Use region cache to speedup bidi_find_paragraph_start.

* src/buffer.h (struct buffer): New member bidi_paragraph_cache.
Rename cache_long_line_scans to cache_long_scans.
* src/buffer.c (bset_cache_long_line_scans): Rename to
bset_cache_long_scans.
(Fget_buffer_create, Fmake_indirect_buffer, Fkill_buffer)
(Fbuffer_swap_text, init_buffer_once): Take bidi_paragraph_cache
into account.
(syms_of_buffer): Rename cache-long-line-scans to
cache-long-scans.  Adjust docstring.
* src/search.c (newline_cache_on_off):
* src/indent.c (width_run_cache_on_off): Adjust users.
* src/bidi.c (bidi_paragraph_cache_on_off): New function.
(bidi_find_paragraph_start): Use bidi_paragraph_cache if needed.
* src/insdel.c (prepare_to_modify_buffer): Invalidate
bidi_paragraph_cache if enabled.
* doc/lispref/positions.texi (Motion by Screen Lines):
* doc/lispref/display.texi (Truncation): Rename `cache-long-line-scans'
to `cache-long-scans'.

1 files changed, 1 insertions, 1 deletions

diff --git a/doc/lispref/positions.texi b/doc/lispref/positions.texi
index e8b6166f63c..119ad98a53d 100644
--- a/doc/lispref/positions.texi
+++ b/doc/lispref/positions.texi
@@ -483,7 +483,7 @@ Display}.
   These functions scan text to determine where screen lines break, and
 thus take time proportional to the distance scanned.  If you intend to
 use them heavily, Emacs provides caches which may improve the
-performance of your code.  @xref{Truncation, cache-long-line-scans}.
+performance of your code.  @xref{Truncation, cache-long-scans}.
 
 @defun vertical-motion count &optional window
 This function moves point to the start of the screen line @var{count}