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| author | Paul Eggert <eggert@cs.ucla.edu> | 2017-07-31 12:31:02 -0700 |
|---|---|---|
| committer | Paul Eggert <eggert@cs.ucla.edu> | 2017-07-31 12:56:51 -0700 |
| commit | 3a8d0cc825635e07da2a90c4ac987b476fc9b05d (patch) | |
| tree | 7a18ef1a777007f05feff6a35ebadc4338330906 /src/dired.c | |
| parent | 192342a3a93a2e467ab589ae2d1ffd5e7acf1398 (diff) | |
| download | emacs-3a8d0cc825635e07da2a90c4ac987b476fc9b05d.tar.gz emacs-3a8d0cc825635e07da2a90c4ac987b476fc9b05d.tar.bz2 emacs-3a8d0cc825635e07da2a90c4ac987b476fc9b05d.zip | |
Avoid most stat calls when completing file names
* admin/merge-gnulib (GNULIB_MODULES): Add d-type.
* lib/gnulib.mk.in, m4/gnulib-comp.m4: Regenerate.
* m4/d-type.m4: New file, copied from gnulib.
* src/dired.c (DT_UNKNOWN, DT_DIR, DT_LINK)
[!HAVE_STRUCT_DIRENT_D_TYPE]: New constants.
(dirent_type): New function.
(file_name_completion): Use it, to avoid unnecessary calls to
stat-like functions on GNU/Linux and other platforms with d_type.
(file_name_completion_stat): Just follow the link; there is no
need to try first with AT_SYMLINK_NOFOLLOW since the directory
entry was already checked to exist.
Diffstat (limited to 'src/dired.c')
| -rw-r--r-- | src/dired.c | 71 |
1 files changed, 41 insertions, 30 deletions
diff --git a/src/dired.c b/src/dired.c index 5ea00fb8db4..288ba6b1038 100644 --- a/src/dired.c +++ b/src/dired.c @@ -64,6 +64,21 @@ dirent_namelen (struct dirent *dp) #endif } +#ifndef HAVE_STRUCT_DIRENT_D_TYPE +enum { DT_UNKNOWN, DT_DIR, DT_LNK }; +#endif + +/* Return the file type of DP. */ +static int +dirent_type (struct dirent *dp) +{ +#ifdef HAVE_STRUCT_DIRENT_D_TYPE + return dp->d_type; +#else + return DT_UNKNOWN; +#endif +} + static DIR * open_directory (Lisp_Object dirname, int *fdp) { @@ -434,7 +449,7 @@ is matched against file and directory names relative to DIRECTORY. */) return file_name_completion (file, directory, 1, Qnil); } -static int file_name_completion_stat (int, struct dirent *, struct stat *); +static bool file_name_completion_dirp (int, struct dirent *, ptrdiff_t); static Lisp_Object file_name_completion (Lisp_Object file, Lisp_Object dirname, bool all_flag, @@ -448,7 +463,6 @@ file_name_completion (Lisp_Object file, Lisp_Object dirname, bool all_flag, Lisp_Object bestmatch, tem, elt, name; Lisp_Object encoded_file; Lisp_Object encoded_dir; - struct stat st; bool directoryp; /* If not INCLUDEALL, exclude files in completion-ignored-extensions as well as "." and "..". Until shown otherwise, assume we can't exclude @@ -512,10 +526,21 @@ file_name_completion (Lisp_Object file, Lisp_Object dirname, bool all_flag, >= 0)) continue; - if (file_name_completion_stat (fd, dp, &st) < 0) - continue; + switch (dirent_type (dp)) + { + case DT_DIR: + directoryp = true; + break; + + case DT_LNK: case DT_UNKNOWN: + directoryp = file_name_completion_dirp (fd, dp, len); + break; + + default: + directoryp = false; + break; + } - directoryp = S_ISDIR (st.st_mode) != 0; tem = Qnil; /* If all_flag is set, always include all. It would not actually be helpful to the user to ignore any possible @@ -781,32 +806,18 @@ scmp (const char *s1, const char *s2, ptrdiff_t len) return len - l; } -static int -file_name_completion_stat (int fd, struct dirent *dp, struct stat *st_addr) +/* Return true if in the directory FD the directory entry DP, whose + string length is LEN, is that of a subdirectory that can be searched. */ +static bool +file_name_completion_dirp (int fd, struct dirent *dp, ptrdiff_t len) { - int value; - -#ifdef MSDOS - /* Some fields of struct stat are *very* expensive to compute on MS-DOS, - but aren't required here. Avoid computing the following fields: - st_inode, st_size and st_nlink for directories, and the execute bits - in st_mode for non-directory files with non-standard extensions. */ - - unsigned short save_djstat_flags = _djstat_flags; - - _djstat_flags = _STAT_INODE | _STAT_EXEC_MAGIC | _STAT_DIRSIZE; -#endif /* MSDOS */ - - /* We want to return success if a link points to a nonexistent file, - but we want to return the status for what the link points to, - in case it is a directory. */ - value = fstatat (fd, dp->d_name, st_addr, AT_SYMLINK_NOFOLLOW); - if (value == 0 && S_ISLNK (st_addr->st_mode)) - fstatat (fd, dp->d_name, st_addr, 0); -#ifdef MSDOS - _djstat_flags = save_djstat_flags; -#endif /* MSDOS */ - return value; + USE_SAFE_ALLOCA; + char *subdir_name = SAFE_ALLOCA (len + 2); + memcpy (subdir_name, dp->d_name, len); + strcpy (subdir_name + len, "/"); + bool dirp = faccessat (fd, subdir_name, F_OK, AT_EACCESS) == 0; + SAFE_FREE (); + return dirp; } static char * |