[gtk/css-lookup-caching: 1/2] lookup: Don't store flat arrays

[Matthias Clasen <matthiasc src gnome org>]

commit 37fa7b06ac1e00615d9d3f8cbe480f9cb2d9d474
Author: Matthias Clasen <mclasen redhat com>
Date:   Sun Jan 26 17:16:19 2020 -0500

    lookup: Don't store flat arrays
    
    Most lookups have 0 or 1 value. We can drastically
    reduce the amount of memory used for lookups, and
    then we can afford to keep them around and avoid
    some lookups in the future.

 gtk/gtkcsslookup.c        | 44 +++++++++++++++++++++++++++++++++++++++++---
 gtk/gtkcsslookupprivate.h |  5 ++++-
 gtk/gtkcssstaticstyle.c   |  5 +++--
 3 files changed, 48 insertions(+), 6 deletions(-)
---
diff --git a/gtk/gtkcsslookup.c b/gtk/gtkcsslookup.c
index 704de1560b..32cd64265f 100644
--- a/gtk/gtkcsslookup.c
+++ b/gtk/gtkcsslookup.c
@@ -24,18 +24,31 @@
 #include "gtkprivatetypebuiltins.h"
 #include "gtkprivate.h"
 
+static void
+free_value (gpointer data)
+{
+  GtkCssLookupValue *value = data;
+
+  gtk_css_value_unref (value->value);
+  if (value->section)
+    gtk_css_section_unref (value->section);
+}
+
 void
 _gtk_css_lookup_init (GtkCssLookup     *lookup)
 {
   memset (lookup, 0, sizeof (*lookup));
 
   lookup->set_values = _gtk_bitmask_new ();
+  lookup->values = g_array_new (FALSE, FALSE, sizeof (GtkCssLookupValue));
+  g_array_set_clear_func (lookup->values, free_value);
 }
 
 void
 _gtk_css_lookup_destroy (GtkCssLookup *lookup)
 {
   _gtk_bitmask_free (lookup->set_values);
+  g_array_unref (lookup->values);
 }
 
 gboolean
@@ -66,11 +79,36 @@ _gtk_css_lookup_set (GtkCssLookup  *lookup,
                      GtkCssSection *section,
                      GtkCssValue   *value)
 {
+  GtkCssLookupValue v;
+
   gtk_internal_return_if_fail (lookup != NULL);
   gtk_internal_return_if_fail (value != NULL);
-  gtk_internal_return_if_fail (lookup->values[id].value == NULL);
+  gtk_internal_return_if_fail (_gtk_css_lookup_is_missing (lookup, id));
+
+  v.value = gtk_css_value_ref (value);
+  v.section = section ? gtk_css_section_ref (section) : NULL;
+  v.id = id;
 
-  lookup->values[id].value = value;
-  lookup->values[id].section = section;
+  g_array_append_val (lookup->values, v);
   lookup->set_values = _gtk_bitmask_set (lookup->set_values, id, TRUE);
 }
+
+GtkCssLookupValue *
+_gtk_css_lookup_get (GtkCssLookup *lookup,
+                     guint         id)
+{
+  gtk_internal_return_val_if_fail (lookup != NULL, NULL);
+
+  if (_gtk_bitmask_get (lookup->set_values, id))
+    {
+      int i;
+      for (i = 0; i < lookup->values->len; i++)
+        {
+          GtkCssLookupValue *value = &g_array_index (lookup->values, GtkCssLookupValue, i);
+          if (value->id == id)
+            return value;
+        }
+    }
+
+  return NULL;
+}
diff --git a/gtk/gtkcsslookupprivate.h b/gtk/gtkcsslookupprivate.h
index b433264c55..0dddbdad91 100644
--- a/gtk/gtkcsslookupprivate.h
+++ b/gtk/gtkcsslookupprivate.h
@@ -33,11 +33,12 @@ typedef struct _GtkCssLookup GtkCssLookup;
 typedef struct {
   GtkCssSection     *section;
   GtkCssValue       *value;
+  guint id;
 } GtkCssLookupValue;
 
 struct _GtkCssLookup {
   GtkBitmask *set_values;
-  GtkCssLookupValue  values[GTK_CSS_PROPERTY_N_PROPERTIES];
+  GArray *values;
 };
 
 void                    _gtk_css_lookup_init                    (GtkCssLookup               *lookup);
@@ -48,6 +49,8 @@ void                    _gtk_css_lookup_set                     (GtkCssLookup
                                                                  guint                       id,
                                                                  GtkCssSection              *section,
                                                                  GtkCssValue                *value);
+GtkCssLookupValue *     _gtk_css_lookup_get                     (GtkCssLookup               *lookup,
+                                                                 guint                       id);
 
 static inline const GtkBitmask *
 _gtk_css_lookup_get_set_values (const GtkCssLookup *lookup)
diff --git a/gtk/gtkcssstaticstyle.c b/gtk/gtkcssstaticstyle.c
index 5a9336ce79..232c4edabb 100644
--- a/gtk/gtkcssstaticstyle.c
+++ b/gtk/gtkcssstaticstyle.c
@@ -211,12 +211,13 @@ gtk_css_ ## NAME ## _values_new_compute (GtkCssStaticStyle *sstyle, \
   for (i = 0; i < G_N_ELEMENTS (NAME ## _props); i++) \
     { \
       guint id = NAME ## _props[i]; \
+      GtkCssLookupValue *value = _gtk_css_lookup_get (lookup, id); \
       gtk_css_static_style_compute_value (sstyle, \
                                           provider, \
                                           parent_style, \
                                           id, \
-                                          lookup->values[id].value, \
-                                          lookup->values[id].section); \
+                                          value ? value->value : NULL, \
+                                          value ? value->section : NULL); \
     } \
 } \
 static GtkBitmask * gtk_css_ ## NAME ## _values_mask; \