* lisp.h (make_gap_1): New prototype.

* buffer.h (GAP_BYTES_DFL, GAP_BYTES_MIN): New macros for the special
gap size values.
* editfns.c (Fbuffer_size): Rename from Fbufsize to fit the common
naming convention.
(syms_of_editfns): Adjust defsubr.  Drop commented-out obsolete code.
* insdel.c (make_gap_larger): Use GAP_BYTES_DFL.
(make_gap_smaller): Use GAP_BYTES_MIN.  Adjust comment.
(make_gap_1): New function to adjust the gap of any buffer.
* coding.c (coding_alloc_by_making_gap): Use it.
* buffer.c (compact_buffer): Likewise.  Use BUF_Z_BYTE, BUF_GAP_SIZE,
GAP_BYTES_DFL and GAP_BYTES_MIN.  Adjust comment.

1 files changed, 10 insertions, 0 deletions

diff --git a/src/buffer.h b/src/buffer.h
index eb6a9d4d3e1..ec9c34b3eb3 100644
--- a/src/buffer.h
+++ b/src/buffer.h
@@ -320,6 +320,16 @@ while (0)
 #define BUF_BYTES_MAX \
   (ptrdiff_t) min (MOST_POSITIVE_FIXNUM - 1, min (SIZE_MAX, PTRDIFF_MAX))
 
+/* Maximum gap size after compact_buffer, in bytes.  Also
+   used in make_gap_larger to get some extra reserved space.  */
+
+#define GAP_BYTES_DFL 2000
+
+/* Minimum gap size after compact_buffer, in bytes.  Also
+   used in make_gap_smaller to avoid too small gap size.  */
+
+#define GAP_BYTES_MIN 20
+
 /* Return the address of byte position N in current buffer.  */
 
 #define BYTE_POS_ADDR(n) \