Revert "Bug 689342 - Lifetime of patterns in pattern_hash may use too much memory"

This reverts commit 7ed3cb89923c376d8b30ae3f977ab9e1a231e430, after
resolving conflicts.

The patch introduced some lifecycle management issues that could easily
cause crashing.  Reverting till the issues are resolved.

1 files changed, 61 insertions, 168 deletions

diff --git a/pango/pangofc-fontmap.c b/pango/pangofc-fontmap.c
index cfe99014..5791753a 100644
--- a/pango/pangofc-fontmap.c
+++ b/pango/pangofc-fontmap.c
@@ -44,10 +44,7 @@
  * - All FcPattern's referenced by any object in the fontmap are uniquified
  *   and cached in the fontmap.  This both speeds lookups based on patterns
  *   faster, and saves memory.  This is handled by fontmap->priv->pattern_hash.
- *   The patterns are refcounted via PangoFcUPattern and removed from
- *   pattern_hash when the reference count reaches zero. This avoids an ever
- *   growing pattern_hash when a very large number of patterns are used within
- *   the same font map (think an infinitely varied zoom factor on the text).
+ *   The patterns are cached indefinitely.
  *
  * - The results of a FcFontSort() are used to populate fontsets.  However,
  *   FcFontSort() relies on the search pattern only, which includes the font
@@ -92,7 +89,6 @@ typedef struct _PangoFcFontFaceData PangoFcFontFaceData;
 typedef struct _PangoFcFace         PangoFcFace;
 typedef struct _PangoFcFamily       PangoFcFamily;
 typedef struct _PangoFcFindFuncInfo PangoFcFindFuncInfo;
-typedef struct _PangoFcUPattern     PangoFcUPattern;
 typedef struct _PangoFcPatterns     PangoFcPatterns;
 typedef struct _PangoFcFontset      PangoFcFontset;
 
@@ -115,7 +111,7 @@ struct _PangoFcFontMapPrivate
 
   GHashTable *font_hash;	/* Maps PangoFcFontKey -> PangoFcFont */
 
-  GHashTable *patterns_hash;	/* Maps PangoFcUPattern -> PangoFcPatterns */
+  GHashTable *patterns_hash;	/* Maps FcPattern -> PangoFcPatterns */
 
   /* pattern_hash is used to make sure we only store one copy of
    * each identical pattern. (Speeds up lookup).
@@ -219,24 +215,13 @@ static gboolean           pango_fc_fontset_key_equal (const PangoFcFontsetKey *k
 static void               pango_fc_font_key_init     (PangoFcFontKey       *key,
 						      PangoFcFontMap       *fcfontmap,
 						      PangoFcFontsetKey    *fontset_key,
-						      PangoFcUPattern      *pattern);
+						      FcPattern            *pattern);
 static PangoFcFontKey    *pango_fc_font_key_copy     (const PangoFcFontKey *key);
 static void               pango_fc_font_key_free     (PangoFcFontKey       *key);
 static guint              pango_fc_font_key_hash     (const PangoFcFontKey *key);
 static gboolean           pango_fc_font_key_equal    (const PangoFcFontKey *key_a,
 						      const PangoFcFontKey *key_b);
 
-static guint              pango_fc_upattern_hash     (const PangoFcUPattern *upattern);
-static gboolean           pango_fc_upattern_equal    (const PangoFcUPattern *upattern_a,
-						      const PangoFcUPattern *upattern_b);
-static void               pango_fc_upattern_free     (PangoFcUPattern       *upattern);
-static PangoFcUPattern   *pango_fc_upattern_create   (FcPattern             *pattern);
-static PangoFcUPattern   *pango_fc_upattern_init_key (PangoFcUPattern       *upattern,
-						      FcPattern             *pattern);
-static PangoFcUPattern   *pango_fc_upattern_ref      (PangoFcUPattern       *upattern);
-static void               pango_fc_upattern_unref    (PangoFcUPattern       *upattern,
-						      PangoFcFontMap        *fcfontmap);
-
 static PangoFcPatterns *pango_fc_patterns_new   (FcPattern       *pat,
 						 PangoFcFontMap  *fontmap);
 static PangoFcPatterns *pango_fc_patterns_ref   (PangoFcPatterns *pats);
@@ -246,8 +231,8 @@ static FcPattern       *pango_fc_patterns_get_font_pattern (PangoFcPatterns *pat
 							    int              i,
 							    gboolean        *prepare);
 
