diff options
| -rw-r--r-- | revision.c | 171 | ||||
| -rwxr-xr-x | t/t6019-rev-list-ancestry-path.sh | 12 | ||||
| -rwxr-xr-x | t/t6111-rev-list-treesame.sh | 8 |
3 files changed, 164 insertions, 27 deletions
@@ -333,6 +333,80 @@ static int everybody_uninteresting(struct commit_list *orig) } /* + * A definition of "relevant" commit that we can use to simplify limited graphs + * by eliminating side branches. + * + * A "relevant" commit is one that is !UNINTERESTING (ie we are including it + * in our list), or that is a specified BOTTOM commit. Then after computing + * a limited list, during processing we can generally ignore boundary merges + * coming from outside the graph, (ie from irrelevant parents), and treat + * those merges as if they were single-parent. TREESAME is defined to consider + * only relevant parents, if any. If we are TREESAME to our on-graph parents, + * we don't care if we were !TREESAME to non-graph parents. + * + * Treating bottom commits as relevant ensures that a limited graph's + * connection to the actual bottom commit is not viewed as a side branch, but + * treated as part of the graph. For example: + * + * ....Z...A---X---o---o---B + * . / + * W---Y + * + * When computing "A..B", the A-X connection is at least as important as + * Y-X, despite A being flagged UNINTERESTING. + * + * And when computing --ancestry-path "A..B", the A-X connection is more + * important than Y-X, despite both A and Y being flagged UNINTERESTING. + */ +static inline int relevant_commit(struct commit *commit) +{ + return (commit->object.flags & (UNINTERESTING | BOTTOM)) != UNINTERESTING; +} + +/* + * Return a single relevant commit from a parent list. If we are a TREESAME + * commit, and this selects one of our parents, then we can safely simplify to + * that parent. + */ +static struct commit *one_relevant_parent(const struct rev_info *revs, + struct commit_list *orig) +{ + struct commit_list *list = orig; + struct commit *relevant = NULL; + + if (!orig) + return NULL; + + /* + * For 1-parent commits, or if first-parent-only, then return that + * first parent (even if not "relevant" by the above definition). + * TREESAME will have been set purely on that parent. + */ + if (revs->first_parent_only || !orig->next) + return orig->item; + + /* + * For multi-parent commits, identify a sole relevant parent, if any. + * If we have only one relevant parent, then TREESAME will be set purely + * with regard to that parent, and we can simplify accordingly. + * + * If we have more than one relevant parent, or no relevant parents + * (and multiple irrelevant ones), then we can't select a parent here + * and return NULL. + */ + while (list) { + struct commit *commit = list->item; + list = list->next; + if (relevant_commit(commit)) { + if (relevant) + return NULL; + relevant = commit; + } + } + return relevant; +} + +/* * The goal is to get REV_TREE_NEW as the result only if the * diff consists of all '+' (and no other changes), REV_TREE_OLD * if the whole diff is removal of old data, and otherwise @@ -502,27 +576,52 @@ static unsigned update_treesame(struct rev_info *revs, struct commit *commit) if (commit->parents && commit->parents->next) { unsigned n; struct treesame_state *st; + struct commit_list *p; + unsigned relevant_parents; + unsigned relevant_change, irrelevant_change; st = lookup_decoration(&revs->treesame, &commit->object); if (!st) die("update_treesame %s", sha1_to_hex(commit->object.sha1)); - commit->object.flags |= TREESAME; - for (n = 0; n < st->nparents; n++) { - if (!st->treesame[n]) { - commit->object.flags &= ~TREESAME; - break; - } + relevant_parents = 0; + relevant_change = irrelevant_change = 0; + for (p = commit->parents, n = 0; p; n++, p = p->next) { + if (relevant_commit(p->item)) { + relevant_change |= !st->treesame[n]; + relevant_parents++; + } else + irrelevant_change |= !st->treesame[n]; } + if (relevant_parents ? relevant_change : irrelevant_change) + commit->object.flags &= ~TREESAME; + else + commit->object.flags |= TREESAME; } return