diff options
| author | Roman Borisov | 2011-03-27 23:24:09 +0200 |
|---|---|---|
| committer | Denys Vlasenko | 2011-03-27 23:24:09 +0200 |
| commit | 95f5c52e6f823c710be807fb86c8b2fafec8a334 (patch) | |
| tree | 61005a2708d0b7171b3c7a2b8566339ee5f51dc3 | |
| parent | 1f4447b2d439e6f11d95746bb5f611c353305859 (diff) | |
| download | busybox-95f5c52e6f823c710be807fb86c8b2fafec8a334.zip busybox-95f5c52e6f823c710be807fb86c8b2fafec8a334.tar.gz | |
diff: optimize diffing of files with the same metadata
Signed-off-by: Roman Borisov <ext-roman.borisov@nokia.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
| -rw-r--r-- | editors/diff.c | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/editors/diff.c b/editors/diff.c index ca4a4ea..3719bb4 100644 --- a/editors/diff.c +++ b/editors/diff.c @@ -952,6 +952,31 @@ int diff_main(int argc UNUSED_PARAM, char **argv) if (gotstdin && (S_ISDIR(stb[0].st_mode) || S_ISDIR(stb[1].st_mode))) bb_error_msg_and_die("can't compare stdin to a directory"); + /* Compare metadata to check if the files are the same physical file. + * + * Comment from diffutils source says: + * POSIX says that two files are identical if st_ino and st_dev are + * the same, but many file systems incorrectly assign the same (device, + * inode) pair to two distinct files, including: + * GNU/Linux NFS servers that export all local file systems as a + * single NFS file system, if a local device number (st_dev) exceeds + * 255, or if a local inode number (st_ino) exceeds 16777215. + */ + if (ENABLE_DESKTOP + && stb[0].st_ino == stb[1].st_ino + && stb[0].st_dev == stb[1].st_dev + && stb[0].st_size == stb[1].st_size + && stb[0].st_mtime == stb[1].st_mtime + && stb[0].st_ctime == stb[1].st_ctime + && stb[0].st_mode == stb[1].st_mode + && stb[0].st_nlink == stb[1].st_nlink + && stb[0].st_uid == stb[1].st_uid + && stb[0].st_gid == stb[1].st_gid + ) { + /* files are physically the same; no need to compare them */ + return STATUS_SAME; + } + if (S_ISDIR(stb[0].st_mode) && S_ISDIR(stb[1].st_mode)) { #if ENABLE_FEATURE_DIFF_DIR diffdir(file, s_start); |