From: ZheNing Hu <adlternative@xxxxxxxxx>
When we use `git for-each-ref`, every ref will allocate
its own output strbuf. But we can reuse the final strbuf
for each step ref's output.
The performance for `git for-each-ref` on the Git repository
itself with performance testing tool `hyperfine` changes from
23.7 ms ± 0.9 ms to 22.2 ms ± 1.0 ms. Optimization is relatively
minor.
At the same time, we apply this optimization to `git tag -l`
and `git branch -l`.
This approach is similar to the one used by 79ed0a5
(cat-file: use a single strbuf for all output, 2018-08-14)
to speed up the cat-file builtin.
Helped-by: Jeff King <peff@xxxxxxxx>
Helped-by: René Scharfe <l.s.r@xxxxxx>
Signed-off-by: ZheNing Hu <adlternative@xxxxxxxxx>
---
builtin/branch.c | 9 +++++----
builtin/for-each-ref.c | 12 ++++++------
builtin/tag.c | 12 ++++++------
3 files changed, 17 insertions(+), 16 deletions(-)
diff --git a/builtin/branch.c b/builtin/branch.c
index bcc00bcf182d..00081de1aed8 100644
--- a/builtin/branch.c
+++ b/builtin/branch.c
@@ -411,6 +411,8 @@ static void print_ref_list(struct ref_filter *filter, struct ref_sorting *sortin
{
int i;
struct ref_array array;
+ struct strbuf out = STRBUF_INIT;
+ struct strbuf err = STRBUF_INIT;
int maxwidth = 0;
const char *remote_prefix = "";
char *to_free = NULL;
@@ -440,8 +442,7 @@ static void print_ref_list(struct ref_filter *filter, struct ref_sorting *sortin
ref_array_sort(sorting, &array);
for (i = 0; i < array.nr; i++) {
- struct strbuf out = STRBUF_INIT;
- struct strbuf err = STRBUF_INIT;
+ strbuf_reset(&out);
if (format_ref_array_item(array.items[i], format, &out, &err))
die("%s", err.buf);
if (column_active(colopts)) {
@@ -452,10 +453,10 @@ static void print_ref_list(struct ref_filter *filter, struct ref_sorting *sortin
fwrite(out.buf, 1, out.len, stdout);
putchar('\n');
}
- strbuf_release(&err);
- strbuf_release(&out);
}
+ strbuf_release(&err);
+ strbuf_release(&out);
ref_array_clear(&array);
free(to_free);
}
diff --git a/builtin/for-each-ref.c b/builtin/for-each-ref.c
index 8520008604e3..bf24c595c526 100644
--- a/builtin/for-each-ref.c
+++ b/builtin/for-each-ref.c
@@ -22,6 +22,8 @@ int cmd_for_each_ref(int argc, const char **argv, const char *prefix)
struct ref_array array;
struct ref_filter filter;
struct ref_format format = REF_FORMAT_INIT;
+ struct strbuf output = STRBUF_INIT;
+ struct strbuf err = STRBUF_INIT;
struct option opts[] = {
OPT_BIT('s', "shell", &format.quote_style,
@@ -81,17 +83,15 @@ int cmd_for_each_ref(int argc, const char **argv, const char *prefix)
if (!maxcount || array.nr < maxcount)
maxcount = array.nr;
for (i = 0; i < maxcount; i++) {
- struct strbuf output = STRBUF_INIT;
- struct strbuf err = STRBUF_INIT;
-
+ strbuf_reset(&output);
if (format_ref_array_item(array.items[i], &format, &output, &err))
die("%s", err.buf);
fwrite(output.buf, 1, output.len, stdout);
putchar('\n');
-
- strbuf_release(&err);
- strbuf_release(&output);
}
+
+ strbuf_release(&err);
+ strbuf_release(&output);
ref_array_clear(&array);
return 0;
}
diff --git a/builtin/tag.c b/builtin/tag.c
index d92d8e110b4d..592af1d154ea 100644
--- a/builtin/tag.c
+++ b/builtin/tag.c
@@ -39,6 +39,8 @@ static int list_tags(struct ref_filter *filter, struct ref_sorting *sorting,
struct ref_format *format)
{
struct ref_array array;
+ struct strbuf output = STRBUF_INIT;
+ struct strbuf err = STRBUF_INIT;
char *to_free = NULL;
int i;
@@ -64,17 +66,15 @@ static int list_tags(struct ref_filter *filter, struct ref_sorting *sorting,
ref_array_sort(sorting, &array);
for (i = 0; i < array.nr; i++) {
- struct strbuf output = STRBUF_INIT;
- struct strbuf err = STRBUF_INIT;
-
+ strbuf_reset(&output);
if (format_ref_array_item(array.items[i], format, &output, &err))
die("%s", err.buf);
fwrite(output.buf, 1, output.len, stdout);
putchar('\n');
-
- strbuf_release(&err);
- strbuf_release(&output);
}
+
+ strbuf_release(&err);
+ strbuf_release(&output);
ref_array_clear(&array);
free(to_free);
--
gitgitgadget
