[gtk+] cssshadowsvalue: Don't heap-allocate shadows

[Timm Bäder <baedert src gnome org>]

commit 773973db78eba52e32d273a67387fd360fcdbb20
Author: Timm Bäder <mail baedert org>
Date:   Sat Sep 30 13:11:51 2017 +0200

    cssshadowsvalue: Don't heap-allocate shadows
    
    This showed up in profiles in certain scenarios, so export a
    _get_n_shadows getter instead and let callers provide a sufficiently
    large allocated array of GskShadows, which we can use with
    g_alloc/g_newa.

 gtk/gtkcssshadowsvalue.c        |   23 ++++++++++-------------
 gtk/gtkcssshadowsvalueprivate.h |    6 ++++--
 gtk/gtkrendericon.c             |   34 ++++++++++++++++++----------------
 gtk/gtksnapshot.c               |   18 ++++++++++--------
 4 files changed, 42 insertions(+), 39 deletions(-)
---
diff --git a/gtk/gtkcssshadowsvalue.c b/gtk/gtkcssshadowsvalue.c
index 40fb07a..bd687dc 100644
--- a/gtk/gtkcssshadowsvalue.c
+++ b/gtk/gtkcssshadowsvalue.c
@@ -268,23 +268,20 @@ _gtk_css_shadows_value_is_none (const GtkCssValue *shadows)
   return shadows->len == 0;
 }
 
-GskShadow *
-gtk_css_shadows_value_get_shadows (const GtkCssValue *shadows,
-                                   gsize             *n_shadows)
+gsize
+gtk_css_shadows_value_get_n_shadows (const GtkCssValue *shadows)
 {
-  GskShadow *result;
-  guint i;
+  return shadows->len;
+}
 
-  result = g_new (GskShadow, shadows->len);
+void
+gtk_css_shadows_value_get_shadows (const GtkCssValue  *shadows,
+                                   GskShadow          *out_shadows)
+{
+  guint i;
 
   for (i = 0; i < shadows->len; i++)
-    {
-      gtk_css_shadow_value_get_shadow (shadows->values[i], &result[i]);
-    }
-
-  *n_shadows = shadows->len;
-
-  return result;
+    gtk_css_shadow_value_get_shadow (shadows->values[i], &out_shadows[i]);
 }
 
 void
diff --git a/gtk/gtkcssshadowsvalueprivate.h b/gtk/gtkcssshadowsvalueprivate.h
index 039c8f0..be2f6b4 100644
--- a/gtk/gtkcssshadowsvalueprivate.h
+++ b/gtk/gtkcssshadowsvalueprivate.h
@@ -36,8 +36,10 @@ GtkCssValue *   _gtk_css_shadows_value_parse          (GtkCssParser
 
 gboolean        _gtk_css_shadows_value_is_none        (const GtkCssValue        *shadows);
 
-GskShadow *     gtk_css_shadows_value_get_shadows     (const GtkCssValue        *shadows,
-                                                       gsize                    *n_shadows);
+gsize           gtk_css_shadows_value_get_n_shadows   (const GtkCssValue        *shadows);
+
+void            gtk_css_shadows_value_get_shadows    (const GtkCssValue        *shadows,
+                                                      GskShadow                *out_shadows);
 
 void            _gtk_css_shadows_value_paint_layout   (const GtkCssValue        *shadows,
                                                        cairo_t                  *cr,
diff --git a/gtk/gtkrendericon.c b/gtk/gtkrendericon.c
index 3ec7a3b..3cecd35 100644
--- a/gtk/gtkrendericon.c
+++ b/gtk/gtkrendericon.c
@@ -118,9 +118,13 @@ gtk_css_style_snapshot_icon (GtkCssStyle            *style,
 
   gtk_css_filter_value_push_snapshot (filter_value, snapshot);
 
