Avoid some small allocations

5 files changed, 78 insertions, 26 deletions

diff --git a/pango/itemize.c b/pango/itemize.c
index 35f17d54..5500d56d 100644
--- a/pango/itemize.c
+++ b/pango/itemize.c
@@ -33,6 +33,7 @@
 #include "pango-emoji-private.h"
 #include "pango-attributes-private.h"
 #include "pango-item-private.h"
+#include "pango-utils-private.h"
 
 #include <hb-ot.h>
 
@@ -292,6 +293,7 @@ struct _ItemizeState
   PangoItem *item;
 
   guint8 *embedding_levels;
+  guint8 embedding_levels_[64];
   int embedding_end_offset;
   const char *embedding_end;
   guint8 embedding;
@@ -433,6 +435,10 @@ itemize_state_init (ItemizeState               *state,
                     PangoAttrIterator          *cached_iter,
                     const PangoFontDescription *desc)
 {
+  unsigned int n_chars;
+
+  n_chars = g_utf8_strlen (text + start_index, length);
+
   state->context = context;
   state->text = text;
   state->end = text + start_index + length;
@@ -447,7 +453,11 @@ itemize_state_init (ItemizeState               *state,
   /* First, apply the bidirectional algorithm to break
    * the text into directional runs.
    */
-  state->embedding_levels = pango_log2vis_get_embedding_levels (text + start_index, length, &base_dir);
+  if (n_chars < 64)
+    state->embedding_levels = state->embedding_levels_;
+  else
+    state->embedding_levels = g_new (guint8, n_chars);
+  pango_log2vis_fill_embedding_levels (text + start_index, length, n_chars, state->embedding_levels, &base_dir);
 
   state->embedding_end_offset = 0;
   state->embedding_end = text + start_index;
@@ -503,7 +513,7 @@ itemize_state_init (ItemizeState               *state,
                                &state->script_end, &state->script);
 
   width_iter_init (&state->width_iter, text + start_index, length);
-  _pango_emoji_iter_init (&state->emoji_iter, text + start_index, length);
+  _pango_emoji_iter_init (&state->emoji_iter, text + start_index, length, n_chars);
 
   if (!PANGO_GRAVITY_IS_VERTICAL (state->context->resolved_gravity))
     state->width_iter.end = state->end;
@@ -1017,7 +1027,8 @@ itemize_state_process_run (ItemizeState *state)
 static void
 itemize_state_finish (ItemizeState *state)
 {
-  g_free (state->embedding_levels);
+  if (state->embedding_levels != state->embedding_levels_)
+    g_free (state->embedding_levels);
   if (state->free_attr_iter)
     pango_attr_iterator_destroy (state->attr_iter);
   _pango_script_iter_fini (&state->script_iter);
diff --git a/pango/pango-bidi-type.c b/pango/pango-bidi-type.c
index f854a1b8..4277dc19 100644
--- a/pango/pango-bidi-type.c
+++ b/pango/pango-bidi-type.c
@@ -29,6 +29,7 @@
 
 #include "pango-bidi-type.h"
 #include "pango-utils.h"
+#include "pango-utils-private.h"
 
 /**
  * pango_bidi_type_for_unichar:
@@ -109,15 +110,37 @@ pango_bidi_type_for_unichar (gunichar ch)
  */
 guint8 *
 pango_log2vis_get_embedding_levels (const gchar    *text,
-				    int             length,
-				    PangoDirection *pbase_dir)
+                                    int             length,
+                                    PangoDirection *pbase_dir)
 {
-  glong n_chars, i;
-  guint8 *embedding_levels_list;
+  unsigned int n_chars;
+  guint8 *embedding_levels;
+
+  if (length < 0)
+    length = strlen (text);
+
+  n_chars = g_utf8_strlen (text, length);
+  embedding_levels = g_new (guint8, n_chars);
+
+  pango_log2vis_fill_embedding_levels (text, length, n_chars, embedding_levels, pbase_dir);
+
+  return embedding_levels;
+}
+
+void
+pango_log2vis_fill_embedding_levels (const gchar    *text,
+                                    int             length,
+                                    unsigned int    n_chars,
+                                    guint8         *embedding_levels_list,
+                                    PangoDirection *pbase_dir)
+{
+  glong i;
   const gchar *p;
   FriBidiParType fribidi_base_dir;
   FriBidiCharType *bidi_types;
+  FriBidiCharType bidi_types_[64];
   FriBidiBracketType *bracket_types;
+  FriBidiBracketType bracket_types_[64];
   FriBidiLevel max_level;
   FriBidiCharType ored_types = 0;
   FriBidiCharType anded_strongs = FRIBIDI_TYPE_RLE;
@@ -145,14 +168,16 @@ pango_log2vis_get_embedding_levels (const gchar    *text,
       break;
     }
 