-static PangoFcUPattern *uniquify_pattern (PangoFcFontMap *fcfontmap,
-					  FcPattern      *pattern);
+static FcPattern *uniquify_pattern (PangoFcFontMap *fcfontmap,
+				    FcPattern      *pattern);
 
 static gpointer
 get_gravity_class (void)
@@ -341,87 +326,6 @@ get_scaled_size (PangoFcFontMap             *fcfontmap,
 }
 
 
-/*
- * PangoFcUPattern
- */
-
-struct _PangoFcUPattern {
-  FcPattern *pattern; /* only element that matters for equality in pattern_hash */
-  guint ref_count;    /* references from outside the pattern_hash */
-};
-
-static guint
-pango_fc_upattern_hash (const PangoFcUPattern *upattern)
-{
-  return FcPatternHash(upattern->pattern);
-}
-
-static gboolean
-pango_fc_upattern_equal (const PangoFcUPattern *upattern_a, const PangoFcUPattern *upattern_b)
-{
-  return FcPatternEqual(upattern_a->pattern, upattern_b->pattern);
-}
-
-static void
-pango_fc_upattern_free (PangoFcUPattern *upattern)
-{
-  if (upattern->ref_count == 0)
-    {
-      FcPatternDestroy(upattern->pattern);
-      g_slice_free(PangoFcUPattern, upattern);
-    }
-}
-
-static PangoFcUPattern *
-pango_fc_upattern_create(FcPattern *pattern)
-{
-  PangoFcUPattern *upat;
-
-  upat = g_slice_new(PangoFcUPattern);
-
-  FcPatternReference(pattern);
-
-  upat->pattern = pattern;
-  upat->ref_count = 1;
-
-  return upat;
-}
-
-static PangoFcUPattern *
-pango_fc_upattern_init_key (PangoFcUPattern *upattern, FcPattern *pattern)
-{
-  upattern->pattern = pattern;
-  upattern->ref_count = 0;
-
-  return upattern;
-}
-
-static PangoFcUPattern *
-pango_fc_upattern_ref (PangoFcUPattern *upattern)
-{
-  g_return_val_if_fail (upattern->ref_count > 0, NULL);
-
-  upattern->ref_count++;
-
-  return upattern;
-}
-
-static void
-pango_fc_upattern_unref (PangoFcUPattern *upattern, PangoFcFontMap *fcfontmap)
-{
-  g_return_if_fail (upattern->ref_count > 0);
-
-  if ( --upattern->ref_count > 0 )
-    return;
-
-  /* Only remove from pattern_hash if we are really in it (and not just the same
-   * pattern). This is not necessarily the case after a cache_clear() call. */
-  if (fcfontmap && fcfontmap->priv->pattern_hash &&
-      upattern == g_hash_table_lookup(fcfontmap->priv->pattern_hash, upattern))
-    g_hash_table_remove (fcfontmap->priv->pattern_hash, upattern);
-  else
-    pango_fc_upattern_free (upattern);
-}
 
 struct _PangoFcFontsetKey {
   PangoFcFontMap *fontmap;
@@ -435,7 +339,7 @@ struct _PangoFcFontsetKey {
 
 struct _PangoFcFontKey {
   PangoFcFontMap *fontmap;
-  PangoFcUPattern *upattern;
+  FcPattern *pattern;
   PangoMatrix matrix;
   gpointer context_key;
 };
@@ -642,7 +546,7 @@ static gboolean
 pango_fc_font_key_equal (const PangoFcFontKey *key_a,
 			 const PangoFcFontKey *key_b)
 {
-  if (key_a->upattern == key_b->upattern &&
+  if (key_a->pattern == key_b->pattern &&
       0 == memcmp (&key_a->matrix, &key_b->matrix, 4 * sizeof (double)))
     {
       if (key_a->context_key && key_b->context_key)
@@ -668,14 +572,14 @@ pango_fc_font_key_hash (const PangoFcFontKey *key)
       hash ^= PANGO_FC_FONT_MAP_GET_CLASS (key->fontmap)->context_key_hash (key->fontmap,
 									    key->context_key);
 
