Compact buffers when idle.

* lisp/compact.el: New file.
* src/buffer.c (compact_buffer, Fcompact_buffer): New function.
(syms_of_buffer): Register Fcompact_buffer.
* src/alloc.c (Fgarbage_collect): Use compact_buffer.
* src/buffer.h (compact_buffer): New prototype.
(struct buffer_text): New member.

1 files changed, 4 insertions, 0 deletions

diff --git a/src/buffer.h b/src/buffer.h
index 8c596835fcc..6f090479a24 100644
--- a/src/buffer.h
+++ b/src/buffer.h
@@ -436,6 +436,9 @@ struct buffer_text
 
     EMACS_INT overlay_modiff;   /* Counts modifications to overlays.  */
 
+    EMACS_INT compact;          /* Set to modiff each time when compact_buffer
+                                   is called for this buffer.  */
+
     /* Minimum value of GPT - BEG since last redisplay that finished.  */
     ptrdiff_t beg_unchanged;
 
@@ -903,6 +906,7 @@ extern struct buffer buffer_local_symbols;
 
 extern void delete_all_overlays (struct buffer *);
 extern void reset_buffer (struct buffer *);
+extern int compact_buffer (struct buffer *);
 extern void evaporate_overlays (ptrdiff_t);
 extern ptrdiff_t overlays_at (EMACS_INT pos, int extend, Lisp_Object **vec_ptr,
                               ptrdiff_t *len_ptr, ptrdiff_t *next_ptr,