[pango] layout/renderer: Don't heap-allocate short lived layout iterators

[Matthias Clasen <matthiasc src gnome org>]

commit 1599288b4f5394a314bfadae5af56d9b60150562
Author: Timm Bäder <mail baedert org>
Date:   Sat Oct 7 18:22:24 2017 +0200

    layout/renderer: Don't heap-allocate short lived layout iterators
    
    Use the new _pango_layout_get_iter and _pango_layout_iter_destroy
    instead.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=788643

 pango/pango-layout.c   |   57 ++++++++++++++++++++++++-----------------------
 pango/pango-renderer.c |   15 ++++++------
 2 files changed, 37 insertions(+), 35 deletions(-)
---
diff --git a/pango/pango-layout.c b/pango/pango-layout.c
index 3c817b6..1e123ef 100644
--- a/pango/pango-layout.c
+++ b/pango/pango-layout.c
@@ -1682,31 +1682,31 @@ pango_layout_index_to_line_and_extents (PangoLayout     *layout,
                                        int              index,
                                        PangoRectangle  *line_rect)
 {
-  PangoLayoutIter *iter;
+  PangoLayoutIter iter;
   PangoLayoutLine *line = NULL;
 
-  iter = pango_layout_get_iter (layout);
+  _pango_layout_get_iter (layout, &iter);
 
-  if (!ITER_IS_INVALID (iter))
+  if (!ITER_IS_INVALID (&iter))
     while (TRUE)
       {
-       PangoLayoutLine *tmp_line = _pango_layout_iter_get_line (iter);
+       PangoLayoutLine *tmp_line = _pango_layout_iter_get_line (&iter);
 
        if (tmp_line->start_index > index)
            break; /* index was in paragraph delimiters */
 
        line = tmp_line;
 
-       pango_layout_iter_get_line_extents (iter, NULL, line_rect);
+       pango_layout_iter_get_line_extents (&iter, NULL, line_rect);
 
        if (line->start_index + line->length > index)
          break;
 
-       if (!pango_layout_iter_next_line (iter))
+       if (!pango_layout_iter_next_line (&iter))
          break; /* Use end of last line */
       }
 
-  pango_layout_iter_free (iter);
+  _pango_layout_iter_destroy (&iter);
 
   return line;
 }
@@ -1983,7 +1983,7 @@ pango_layout_xy_to_index (PangoLayout *layout,
                          int         *index,
                          gint        *trailing)
 {
-  PangoLayoutIter *iter;
+  PangoLayoutIter iter;
   PangoLayoutLine *prev_line = NULL;
   PangoLayoutLine *found = NULL;
   int found_line_x = 0;
@@ -1994,15 +1994,15 @@ pango_layout_xy_to_index (PangoLayout *layout,
 
   g_return_val_if_fail (PANGO_IS_LAYOUT (layout), FALSE);
 
-  iter = pango_layout_get_iter (layout);
+  _pango_layout_get_iter (layout, &iter);
 
   do
     {
       PangoRectangle line_logical;
       int first_y, last_y;
 
-      pango_layout_iter_get_line_extents (iter, NULL, &line_logical);
-      pango_layout_iter_get_line_yrange (iter, &first_y, &last_y);
+      pango_layout_iter_get_line_extents (&iter, NULL, &line_logical);
+      pango_layout_iter_get_line_yrange (&iter, &first_y, &last_y);
 
       if (y < first_y)
        {
@@ -2016,27 +2016,27 @@ pango_layout_xy_to_index (PangoLayout *layout,
              if (prev_line == NULL)
                outside = TRUE; /* off the top */
 
-             found = _pango_layout_iter_get_line (iter);
+             found = _pango_layout_iter_get_line (&iter);
              found_line_x = x - line_logical.x;
            }
        }
       else if (y >= first_y &&
               y < last_y)
        {
-         found = _pango_layout_iter_get_line (iter);
+         found = _pango_layout_iter_get_line (&iter);
          found_line_x = x - line_logical.x;
        }
 
-      prev_line = _pango_layout_iter_get_line (iter);
+      prev_line = _pango_layout_iter_get_line (&iter);
       prev_last = last_y;
       prev_line_x = x - line_logical.x;
 
       if (found != NULL)
        break;
     }
-  while (pango_layout_iter_next_line (iter));
+  while (pango_layout_iter_next_line (&iter));
 
-  pango_layout_iter_free (iter);
+  _pango_layout_iter_destroy (&iter);
 
   if (found == NULL)
     {
@@ -2076,7 +2076,7 @@ pango_layout_index_to_pos (PangoLayout    *layout,
                           PangoRectangle *pos)
 {
   PangoRectangle logical_rect;
-  PangoLayoutIter *iter;
+  PangoLayoutIter iter;
   PangoLayoutLine *layout_line = NULL;
   int x_pos;
 
