Commit 28e969dd authored by Jim Blandy's avatar Jim Blandy

* buffer.c: #include region-cache.h.

(Fget_buffer_create): Initialize new members of struct buffer.
(Fkill_buffer): Free memory occupied by caches.
(init_buffer_once): Set default value for cache_long_line_scans in
buffer_defaults, and give it a bit in buffer_local_flags.
(syms_of_buffer): Add DEFVAR_PER_BUFFER for cache_long_line_scans.
parent e8951513
......@@ -34,6 +34,7 @@ the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
#include "window.h"
#include "commands.h"
#include "buffer.h"
#include "region-cache.h"
#include "indent.h"
#include "blockinput.h"
......@@ -248,6 +249,10 @@ The value is never nil.")
BUF_Z (b) = 1;
BUF_MODIFF (b) = 1;
b->newline_cache = 0;
b->width_run_cache = 0;
b->width_table = Qnil;
/* Put this on the chain of all buffers including killed ones. */
b->next = all_buffers;
all_buffers = b;
......@@ -840,6 +845,17 @@ with `delete-process'.")
b->name = Qnil;
if (b->newline_cache)
free_region_cache (b->newline_cache);
b->newline_cache = 0;
if (b->width_run_cache)
free_region_cache (b->width_run_cache);
b->width_run_cache = 0;
b->width_table = Qnil;
b->undo_list = Qnil;
......@@ -2479,6 +2495,7 @@ init_buffer_once ()
XSETFASTINT (buffer_defaults.fill_column, 70);
XSETFASTINT (buffer_defaults.left_margin, 0);
buffer_defaults.cache_long_line_scans = Qnil;
/* Assign the local-flags to the slots that have default values.
The local flag is a bit that is used in the buffer
......@@ -2518,6 +2535,7 @@ init_buffer_once ()
XSETFASTINT (buffer_local_flags.abbrev_table, 0x1000);
XSETFASTINT (buffer_local_flags.display_table, 0x2000);
XSETFASTINT (buffer_local_flags.syntax_table, 0x8000);
XSETFASTINT (buffer_local_flags.cache_long_line_scans, 0x10000);
#ifdef MSDOS
XSETFASTINT (buffer_local_flags.buffer_file_type, 0x4000);
......@@ -2971,6 +2989,23 @@ If the value of the variable is t, undo information is not recorded.");
"Non-nil means the mark and region are currently active in this buffer.\n\
Automatically local in all buffers.");
DEFVAR_PER_BUFFER ("cache-long-line-scans", &current_buffer->cache_long_line_scans, Qnil,
"Non-nil means that Emacs should use caches to handle long lines faster.\n\
Emacs moves from one line to the next by scanning the buffer for\n\
newlines, and it implements columnar operations like move-to-column by\n\
scanning the buffer, adding character widths as it goes. If the\n\
buffer's lines are very long (say, more than 500 characters), these\n\
scans can slow Emacs down a great deal.\n\
If this variable is non-nil, Emacs caches the results of its scans,\n\
and avoids rescanning regions of the buffer until they are modified.\n\
If this variable is non-nil, short scans will become slightly slower,\n\
and the caches will use memory roughly proportional to the number of\n\
newlines and characters whose visual representation can occupy more than\n\
one column.");
DEFVAR_LISP ("transient-mark-mode", &Vtransient_mark_mode,
"*Non-nil means deactivate the mark when the buffer contents change.");
Vtransient_mark_mode = Qnil;
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