diff options
Diffstat (limited to 'commit-reach.c')
| -rw-r--r-- | commit-reach.c | 692 |
1 files changed, 692 insertions, 0 deletions
diff --git a/commit-reach.c b/commit-reach.c new file mode 100644 index 0000000000..a9da65c462 --- /dev/null +++ b/commit-reach.c @@ -0,0 +1,692 @@ +#include "cache.h" +#include "commit.h" +#include "commit-graph.h" +#include "decorate.h" +#include "prio-queue.h" +#include "tree.h" +#include "ref-filter.h" +#include "revision.h" +#include "tag.h" +#include "commit-reach.h" + +/* Remember to update object flag allocation in object.h */ +#define REACHABLE (1u<<15) +#define PARENT1 (1u<<16) +#define PARENT2 (1u<<17) +#define STALE (1u<<18) +#define RESULT (1u<<19) + +static const unsigned all_flags = (PARENT1 | PARENT2 | STALE | RESULT); + +static int queue_has_nonstale(struct prio_queue *queue) +{ + int i; + for (i = 0; i < queue->nr; i++) { + struct commit *commit = queue->array[i].data; + if (!(commit->object.flags & STALE)) + return 1; + } + return 0; +} + +/* all input commits in one and twos[] must have been parsed! */ +static struct commit_list *paint_down_to_common(struct commit *one, int n, + struct commit **twos, + int min_generation) +{ + struct prio_queue queue = { compare_commits_by_gen_then_commit_date }; + struct commit_list *result = NULL; + int i; + uint32_t last_gen = GENERATION_NUMBER_INFINITY; + + if (!min_generation) + queue.compare = compare_commits_by_commit_date; + + one->object.flags |= PARENT1; + if (!n) { + commit_list_append(one, &result); + return result; + } + prio_queue_put(&queue, one); + + for (i = 0; i < n; i++) { + twos[i]->object.flags |= PARENT2; + prio_queue_put(&queue, twos[i]); + } + + while (queue_has_nonstale(&queue)) { + struct commit *commit = prio_queue_get(&queue); + struct commit_list *parents; + int flags; + + if (min_generation && commit->generation > last_gen) + BUG("bad generation skip %8x > %8x at %s", + commit->generation, last_gen, + oid_to_hex(&commit->object.oid)); + last_gen = commit->generation; + + if (commit->generation < min_generation) + break; + + flags = commit->object.flags & (PARENT1 | PARENT2 | STALE); + if (flags == (PARENT1 | PARENT2)) { + if (!(commit->object.flags & RESULT)) { + commit->object.flags |= RESULT; + commit_list_insert_by_date(commit, &result); + } + /* Mark parents of a found merge stale */ + flags |= STALE; + } + parents = commit->parents; + while (parents) { + struct commit *p = parents->item; + parents = parents->next; + if ((p->object.flags & flags) == flags) + continue; + if (parse_commit(p)) + return NULL; + p->object.flags |= flags; + prio_queue_put(&queue, p); + } + } + + clear_prio_queue(&queue); + return result; +} + +static struct commit_list *merge_bases_many(struct commit *one, int n, struct commit **twos) +{ + struct commit_list *list = NULL; + struct commit_list *result = NULL; + int i; + + for (i = 0; i < n; i++) { + if (one == twos[i]) + /* + * We do not mark this even with RESULT so we do not + * have to clean it up. + */ + return commit_list_insert(one, &result); + } + + if (parse_commit(one)) + return NULL; + for (i = 0; i < n; i++) { + if (parse_commit(twos[i])) + return NULL; + } + + list = paint_down_to_common(one, n, twos, 0); + + while (list) { + struct commit *commit = pop_commit(&list); + if (!(commit->object.flags & STALE)) + commit_list_insert_by_date(commit, &result); + } + return result; +} + +struct commit_list *get_octopus_merge_bases(struct commit_list *in) +{ + struct commit_list *i, *j, *k, *ret = NULL; + + if (!in) + return ret; + + commit_list_insert(in->item, &ret); + + for (i = in->next; i; i = i->next) { + struct commit_list *new_commits = NULL, *end = NULL; + + for (j = ret; j; j = j->next) { + struct commit_list *bases; + bases = get_merge_bases(i->item, j->item); + if (!new_commits) + new_commits = bases; + else + end->next = bases; + for (k = bases; k; k = k->next) + end = k; + } + ret = new_commits; + } + return ret; +} + +static int remove_redundant(struct commit **array, int cnt) +{ + /* + * Some commit in the array may be an ancestor of + * another commit. Move