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-rw-r--r--commit.c778
1 files changed, 778 insertions, 0 deletions
diff --git a/commit.c b/commit.c
new file mode 100644
index 0000000..dc0c5bf
--- /dev/null
+++ b/commit.c
@@ -0,0 +1,778 @@
+#include "cache.h"
+#include "tag.h"
+#include "commit.h"
+#include "pkt-line.h"
+#include "utf8.h"
+#include "diff.h"
+#include "revision.h"
+
+int save_commit_buffer = 1;
+
+const char *commit_type = "commit";
+
+static struct commit *check_commit(struct object *obj,
+ const unsigned char *sha1,
+ int quiet)
+{
+ if (obj->type != OBJ_COMMIT) {
+ if (!quiet)
+ error("Object %s is a %s, not a commit",
+ sha1_to_hex(sha1), typename(obj->type));
+ return NULL;
+ }
+ return (struct commit *) obj;
+}
+
+struct commit *lookup_commit_reference_gently(const unsigned char *sha1,
+ int quiet)
+{
+ struct object *obj = deref_tag(parse_object(sha1), NULL, 0);
+
+ if (!obj)
+ return NULL;
+ return check_commit(obj, sha1, quiet);
+}
+
+struct commit *lookup_commit_reference(const unsigned char *sha1)
+{
+ return lookup_commit_reference_gently(sha1, 0);
+}
+
+struct commit *lookup_commit(const unsigned char *sha1)
+{
+ struct object *obj = lookup_object(sha1);
+ if (!obj)
+ return create_object(sha1, OBJ_COMMIT, alloc_commit_node());
+ if (!obj->type)
+ obj->type = OBJ_COMMIT;
+ return check_commit(obj, sha1, 0);
+}
+
+static unsigned long parse_commit_date(const char *buf, const char *tail)
+{
+ unsigned long date;
+ const char *dateptr;
+
+ if (buf + 6 >= tail)
+ return 0;
+ if (memcmp(buf, "author", 6))
+ return 0;
+ while (buf < tail && *buf++ != '\n')
+ /* nada */;
+ if (buf + 9 >= tail)
+ return 0;
+ if (memcmp(buf, "committer", 9))
+ return 0;
+ while (buf < tail && *buf++ != '>')
+ /* nada */;
+ if (buf >= tail)
+ return 0;
+ dateptr = buf;
+ while (buf < tail && *buf++ != '\n')
+ /* nada */;
+ if (buf >= tail)
+ return 0;
+ /* dateptr < buf && buf[-1] == '\n', so strtoul will stop at buf-1 */
+ date = strtoul(dateptr, NULL, 10);
+ if (date == ULONG_MAX)
+ date = 0;
+ return date;
+}
+
+static struct commit_graft **commit_graft;
+static int commit_graft_alloc, commit_graft_nr;
+
+static int commit_graft_pos(const unsigned char *sha1)
+{
+ int lo, hi;
+ lo = 0;
+ hi = commit_graft_nr;
+ while (lo < hi) {
+ int mi = (lo + hi) / 2;
+ struct commit_graft *graft = commit_graft[mi];
+ int cmp = hashcmp(sha1, graft->sha1);
+ if (!cmp)
+ return mi;
+ if (cmp < 0)
+ hi = mi;
+ else
+ lo = mi + 1;
+ }
+ return -lo - 1;
+}
+
+int register_commit_graft(struct commit_graft *graft, int ignore_dups)
+{
+ int pos = commit_graft_pos(graft->sha1);
+
+ if (0 <= pos) {
+ if (ignore_dups)
+ free(graft);
+ else {
+ free(commit_graft[pos]);
+ commit_graft[pos] = graft;
+ }
+ return 1;
+ }
+ pos = -pos - 1;
+ if (commit_graft_alloc <= ++commit_graft_nr) {
+ commit_graft_alloc = alloc_nr(commit_graft_alloc);
+ commit_graft = xrealloc(commit_graft,
+ sizeof(*commit_graft) *
+ commit_graft_alloc);
+ }
+ if (pos < commit_graft_nr)
+ memmove(commit_graft + pos + 1,
+ commit_graft + pos,
+ (commit_graft_nr - pos - 1) *
+ sizeof(*commit_graft));
+ commit_graft[pos] = graft;
+ return 0;
+}
+
+struct commit_graft *read_graft_line(char *buf, int len)
+{
+ /* The format is just "Commit Parent1 Parent2 ...\n" */