-  shadows = gtk_css_shadows_value_get_shadows (shadows_value, &n_shadows);
-  if (shadows)
-    gtk_snapshot_push_shadow (snapshot, shadows, n_shadows, "IconShadow<%zu>", n_shadows);
+  n_shadows = gtk_css_shadows_value_get_n_shadows (shadows_value);
+  if (n_shadows > 0)
+    {
+      shadows = g_newa (GskShadow, n_shadows);
+      gtk_css_shadows_value_get_shadows (shadows_value, shadows);
+      gtk_snapshot_push_shadow (snapshot, shadows, n_shadows, "IconShadow<%zu>", n_shadows);
+    }
 
   if (graphene_matrix_is_identity (&transform_matrix))
     {
@@ -143,11 +147,8 @@ gtk_css_style_snapshot_icon (GtkCssStyle            *style,
       gtk_snapshot_pop (snapshot);
     }
 
-  if (shadows)
-    {
-      gtk_snapshot_pop (snapshot);
-      g_free (shadows);
-    }
+  if (n_shadows > 0)
+    gtk_snapshot_pop (snapshot);
   
   gtk_css_filter_value_pop_snapshot (filter_value, snapshot);
 }
@@ -295,9 +296,13 @@ gtk_css_style_snapshot_icon_texture (GtkCssStyle *style,
 
   gtk_css_filter_value_push_snapshot (filter_value, snapshot);
 
-  shadows = gtk_css_shadows_value_get_shadows (shadows_value, &n_shadows);
-  if (shadows)
-    gtk_snapshot_push_shadow (snapshot, shadows, n_shadows, "IconShadow<%zu>", n_shadows);
+  n_shadows = gtk_css_shadows_value_get_n_shadows (shadows_value);
+  if (n_shadows > 0)
+    {
+      shadows = g_newa (GskShadow, n_shadows);
+      gtk_css_shadows_value_get_shadows (shadows_value, shadows);
+      gtk_snapshot_push_shadow (snapshot, shadows, n_shadows, "IconShadow<%zu>", n_shadows);
+    }
 
   if (graphene_matrix_is_identity (&transform_matrix))
     {
@@ -322,11 +327,8 @@ gtk_css_style_snapshot_icon_texture (GtkCssStyle *style,
       gtk_snapshot_pop (snapshot);
     }
 
-  if (shadows)
-    {
-      gtk_snapshot_pop (snapshot);
-      g_free (shadows);
-    }
+  if (n_shadows > 0)
+    gtk_snapshot_pop (snapshot);
   
   gtk_css_filter_value_pop_snapshot (filter_value, snapshot);
 }
diff --git a/gtk/gtksnapshot.c b/gtk/gtksnapshot.c
index 7f5a1f1..293046b 100644
--- a/gtk/gtksnapshot.c
+++ b/gtk/gtksnapshot.c
@@ -1396,18 +1396,20 @@ gtk_snapshot_render_layout (GtkSnapshot     *snapshot,
   fg_color = _gtk_css_rgba_value_get_rgba (_gtk_style_context_peek_property (context, 
GTK_CSS_PROPERTY_COLOR));
 
   shadows_value = _gtk_style_context_peek_property (context, GTK_CSS_PROPERTY_TEXT_SHADOW);
-  shadows = gtk_css_shadows_value_get_shadows (shadows_value, &n_shadows);
-  if (shadows)
-    gtk_snapshot_push_shadow (snapshot, shadows, n_shadows, "TextShadow<%zu>", n_shadows);
+  n_shadows = gtk_css_shadows_value_get_n_shadows (shadows_value);
 
-  gsk_pango_show_layout (snapshot, fg_color, layout);
-
-  if (shadows)
+  if (n_shadows > 0)
     {
-      gtk_snapshot_pop (snapshot);
-      g_free (shadows);
+      shadows = g_newa (GskShadow, n_shadows);
+      gtk_css_shadows_value_get_shadows (shadows_value, shadows);
+      gtk_snapshot_push_shadow (snapshot, shadows, n_shadows, "TextShadow<%zu>", n_shadows);
     }
 
+  gsk_pango_show_layout (snapshot, fg_color, layout);
+
+  if (n_shadows > 0)
+    gtk_snapshot_pop (snapshot);
+
   gtk_snapshot_offset (snapshot, -x, -y);
 }