[PATCH v8] revision.c: implement --max-count-oldest
- From
Mirko Faina <mroik@delayed.space>
- Date
- May 19, 2026, 00:55 UTC
- Message-ID
- <8210d60832b9a58aa4d71fc3790e44d8989564ce.1779152064.git.mroik@delayed.space>
- In-Reply-To
- <463cc8e2764edb7de3d379f615f5cfbd0919bfa3.1778887662.git.mroik@delayed.space>
--max-count is a commit limiting option sets a maximum amount of commits to be shown. If a user wants to see only the first N commits of the history (the oldest commits) they'd have to do something like
git log $(git rev-list HEAD | tail -n N | head -n 1)
This is not very user-friendly.
Teach get_revision() the --max-count-oldest option.
Signed-off-by: Mirko Faina <mroik@delayed.space> --- Documentation/rev-list-options.adoc | 5 +- revision.c | 111 +++++++++++++++++++++++++++- revision.h | 2 + t/t4202-log.sh | 41 ++++++++++ 4 files changed, 155 insertions(+), 4 deletions(-)
diff --git a/Documentation/rev-list-options.adoc b/Documentation/rev-list-options.adoc index 2d195a1474..e8c88d0f1c 100644 --- a/Documentation/rev-list-options.adoc +++ b/Documentation/rev-list-options.adoc @@ -16,7 +16,10 @@ ordering and formatting options, such as `--reverse`. `-<number>`:: `-n <number>`:: `--max-count=<number>`:: - Limit the output to _<number>_ commits. + Limit the output to the first _<number>_ commits that would be shown. + +`--max-count-oldest=<number>`:: + Limit the output to the last _<number>_ commits that would be shown. `--skip=<number>`:: Skip _<number>_ commits before starting to show the commit output. diff --git a/revision.c b/revision.c index 599b3a66c3..5d53db3152 100644 --- a/revision.c +++ b/revision.c @@ -2339,10 +2339,28 @@ static int handle_revision_opt(struct rev_info *revs, int argc, const char **arg } if ((argcount = parse_long_opt("max-count", argv, &optarg))) { + if (revs->max_count_type == 1) + die_for_incompatible_opt2(1, "--max-count", 1, + "--max-count-oldest"); revs->max_count = parse_count(optarg); revs->no_walk = 0; + revs->max_count_type = 0; return argcount; + } else if ((argcount = parse_long_opt("max-count-oldest", argv, &optarg))) { + if (revs->max_count_type == 0 && revs->max_count != -1) + die_for_incompatible_opt2(1, "--max-count", 1, + "--max-count-oldest"); + if (revs->skip_count > 0) + die_for_incompatible_opt2(1, "--skip", 1, + "--max-count-oldest"); + revs->max_count = parse_count(optarg); + revs->no_walk = 0; + revs->max_count_type = 1; + revs->max_count_stage = 0; } else if ((argcount = parse_long_opt("skip", argv, &optarg))) { + if (revs->max_count_type == 1) + die_for_incompatible_opt2(1, "--skip", 1, + "--max-count-oldest"); revs->skip_count = parse_count(optarg); return argcount; } else if ((*arg == '-') && isdigit(arg[1])) { @@ -4521,15 +4539,91 @@ static struct commit *get_revision_internal(struct rev_info *revs) return c; } +static void retrieve_oldest_commits(struct rev_info *revs, + struct commit_list **queue) +{ + struct commit *c; + int max_count = revs->max_count; + int queuei_count = 0; + int queueo_count = 0; + struct commit_list *queueo = NULL; + struct commit_list *queuei = NULL; + struct commit_list *reversed_queue = NULL; + struct commit_list *p; + + revs->max_count = -1; + while ((c = get_revision_internal(revs))) { + /* + * We need to reset SHOWN status otherwise --graph breaks. + * It is fine to do, get_revision_internal() doesn't consider + * children commits as they have been already processed and the + * traversal happens only child to parent. + * + * We do this because the --graph machinery relies on the status + * of the parents to decide how the printing will happen. + * + * We can't simply replace this instruction with a + * graph_update() as it doesn't do the actualy printing, we'd + * have to remove any commit that goes over the + * --max-count-oldest limit from revs->graph. + */ + c->object.flags &= ~(SHOWN | CHILD_SHOWN); + commit_list_insert(c, &queuei); + if (!