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| author | Paul Eggert <eggert@cs.ucla.edu> | 2017-08-12 14:00:17 -0700 |
|---|---|---|
| committer | Paul Eggert <eggert@cs.ucla.edu> | 2017-08-12 15:14:45 -0700 |
| commit | a6ad98ad66e1d0c0dac5f25ba91e11d0cf9da725 (patch) | |
| tree | 183748df6a5b71f1b48deecc824eef27939ff2f8 /src/filelock.c | |
| parent | 9eb30cb03613ae158c870d603a05a6a6393dc485 (diff) | |
| download | emacs-a6ad98ad66e1d0c0dac5f25ba91e11d0cf9da725.tar.gz emacs-a6ad98ad66e1d0c0dac5f25ba91e11d0cf9da725.tar.bz2 emacs-a6ad98ad66e1d0c0dac5f25ba91e11d0cf9da725.zip | |
Improve make-temp-file performance on local files
For the motivation behind this patch, please see Bug#28023 and:
http://emacshorrors.com/posts/make-temp-name.html
Although, given the recent changes to Tramp, the related security
problem in make-temp-file is already fixed, make-temp-file still has
several unnecessary system calls. In the typical case on GNU/Linux,
this patch replaces 8 syscalls (symlink, open, close, readlinkat, uname,
getpid, unlink, umask) by 2 (open, close).
* admin/merge-gnulib (GNULIB_MODULES): Add tempname, now
that Emacs is using it directly.
* configure.ac (AUTO_DEPEND): Remove AC_SYS_LONG_FILE_NAMES;
no longer needed.
* lib/gnulib.mk.in, m4/gnulib-comp.m4: Regenerate.
* lisp/files.el (files--make-magic-temp-file): Rename from
make-temp-file.
(make-temp-file): Use make-temp-file-internal for
non-magic file names.
* src/fileio.c: Include tempname.h.
(make_temp_name_tbl, make_temp_name_count)
(make_temp_name_count_initialized_p, make_temp_name): Remove.
(Fmake_temp_file_internal): New function.
(Fmake_temp_name): Use it.
* src/filelock.c (get_boot_time): Use Fmake_temp_file_internal
instead of make_temp_name.
Diffstat (limited to 'src/filelock.c')
| -rw-r--r-- | src/filelock.c | 13 |
1 files changed, 5 insertions, 8 deletions
diff --git a/src/filelock.c b/src/filelock.c index dd8cb28c425..3d6941695ae 100644 --- a/src/filelock.c +++ b/src/filelock.c @@ -206,14 +206,11 @@ get_boot_time (void) WTMP_FILE, counter); if (! NILP (Ffile_exists_p (tempname))) { - /* The utmp functions on mescaline.gnu.org accept only - file names up to 8 characters long. Choose a 2 - character long prefix, and call make_temp_file with - second arg non-zero, so that it will add not more - than 6 characters to the prefix. */ - filename = Fexpand_file_name (build_string ("wt"), - Vtemporary_file_directory); - filename = make_temp_name (filename, 1); + /* The utmp functions on older systems accept only file + names up to 8 bytes long. Choose a 2 byte prefix, so + the 6-byte suffix does not make the name too long. */ + filename = Fmake_temp_file_internal (build_string ("wt"), Qnil, + empty_unibyte_string); CALLN (Fcall_process, build_string ("gzip"), Qnil, list2 (QCfile, filename), Qnil, build_string ("-cd"), tempname); |