@@ -2658,6 +2658,12 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, struct s
if (revs->diffopt.objfind)
revs->simplify_history = 0;
+ if (revs->line_level_traverse) {
+ if (want_ancestry(revs))
+ revs->limited = 1;
+ revs->topo_order = 1;
+ }
+
if (revs->topo_order && !generation_numbers_enabled(the_repository))
revs->limited = 1;
@@ -2677,11 +2683,6 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, struct s
revs->diffopt.abbrev = revs->abbrev;
- if (revs->line_level_traverse) {
- revs->limited = 1;
- revs->topo_order = 1;
- }
-
diff_setup_done(&revs->diffopt);
grep_commit_pattern_type(GREP_PATTERN_TYPE_UNSPECIFIED,
The previous patch made it possible to perform line-level filtering during history traversal instead of in an expensive preprocessing step, but it still requires some simpler preprocessing steps, notably topo-ordering. However, nowadays we have commit-graphs storing generation numbers, which make it possible to incrementally traverse the history in topological order, without the preparatory limit_list() and sort_in_topological_order() steps; see b45424181e (revision.c: generation-based topo-order algorithm, 2018-11-01). This patch combines the two, so we can do both the topo-ordering and the line-level filtering during history traversal, eliminating even those simpler preprocessing steps, and thus further reducing the delay before showing the first commit modifying the given line range. The 'revs->limited' flag plays the central role in this, because, due to limitations of the current implementation, the generation number-based topo-ordering is only enabled when this flag remains unset. Line-level log, however, always sets this flag in setup_revisions() ever since the feature was introduced in 12da1d1f6f (Implement line-history search (git log -L), 2013-03-28). The reason for setting 'limited' is unclear, though, because the line-level log itself doesn't directly depend on it, and it doesn't affect how the limit_list() function limits the revision range. However, there is an indirect dependency: the line-level log requires topo-ordering, and the "traditional" sort_in_topological_order() requires an already limited commit list since e6c3505b44 (Make sure we generate the whole commit list before trying to sort it topologically, 2005-07-06). The new, generation numbers-based topo-ordering doesn't require a limited commit list anymore. So don't set 'revs->limited' for line-level log, unless it is really necessary, namely: - The user explicitly requested parent rewriting, because that is still done in the line_log_filter() preprocessing step (see previous patch), which requires sort_in_topological_order() and in turn limit_list() as well. - A commit-graph file is not available or it doesn't yet contain generation numbers. In these cases we had to fall back on sort_in_topological_order() and in turn limit_list(). The existing condition with generation_numbers_enabled() has already ensured that the 'limited' flag is set in these cases; this patch just makes sure that the line-level log sets 'revs->topo_order' before that condition. While the reduced delay before showing the first commit is measurable in git.git, it takes a bigger repository to make it clearly noticable. In both cases below the line ranges were chosen so that they were modified rather close to the starting revisions, so the effect of this change is most noticable. # git.git $ time git --no-pager log -L:read_alternate_refs:sha1-file.c -1 v2.23.0 Before: real 0m0.107s user 0m0.091s sys 0m0.013s After: real 0m0.058s user 0m0.050s sys 0m0.005s # linux.git $ time git --no-pager log \ -L:build_restore_work_registers:arch/mips/mm/tlbex.c -1 v5.2 Before: real 0m1.129s user 0m1.061s sys 0m0.069s After: real 0m0.096s user 0m0.087s sys 0m0.009s Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com> --- Notes: FWIW, that line-level log sets 'limited' in addition to 'topo_order' thing was already part of the first submitted iteration of the line-level log patch series: https://public-inbox.org/git/1277558857-23103-4-git-send-email-struggleyb.nku@gmail.com/#Z30revision.c But it was never discussed during review. revision.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-)