Improve error handling in high-frequency functions: Only warn once.

2006-01-30  Behdad Esfahbod  <behdad@gnome.org>

        * pango/shape.c (pango_shape):
        * pango/fonts.c (pango_font_get_glyph_extents):
        * pango/pangocairo-font.c (_pango_cairo_font_install):
        Improve error handling in high-frequency functions:  Only warn
        once.

        * pango-impl-utils.h, pangoutils.h:
        * pangocairo-private.h, pangocairo-font.c:
        Add machinery for above: _pango_warning_history and
        _pango_cairo_warning_history.

6 files changed, 71 insertions, 17 deletions

diff --git a/pango/fonts.c b/pango/fonts.c
index 2142d58b..4835a198 100644
--- a/pango/fonts.c
+++ b/pango/fonts.c
@@ -24,6 +24,7 @@
 #include <math.h>
 #include <string.h>
 
+#include "pango-impl-utils.h"
 #include "pango-types.h"
 #include "pango-font.h"
 #include "pango-fontmap.h"
@@ -1163,7 +1164,30 @@ pango_font_get_glyph_extents  (PangoFont      *font,
 			       PangoRectangle *ink_rect,
 			       PangoRectangle *logical_rect)
 {
-  g_return_if_fail (font != NULL);
+  if (G_UNLIKELY (font == NULL))
+    {
+      
+      if (!_pango_warning_history.get_glyph_extents)
+        {
+	  _pango_warning_history.get_glyph_extents = TRUE;
+	  g_critical ("pango_font_get_glyph_extents called with font == NULL, expect ugly output");
+	}
+      if (ink_rect)
+        {
+	  ink_rect->x = 0;
+	  ink_rect->y = 0;
+	  ink_rect->height = 12 * PANGO_SCALE;
+	  ink_rect->width = 12 * PANGO_SCALE;
+        }
+      if (logical_rect)
+        {
+	  logical_rect->x = 0;
+	  logical_rect->y = 0;
+	  logical_rect->height = 12 * PANGO_SCALE;
+	  logical_rect->width = 12 * PANGO_SCALE;
+	}
+      return;
+    }
 
   PANGO_FONT_GET_CLASS (font)->get_glyph_extents (font, glyph, ink_rect, logical_rect);
 }
diff --git a/pango/pango-impl-utils.h b/pango/pango-impl-utils.h
index 7dabeb47..7e1d3136 100644
--- a/pango/pango-impl-utils.h
+++ b/pango/pango-impl-utils.h
@@ -72,6 +72,18 @@ prefix ## _get_type (void)				                   \
 			 class_init, instance_init,		\
 			 parent_type, G_TYPE_FLAG_ABSTRACT)
 
+
+
+typedef struct _PangoWarningHistory PangoWarningHistory;
+
+struct _PangoWarningHistory {
+  guint shape_font		: 1; 
+  guint shape_shape_engine	: 1;
+  guint get_glyph_extents	: 1;
+}; 
+
+extern PangoWarningHistory _pango_warning_history;
+
 G_END_DECLS
 
 #endif /* __PANGO_IMPL_UTILS_H__ */
diff --git a/pango/pango-utils.c b/pango/pango-utils.c
index fce42896..5ae1246f 100644
--- a/pango/pango-utils.c
+++ b/pango/pango-utils.c
@@ -25,8 +25,9 @@
 #include <string.h>
 #include <stdlib.h>
 
-#include "pango-font.h"
+#include "pango-impl-utils.h"
 #include "pango-utils.h"
+#include "pango-font.h"
 
 #include <glib/gstdio.h>
 
@@ -57,6 +58,8 @@ struct PangoAlias
 
 static GHashTable *pango_aliases_ht = NULL;
 
