diff options
Diffstat (limited to 'commit.c')
-rw-r--r-- | commit.c | 847 |
1 files changed, 847 insertions, 0 deletions
diff --git a/commit.c b/commit.c new file mode 100644 index 0000000..e9b0750 --- /dev/null +++ b/commit.c @@ -0,0 +1,847 @@ +#include "cache.h" +#include "tag.h" +#include "commit.h" +#include "pkt-line.h" +#include "utf8.h" +#include "diff.h" +#include "revision.h" +#include "notes.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) +{ + 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 */ + return strtoul(dateptr, NULL, 10); +} + +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; + + while (len && isspace(buf[len-1])) + 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; +} + +static 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(struct strbuf *out, 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_buf_write(out, "shallow %s", hex); + else { + strbuf_addstr(out, hex); + strbuf_addch(out, '\n'); + } + } + 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) + memmove(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; + /* + * The clone is shallow if nr_parent < 0, and we must + * not traverse its real parents even when we unhide them. + */ + if (graft && (graft->nr_parent < 0 || grafts_replace_parents)) + 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 *next; + int flags; + + commit = list->item; + next = list->next; + free(list); + list = next; + + 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 *next = list->next; + if (!(list->item->object.flags & STALE)) + insert_by_date(list->item, &result); + free(list); + list = next; + } + 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 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, 1)) + return 1; + } + return 0; +} + +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; +} + +static const char commit_utf8_warn[] = +"Warning: commit message does not conform to UTF-8.\n" +"You may want to amend it after fixing the message, or set the config\n" +"variable i18n.commitencoding to the encoding your project uses.\n"; + +int commit_tree(const char *msg, unsigned char *tree, + struct commit_list *parents, unsigned char *ret, + const char *author) +{ + int result; + int encoding_is_utf8; + struct strbuf buffer; + + assert_sha1_type(tree, OBJ_TREE); + + /* Not having i18n.commitencoding is the same as having utf-8 */ + encoding_is_utf8 = is_encoding_utf8(git_commit_encoding); + + strbuf_init(&buffer, 8192); /* should avoid reallocs for the headers */ + strbuf_addf(&buffer, "tree %s\n", sha1_to_hex(tree)); + + /* + * NOTE! This ordering means that the same exact tree merged with a + * different order of parents will be a _different_ changeset even + * if everything else stays the same. + */ + while (parents) { + struct commit_list *next = parents->next; + strbuf_addf(&buffer, "parent %s\n", + sha1_to_hex(parents->item->object.sha1)); + free(parents); + parents = next; + } + + /* Person/date information */ + if (!author) + author = git_author_info(IDENT_ERROR_ON_NO_NAME); + strbuf_addf(&buffer, "author %s\n", author); + strbuf_addf(&buffer, "committer %s\n", git_committer_info(IDENT_ERROR_ON_NO_NAME)); + if (!encoding_is_utf8) + strbuf_addf(&buffer, "encoding %s\n", git_commit_encoding); + strbuf_addch(&buffer, '\n'); + + /* And add the comment */ + strbuf_addstr(&buffer, msg); + + /* And check the encoding */ + if (encoding_is_utf8 && !is_utf8(buffer.buf)) + fprintf(stderr, commit_utf8_warn); + + result = write_sha1_file(buffer.buf, buffer.len, commit_type, ret); + strbuf_release(&buffer); + return result; +} |