(c->object.flags & BOUNDARY)) + queuei_count++; + while (queuei_count + queueo_count > max_count) { + if (!queueo_count) { + while ((c = pop_commit(&queuei))) { + commit_list_insert(c, &queueo); + queueo_count++; + } + queuei_count = 0; + } + c = pop_commit(&queueo); + queueo_count--; + /* We need to do this otherwise we'll discard the + * commits that go over the --max-count-oldest limit but + * not their respective boundaries. This matters only if + * we're discarding the commit right before the boundary. + */ + for (p = c->parents; p; p = p->next) + p->item->object.flags &= ~CHILD_SHOWN; + } + } + + while ((c = pop_commit(&queueo))) + commit_list_insert(c, &reversed_queue); + while ((c = pop_commit(&queuei))) + commit_list_insert(c, &queueo); + while ((c = pop_commit(&queueo))) + commit_list_insert(c, &reversed_queue); + + while ((c = pop_commit(&reversed_queue))) + commit_list_insert(c, queue); +} + struct commit *get_revision(struct rev_info *revs) { struct commit *c; struct commit_list *reversed; + struct commit_list *queue = NULL; + struct commit_list *p; + + if (revs->max_count_type == 1 && !revs->max_count_stage) { + retrieve_oldest_commits(revs, &queue); + commit_list_free(revs->commits); + revs->commits = queue; + revs->max_count_stage = 1; + } if (revs->reverse) { reversed = NULL; - while ((c = get_revision_internal(revs))) - commit_list_insert(c, &reversed); + if (revs->max_count_type == 1) + while ((c = pop_commit(&revs->commits))) + commit_list_insert(c, &reversed); + else + while ((c = get_revision_internal(revs))) + commit_list_insert(c, &reversed); commit_list_free(revs->commits); revs->commits = reversed; revs->reverse = 0; @@ -4543,7 +4637,18 @@ struct commit *get_revision(struct rev_info *revs) return c; } - c = get_revision_internal(revs); + if (revs->max_count_stage) { + c = pop_commit(&revs->commits); + if (c) { + c->object.flags |= SHOWN; + if (!(c->object.flags & BOUNDARY)) + for (p = c->parents; p; p = p->next) + p->item->object.flags |= CHILD_SHOWN; + } + } else { + c = get_revision_internal(revs); + } + if (c && revs->graph) graph_update(revs->graph, c); if (!c) { diff --git a/revision.h b/revision.h index 584f1338b5..e157463cb1 100644 --- a/revision.h +++ b/revision.h @@ -309,6 +309,8 @@ struct rev_info { /* special limits */ int skip_count; int max_count; + unsigned int max_count_type:1; + unsigned int max_count_stage:1; timestamp_t max_age; timestamp_t max_age_as_filter; timestamp_t min_age; diff --git a/t/t4202-log.sh b/t/t4202-log.sh index 05cee9e41b..c3c1b862d3 100755 --- a/t/t4202-log.sh +++ b/t/t4202-log.sh @@ -1882,6 +1882,47 @@ test_expect_success 'log --graph with --name-status' ' test_cmp_graph --name-status tangle..reach ' +test_expect_success 'log --max-count-oldest=3 --oneline' ' + test_when_finished rm expect && + git log --oneline | tail -n3 >expect && + git log --oneline --max-count-oldest=3 >actual && + test_cmp expect actual +' + +test_expect_success 'log --max-count-oldest=3 --reverse --oneline' ' + test_when_finished rm expect && + git log --oneline --reverse | head -n3 >expect && + git log --oneline --max-count-oldest=3 --reverse >actual && + test_cmp expect actual +' + +test_expect_success 'log --max-count-oldest with --max-count' ' + test_when_finished rm stderr && + test_must_fail git log --max-count-oldest=3 --max-count=3 2>stderr && + test_grep "cannot be used together" stderr +' + +test_expect_success 'log --max-count-oldest with --skip' ' + test_when_finished rm stderr && + test_must_fail git log --max-count-oldest=3 --skip=1 2>stderr && + test_grep "cannot be used together" stderr +' + +test_expect_success 'log --max-count-oldest=1000 --graph --boundary' ' + test_when_finished rm expect actual && + git log --graph --boundary >expect && + git log --max-count-oldest=1000 --graph --boundary >actual && + test_cmp expect actual +' + +test_expect_success 'log --oneline --graph --boundary --max-count-oldest=1' ' + test_when_finished rm actual && + echo 2 >expect && + git log --oneline --graph --boundary --max-count-oldest=1 HEAD~1..HEAD \ + | wc -l >actual && + test_cmp expect actual +' + cat >expect <<-\EOF * reach |
-- 2.54.0