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-rw-r--r--commit-reach.c761
1 files changed, 761 insertions, 0 deletions
diff --git a/commit-reach.c b/commit-reach.c
new file mode 100644
index 0000000..d5a39de
--- /dev/null
+++ b/commit-reach.c
@@ -0,0 +1,761 @@
+#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;
+}
+
+struct commit_list *get_reachable_subset(struct commit **from, int nr_from,
+ struct commit **to, int nr_to,
+ unsigned int reachable_flag)
+{
+ struct commit **item;
+ struct commit *current;
+ struct commit_list *found_commits = NULL;
+ struct commit **to_last = to + nr_to;
+ struct commit **from_last = from + nr_from;
+ uint32_t min_generation = GENERATION_NUMBER_INFINITY;
+ int num_to_find = 0;
+
+ struct prio_queue queue = { compare_commits_by_gen_then_commit_date };
+
+ for (item = to; item < to_last; item++) {
+ struct commit *c = *item;
+
+ parse_commit(c);
+ if (c->generation < min_generation)
+ min_generation = c->generation;
+
+ if (!(c->object.flags & PARENT1)) {
+ c->object.flags |= PARENT1;
+ num_to_find++;
+ }
+ }
+
+ for (item = from; item < from_last; item++) {
+ struct commit *c = *item;
+ if (!(c->object.flags & PARENT2)) {
+ c->object.flags |= PARENT2;
+ parse_commit(c);
+
+ prio_queue_put(&queue, *item);
+ }
+ }
+
+ while (num_to_find && (current = prio_queue_get(&queue)) != NULL) {
+ struct commit_list *parents;
+
+ if (current->object.flags & PARENT1) {
+ current->object.flags &= ~PARENT1;
+ current->object.flags |= reachable_flag;
+ commit_list_insert(current, &found_commits);
+ num_to_find--;
+ }
+
+ for (parents = current->parents; parents; parents = parents->next) {
+ struct commit *p = parents->item;
+
+ parse_commit(p);
+
+ if (p->generation < min_generation)
+ continue;
+
+ if (p->object.flags & PARENT2)
+ continue;
+
+ p->object.flags |= PARENT2;
+ prio_queue_put(&queue, p);
+ }
+ }
+
+ clear_commit_marks_many(nr_to, to, PARENT1);
+ clear_commit_marks_many(nr_from, from, PARENT2);
+
+ return found_commits;
+}