@@ -2084,20 +2084,20 @@ pango_layout_index_to_pos (PangoLayout    *layout,
   g_return_if_fail (index >= 0);
   g_return_if_fail (pos != NULL);
 
-  iter = pango_layout_get_iter (layout);
+  _pango_layout_get_iter (layout, &iter);
 
-  if (!ITER_IS_INVALID (iter))
+  if (!ITER_IS_INVALID (&iter))
     {
       while (TRUE)
        {
-         PangoLayoutLine *tmp_line = _pango_layout_iter_get_line (iter);
+         PangoLayoutLine *tmp_line = _pango_layout_iter_get_line (&iter);
 
          if (tmp_line->start_index > index)
            {
-             /* index is in the paragraph delimiters, move to
+             /* index is in the paragraph delim&iters, move to
               * end of previous line
               *
-              * This shouldn’t occur in the first loop iteration as the first
+              * This shouldn’t occur in the first loop &iteration as the first
               * line’s start_index should always be 0.
               */
              g_assert (layout_line != NULL);
@@ -2107,12 +2107,12 @@ pango_layout_index_to_pos (PangoLayout    *layout,
 
          layout_line = tmp_line;
 
-         pango_layout_iter_get_line_extents (iter, NULL, &logical_rect);
+         pango_layout_iter_get_line_extents (&iter, NULL, &logical_rect);
 
          if (layout_line->start_index + layout_line->length > index)
            break;
 
-         if (!pango_layout_iter_next_line (iter))
+         if (!pango_layout_iter_next_line (&iter))
            {
              index = layout_line->start_index + layout_line->length;
              break;
@@ -2134,7 +2134,7 @@ pango_layout_index_to_pos (PangoLayout    *layout,
        pos->width = 0;
     }
 
-  pango_layout_iter_free (iter);
+  _pango_layout_iter_destroy (&iter);
 }
 
 static void
@@ -2835,11 +2835,12 @@ int
 pango_layout_get_baseline (PangoLayout    *layout)
 {
   int baseline;
+  PangoLayoutIter iter;
 
   /* XXX this is so inefficient */
-  PangoLayoutIter *iter = pango_layout_get_iter (layout);
-  baseline = pango_layout_iter_get_baseline (iter);
-  pango_layout_iter_free (iter);
+  _pango_layout_get_iter (layout, &iter);
+  baseline = pango_layout_iter_get_baseline (&iter);
+  _pango_layout_iter_destroy (&iter);
 
   return baseline;
 }
diff --git a/pango/pango-renderer.c b/pango/pango-renderer.c
index 01b9615..f82c4e4 100644
--- a/pango/pango-renderer.c
+++ b/pango/pango-renderer.c
@@ -24,6 +24,7 @@
 
 #include "pango-renderer.h"
 #include "pango-impl-utils.h"
+#include "pango-layout-private.h"
 
 #define N_RENDER_PARTS 4
 
@@ -162,7 +163,7 @@ pango_renderer_draw_layout (PangoRenderer    *renderer,
                            int               x,
                            int               y)
 {
-  PangoLayoutIter *iter;
+  PangoLayoutIter iter;
 
   g_return_if_fail (PANGO_IS_RENDERER (renderer));
   g_return_if_fail (PANGO_IS_LAYOUT (layout));
@@ -179,7 +180,7 @@ pango_renderer_draw_layout (PangoRenderer    *renderer,
 
   pango_renderer_activate (renderer);
 
-  iter = pango_layout_get_iter (layout);
+  _pango_layout_get_iter (layout, &iter);
 
   do
     {
@@ -187,19 +188,19 @@ pango_renderer_draw_layout (PangoRenderer    *renderer,
       PangoLayoutLine *line;
       int              baseline;
 
-      line = pango_layout_iter_get_line_readonly (iter);
+      line = pango_layout_iter_get_line_readonly (&iter);
 
-      pango_layout_iter_get_line_extents (iter, NULL, &logical_rect);
-      baseline = pango_layout_iter_get_baseline (iter);
+      pango_layout_iter_get_line_extents (&iter, NULL, &logical_rect);
+      baseline = pango_layout_iter_get_baseline (&iter);
 
       pango_renderer_draw_layout_line (renderer,
                                       line,
                                       x + logical_rect.x,
                                       y + baseline);
     }
-  while (pango_layout_iter_next_line (iter));
+  while (pango_layout_iter_next_line (&iter));
 
-  pango_layout_iter_free (iter);
+  _pango_layout_iter_destroy (&iter);
 
   pango_renderer_deactivate (renderer);
 }