+ int i;
+ struct commit_graft *graft = NULL;
+
+ if (buf[len-1] == '\n')
+ buf[--len] = 0;
+ if (buf[0] == '#' || buf[0] == '\0')
+ return NULL;
+ if ((len + 1) % 41) {
+ bad_graft_data:
+ error("bad graft data: %s", buf);
+ free(graft);
+ return NULL;
+ }
+ i = (len + 1) / 41 - 1;
+ graft = xmalloc(sizeof(*graft) + 20 * i);
+ graft->nr_parent = i;
+ if (get_sha1_hex(buf, graft->sha1))
+ goto bad_graft_data;
+ for (i = 40; i < len; i += 41) {
+ if (buf[i] != ' ')
+ goto bad_graft_data;
+ if (get_sha1_hex(buf + i + 1, graft->parent[i/41]))
+ goto bad_graft_data;
+ }
+ return graft;
+}
+
+int read_graft_file(const char *graft_file)
+{
+ FILE *fp = fopen(graft_file, "r");
+ char buf[1024];
+ if (!fp)
+ return -1;
+ while (fgets(buf, sizeof(buf), fp)) {
+ /* The format is just "Commit Parent1 Parent2 ...\n" */
+ int len = strlen(buf);
+ struct commit_graft *graft = read_graft_line(buf, len);
+ if (!graft)
+ continue;
+ if (register_commit_graft(graft, 1))
+ error("duplicate graft data: %s", buf);
+ }
+ fclose(fp);
+ return 0;
+}
+
+static void prepare_commit_graft(void)
+{
+ static int commit_graft_prepared;
+ char *graft_file;
+
+ if (commit_graft_prepared)
+ return;
+ graft_file = get_graft_file();
+ read_graft_file(graft_file);
+ /* make sure shallows are read */
+ is_repository_shallow();
+ commit_graft_prepared = 1;
+}
+
+struct commit_graft *lookup_commit_graft(const unsigned char *sha1)
+{
+ int pos;
+ prepare_commit_graft();
+ pos = commit_graft_pos(sha1);
+ if (pos < 0)
+ return NULL;
+ return commit_graft[pos];
+}
+
+int write_shallow_commits(int fd, int use_pack_protocol)
+{
+ int i, count = 0;
+ for (i = 0; i < commit_graft_nr; i++)
+ if (commit_graft[i]->nr_parent < 0) {
+ const char *hex =
+ sha1_to_hex(commit_graft[i]->sha1);
+ count++;
+ if (use_pack_protocol)
+ packet_write(fd, "shallow %s", hex);
+ else {
+ if (write_in_full(fd, hex, 40) != 40)
+ break;
+ if (write_in_full(fd, "\n", 1) != 1)
+ break;
+ }
+ }
+ return count;
+}
+
+int unregister_shallow(const unsigned char *sha1)
+{
+ int pos = commit_graft_pos(sha1);
+ if (pos < 0)
+ return -1;
+ if (pos + 1 < commit_graft_nr)
+ memcpy(commit_graft + pos, commit_graft + pos + 1,
+ sizeof(struct commit_graft *)
+ * (commit_graft_nr - pos - 1));
+ commit_graft_nr--;
+ return 0;
+}
+
+int parse_commit_buffer(struct commit *item, void *buffer, unsigned long size)
+{
+ char *tail = buffer;
+ char *bufptr = buffer;
+ unsigned char parent[20];
+ struct commit_list **pptr;
+ struct commit_graft *graft;
+
+ if (item->object.parsed)
+ return 0;
+ item->object.parsed = 1;
+ tail += size;
+ if (tail <= bufptr + 46 || memcmp(bufptr, "tree ", 5) || bufptr[45] != '\n')
+ return error("bogus commit object %s", sha1_to_hex(item->object.sha1));
+ if (get_sha1_hex(bufptr + 5, parent) < 0)
+ return error("bad tree pointer in commit %s",
+ sha1_to_hex(item->object.sha1));
+ item->tree = lookup_tree(parent);
+ bufptr += 46; /* "tree " + "hex sha1" + "\n" */
+ pptr = &item->parents;
+
+ graft = lookup_commit_graft(item->object.sha1);
+ while (bufptr + 48 < tail && !memcmp(bufptr, "parent ", 7)) {
+ struct commit *new_parent;
+
+ if (tail <= bufptr + 48 ||
+ get_sha1_hex(bufptr + 7, parent) ||
+ bufptr[47] != '\n')
+ return error("bad parents in commit %s", sha1_to_hex(item->object.sha1));
