeg2Class;
 
 typedef enum
 {
@@ -105,12 +97,6 @@ struct _GstVaapiEncoderMpeg2
   guint32 frame_num;            /* same value picture header, but it's not mod by 1024 */
 };
 
-struct _GstVaapiEncoderMpeg2Class
-{
-  /*< private > */
-  GstVaapiEncoderClass parent_class;
-};
-
 G_END_DECLS
 
 #endif /* GST_VAAPI_ENCODER_MPEG2_PRIV_H */
diff --git a/gst-libs/gst/vaapi/gstvaapiencoder_priv.h b/gst-libs/gst/vaapi/gstvaapiencoder_priv.h
index 8b78ac95..e18fe588 100644
--- a/gst-libs/gst/vaapi/gstvaapiencoder_priv.h
+++ b/gst-libs/gst/vaapi/gstvaapiencoder_priv.h
@@ -105,10 +105,10 @@ struct _GstVaapiEncoder
 
 struct _GstVaapiEncoderClass
 {
-  GObjectClass parent_class;
+  GstVaapiMiniObjectClass parent_class;
 
   gboolean              (*init)         (GstVaapiEncoder * encoder);
-  void                  (*destroy)      (GstVaapiEncoder * encoder);
+  void                  (*finalize)     (GstVaapiEncoder * encoder);
 
   GstCaps *             (*set_format)   (GstVaapiEncoder * encoder,
                                          GstVideoCodecState * in_state,
@@ -132,13 +132,31 @@ struct _GstVaapiEncoderClass
                                            GstBuffer ** codec_data);
 };
 
-void
-gst_vaapi_encoder_class_init (GstVaapiEncoderClass * klass);
+#define GST_VAAPI_ENCODER_CLASS_HOOK(codec, func) \
+  .func = G_PASTE (G_PASTE (G_PASTE (gst_vaapi_encoder_,codec),_), func)
+
+#define GST_VAAPI_ENCODER_CLASS_INIT_BASE(CODEC)                \
+  .parent_class = {                                             \
+    .size = sizeof (G_PASTE (GstVaapiEncoder, CODEC)),          \
+    .finalize = (GDestroyNotify) gst_vaapi_encoder_finalize     \
+  }
 
+#define GST_VAAPI_ENCODER_CLASS_INIT(CODEC, codec)              \
+  GST_VAAPI_ENCODER_CLASS_INIT_BASE (CODEC),                    \
+    GST_VAAPI_ENCODER_CLASS_HOOK (codec, init),                 \
+    GST_VAAPI_ENCODER_CLASS_HOOK (codec, finalize),             \
+    GST_VAAPI_ENCODER_CLASS_HOOK (codec, set_format),           \
+    GST_VAAPI_ENCODER_CLASS_HOOK (codec, get_context_info),     \
+    GST_VAAPI_ENCODER_CLASS_HOOK (codec, reordering),           \
+    GST_VAAPI_ENCODER_CLASS_HOOK (codec, encode),               \
+    GST_VAAPI_ENCODER_CLASS_HOOK (codec, flush)
+
+G_GNUC_INTERNAL
 GstVaapiEncoder *
 gst_vaapi_encoder_new (const GstVaapiEncoderClass * klass,
     GstVaapiDisplay * display);
 
+G_GNUC_INTERNAL
 void
 gst_vaapi_encoder_finalize (GstVaapiEncoder * encoder);