commit->object.flags & TREESAME; } +static inline int limiting_can_increase_treesame(const struct rev_info *revs) +{ + /* + * TREESAME is irrelevant unless prune && dense; + * if simplify_history is set, we can't have a mixture of TREESAME and + * !TREESAME INTERESTING parents (and we don't have treesame[] + * decoration anyway); + * if first_parent_only is set, then the TREESAME flag is locked + * against the first parent (and again we lack treesame[] decoration). + */ + return revs->prune && revs->dense && + !revs->simplify_history && + !revs->first_parent_only; +} + static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit) { struct commit_list **pp, *parent; struct treesame_state *ts = NULL; - int tree_changed = 0, nth_parent; + int relevant_change = 0, irrelevant_change = 0; + int relevant_parents, nth_parent; /* * If we don't do pruning, everything is interesting @@ -546,10 +645,12 @@ static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit) if (!revs->dense && !commit->parents->next) return; - for (pp = &commit->parents, nth_parent = 0; + for (pp = &commit->parents, nth_parent = 0, relevant_parents = 0; (parent = *pp) != NULL; pp = &parent->next, nth_parent++) { struct commit *p = parent->item; + if (relevant_commit(p)) + relevant_parents++; if (nth_parent == 1) { /* @@ -573,7 +674,7 @@ static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit) !revs->simplify_history && !(commit->object.flags & UNINTERESTING)) { ts = initialise_treesame(revs, commit); - if (!tree_changed) + if (!(irrelevant_change || relevant_change)) ts->treesame[0] = 1; } } @@ -619,14 +720,27 @@ static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit) /* fallthrough */ case REV_TREE_OLD: case REV_TREE_DIFFERENT: - tree_changed = 1; + if (relevant_commit(p)) + relevant_change = 1; + else + irrelevant_change = 1; continue; } die("bad tree compare for commit %s", sha1_to_hex(commit->object.sha1)); } - if (tree_changed) - return; - commit->object.flags |= TREESAME; + + /* + * TREESAME is straightforward for single-parent commits. For merge + * commits, it is most useful to define it so that "irrelevant" + * parents cannot make us !TREESAME - if we have any relevant + * parents, then we only consider TREESAMEness with respect to them, + * allowing irrelevant merges from uninteresting branches to be + * simplified away. Only if we have only irrelevant parents do we + * base TREESAME on them. Note that this logic is replicated in + * update_treesame, which should be kept in sync. + */ + if (relevant_parents ? !relevant_change : !irrelevant_change) + commit->object.flags |= TREESAME; } static void commit_list_insert_by_date_cached(struct commit *p, struct commit_list **head, @@ -998,6 +1112,18 @@ static int limit_list(struct rev_info *revs) free_commit_list(bottom); } + /* + * Check if any commits have become TREESAME by some of their parents + * becoming UNINTERESTING. + */ + if (limiting_can_increase_treesame(revs)) + for (list = newlist; list; list = list->next) { + struct commit *c = list->item; + if (c->object.flags & (UNINTERESTING | TREESAME)) + continue; + update_treesame(revs, c); + } + revs->commits = newlist; return 0; } @@ -2248,6 +2374,7 @@ static int remove_marked_parents(struct rev_info *revs, struct commit *commit) static struct commit_list **simplify_one(struct rev_info *revs, struct commit *commit, struct commit_list **tail) { struct commit_list *p; + struct commit *parent; struct merge_simplify_state *st, *pst; int cnt; @@ -2336,19 +2463,20 @@ static struct commit_list **simplify_one(struct rev_info *revs, struct commit *c /* * A commit simplifies to itself if it is a root, if it is * UNINTERESTING, if it touches the given paths, or if it is a - * merge and its parents simplify to more than one commit + * merge and its parents don't simplify to one relevant commit * (the first two cases are already handled at the beginning of * this function). * - * Otherwise, it simplifies to what its sole parent simplifies to. + * Otherwise, it simplifies to what its sole relevant parent + * simplifies to. */ if (!cnt || (commit->object.flags & UNINTERESTING) || !