+ bufptr += 48;
+ if (graft)
+ continue;
+ new_parent = lookup_commit(parent);
+ if (new_parent)
+ pptr = &commit_list_insert(new_parent, pptr)->next;
+ }
+ if (graft) {
+ int i;
+ struct commit *new_parent;
+ for (i = 0; i < graft->nr_parent; i++) {
+ new_parent = lookup_commit(graft->parent[i]);
+ if (!new_parent)
+ continue;
+ pptr = &commit_list_insert(new_parent, pptr)->next;
+ }
+ }
+ item->date = parse_commit_date(bufptr, tail);
+
+ return 0;
+}
+
+int parse_commit(struct commit *item)
+{
+ enum object_type type;
+ void *buffer;
+ unsigned long size;
+ int ret;
+
+ if (!item)
+ return -1;
+ if (item->object.parsed)
+ return 0;
+ buffer = read_sha1_file(item->object.sha1, &type, &size);
+ if (!buffer)
+ return error("Could not read %s",
+ sha1_to_hex(item->object.sha1));
+ if (type != OBJ_COMMIT) {
+ free(buffer);
+ return error("Object %s not a commit",
+ sha1_to_hex(item->object.sha1));
+ }
+ ret = parse_commit_buffer(item, buffer, size);
+ if (save_commit_buffer && !ret) {
+ item->buffer = buffer;
+ return 0;
+ }
+ free(buffer);
+ return ret;
+}
+
+struct commit_list *commit_list_insert(struct commit *item, struct commit_list **list_p)
+{
+ struct commit_list *new_list = xmalloc(sizeof(struct commit_list));
+ new_list->item = item;
+ new_list->next = *list_p;
+ *list_p = new_list;
+ return new_list;
+}
+
+unsigned commit_list_count(const struct commit_list *l)
+{
+ unsigned c = 0;
+ for (; l; l = l->next )
+ c++;
+ return c;
+}
+
+void free_commit_list(struct commit_list *list)
+{
+ while (list) {
+ struct commit_list *temp = list;
+ list = temp->next;
+ free(temp);
+ }
+}
+
+struct commit_list * insert_by_date(struct commit *item, struct commit_list **list)
+{
+ struct commit_list **pp = list;
+ struct commit_list *p;
+ while ((p = *pp) != NULL) {
+ if (p->item->date < item->date) {
+ break;
+ }
+ pp = &p->next;
+ }
+ return commit_list_insert(item, pp);
+}
+
+
+void sort_by_date(struct commit_list **list)
+{
+ struct commit_list *ret = NULL;
+ while (*list) {
+ insert_by_date((*list)->item, &ret);
+ *list = (*list)->next;
+ }
+ *list = ret;
+}
+
+struct commit *pop_most_recent_commit(struct commit_list **list,
+ unsigned int mark)
+{
+ struct commit *ret = (*list)->item;
+ struct commit_list *parents = ret->parents;
+ struct commit_list *old = *list;
+
+ *list = (*list)->next;
+ free(old);
+
+ while (parents) {
+ struct commit *commit = parents->item;
+ if (!parse_commit(commit) && !(commit->object.flags & mark)) {
+ commit->object.flags |= mark;
+ insert_by_date(commit, list);
+ }
+ parents = parents->next;
+ }
+ return ret;
+}
+
+void clear_commit_marks(struct commit *commit, unsigned int mark)
+{
+ while (commit) {
+ struct commit_list *parents;
+
+ if (!(mark & commit->object.flags))
+ return;
+
+ commit->object.flags &= ~mark;
+
+ parents = commit->parents;
+ if (!parents)
+ return;
+
+ while ((parents = parents->next))
+ clear_commit_marks(parents->item, mark);
+
+ commit = commit->parents->item;
+ }
+}
+
+struct commit *pop_commit(struct commit_list **stack)
+{
+ struct commit_list *top = *stack;
+ struct commit *item = top ? top->item : NULL;
+
+ if (top) {
+ *stack = top->next;
+ free(top);
+ }
+ return item;
+}
+
+/*
+ * Performs an in-place topological sort on the list supplied.
