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git/builtin-reflog.c
Brandon Casey 55f1056537 git-reflog: add option --updateref to write the last reflog sha1 into the ref
Certain sanity checks on the reflog assume that the sha1 of the top reflog
entry will be equal to the sha1 stored in the ref.

When reflog entries are deleted, this assumption may not hold. This patch
adds a new option to git-reflog which causes the subcommands "expire" and
"delete" to update the ref with the sha1 of the top-most reflog entry.

Signed-off-by: Brandon Casey <casey@nrlssc.navy.mil>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-02-22 22:57:38 -08:00

533 lines
13 KiB
C

#include "cache.h"
#include "builtin.h"
#include "commit.h"
#include "refs.h"
#include "dir.h"
#include "tree-walk.h"
#include "diff.h"
#include "revision.h"
#include "reachable.h"
/*
* reflog expire
*/
static const char reflog_expire_usage[] =
"git-reflog (show|expire) [--verbose] [--dry-run] [--stale-fix] [--expire=<time>] [--expire-unreachable=<time>] [--all] <refs>...";
static const char reflog_delete_usage[] =
"git-reflog delete [--verbose] [--dry-run] [--rewrite] [--updateref] <refs>...";
static unsigned long default_reflog_expire;
static unsigned long default_reflog_expire_unreachable;
struct cmd_reflog_expire_cb {
struct rev_info revs;
int dry_run;
int stalefix;
int rewrite;
int updateref;
int verbose;
unsigned long expire_total;
unsigned long expire_unreachable;
int recno;
};
struct expire_reflog_cb {
FILE *newlog;
const char *ref;
struct commit *ref_commit;
struct cmd_reflog_expire_cb *cmd;
unsigned char last_kept_sha1[20];
};
struct collected_reflog {
unsigned char sha1[20];
char reflog[FLEX_ARRAY];
};
struct collect_reflog_cb {
struct collected_reflog **e;
int alloc;
int nr;
};
#define INCOMPLETE (1u<<10)
#define STUDYING (1u<<11)
static int tree_is_complete(const unsigned char *sha1)
{
struct tree_desc desc;
struct name_entry entry;
int complete;
struct tree *tree;
tree = lookup_tree(sha1);
if (!tree)
return 0;
if (tree->object.flags & SEEN)
return 1;
if (tree->object.flags & INCOMPLETE)
return 0;
if (!tree->buffer) {
enum object_type type;
unsigned long size;
void *data = read_sha1_file(sha1, &type, &size);
if (!data) {
tree->object.flags |= INCOMPLETE;
return 0;
}
tree->buffer = data;
tree->size = size;
}
init_tree_desc(&desc, tree->buffer, tree->size);
complete = 1;
while (tree_entry(&desc, &entry)) {
if (!has_sha1_file(entry.sha1) ||
(S_ISDIR(entry.mode) && !tree_is_complete(entry.sha1))) {
tree->object.flags |= INCOMPLETE;
complete = 0;
}
}
free(tree->buffer);
tree->buffer = NULL;
if (complete)
tree->object.flags |= SEEN;
return complete;
}
static int commit_is_complete(struct commit *commit)
{
struct object_array study;
struct object_array found;
int is_incomplete = 0;
int i;
/* early return */
if (commit->object.flags & SEEN)
return 1;
if (commit->object.flags & INCOMPLETE)
return 0;
/*
* Find all commits that are reachable and are not marked as
* SEEN. Then make sure the trees and blobs contained are
* complete. After that, mark these commits also as SEEN.
* If some of the objects that are needed to complete this
* commit are missing, mark this commit as INCOMPLETE.
*/
memset(&study, 0, sizeof(study));
memset(&found, 0, sizeof(found));
add_object_array(&commit->object, NULL, &study);
add_object_array(&commit->object, NULL, &found);
commit->object.flags |= STUDYING;
while (study.nr) {
struct commit *c;
struct commit_list *parent;
c = (struct commit *)study.objects[--study.nr].item;
if (!c->object.parsed && !parse_object(c->object.sha1))
c->object.flags |= INCOMPLETE;
if (c->object.flags & INCOMPLETE) {
is_incomplete = 1;
break;
}
else if (c->object.flags & SEEN)
continue;
for (parent = c->parents; parent; parent = parent->next) {
struct commit *p = parent->item;
if (p->object.flags & STUDYING)
continue;
p->object.flags |= STUDYING;
add_object_array(&p->object, NULL, &study);
add_object_array(&p->object, NULL, &found);
}
}
if (!is_incomplete) {
/*
* make sure all commits in "found" array have all the
* necessary objects.
*/
for (i = 0; i < found.nr; i++) {
struct commit *c =
(struct commit *)found.objects[i].item;
if (!tree_is_complete(c->tree->object.sha1)) {
is_incomplete = 1;
c->object.flags |= INCOMPLETE;
}
}
if (!is_incomplete) {
/* mark all found commits as complete, iow SEEN */
for (i = 0; i < found.nr; i++)
found.objects[i].item->flags |= SEEN;
}
}
/* clear flags from the objects we traversed */
