[PATCH 2/2] [GSOC] ref-filter: reuse output buffer
- From
ZheNing Hu via GitGitGadget <gitgitgadget@gmail.com>
- Date
- Apr 19, 2021, 11:28 UTC
- Message-ID
- <1c7a69ba072ac740273ef06972122f74cf3fa684.1618831726.git.gitgitgadget@gmail.com>
- In-Reply-To
- <pull.935.git.1618831726.gitgitgadget@gmail.com>
From: ZheNing Hu <adlternative@gmail.com>
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@peff.net> Helped-by: René Scharfe <l.s.r@web.de> Signed-off-by: ZheNing Hu <adlternative@gmail.com> --- 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);
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