-  if (length < 0)
-    length = strlen (text);
-
-  n_chars = g_utf8_strlen (text, length);
-
-  bidi_types = g_new (FriBidiCharType, n_chars);
-  bracket_types = g_new (FriBidiBracketType, n_chars);
-  embedding_levels_list = g_new (guint8, n_chars);
+  if (n_chars < 64)
+    {
+      bidi_types = bidi_types_;
+      bracket_types = bracket_types_;
+    }
+  else
+    {
+      bidi_types = g_new (FriBidiCharType, n_chars);
+      bracket_types = g_new (FriBidiBracketType, n_chars);
+    }
 
   for (i = 0, p = text; p < text + length; p = g_utf8_next_char(p), i++)
     {
@@ -232,12 +257,13 @@ pango_log2vis_get_embedding_levels (const gchar    *text,
     }
 
 resolved:
-  g_free (bidi_types);
-  g_free (bracket_types);
+  if (n_chars >= 64)
+    {
+      g_free (bidi_types);
+      g_free (bracket_types);
+    }
 
   *pbase_dir = (fribidi_base_dir == FRIBIDI_PAR_LTR) ?  PANGO_DIRECTION_LTR : PANGO_DIRECTION_RTL;
-
-  return embedding_levels_list;
 }
 
 /**
diff --git a/pango/pango-emoji-private.h b/pango/pango-emoji-private.h
index d5cbccf4..6f0d86f9 100644
--- a/pango/pango-emoji-private.h
+++ b/pango/pango-emoji-private.h
@@ -41,14 +41,16 @@ struct _PangoEmojiIter
   gboolean is_emoji;
 
   unsigned char *types;
+  unsigned char types_[64];
   unsigned int n_chars;
   unsigned int cursor;
 };
 
 PangoEmojiIter *
 _pango_emoji_iter_init (PangoEmojiIter *iter,
-			const char     *text,
-			int             length);
+                        const char     *text,
+                        int             length,
+                        unsigned int    n_chars);
 
 gboolean
 _pango_emoji_iter_next (PangoEmojiIter *iter);
diff --git a/pango/pango-emoji.c b/pango/pango-emoji.c
index e1f16dba..83ebfe6e 100644
--- a/pango/pango-emoji.c
+++ b/pango/pango-emoji.c
@@ -213,14 +213,19 @@ typedef unsigned char *emoji_text_iter_t;
 
 PangoEmojiIter *
 _pango_emoji_iter_init (PangoEmojiIter *iter,
-			const char     *text,
-			int             length)
+                        const char     *text,
+                        int             length,
+                        unsigned int    n_chars)
 {
-  unsigned int n_chars = g_utf8_strlen (text, length);
-  unsigned char *types = g_malloc (n_chars);
+  unsigned char *types;
   unsigned int i;
   const char *p;
 
+  if (n_chars < 64)
+    types = iter->types_;
+  else
+    types = g_malloc (n_chars);
+
   p = text;
   for (i = 0; i < n_chars; i++)
   {
@@ -247,7 +252,8 @@ _pango_emoji_iter_init (PangoEmojiIter *iter,
 void
 _pango_emoji_iter_fini (PangoEmojiIter *iter)
 {
-  g_free (iter->types);
+  if (iter->types != iter->types_)
+    g_free (iter->types);
 }
 
 gboolean
diff --git a/pango/pango-utils-private.h b/pango/pango-utils-private.h
index 4087dc14..78b06113 100644
--- a/pango/pango-utils-private.h
+++ b/pango/pango-utils-private.h
@@ -54,6 +54,13 @@ const char *   pango_get_sysconf_subdirectory (void) G_GNUC_PURE;
 PANGO_DEPRECATED
 const char *   pango_get_lib_subdirectory (void) G_GNUC_PURE;
 
+void pango_log2vis_fill_embedding_levels (const char     *text,
+                                          int             length,
+                                          unsigned int    n_chars,
+                                          guint8         *embedding_levels,
+                                          PangoDirection *pbase_dir);
+
+
 G_END_DECLS
 
 #endif /* __PANGO_UTILS_PRIATE_H__ */