[vte/wip/egmont/bidi: 95/107] etap6

[Egmont Koblinger <egmontkob src gnome org>]

commit 99e1e2a6cb1a3864df0e43097a826046371481a1
Author: Egmont Koblinger <egmont gmail com>
Date:   Fri May 24 12:39:11 2019 +0200

    etap6

 src/ringview.cc | 71 ++++++++++++++++++++++++++++-----------------------------
 1 file changed, 35 insertions(+), 36 deletions(-)
---
diff --git a/src/ringview.cc b/src/ringview.cc
index cd1ee311..a62bafb0 100644
--- a/src/ringview.cc
+++ b/src/ringview.cc
@@ -20,16 +20,16 @@
  * RingView provides a "view" to a continuous segment of the Ring (or stream),
  * typically the user visible area.
  *
- * It computes additional data that are necessary to display the contents
- * properly, but are not needed for the terminal emulation logic. In order to
- * save tons of resources, these data are computed when the Ring's contents are
- * about to be displayed, rather than whenever they change.
+ * It computes additional data that are needed to display the contents (or handle
+ * user events such as mouse click), but not needed for the terminal emulation logic.
+ * In order to save tons of resources, these data are computed when the Ring's
+ * contents are about to be displayed, rather than whenever they change.
  *
- * In addition to the area covered by the Ringview, context lines are also
- * taken into account up to the next hard newline or a safety limit.
+ * For computing these data, context lines (outside of the specified region of the
+ * Ring) are also taken into account up to the next hard newline or a safety limit.
  *
- * Currently RingView is used for BiDi: to figure out which character is mapped
- * to which visual position.
+ * Currently RingView is used for BiDi: to figure out which logical character is
+ * mapped to which visual position.
  *
  * Future possible uses include "highlight all" for the search match, and
  * syntax highlighting. URL autodetection might also be ported to this
@@ -38,19 +38,11 @@
 
 #include <config.h>
 
-#ifdef WITH_FRIBIDI
-#include <fribidi.h>
-#endif
-
 #include "bidi.hh"
 #include "debug.h"
 #include "vtedefines.hh"
 #include "vteinternal.hh"
 
-#ifdef WITH_FRIBIDI
-static_assert (sizeof (gunichar) == sizeof (FriBidiChar), "Whoooo");
-#endif
-
 using namespace vte::base;
 
 RingView::RingView()
@@ -71,49 +63,53 @@ RingView::~RingView()
         delete m_bidirunner;
 }
 
-/* Pausing a RingView frees up pretty much all of its memory. This is to be
- * used when the terminal is unlikely to be painted in the near future, e.g.
- * the widget is unmapped. Not to be called too frequently, in order to avoid
- * memory fragmentation. The RingView is unpaused automatically on demand.
+/* Pausing a RingView frees up pretty much all of its memory.
+ *
+ * This is to be used when the terminal is unlikely to be painted or interacted with
+ * in the near future, e.g. the widget is unmapped. Not to be called too frequently,
+ * in order to avoid memory fragmentation.
+ *
+ * The RingView is unpaused automatically on demand.
  */
 void RingView::pause()
 {
         if (m_paused)
                 return;
 
-        for (int i = 0; i < m_bidirows_alloc_len; i++) {
-                delete m_bidirows[i];
-        }
-        g_free (m_bidirows);
-        m_bidirows_alloc_len = 0;
-
         for (int i = 0; i < m_rows_alloc_len; i++) {
                 _vte_row_data_fini(m_rows[i]);
         }
         g_free (m_rows);
         m_rows_alloc_len = 0;
 
+        for (int i = 0; i < m_bidirows_alloc_len; i++) {
+                delete m_bidirows[i];
+        }
+        g_free (m_bidirows);
+        m_bidirows_alloc_len = 0;
+
         m_invalid = true;
         m_paused = true;
 }
 
+/* Allocate (again) the required memory. */
 void RingView::unpause()
 {
         g_assert_cmpint (m_len, >=, 1);
 
-        m_bidirows_alloc_len = m_len;
-        m_bidirows = (BidiRow **) g_malloc (sizeof (BidiRow *) * m_bidirows_alloc_len);
-        for (int i = 0; i < m_bidirows_alloc_len; i++) {
-                m_bidirows[i] = new BidiRow();
-        }
-
-        m_rows_alloc_len = m_len + 10;  /* a bit of random heuristics */
+        m_rows_alloc_len = m_len + 16;  /* a bit of random heuristics for context lines */
         m_rows = (VteRowData **) g_malloc (sizeof (VteRowData *) * m_rows_alloc_len);
         for (int i = 0; i < m_rows_alloc_len; i++) {
                 m_rows[i] = (VteRowData *) malloc (sizeof (VteRowData));
                 _vte_row_data_init (m_rows[i]);
         }
 
+        m_bidirows_alloc_len = m_len;
+        m_bidirows = (BidiRow **) g_malloc (sizeof (BidiRow *) * m_bidirows_alloc_len);
+        for (int i = 0; i < m_bidirows_alloc_len; i++) {
+                m_bidirows[i] = new BidiRow();
+        }
+
         m_invalid = true;
         m_paused = false;
 }
@@ -143,10 +139,13 @@ void RingView::set_rows(vte::grid::row_t start, vte::grid::row_t len)
         if (start == m_start && len == m_len)
                 return;
 
+        /* m_rows is expended on demand in update() */
+
+        /* m_bidirows needs exactly these many lines */
         if (G_UNLIKELY (!m_paused && len > m_bidirows_alloc_len)) {
                 int i = m_bidirows_alloc_len;
                 while (len > m_bidirows_alloc_len) {
-                        m_bidirows_alloc_len *= 2;
+                        m_bidirows_alloc_len *= 1.25 /* whatever */;
                 }
                 m_bidirows = (BidiRow **) g_realloc (m_bidirows, sizeof (BidiRow *) * m_bidirows_alloc_len);
                 for (; i < m_bidirows_alloc_len; i++) {
@@ -199,7 +198,7 @@ void RingView::maybe_update()
         m_top = row;
         while (row < m_start + m_len) {
                 if (m_rows_len == m_rows_alloc_len) {
-                        m_rows_alloc_len *= 2;
+                        m_rows_alloc_len *= 1.25 /* whatever */;
                         m_rows = (VteRowData **) g_realloc (m_rows, sizeof (VteRowData *) * 
m_rows_alloc_len);
                         for (int j = m_rows_len; j < m_rows_alloc_len; j++) {
                                 m_rows[j] = (VteRowData *) malloc (sizeof (VteRowData));
@@ -212,7 +211,7 @@ void RingView::maybe_update()
                         _vte_row_data_copy (row_data, m_rows[m_rows_len]);
                } else {
                        // FIXME
-                       _vte_row_data_shrink (m_rows[m_rows_len], 0);
+                       _vte_row_data_clear (m_rows[m_rows_len]);
                }
                 m_rows_len++;
                 row++;