-    return (hash ^ GPOINTER_TO_UINT (key->upattern));
+    return (hash ^ GPOINTER_TO_UINT (key->pattern));
 }
 
 static void
 pango_fc_font_key_free (PangoFcFontKey *key)
 {
-  if (key->upattern)
-    pango_fc_upattern_unref(key->upattern, key->fontmap);
+  if (key->pattern)
+    FcPatternDestroy (key->pattern);
 
   if (key->context_key)
     PANGO_FC_FONT_MAP_GET_CLASS (key->fontmap)->context_key_free (key->fontmap,
@@ -690,7 +594,8 @@ pango_fc_font_key_copy (const PangoFcFontKey *old)
   PangoFcFontKey *key = g_slice_new (PangoFcFontKey);
 
   key->fontmap = old->fontmap;
-  key->upattern = pango_fc_upattern_ref (old->upattern);
+  FcPatternReference (old->pattern);
+  key->pattern = old->pattern;
   key->matrix = old->matrix;
   if (old->context_key)
     key->context_key = PANGO_FC_FONT_MAP_GET_CLASS (key->fontmap)->context_key_copy (key->fontmap,
@@ -705,10 +610,10 @@ static void
 pango_fc_font_key_init (PangoFcFontKey    *key,
 			PangoFcFontMap    *fcfontmap,
 			PangoFcFontsetKey *fontset_key,
-			PangoFcUPattern   *upattern)
+			FcPattern         *pattern)
 {
   key->fontmap = fcfontmap;
-  key->upattern = upattern;
+  key->pattern = pattern;
   key->matrix = *pango_fc_fontset_key_get_matrix (fontset_key);
   key->context_key = pango_fc_fontset_key_get_context_key (fontset_key);
 }
@@ -728,7 +633,7 @@ pango_fc_font_key_init (PangoFcFontKey    *key,
 const FcPattern *
 pango_fc_font_key_get_pattern (const PangoFcFontKey *key)
 {
-  return key->upattern->pattern;
+  return key->pattern;
 }
 
 /**
@@ -773,7 +678,7 @@ struct _PangoFcPatterns {
 
   PangoFcFontMap *fontmap;
 
-  PangoFcUPattern *upattern;
+  FcPattern *pattern;
   FcPattern *match;
   FcFontSet *fontset;
 };
@@ -782,25 +687,22 @@ static PangoFcPatterns *
 pango_fc_patterns_new (FcPattern *pat, PangoFcFontMap *fontmap)
 {
   PangoFcPatterns *pats;
-  PangoFcUPattern *upat;
 
-  upat = uniquify_pattern (fontmap, pat);
-  pats = g_hash_table_lookup (fontmap->priv->patterns_hash, upat);
+  pat = uniquify_pattern (fontmap, pat);
+  pats = g_hash_table_lookup (fontmap->priv->patterns_hash, pat);
   if (pats)
-    {
-      pango_fc_upattern_unref(upat, fontmap);
-      return pango_fc_patterns_ref (pats);
-    }
+    return pango_fc_patterns_ref (pats);
 
   pats = g_slice_new0 (PangoFcPatterns);
 
   pats->fontmap = fontmap;
 
   pats->ref_count = 1;
-  pats->upattern = upat;
+  FcPatternReference (pat);
+  pats->pattern = pat;
 
   g_hash_table_insert (fontmap->priv->patterns_hash,
-		       pats->upattern, pats);
+		       pats->pattern, pats);
 
   return pats;
 }
@@ -828,12 +730,12 @@ pango_fc_patterns_unref (PangoFcPatterns *pats)
   /* Only remove from fontmap hash if we are in it.  This is not necessarily
    * the case after a cache_clear() call. */
   if (pats->fontmap->priv->patterns_hash &&
-      pats == g_hash_table_lookup (pats->fontmap->priv->patterns_hash, pats->upattern))
+      pats == g_hash_table_lookup (pats->fontmap->priv->patterns_hash, pats->pattern))
     g_hash_table_remove (pats->fontmap->priv->patterns_hash,
-			 pats->upattern);
+			 pats->pattern);
 
