[vte/vte-0-34] [ring] Rename variables for readability

[Behdad Esfahbod <behdad src gnome org>]

commit fe79b99acf38945b124ad33c3af145d68ce8f5ff
Author: Behdad Esfahbod <behdad behdad org>
Date:   Fri Sep 27 17:26:58 2013 -0400

    [ring] Rename variables for readability
    
    Patch from Egmont Koblinger.
    
    Part of Bug 708496 - Lines disappear after positioning back the cursor

 src/ring.c |   81 ++++++++++++++++++++++++++++++++++--------------------------
 src/ring.h |    5 ++-
 2 files changed, 49 insertions(+), 37 deletions(-)
---
diff --git a/src/ring.c b/src/ring.c
index db4edec..6200a36 100644
--- a/src/ring.c
+++ b/src/ring.c
@@ -66,8 +66,8 @@ _vte_ring_init (VteRing *ring, gulong max_rows)
        ring->text_stream = _vte_file_stream_new ();
        ring->row_stream = _vte_file_stream_new ();
 
-       ring->last_attr.text_offset = 0;
-       ring->last_attr.attr.i = basic_cell.i.attr;
+       ring->last_attr_text_start_offset = 0;
+       ring->last_attr.i = basic_cell.i.attr;
        ring->utf8_buffer = g_string_sized_new (128);
 
        _vte_row_data_init (&ring->cached_row);
@@ -96,8 +96,8 @@ _vte_ring_fini (VteRing *ring)
 }
 
 typedef struct _VteRowRecord {
-       gsize text_offset;
-       gsize attr_offset;
+       gsize text_start_offset;  // offset where text of this row begins
+       gsize attr_start_offset;  // offset of the first character's attributes
 } VteRowRecord;
 
 static gboolean
@@ -122,8 +122,8 @@ _vte_ring_freeze_row (VteRing *ring, gulong position, const VteRowData *row)
 
        _vte_debug_print (VTE_DEBUG_RING, "Freezing row %lu.\n", position);
 
-       record.text_offset = _vte_stream_head (ring->text_stream);
-       record.attr_offset = _vte_stream_head (ring->attr_stream);
+       record.text_start_offset = _vte_stream_head (ring->text_stream);
+       record.attr_start_offset = _vte_stream_head (ring->attr_stream);
 
        g_string_set_size (buffer, 0);
        for (i = 0, cell = row->cells; i < row->len; i++, cell++) {
@@ -143,23 +143,30 @@ _vte_ring_freeze_row (VteRing *ring, gulong position, const VteRowData *row)
                 */
                attr.s = cell->attr;
                if (G_LIKELY (!attr.s.fragment)) {
-
-                       if (ring->last_attr.attr.i != attr.i) {
-                               ring->last_attr.text_offset = record.text_offset + buffer->len;
-                               _vte_stream_append (ring->attr_stream, (const char *) &ring->last_attr, 
sizeof (ring->last_attr));
+                       VteCellAttrChange attr_change;
+
+                       if (ring->last_attr.i != attr.i) {
+                               ring->last_attr_text_start_offset = record.text_start_offset + buffer->len;
+                               memset(&attr_change, 0, sizeof (attr_change));
+                               attr_change.text_end_offset = ring->last_attr_text_start_offset;
+                               attr_change.attr = ring->last_attr;
+                               _vte_stream_append (ring->attr_stream, (const char *) &attr_change, sizeof 
(attr_change));
                                if (!buffer->len)
                                        /* This row doesn't use last_attr, adjust */
-                                       record.attr_offset += sizeof (ring->last_attr);
-                               ring->last_attr.attr = attr;
+                                       record.attr_start_offset += sizeof (attr_change);
+                               ring->last_attr = attr;
                        }
 
                        num_chars = _vte_unistr_strlen (cell->c);
                        if (num_chars > 1) {
                                attr.s.columns = 0;
-                               ring->last_attr.text_offset = record.text_offset + buffer->len
-                                                           + g_unichar_to_utf8 (_vte_unistr_get_base 
(cell->c), NULL);
-                               _vte_stream_append (ring->attr_stream, (const char *) &ring->last_attr, 
sizeof (ring->last_attr));
-                               ring->last_attr.attr = attr;
+                               ring->last_attr_text_start_offset = record.text_start_offset + buffer->len
+                                                                 + g_unichar_to_utf8 (_vte_unistr_get_base 
(cell->c), NULL);
+                               memset(&attr_change, 0, sizeof (attr_change));
+                               attr_change.text_end_offset = ring->last_attr_text_start_offset;
+                               attr_change.attr = ring->last_attr;
+                               _vte_stream_append (ring->attr_stream, (const char *) &attr_change, sizeof 
(attr_change));
+                               ring->last_attr = attr;
                        }
 
                        _vte_unistr_append_to_string (cell->c, buffer);
@@ -186,7 +193,7 @@ _vte_ring_thaw_row (VteRing *ring, gulong position, VteRowData *row, gboolean do
 
        _vte_row_data_clear (row);
 
-       attr_change.text_offset = 0;
+       attr_change.text_end_offset = 0;
 
        if (!_vte_ring_read_row_record (ring, &records[0], position))
                return;
@@ -194,10 +201,10 @@ _vte_ring_thaw_row (VteRing *ring, gulong position, VteRowData *row, gboolean do
                if (!_vte_ring_read_row_record (ring, &records[1], position + 1))
                        return;
        } else
-               records[1].text_offset = _vte_stream_head (ring->text_stream);
+               records[1].text_start_offset = _vte_stream_head (ring->text_stream);
 
