diff options
Diffstat (limited to 'commit-reach.c')
-rw-r--r-- | commit-reach.c | 360 |
1 files changed, 360 insertions, 0 deletions
diff --git a/commit-reach.c b/commit-reach.c new file mode 100644 index 0000000000..8ab6044414 --- /dev/null +++ b/commit-reach.c @@ -0,0 +1,360 @@ +#include "cache.h" +#include "prio-queue.h" +#include "commit.h" +#include "commit-reach.h" + +/* Remember to update object flag allocation in object.h */ +#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; + + 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 (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; + 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; +} |