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Copy pathcommit.c
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793 lines (703 loc) · 17.4 KB
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#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;
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(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 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;
}
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