such commit to the end of + * the array, and return the number of commits that + * are independent from each other. + */ + struct commit **work; + unsigned char *redundant; + int *filled_index; + int i, j, filled; + + work = xcalloc(cnt, sizeof(*work)); + redundant = xcalloc(cnt, 1); + ALLOC_ARRAY(filled_index, cnt - 1); + + for (i = 0; i < cnt; i++) + parse_commit(array[i]); + for (i = 0; i < cnt; i++) { + struct commit_list *common; + uint32_t min_generation = array[i]->generation; + + if (redundant[i]) + continue; + for (j = filled = 0; j < cnt; j++) { + if (i == j || redundant[j]) + continue; + filled_index[filled] = j; + work[filled++] = array[j]; + + if (array[j]->generation < min_generation) + min_generation = array[j]->generation; + } + common = paint_down_to_common(array[i], filled, work, + min_generation); + if (array[i]->object.flags & PARENT2) + redundant[i] = 1; + for (j = 0; j < filled; j++) + if (work[j]->object.flags & PARENT1) + redundant[filled_index[j]] = 1; + clear_commit_marks(array[i], all_flags); + clear_commit_marks_many(filled, work, all_flags); + free_commit_list(common); + } + + /* Now collect the result */ + COPY_ARRAY(work, array, cnt); + for (i = filled = 0; i < cnt; i++) + if (!redundant[i]) + array[filled++] = work[i]; + for (j = filled, i = 0; i < cnt; i++) + if (redundant[i]) + array[j++] = work[i]; + free(work); + free(redundant); + free(filled_index); + return filled; +} + +static struct commit_list *get_merge_bases_many_0(struct commit *one, + int n, + struct commit **twos, + int cleanup) +{ + struct commit_list *list; + struct commit **rslt; + struct commit_list *result; + int cnt, i; + + result = merge_bases_many(one, n, twos); + for (i = 0; i < n; i++) { + if (one == twos[i]) + return result; + } + if (!result || !result->next) { + if (cleanup) { + clear_commit_marks(one, all_flags); + clear_commit_marks_many(n, twos, all_flags); + } + return result; + } + + /* There are more than one */ + cnt = commit_list_count(result); + rslt = xcalloc(cnt, sizeof(*rslt)); + for (list = result, i = 0; list; list = list->next) + rslt[i++] = list->item; + free_commit_list(result); + + clear_commit_marks(one, all_flags); + clear_commit_marks_many(n, twos, all_flags); + + cnt = remove_redundant(rslt, cnt); + result = NULL; + for (i = 0; i < cnt; i++) + commit_list_insert_by_date(rslt[i], &result); + free(rslt); + return result; +} + +struct commit_list *get_merge_bases_many(struct commit *one, + int n, + struct commit **twos) +{ + return get_merge_bases_many_0(one, n, twos, 1); +} + +struct commit_list *get_merge_bases_many_dirty(struct commit *one, + int n, + struct commit **twos) +{ + return get_merge_bases_many_0(one, n, twos, 0); +} + +struct commit_list *get_merge_bases(struct commit *one, struct commit *two) +{ + return get_merge_bases_many_0(one, 1, &two, 1); +} + +/* + * Is "commit" a descendant of one of the elements on the "with_commit" list? + */ +int is_descendant_of(struct commit *commit, struct commit_list *with_commit) +{ + if (!with_commit) + return 1; + + if (generation_numbers_enabled(the_repository)) { + struct commit_list *from_list = NULL; + int result; + commit_list_insert(commit, &from_list); + result = can_all_from_reach(from_list, with_commit, 0); + free_commit_list(from_list); + return result; + } else { + while (with_commit) { + struct commit *other; + + other = with_commit->item; + with_commit = with_commit->next; + if (in_merge_bases(other, commit)) + return 1; + } + return 0; + } +} + +/* + * Is "commit" an ancestor of one of the "references"? + */ +int in_merge_bases_many(struct commit *commit, int nr_reference, struct commit **reference) +{ + struct commit_list *bases; + int ret = 0, i; + uint32_t min_generation = GENERATION_NUMBER_INFINITY; + + if (parse_commit(commit)) + return ret; + for (i = 0; i < nr_reference; i++) { + if (parse_commit(reference[i])) + return ret; + if (reference[i]->generation < min_generation) + min_generation = reference[i]->generation; + } + + if (commit->generation > min_generation) + return ret; + + bases = paint_down_to_common(commit, nr_reference, reference, commit->generation); + if (commit->object.flags & PARENT2) + ret = 1; + clear_commit_marks(commit, all_flags); + clear_commit_marks_many(nr_reference, reference, all_flags); + free_commit_list(bases); + return ret; +} + +/* + * Is "commit" an ancestor of (i.e. reachable from) the "reference"? + */ +int in_merge_bases(struct commit *commit, struct commit *reference) +{ + return in_merge_bases_many(commit, 1, &reference); +} + +struct commit_list *reduce_heads(struct commit_list *heads) +{ + struct commit_list *p; + struct commit_list *result = NULL, **tail = &result; + struct commit **array; + int num_head, i; + + if (!heads) + return NULL; + + /* Uniquify */ + for (p = heads; p; p = p->next) + p->item->object.flags &= ~STALE; + for (p = heads, num_head = 0; p; p = p->next) { + if (p->item->object.flags & STALE) + continue; + p->item->object.flags |= STALE; + num_head++; + } + array = xcalloc(num_head, sizeof(*array)); + for (p = heads, i = 0; p; p = p->next) { + if (p->item->object.flags & STALE) { + array[i++] = p->item; + p->item->object.flags &= ~STALE; + } + } + num_head = remove_redundant(array, num_head); + for (i = 0; i < num_head; i++) + tail = &commit_list_insert(array[i], tail)->next; + free(array); + return result; +} + +void reduce_heads_replace(struct commit_list **heads) +{ + struct commit_list *result = reduce_heads(*heads); + free_commit_list(*heads); + *heads = result; +} + +int ref_newer(const struct object_id *new_oid, const struct object_id *old_oid) +{ + struct object *o; + struct commit *old_commit, *new_commit; + struct commit_list *old_commit_list = NULL; + + /* + * Both new_commit and old_commit must be commit-ish and new_commit is descendant of + * old_commit. Otherwise we require --force. + */ + o = deref_tag(the_repository, parse_object(the_repository, old_oid), + NULL, 0); + if (!o || o->type != OBJ_COMMIT) + return 0; + old_commit = (struct commit *) o; + + o = deref_tag(the_repository, parse_object(the_repository, new_oid), + NULL, 0); + if (!o || o->type != OBJ_COMMIT) + return 0; + new_commit = (struct commit *) o; + + if (parse_commit(new_commit) < 0) + return 0; + + commit_list_insert(old_commit, &old_commit_list); + return is_descendant_of(new_commit, old_commit_list); +} + +/* + * 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 (oideq(&want->item->object.oid, &c->object.oid)) + return 1; + return 0; +} + +/* + * Test whether the candidate 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, + struct contains_cache *cache, + uint32_t cutoff) +{ + enum contains_result *cached = contains_cache_at(cache, candidate); + + /* If we already have the answer cached, return that. */ + if (*cached) + return *cached; + + /* or are we it? */ + if (in_commit_list(want, candidate)) { + *cached = CONTAINS_YES; + return CONTAINS_YES; + } + + /* Otherwise, we don't know; prepare to recurse */ + parse_commit_or_die(candidate); + + if (candidate->generation < cutoff) + return CONTAINS_NO; + + return CONTAINS_UNKNOWN; +} + +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_cache *cache) +{ + struct contains_stack contains_stack = { 0, 0, NULL }; + enum contains_result result; + uint32_t cutoff = GENERATION_NUMBER_INFINITY; + const struct commit_list *p; + + for (p = want; p; p = p->next) { + struct commit *c = p->item; + load_commit_graph_info(the_repository, c); + if (c->generation < cutoff) + cutoff = c->generation; + } + + result = contains_test(candidate, want, cache, cutoff); + 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) { + *contains_cache_at(cache, commit) = CONTAINS_NO; + contains_stack.nr--; + } + /* + * If we just popped the stack, parents->item has been marked, + * therefore contains_test will return a meaningful yes/no. + */ + else switch (contains_test(parents->item, want, cache, cutoff)) { + case CONTAINS_YES: + *contains_cache_at(cache, commit) = CONTAINS_YES; + 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, cache, cutoff); +} + +int commit_contains(struct ref_filter *filter, struct commit *commit, + struct commit_list *list, struct