@matheusbsbs / matheus-bagliano / commits / 8e16effe97

blame: remove unnecessary use of get_commit_info()

When `git blame --color-by-age`, the determine_line_heat() is called to select how to color the output based on the commit's author date. It uses the get_commit_info() to parse the information into a `commit_info` structure, however, this is actually unnecessary because the determine_line_heat() caller also does the same. Instead, let's change the determine_line_heat() to take a `commit_info` structure and remove the internal call to get_commit_info() thus cleaning up and optimizing the code path. Enabling Git's trace2 API in order to record the execution time for every call to determine_line_heat() function: + trace2_region_enter("blame", "determine_line_heat", the_repository); determine_line_heat(ent, &default_color); + trace2_region_enter("blame", "determine_line_heat", the_repository); Then, running `git blame` for "kernel/fork.c" in linux.git and summing all the execution time for every call (around 1.3k calls) resulted in 2.6x faster execution (best out 3): git built from 328c109303 (The eighth batch, 2021-02-12) = 42ms git built from 328c109303 + this change = 16ms Signed-off-by: Rafael Silva <rafaeloliveira.cs@gmail.com> Reviewed-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Rafael Silva committed Feb 17, 2021 at 15:54 UTC 8e16effe97f9963a77aa977a38318d8a50d96312

1 file changed +3 -5

builtin/blame.c

+3 -5

index 2c1c02c455..bd1d253a21 100644 --- a/builtin/blame.c +++ b/builtin/blame.c @@ -425,13 +425,11 @@ static void setup_default_color_by_age(void) parse_color_fields("blue,12 month ago,white,1 month ago,red"); } -static void determine_line_heat(struct blame_entry *ent, const char **dest_color) +static void determine_line_heat(struct commit_info *ci, const char **dest_color) { int i = 0; - struct commit_info ci; - get_commit_info(ent->suspect->commit, &ci, 1); - while (i < colorfield_nr && ci.author_time > colorfield[i].hop) + while (i < colorfield_nr && ci->author_time > colorfield[i].hop) i++; *dest_color = colorfield[i].col; @@ -453,7 +451,7 @@ static void emit_other(struct blame_scoreboard *sb, struct blame_entry *ent, int cp = blame_nth_line(sb, ent->lno); if (opt & OUTPUT_SHOW_AGE_WITH_COLOR) { - determine_line_heat(ent, &default_color); + determine_line_heat(&ci, &default_color); color = default_color; reset = GIT_COLOR_RESET; }