(commit->object.flags & TREESAME) || - (1 < cnt)) + (parent = one_relevant_parent(revs, commit->parents)) == NULL) st->simplified = commit; else { - pst = locate_simplify_state(revs, commit->parents->item); + pst = locate_simplify_state(revs, parent); st->simplified = pst->simplified; } return tail; @@ -2445,7 +2573,8 @@ int prepare_revision_walk(struct rev_info *revs) free(list); /* Signal whether we need per-parent treesame decoration */ - if (revs->simplify_merges) + if (revs->simplify_merges || + (revs->limited && limiting_can_increase_treesame(revs))) revs->treesame.name = "treesame"; if (revs->no_walk != REVISION_WALK_NO_WALK_UNSORTED) @@ -2479,15 +2608,15 @@ static enum rewrite_result rewrite_one(struct rev_info *revs, struct commit **pp if (!revs->limited) if (add_parents_to_list(revs, p, &revs->commits, &cache) < 0) return rewrite_one_error; - if (p->parents && p->parents->next) - return rewrite_one_ok; if (p->object.flags & UNINTERESTING) return rewrite_one_ok; if (!(p->object.flags & TREESAME)) return rewrite_one_ok; if (!p->parents) return rewrite_one_noparents; - *pp = p->parents->item; + if ((p = one_relevant_parent(revs, p->parents)) == NULL) + return rewrite_one_ok; + *pp = p; } } diff --git a/t/t6019-rev-list-ancestry-path.sh b/t/t6019-rev-list-ancestry-path.sh index 5ad96e3..dabebae 100755 --- a/t/t6019-rev-list-ancestry-path.sh +++ b/t/t6019-rev-list-ancestry-path.sh @@ -18,7 +18,8 @@ test_description='--ancestry-path' # --ancestry-path F...I == F H I # # G..M -- G.t == [nothing - was dropped in "-s ours" merge L] -# --ancestry-path G..M -- G.t == H J L +# --ancestry-path G..M -- G.t == L +# --ancestry-path --simplify-merges G^..M -- G.t == G L . ./test-lib.sh @@ -101,8 +102,15 @@ test_expect_success 'rev-list G..M -- G.t' ' ' test_expect_success 'rev-list --ancestry-path G..M -- G.t' ' - for c in H J L; do echo $c; done >expect && + echo L >expect && git rev-list --ancestry-path --format=%s G..M -- G.t | + sed -e "/^commit /d" >actual && + test_cmp expect actual +' + +test_expect_success 'rev-list --ancestry-path --simplify-merges G^..M -- G.t' ' + for c in G L; do echo $c; done >expect && + git rev-list --ancestry-path --simplify-merges --format=%s G^..M -- G.t | sed -e "/^commit /d" | sort >actual && test_cmp expect actual diff --git a/t/t6111-rev-list-treesame.sh b/t/t6111-rev-list-treesame.sh index 484b69b..e32b373 100755 --- a/t/t6111-rev-list-treesame.sh +++ b/t/t6111-rev-list-treesame.sh @@ -138,9 +138,9 @@ check_result 'M L G' F..M --first-parent -- file # Note that G is pruned when E is the bottom, even if it's the same commit list # If we want history since E, then we're quite happy to ignore G that took E. check_result 'M L K J I H G' E..M --ancestry-path -check_outcome failure 'M L J I H' E..M --ancestry-path -- file # includes G +check_result 'M L J I H' E..M --ancestry-path -- file check_outcome failure '(LH)M (K)L (EJ)K (I)J (E)I (E)H' E..M --ancestry-path --parents -- file # includes G -check_outcome failure '(LH)M (E)H (J)L (I)J (E)I' E..M --ancestry-path --simplify-merges -- file # includes G +check_result '(LH)M (E)H (J)L (I)J (E)I' E..M --ancestry-path --simplify-merges -- file # Should still be able to ignore I-J branch in simple log, despite limiting # to G. @@ -167,9 +167,9 @@ check_result 'F D' B..F --full-history -- file check_result '(D)F (BA)D' B..F --full-history --parents -- file check_result '(B)F' B..F --simplify-merges -- file check_result 'F D' B..F --ancestry-path -check_outcome failure 'F' B..F --ancestry-path -- file # includes D +check_result 'F' B..F --ancestry-path -- file check_outcome failure 'F' B..F --ancestry-path --parents -- file # includes D -check_outcome failure 'F' B..F --ancestry-path --simplify-merges -- file # includes D +check_result 'F' B..F --ancestry-path --simplify-merges -- file check_result 'F D' B..F --first-parent check_result 'F' B..F --first-parent -- file |