-       g_string_set_size (buffer, records[1].text_offset - records[0].text_offset);
-       if (!_vte_stream_read (ring->text_stream, records[0].text_offset, buffer->str, buffer->len))
+       g_string_set_size (buffer, records[1].text_start_offset - records[0].text_start_offset);
+       if (!_vte_stream_read (ring->text_stream, records[0].text_start_offset, buffer->str, buffer->len))
                return;
 
        record = records[0];
@@ -211,13 +218,13 @@ _vte_ring_thaw_row (VteRing *ring, gulong position, VteRowData *row, gboolean do
        end = p + buffer->len;
        while (p < end) {
 
-               if (record.text_offset >= ring->last_attr.text_offset) {
-                       attr = ring->last_attr.attr;
+               if (record.text_start_offset >= ring->last_attr_text_start_offset) {
+                       attr = ring->last_attr;
                } else {
-                       if (record.text_offset >= attr_change.text_offset) {
-                               if (!_vte_stream_read (ring->attr_stream, record.attr_offset, (char *) 
&attr_change, sizeof (attr_change)))
+                       if (record.text_start_offset >= attr_change.text_end_offset) {
+                               if (!_vte_stream_read (ring->attr_stream, record.attr_start_offset, (char *) 
&attr_change, sizeof (attr_change)))
                                        return;
-                               record.attr_offset += sizeof (attr_change);
+                               record.attr_start_offset += sizeof (attr_change);
                        }
                        attr = attr_change.attr;
                }
@@ -226,7 +233,7 @@ _vte_ring_thaw_row (VteRing *ring, gulong position, VteRowData *row, gboolean do
                cell.c = g_utf8_get_char (p);
 
                q = g_utf8_next_char (p);
-               record.text_offset += q - p;
+               record.text_start_offset += q - p;
                p = q;
 
                if (G_UNLIKELY (cell.attr.columns == 0)) {
@@ -251,14 +258,18 @@ _vte_ring_thaw_row (VteRing *ring, gulong position, VteRowData *row, gboolean do
        }
 
        if (do_truncate) {
-               if (records[0].text_offset < ring->last_attr.text_offset)
-                       if (!_vte_stream_read (ring->attr_stream, records[0].attr_offset, (char *) 
&ring->last_attr, sizeof (ring->last_attr))) {
-                               ring->last_attr.text_offset = 0;
-                               ring->last_attr.attr.i = basic_cell.i.attr;
+               if (records[0].text_start_offset < ring->last_attr_text_start_offset) {
+                       if (_vte_stream_read (ring->attr_stream, records[0].attr_start_offset, (char *) 
&attr_change, sizeof (attr_change))) {
+                               ring->last_attr_text_start_offset = attr_change.text_end_offset;
+                               ring->last_attr = attr_change.attr;
+                       } else {
+                               ring->last_attr_text_start_offset = 0;
+                               ring->last_attr.i = basic_cell.i.attr;
                        }
+               }
                _vte_stream_truncate (ring->row_stream, position * sizeof (record));
-               _vte_stream_truncate (ring->attr_stream, records[0].attr_offset);
-               _vte_stream_truncate (ring->text_stream, records[0].text_offset);
+               _vte_stream_truncate (ring->attr_stream, records[0].attr_start_offset);
+               _vte_stream_truncate (ring->text_stream, records[0].text_start_offset);
        }
 }
 
@@ -271,8 +282,8 @@ _vte_ring_reset_streams (VteRing *ring, gulong position)
        _vte_stream_reset (ring->text_stream, 0);
        _vte_stream_reset (ring->attr_stream, 0);
 
-       ring->last_attr.text_offset = 0;
-       ring->last_attr.attr.i = basic_cell.i.attr;
+       ring->last_attr_text_start_offset = 0;
+       ring->last_attr.i = basic_cell.i.attr;
 
        ring->last_page = position;
 }
@@ -614,7 +625,7 @@ _vte_ring_write_contents (VteRing *ring,
                /* XXX what to do in case of error? */
                if (_vte_ring_read_row_record (ring, &record, ring->start)) {
                        if (!_vte_stream_write_contents (ring->text_stream, stream,
-                                                        record.text_offset,
+                                                        record.text_start_offset,
                                                         cancellable, error))
                                return FALSE;
                }
diff --git a/src/ring.h b/src/ring.h
index 50dd5a2..d39b690 100644
--- a/src/ring.h
+++ b/src/ring.h
@@ -33,7 +33,7 @@ G_BEGIN_DECLS
 
 
 typedef struct _VteCellAttrChange {
-       gsize text_offset;
+       gsize text_end_offset;  // offset of first character no longer using this attr
        VteIntCellAttr attr;
 } VteCellAttrChange;
 
@@ -55,7 +55,8 @@ struct _VteRing {
        /* Storage */
        gulong last_page;
        VteStream *attr_stream, *text_stream, *row_stream;
-       VteCellAttrChange last_attr;
+       gsize last_attr_text_start_offset;
+       VteIntCellAttr last_attr;
        GString *utf8_buffer;
 
        VteRowData cached_row;