+ */
+void sort_in_topological_order(struct commit_list ** list, int lifo)
+{
+ struct commit_list *next, *orig = *list;
+ struct commit_list *work, **insert;
+ struct commit_list **pptr;
+
+ if (!orig)
+ return;
+ *list = NULL;
+
+ /* Mark them and clear the indegree */
+ for (next = orig; next; next = next->next) {
+ struct commit *commit = next->item;
+ commit->indegree = 1;
+ }
+
+ /* update the indegree */
+ for (next = orig; next; next = next->next) {
+ struct commit_list * parents = next->item->parents;
+ while (parents) {
+ struct commit *parent = parents->item;
+
+ if (parent->indegree)
+ parent->indegree++;
+ parents = parents->next;
+ }
+ }
+
+ /*
+ * find the tips
+ *
+ * tips are nodes not reachable from any other node in the list
+ *
+ * the tips serve as a starting set for the work queue.
+ */
+ work = NULL;
+ insert = &work;
+ for (next = orig; next; next = next->next) {
+ struct commit *commit = next->item;
+
+ if (commit->indegree == 1)
+ insert = &commit_list_insert(commit, insert)->next;
+ }
+
+ /* process the list in topological order */
+ if (!lifo)
+ sort_by_date(&work);
+
+ pptr = list;
+ *list = NULL;
+ while (work) {
+ struct commit *commit;
+ struct commit_list *parents, *work_item;
+
+ work_item = work;
+ work = work_item->next;
+ work_item->next = NULL;
+
+ commit = work_item->item;
+ for (parents = commit->parents; parents ; parents = parents->next) {
+ struct commit *parent=parents->item;
+
+ if (!parent->indegree)
+ continue;
+
+ /*
+ * parents are only enqueued for emission
+ * when all their children have been emitted thereby
+ * guaranteeing topological order.
+ */
+ if (--parent->indegree == 1) {
+ if (!lifo)
+ insert_by_date(parent, &work);
+ else
+ commit_list_insert(parent, &work);
+ }
+ }
+ /*
+ * work_item is a commit all of whose children
+ * have already been emitted. we can emit it now.
+ */
+ commit->indegree = 0;
+ *pptr = work_item;
+ pptr = &work_item->next;
+ }
+}
+
+/* merge-base stuff */
+
+/* bits #0..15 in revision.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 struct commit *interesting(struct commit_list *list)
+{
+ while (list) {
+ struct commit *commit = list->item;
+ list = list->next;
+ if (commit->object.flags & STALE)
+ continue;
+ return commit;
+ }
+ return NULL;
+}
+
+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;
+ }
+
+ one->object.flags |= PARENT1;
+ insert_by_date(one, &list);
+ for (i = 0; i < n; i++) {
+ twos[i]->object.flags |= PARENT2;
+ insert_by_date(twos[i], &list);
+ }
+
+ while (interesting(list)) {
+ struct commit *commit;
+ struct commit_list *parents;
+ struct commit_list *n;
+ int flags;
+
+ commit = list->item;
+ n = list->next;
+ free(list);
+ list = n;
+
+ flags = commit->object.flags & (PARENT1 | PARENT2 | STALE);
+ if (flags == (PARENT1 | PARENT2)) {
+ if (!(commit->object.flags & RESULT)) {
+ commit->object.flags |= RESULT;
+ 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;
+ insert_by_date(p, &list);
+ }
+ }
+
+ /* Clean up the result to remove stale ones */
+ free_commit_list(list);
+ list = result; result = NULL;
+ while (list) {
+ struct commit_list *n = list->next;
+ if (!(list->item->object.flags & STALE))
+ insert_by_date(list->item, &result);
+ free(list);
+ list = n;
+ }
+ return result;
+}
+
+struct commit_list *get_octopus_merge_bases(struct commit_list *in)
+{
+ struct commit_list *i, *j, *k, *ret = NULL;
+ struct commit_list **pptr = &ret;
+
+ for (i = in; i; i = i->next) {
+ if (!ret)
+ pptr = &commit_list_insert(i->item, pptr)->next;
