path: root/diff.h
diff options
authorJohan Herland <>2011-04-29 09:36:21 (GMT)
committerJunio C Hamano <>2011-04-29 18:22:55 (GMT)
commit1c57a627bf269f3c83c48ad724cd8b14292502ef (patch)
treecf9a49d2ff4665e31f21c4885ce9193dccf87d78 /diff.h
parent712d2c7dd893212756c21787fc12d6f71327e167 (diff)
New --dirstat=lines mode, doing dirstat analysis based on diffstat
This patch adds an alternative implementation of show_dirstat(), called show_dirstat_by_line(), which uses the more expensive diffstat analysis (as opposed to show_dirstat()'s own (relatively inexpensive) analysis) to derive the numbers from which the --dirstat output is computed. The alternative implementation is controlled by the new "lines" parameter to the --dirstat option (or the diff.dirstat config variable). For binary files, the diffstat analysis counts bytes instead of lines, so to prevent binary files from dominating the dirstat results, the byte counts for binary files are divided by 64 before being compared to their textual/line-based counterparts. This is a stupid and ugly - but very cheap - heuristic. In linux-2.6.git, running the three different --dirstat modes: time git diff v2.6.20..v2.6.30 --dirstat=changes > /dev/null vs. time git diff v2.6.20..v2.6.30 --dirstat=lines > /dev/null vs. time git diff v2.6.20..v2.6.30 --dirstat=files > /dev/null yields the following average runtimes on my machine: - "changes" (default): ~6.0 s - "lines": ~9.6 s - "files": ~0.1 s So, as expected, there's a considerable performance hit (~60%) by going through the full diffstat analysis as compared to the default "changes" analysis (obviously, "files" is much faster than both). As such, the "lines" mode is probably only useful if you really need the --dirstat numbers to be consistent with the numbers returned from the other --*stat options. The patch also includes documentation and tests for the new dirstat mode. Improved-by: Junio C Hamano <> Signed-off-by: Johan Herland <> Signed-off-by: Junio C Hamano <>
Diffstat (limited to 'diff.h')
1 files changed, 1 insertions, 0 deletions
diff --git a/diff.h b/diff.h
index 90f491e..937a903 100644
--- a/diff.h
+++ b/diff.h
@@ -78,6 +78,7 @@ typedef struct strbuf *(*diff_prefix_fn_t)(struct diff_options *opt, void *data)
+#define DIFF_OPT_DIRSTAT_BY_LINE (1 << 28)
#define DIFF_OPT_TST(opts, flag) ((opts)->flags & DIFF_OPT_##flag)
#define DIFF_OPT_SET(opts, flag) ((opts)->flags |= DIFF_OPT_##flag)