contains_cache *cache) +{ + if (filter->with_commit_tag_algo) + return contains_tag_algo(commit, list, cache) == CONTAINS_YES; + return is_descendant_of(commit, list); +} + +static int compare_commits_by_gen(const void *_a, const void *_b) +{ + const struct commit *a = *(const struct commit * const *)_a; + const struct commit *b = *(const struct commit * const *)_b; + + if (a->generation < b->generation) + return -1; + if (a->generation > b->generation) + return 1; + return 0; +} + +int can_all_from_reach_with_flag(struct object_array *from, + unsigned int with_flag, + unsigned int assign_flag, + time_t min_commit_date, + uint32_t min_generation) +{ + struct commit **list = NULL; + int i; + int nr_commits; + int result = 1; + + ALLOC_ARRAY(list, from->nr); + nr_commits = 0; + for (i = 0; i < from->nr; i++) { + struct object *from_one = from->objects[i].item; + + if (!from_one || from_one->flags & assign_flag) + continue; + + from_one = deref_tag(the_repository, from_one, + "a from object", 0); + if (!from_one || from_one->type != OBJ_COMMIT) { + /* + * no way to tell if this is reachable by + * looking at the ancestry chain alone, so + * leave a note to ourselves not to worry about + * this object anymore. + */ + from->objects[i].item->flags |= assign_flag; + continue; + } + + list[nr_commits] = (struct commit *)from_one; + if (parse_commit(list[nr_commits]) || + list[nr_commits]->generation < min_generation) { + result = 0; + goto cleanup; + } + + nr_commits++; + } + + QSORT(list, nr_commits, compare_commits_by_gen); + + for (i = 0; i < nr_commits; i++) { + /* DFS from list[i] */ + struct commit_list *stack = NULL; + + list[i]->object.flags |= assign_flag; + commit_list_insert(list[i], &stack); + + while (stack) { + struct commit_list *parent; + + if (stack->item->object.flags & (with_flag | RESULT)) { + pop_commit(&stack); + if (stack) + stack->item->object.flags |= RESULT; + continue; + } + + for (parent = stack->item->parents; parent; parent = parent->next) { + if (parent->item->object.flags & (with_flag | RESULT)) + stack->item->object.flags |= RESULT; + + if (!(parent->item->object.flags & assign_flag)) { + parent->item->object.flags |= assign_flag; + + if (parse_commit(parent->item) || + parent->item->date < min_commit_date || + parent->item->generation < min_generation) + continue; + + commit_list_insert(parent->item, &stack); + break; + } + } + + if (!parent) + pop_commit(&stack); + } + + if (!(list[i]->object.flags & (with_flag | RESULT))) { + result = 0; + goto cleanup; + } + } + +cleanup: + clear_commit_marks_many(nr_commits, list, RESULT | assign_flag); + free(list); + + for (i = 0; i < from->nr; i++) + from->objects[i].item->flags &= ~assign_flag; + + return result; +} + +int can_all_from_reach(struct commit_list *from, struct commit_list *to, + int cutoff_by_min_date) +{ + struct object_array from_objs = OBJECT_ARRAY_INIT; + time_t min_commit_date = cutoff_by_min_date ? from->item->date : 0; + struct commit_list *from_iter = from, *to_iter = to; + int result; + uint32_t min_generation = GENERATION_NUMBER_INFINITY; + + while (from_iter) { + add_object_array(&from_iter->item->object, NULL, &from_objs); + + if (!parse_commit(from_iter->item)) { + if (from_iter->item->date < min_commit_date) + min_commit_date = from_iter->item->date; + + if (from_iter->item->generation < min_generation) + min_generation = from_iter->item->generation; + } + + from_iter = from_iter->next; + } + + while (to_iter) { + if (!parse_commit(to_iter->item)) { + if (to_iter->item->date < min_commit_date) + min_commit_date = to_iter->item->date; + + if (to_iter->item->generation < min_generation) + min_generation = to_iter->item->generation; + } + + to_iter->item->object.flags |= PARENT2; + + to_iter = to_iter->next; + } + + result = can_all_from_reach_with_flag(&from_objs, PARENT2, PARENT1, + min_commit_date, min_generation); + + while (from) { + clear_commit_marks(from->item, PARENT1); + from = from->next; + } + + while (to) { + clear_commit_marks(to->item, PARENT2); + to = to->next; + } + + object_array_clear(&from_objs); + return result; +} |