+ else {
+ struct commit_list *new = NULL, *end = NULL;
+
+ for (j = ret; j; j = j->next) {
+ struct commit_list *bases;
+ bases = get_merge_bases(i->item, j->item, 1);
+ if (!new)
+ new = bases;
+ else
+ end->next = bases;
+ for (k = bases; k; k = k->next)
+ end = k;
+ }
+ ret = new;
+ }
+ }
+ return ret;
+}
+
+struct commit_list *get_merge_bases_many(struct commit *one,
+ int n,
+ struct commit **twos,
+ int cleanup)
+{
+ struct commit_list *list;
+ struct commit **rslt;
+ struct commit_list *result;
+ int cnt, i, j;
+
+ 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);
+ for (i = 0; i < n; i++)
+ clear_commit_marks(twos[i], all_flags);
+ }
+ return result;
+ }
+
+ /* There are more than one */
+ cnt = 0;
+ list = result;
+ while (list) {
+ list = list->next;
+ cnt++;
+ }
+ 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);
+ for (i = 0; i < n; i++)
+ clear_commit_marks(twos[i], all_flags);
+ for (i = 0; i < cnt - 1; i++) {
+ for (j = i+1; j < cnt; j++) {
+ if (!rslt[i] || !rslt[j])
+ continue;
+ result = merge_bases_many(rslt[i], 1, &rslt[j]);
+ clear_commit_marks(rslt[i], all_flags);
+ clear_commit_marks(rslt[j], all_flags);
+ for (list = result; list; list = list->next) {
+ if (rslt[i] == list->item)
+ rslt[i] = NULL;
+ if (rslt[j] == list->item)
+ rslt[j] = NULL;
+ }
+ }
+ }
+
+ /* Surviving ones in rslt[] are the independent results */
+ result = NULL;
+ for (i = 0; i < cnt; i++) {
+ if (rslt[i])
+ insert_by_date(rslt[i], &result);
+ }
+ free(rslt);
+ return result;
+}
+
+struct commit_list *get_merge_bases(struct commit *one, struct commit *two,
+ int cleanup)
+{
+ return get_merge_bases_many(one, 1, &two, cleanup);
+}
+
+int in_merge_bases(struct commit *commit, struct commit **reference, int num)
+{
+ struct commit_list *bases, *b;
+ int ret = 0;
+
+ if (num == 1)
+ bases = get_merge_bases(commit, *reference, 1);
+ else
+ die("not yet");
+ for (b = bases; b; b = b->next) {
+ if (!hashcmp(commit->object.sha1, b->item->object.sha1)) {
+ ret = 1;
+ break;
+ }
+ }
+
+ free_commit_list(bases);
+ return ret;
+}
+
+struct commit_list *reduce_heads(struct commit_list *heads)
+{
+ struct commit_list *p;
+ struct commit_list *result = NULL, **tail = &result;
+ struct commit **other;
+ size_t num_head, num_other;
+
+ if (!heads)
+ return NULL;
+
+ /* Avoid unnecessary reallocations */
+ for (p = heads, num_head = 0; p; p = p->next)
+ num_head++;
+ other = xcalloc(sizeof(*other), num_head);
+
+ /* For each commit, see if it can be reached by others */
+ for (p = heads; p; p = p->next) {
+ struct commit_list *q, *base;
+
+ /* Do we already have this in the result? */
+ for (q = result; q; q = q->next)
+ if (p->item == q->item)
+ break;
+ if (q)
+ continue;
+
+ num_other = 0;
+ for (q = heads; q; q = q->next) {
+ if (p->item == q->item)
+ continue;
+ other[num_other++] = q->item;
+ }
+ if (num_other)
+ base = get_merge_bases_many(p->item, num_other, other, 1);
+ else
+ base = NULL;
+ /*
+ * If p->item does not have anything common with other
+ * commits, there won't be any merge base. If it is
+ * reachable from some of the others, p->item will be
+ * the merge base. If its history is connected with
+ * others, but p->item is not reachable by others, we
+ * will get something other than p->item back.
+ */
+ if (!base || (base->item != p->item))
+ tail = &(commit_list_insert(p->item, tail)->next);
+ free_commit_list(base);
+ }
+ free(other);
+ return result;
+}
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