From ee2bd06b0f735a00ce0216ca1d3391b13722d987 Mon Sep 17 00:00:00 2001 From: Karthik Nayak Date: Tue, 7 Jul 2015 21:36:16 +0530 Subject: ref-filter: implement '--contains' option 'tag -l' and 'branch -l' have two different ways of finding out if a certain ref contains a commit. Implement both these methods in ref-filter and give the caller of ref-filter API the option to pick which implementation to be used. 'branch -l' uses 'is_descendant_of()' from commit.c which is left as the default implementation to be used. 'tag -l' uses a more specific algorithm since ffc4b80. This implementation is used whenever the 'with_commit_tag_algo' bit is set in 'struct ref_filter'. Mentored-by: Christian Couder Mentored-by: Matthieu Moy Signed-off-by: Karthik Nayak Signed-off-by: Junio C Hamano --- ref-filter.c | 114 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 113 insertions(+), 1 deletion(-) (limited to 'ref-filter.c') diff --git a/ref-filter.c b/ref-filter.c index 0d7ec446dc..409b94fcfb 100644 --- a/ref-filter.c +++ b/ref-filter.c @@ -818,6 +818,114 @@ static void get_ref_atom_value(struct ref_array_item *ref, int atom, struct atom *v = &ref->value[atom]; } +enum contains_result { + CONTAINS_UNKNOWN = -1, + CONTAINS_NO = 0, + CONTAINS_YES = 1 +}; + +/* + * Mimicking the real stack, this stack lives on the heap, avoiding stack + * overflows. + * + * At each recursion step, the stack items points to the commits whose + * ancestors are to be inspected. + */ +struct contains_stack { + int nr, alloc; + struct contains_stack_entry { + struct commit *commit; + struct commit_list *parents; + } *contains_stack; +}; + +static int in_commit_list(const struct commit_list *want, struct commit *c) +{ + for (; want; want = want->next) + if (!hashcmp(want->item->object.sha1, c->object.sha1)) + return 1; + return 0; +} + +/* + * Test whether the candidate or one of its parents is contained in the list. + * Do not recurse to find out, though, but return -1 if inconclusive. + */ +static enum contains_result contains_test(struct commit *candidate, + const struct commit_list *want) +{ + /* was it previously marked as containing a want commit? */ + if (candidate->object.flags & TMP_MARK) + return 1; + /* or marked as not possibly containing a want commit? */ + if (candidate->object.flags & UNINTERESTING) + return 0; + /* or are we it? */ + if (in_commit_list(want, candidate)) { + candidate->object.flags |= TMP_MARK; + return 1; + } + + if (parse_commit(candidate) < 0) + return 0; + + return -1; +} + +static void push_to_contains_stack(struct commit *candidate, struct contains_stack *contains_stack) +{ + ALLOC_GROW(contains_stack->contains_stack, contains_stack->nr + 1, contains_stack->alloc); + contains_stack->contains_stack[contains_stack->nr].commit = candidate; + contains_stack->contains_stack[contains_stack->nr++].parents = candidate->parents; +} + +static enum contains_result contains_tag_algo(struct commit *candidate, + const struct commit_list *want) +{ + struct contains_stack contains_stack = { 0, 0, NULL }; + int result = contains_test(candidate, want); + + if (result != CONTAINS_UNKNOWN) + return result; + + push_to_contains_stack(candidate, &contains_stack); + while (contains_stack.nr) { + struct contains_stack_entry *entry = &contains_stack.contains_stack[contains_stack.nr - 1]; + struct commit *commit = entry->commit; + struct commit_list *parents = entry->parents; + + if (!parents) { + commit->object.flags |= UNINTERESTING; + contains_stack.nr--; + } + /* + * If we just popped the stack, parents->item has been marked, + * therefore contains_test will return a meaningful 0 or 1. + */ + else switch (contains_test(parents->item, want)) { + case CONTAINS_YES: + commit->object.flags |= TMP_MARK; + contains_stack.nr--; + break; + case CONTAINS_NO: + entry->parents = parents->next; + break; + case CONTAINS_UNKNOWN: + push_to_contains_stack(parents->item, &contains_stack); + break; + } + } + free(contains_stack.contains_stack); + return contains_test(candidate, want); +} + +static int commit_contains(struct ref_filter *filter, struct commit *commit) +{ + if (filter->with_commit_tag_algo) + return contains_tag_algo(commit, filter->with_commit); + return is_descendant_of(commit, filter->with_commit); +} + /* * Return 1 if the refname matches one of the patterns, otherwise 0. * A pattern can be path prefix (e.g. a refname "refs/heads/master" @@ -917,10 +1025,14 @@ static int ref_filter_handler(const char *refname, const struct object_id *oid, * obtain the commit using the 'oid' available and discard all * non-commits early. The actual filtering is done later. */ - if (filter->merge_commit) { + if (filter->merge_commit || filter->with_commit) { commit = lookup_commit_reference_gently(oid->hash, 1); if (!commit) return 0; + /* We perform the filtering for the '--contains' option */ + if (filter->with_commit && + !commit_contains(filter, commit)) + return 0; } /* -- cgit v1.2.3