This patch adds an alternative implementation of show_dirstat(), called
show_dirstat_based_on_diffstat(), which uses the more expensive diffstat
analysis (as opposed to --dirstat's own (inexpensive) analysis) to derive
the numbers from which the --dirstat output is computed.
The alternative implementation is controlled by a new config variable called
diff.dirstatBasedOnDiffstat.
In linux-2.6.git, running
time git diff v2.6.20..v2.6.30 --dirstat=0 > /dev/null
with and without diff.dirstatBasedOnDiffstat enabled yields the following
average runtimes on my machine:
- disabled: ~6.0 s
- enabled: ~9.7 s
So, as expected, there's a considerable performance hit (>60%) by going
through the full diffstat analysis. As such, the new option is probably
only useful if you really need the --dirstat numbers to be consistent with
the numbers returned from the other --*stat options.
In --dirstat-by-file mode, the diffstat analysis is obviously a waste of time,
so --dirstat-by-file automatically disabled diff.dirstatBasedOnDiffstat.
Signed-off-by: Johan Herland <johan@xxxxxxxxxxx>
---
This might not be worth applying at all, but if it is, I can send a re-roll
with documentation and more user-friendlyness.
Have fun! :)
...Johan
diff.c | 53 +++++++++++++++++++++++++++++++++++++++++++++++++++--
1 files changed, 51 insertions(+), 2 deletions(-)
diff --git a/diff.c b/diff.c
index 5376d01..a496ba6 100644
--- a/diff.c
+++ b/diff.c
@@ -31,6 +31,7 @@ static const char *external_diff_cmd_cfg;
int diff_auto_refresh_index = 1;
static int diff_mnemonic_prefix;
static int diff_no_prefix;
+static int dirstat_based_on_diffstat;
static struct diff_options default_diff_options;
static char diff_colors[][COLOR_MAXLEN] = {
@@ -103,6 +104,10 @@ int git_diff_ui_config(const char *var, const char *value, void *cb)
diff_no_prefix = git_config_bool(var, value);
return 0;
}
+ if (!strcmp(var, "diff.dirstatbasedondiffstat")) {
+ dirstat_based_on_diffstat = git_config_bool(var, value);
+ return 0;
+ }
if (!strcmp(var, "diff.external"))
return git_config_string(&external_diff_cmd_cfg, var, value);
if (!strcmp(var, "diff.wordregex"))
@@ -1619,6 +1624,43 @@ found_damage:
gather_dirstat(options, &dir, changed, "", 0);
}
+static void show_dirstat_based_on_diffstat(struct diffstat_t *data, struct diff_options
*options)
+{
+ int i;
+ unsigned long changed;
+ struct dirstat_dir dir;
+
+ if (data->nr == 0)
+ return;
+
+ dir.files = NULL;
+ dir.alloc = 0;
+ dir.nr = 0;
+ dir.percent = options->dirstat_percent;
+ dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
+
+ changed = 0;
+ for (i = 0; i < data->nr; i++) {
+ struct diffstat_file *file = data->files[i];
+ unsigned long damage;
+
+ damage = file->added + file->deleted;
+ ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
+ dir.files[dir.nr].name = file->name;
+ dir.files[dir.nr].changed = damage;
+ changed += damage;
+ dir.nr++;
+ }
+
+ /* This can happen even with many files, if everything was renames */
+ if (!changed)
+ return;
+
+ /* Show all directories with more than x% of the changes */
+ qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
+ gather_dirstat(options, &dir, changed, "", 0);
+}
+
static void free_diffstat_info(struct diffstat_t *diffstat)
{
int i;
@@ -4012,7 +4054,12 @@ void diff_flush(struct diff_options *options)
separator++;
}
- if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT)) {
+ // --dirstat-by-file REALLY don't need the full diffstat analysis
+ if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE))
+ dirstat_based_on_diffstat = 0;
+
+ if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
+ ((output_format & DIFF_FORMAT_DIRSTAT) && dirstat_based_on_diffstat)) {
struct diffstat_t diffstat;
memset(&diffstat, 0, sizeof(struct diffstat_t));
@@ -4027,10 +4074,12 @@ void diff_flush(struct diff_options *options)
show_stats(&diffstat, options);
if (output_format & DIFF_FORMAT_SHORTSTAT)
show_shortstats(&diffstat, options);
+ if (output_format & DIFF_FORMAT_DIRSTAT)
+ show_dirstat_based_on_diffstat(&diffstat, options);
free_diffstat_info(&diffstat);
separator++;
}
- if (output_format & DIFF_FORMAT_DIRSTAT)
+ if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_based_on_diffstat)
show_dirstat(options);
if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
--
1.7.5.rc1.3.g4d7b
--
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