-  if (pats->upattern)
-    pango_fc_upattern_unref (pats->upattern, pats->fontmap);
+  if (pats->pattern)
+    FcPatternDestroy (pats->pattern);
 
   if (pats->match)
     FcPatternDestroy (pats->match);
@@ -847,7 +749,7 @@ pango_fc_patterns_unref (PangoFcPatterns *pats)
 static FcPattern *
 pango_fc_patterns_get_pattern (PangoFcPatterns *pats)
 {
-  return pats->upattern->pattern;
+  return pats->pattern;
 }
 
 static FcPattern *
@@ -858,21 +760,27 @@ pango_fc_patterns_get_font_pattern (PangoFcPatterns *pats, int i, gboolean *prep
       FcResult result;
       if (!pats->match && !pats->fontset)
         {
-	  pats->match = FcFontMatch (NULL, pats->upattern->pattern, &result);
+	  pats->match = FcFontMatch (NULL, pats->pattern, &result);
+#ifdef FC_PATTERN
+	  /* The FC_PATTERN element, which points back to our the original
+	   * pattern defeats our hash tables.
+	   */
+	  FcPatternDel (pats->match, FC_PATTERN);
+#endif /* FC_PATTERN */
 	}
 
       if (pats->match)
-        {
+	{
 	  *prepare = FALSE;
 	  return pats->match;
-        }
+	}
     }
   else
     {
       if (!pats->fontset)
         {
 	  FcResult result;
-	  pats->fontset = FcFontSort (NULL, pats->upattern->pattern, FcTrue, NULL, &result);
+	  pats->fontset = FcFontSort (NULL, pats->pattern, FcTrue, NULL, &result);
 	  if (pats->match)
 	    {
 	      FcPatternDestroy (pats->match);
@@ -959,20 +867,21 @@ pango_fc_fontset_load_next_font (PangoFcFontset *fontset)
 
       if (G_UNLIKELY (!font_pattern))
 	return NULL;
-    }
 
 #ifdef FC_PATTERN
-    /* The FC_PATTERN element, which points back to our the original
-     * pattern defeats our hash tables.
-     */
-    FcPatternDel (font_pattern, FC_PATTERN);
+	/* The FC_PATTERN element, which points back to our the original
+	 * pattern defeats our hash tables.
+	 */
+	FcPatternDel (font_pattern, FC_PATTERN);
 #endif /* FC_PATTERN */
+    }
 
   font = pango_fc_font_map_new_font (fontset->key->fontmap,
 				     fontset->key,
 				     font_pattern);
 
-  FcPatternDestroy (font_pattern);
+  if (prepare)
+    FcPatternDestroy (font_pattern);
 
   return font;
 }
@@ -1154,9 +1063,9 @@ pango_fc_font_map_init (PangoFcFontMap *fcfontmap)
 
   priv->patterns_hash = g_hash_table_new (NULL, NULL);
 
-  priv->pattern_hash = g_hash_table_new_full ((GHashFunc) pango_fc_upattern_hash,
-					      (GEqualFunc) pango_fc_upattern_equal,
-					      (GDestroyNotify) pango_fc_upattern_free,
+  priv->pattern_hash = g_hash_table_new_full ((GHashFunc) FcPatternHash,
+					      (GEqualFunc) FcPatternEqual,
+					      (GDestroyNotify) FcPatternDestroy,
 					      NULL);
 
   priv->font_face_data_hash = g_hash_table_new_full ((GHashFunc)pango_fc_font_face_data_hash,
@@ -1591,27 +1500,23 @@ pango_fc_make_pattern (const  PangoFontDescription *description,
   return pattern;
 }
 
-/* The returned PangoFcUPattern should be unreferenced via
- * pango_fc_upattern_unref() when done with it. */
-static PangoFcUPattern *
+static FcPattern *
 uniquify_pattern (PangoFcFontMap *fcfontmap,
 		  FcPattern      *pattern)
 {
   PangoFcFontMapPrivate *priv = fcfontmap->priv;
-  PangoFcUPattern upat_key;
-  PangoFcUPattern *upattern;
+  FcPattern *old_pattern;
 