+PangoWarningHistory _pango_warning_history = {};
+
 /**
  * pango_trim_string:
  * @str: a string
@@ -1461,7 +1464,6 @@ pango_log2vis_get_embedding_levels (const gchar    *str,
 				    PangoDirection *pbase_dir)
 {
   FriBidiCharType fribidi_base_dir;
-  gboolean result;
   guint8 *embedding_levels_list;
 
   switch (*pbase_dir)
diff --git a/pango/pangocairo-font.c b/pango/pangocairo-font.c
index a727e053..ee98020f 100644
--- a/pango/pangocairo-font.c
+++ b/pango/pangocairo-font.c
@@ -21,10 +21,13 @@
 
 #include <config.h>
 
+#include "pango-impl-utils.h"
 #include "pangocairo.h"
 #include "pangocairo-private.h"
 #include "pango-utils.h"
 
+PangoCairoWarningHistory _pango_cairo_warning_history = {};
+
 GType
 pango_cairo_font_get_type (void)
 {
@@ -68,7 +71,15 @@ void
 _pango_cairo_font_install (PangoCairoFont *font,
 			   cairo_t        *cr)
 {
-  g_return_if_fail (PANGO_IS_CAIRO_FONT (font));
+  if (G_UNLIKELY (!PANGO_IS_CAIRO_FONT (font)))
+    {
+      if (!_pango_cairo_warning_history.font_install)
+        {
+	  _pango_cairo_warning_history.font_install = TRUE;
+	  g_critical ("_pango_cairo_font_install called with font == NULL, expect ugly output");
+	}
+      return;
+    }
   
   (* PANGO_CAIRO_FONT_GET_IFACE (font)->install) (font, cr);
 }
diff --git a/pango/pangocairo-private.h b/pango/pangocairo-private.h
index 290c761c..48d3c0f3 100644
--- a/pango/pangocairo-private.h
+++ b/pango/pangocairo-private.h
@@ -103,6 +103,14 @@ void _pango_cairo_get_glyph_extents_missing (PangoCairoFont *cfont,
 					     PangoRectangle *ink_rect,
 					     PangoRectangle *logical_rect);
 
+typedef struct _PangoCairoWarningHistory PangoCairoWarningHistory;
+
+struct _PangoCairoWarningHistory {
+  guint font_install		: 1;
+}; 
+
+extern PangoCairoWarningHistory _pango_cairo_warning_history;
+
 G_END_DECLS
 
 #endif /* __PANGOCAIRO_PRIVATE_H__ */
diff --git a/pango/shape.c b/pango/shape.c
index 3020007a..37fc34d2 100644
--- a/pango/shape.c
+++ b/pango/shape.c
@@ -20,8 +20,10 @@
  */
 
 #include <config.h>
-#include <pango/pango-glyph.h>
-#include <pango/pango-engine-private.h>
+
+#include "pango-impl-utils.h"
+#include "pango-glyph.h"
+#include "pango-engine-private.h"
 
 /**
  * pango_shape:
@@ -82,20 +84,15 @@ pango_shape (const gchar      *text,
     }
   else
     {
-      static struct {
-        guint font : 1; 
-	guint shape_engine : 1;
-      } warned = { FALSE, FALSE };
-      
-      if (!analysis->shape_engine && !warned.shape_engine)
+      if (!analysis->shape_engine && !_pango_warning_history.shape_shape_engine)
         {
-	  g_critical ("pango_shape called with analysis->shape_engine == NULL");
-	  warned.font = TRUE;
+	  _pango_warning_history.shape_font = TRUE;
+	  g_critical ("pango_shape called with analysis->shape_engine == NULL, expect ugly output");
 	}
-      if (!analysis->font && !warned.font)
+      if (!analysis->font && !_pango_warning_history.shape_font)
         {
-	  g_critical ("pango_shape called with analysis->font == NULL");
-	  warned.font = TRUE;
+	  _pango_warning_history.shape_font = TRUE;
+	  g_critical ("pango_shape called with analysis->font == NULL, expect ugly output");
 	}
 
       glyphs->num_glyphs = 0;