-  upattern = g_hash_table_lookup (priv->pattern_hash,
-				  pango_fc_upattern_init_key(&upat_key, pattern));
-  if ( upattern )
+  old_pattern = g_hash_table_lookup (priv->pattern_hash, pattern);
+  if (old_pattern)
     {
-      return pango_fc_upattern_ref (upattern);
+      return old_pattern;
     }
   else
     {
-      upattern = pango_fc_upattern_create(pattern);
-      g_hash_table_insert (priv->pattern_hash, upattern, upattern);
-      return upattern;
+      FcPatternReference (pattern);
+      g_hash_table_insert (priv->pattern_hash, pattern, pattern);
+      return pattern;
     }
 }
 
@@ -1622,7 +1527,6 @@ pango_fc_font_map_new_font (PangoFcFontMap    *fcfontmap,
 {
   PangoFcFontMapClass *class;
   PangoFcFontMapPrivate *priv = fcfontmap->priv;
-  PangoFcUPattern *umatch;
   FcPattern *pattern;
   PangoFcFont *fcfont;
   PangoFcFontKey key;
@@ -1630,16 +1534,13 @@ pango_fc_font_map_new_font (PangoFcFontMap    *fcfontmap,
   if (priv->closed)
     return NULL;
 
-  umatch = uniquify_pattern (fcfontmap, match);
+  match = uniquify_pattern (fcfontmap, match);
 
-  pango_fc_font_key_init (&key, fcfontmap, fontset_key, umatch);
+  pango_fc_font_key_init (&key, fcfontmap, fontset_key, match);
 
   fcfont = g_hash_table_lookup (priv->font_hash, &key);
   if (fcfont)
-    {
-      pango_fc_upattern_unref(umatch, fcfontmap);
-      return g_object_ref (fcfont);
-    }
+    return g_object_ref (fcfont);
 
   class = PANGO_FC_FONT_MAP_GET_CLASS (fcfontmap);
 
@@ -1651,7 +1552,6 @@ pango_fc_font_map_new_font (PangoFcFontMap    *fcfontmap,
     {
       const PangoMatrix *pango_matrix = pango_fc_fontset_key_get_matrix (fontset_key);
       FcMatrix fc_matrix, *fc_matrix_val;
-      PangoFcUPattern *upattern;
       int i;
 
       /* Fontconfig has the Y axis pointing up, Pango, down.
@@ -1661,7 +1561,7 @@ pango_fc_font_map_new_font (PangoFcFontMap    *fcfontmap,
       fc_matrix.yx = - pango_matrix->yx;
       fc_matrix.yy = pango_matrix->yy;
 
-      pattern = FcPatternDuplicate (umatch->pattern);
+      pattern = FcPatternDuplicate (match);
 
       for (i = 0; FcPatternGetMatrix (pattern, FC_MATRIX, i, &fc_matrix_val) == FcResultMatch; i++)
 	FcMatrixMultiply (&fc_matrix, &fc_matrix, fc_matrix_val);
@@ -1669,18 +1569,13 @@ pango_fc_font_map_new_font (PangoFcFontMap    *fcfontmap,
       FcPatternDel (pattern, FC_MATRIX);
       FcPatternAddMatrix (pattern, FC_MATRIX, &fc_matrix);
 
-      upattern = uniquify_pattern (fcfontmap, pattern);
-      fcfont = class->new_font (fcfontmap, upattern->pattern);
-      pango_fc_upattern_unref(upattern, fcfontmap);
+      fcfont = class->new_font (fcfontmap, uniquify_pattern (fcfontmap, pattern));
 
       FcPatternDestroy (pattern);
     }
 
   if (!fcfont)
-    {
-      pango_fc_upattern_unref(umatch, fcfontmap);
-      return NULL;
-    }
+    return NULL;
 
   fcfont->matrix = key.matrix;
   /* In case the backend didn't set the fontmap */
@@ -1692,8 +1587,6 @@ pango_fc_font_map_new_font (PangoFcFontMap    *fcfontmap,
   /* cache it on fontmap */
   pango_fc_font_map_add (fcfontmap, &key, fcfont);
 
-  pango_fc_upattern_unref(umatch, fcfontmap);
-
   return (PangoFont *)fcfont;
 }