for (i = 0; i < found.nr; i++)
found.objects[i].item->flags &= ~STUDYING;
if (is_incomplete)
commit->object.flags |= INCOMPLETE;
else {
/*
* If we come here, we have (1) traversed the ancestry chain
* from the "commit" until we reach SEEN commits (which are
* known to be complete), and (2) made sure that the commits
* encountered during the above traversal refer to trees that
* are complete. Which means that we know *all* the commits
* we have seen during this process are complete.
*/
for (i = 0; i < found.nr; i++)
found.objects[i].item->flags |= SEEN;
}
/* free object arrays */
free(study.objects);
free(found.objects);
return !is_incomplete;
}
static int keep_entry(struct commit **it, unsigned char *sha1)
{
struct commit *commit;
if (is_null_sha1(sha1))
return 1;
commit = lookup_commit_reference_gently(sha1, 1);
if (!commit)
return 0;
/*
* Make sure everything in this commit exists.
*
* We have walked all the objects reachable from the refs
* and cache earlier. The commits reachable by this commit
* must meet SEEN commits -- and then we should mark them as
* SEEN as well.
*/
if (!commit_is_complete(commit))
return 0;
*it = commit;
return 1;
}
static int expire_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
const char *email, unsigned long timestamp, int tz,
const char *message, void *cb_data)
{
struct expire_reflog_cb *cb = cb_data;
struct commit *old, *new;
if (timestamp < cb->cmd->expire_total)
goto prune;
if (cb->cmd->rewrite)
osha1 = cb->last_kept_sha1;
old = new = NULL;
if (cb->cmd->stalefix &&
(!keep_entry(&old, osha1) || !keep_entry(&new, nsha1)))
goto prune;
if (timestamp < cb->cmd->expire_unreachable) {
if (!cb->ref_commit)
goto prune;
if (!old && !is_null_sha1(osha1))
old = lookup_commit_reference_gently(osha1, 1);
if (!new && !is_null_sha1(nsha1))
new = lookup_commit_reference_gently(nsha1, 1);
if ((old && !in_merge_bases(old, &cb->ref_commit, 1)) ||
(new && !in_merge_bases(new, &cb->ref_commit, 1)))
goto prune;
}
if (cb->cmd->recno && --(cb->cmd->recno) == 0)
goto prune;
if (cb->newlog) {
char sign = (tz < 0) ? '-' : '+';
int zone = (tz < 0) ? (-tz) : tz;
fprintf(cb->newlog, "%s %s %s %lu %c%04d\t%s",
sha1_to_hex(osha1), sha1_to_hex(nsha1),
email, timestamp, sign, zone,
message);
hashcpy(cb->last_kept_sha1, nsha1);
}
if (cb->cmd->verbose)
printf("keep %s", message);
return 0;
prune:
if (!cb->newlog || cb->cmd->verbose)
printf("%sprune %s", cb->newlog ? "" : "would ", message);
return 0;
}
static int expire_reflog(const char *ref, const unsigned char *sha1, int unused, void *cb_data)
{
struct cmd_reflog_expire_cb *cmd = cb_data;
struct expire_reflog_cb cb;
struct ref_lock *lock;
char *log_file, *newlog_path = NULL;
int status = 0;
memset(&cb, 0, sizeof(cb));
/* we take the lock for the ref itself to prevent it from
* getting updated.
*/
lock = lock_any_ref_for_update(ref, sha1, 0);
if (!lock)
return error("cannot lock ref '%s'", ref);
log_file = xstrdup(git_path("logs/%s", ref));
if (!file_exists(log_file))
goto finish;
if (!cmd->dry_run) {
newlog_path = xstrdup(git_path("logs/%s.lock", ref));
cb.newlog = fopen(newlog_path, "w");
}
cb.ref_commit = lookup_commit_reference_gently(sha1, 1);
cb.ref = ref;
cb.cmd = cmd;
for_each_reflog_ent(ref, expire_reflog_ent, &cb);
finish:
if (cb.newlog) {
if (fclose(cb.newlog)) {
status |= error("%s: %s", strerror(errno),
newlog_path);
unlink(newlog_path);
} else if (cmd->updateref &&
(write_in_full(lock->lock_fd,
sha1_to_hex(cb.last_kept_sha1), 40) != 40 ||
write_in_full(lock->lock_fd, "\n", 1) != 1 ||
close_ref(lock) < 0)) {
status |= error("Couldn't write %s",
lock->lk->filename);
unlink(newlog_path);
} else if (rename(newlog_path, log_file)) {
status |= error("cannot rename %s to %s",
newlog_path, log_file);
unlink(newlog_path);
} else if (cmd->updateref && commit_ref(lock)) {
status |= error("Couldn't set %s", lock->ref_name);
}
}
free(newlog_path);
free(log_file);
unlock_ref(lock);
return status;
}
static int collect_reflog(const char *ref, const unsigned char *sha1, int unused, void *cb_data)
{
struct collected_reflog *e;
struct collect_reflog_cb *cb = cb_data;
size_t namelen = strlen(ref);
e = xmalloc(sizeof(*e) + namelen + 1);
hashcpy(e->sha1, sha1);
memcpy(e->reflog, ref, namelen + 1);
ALLOC_GROW(cb->e, cb->nr + 1, cb->alloc);
cb->e[cb->nr++] = e;
return 0;
}
static int reflog_expire_config(const char *var, const char *value)
{
if (!strcmp(var, "gc.reflogexpire")) {
if (!value)
config_error_nonbool(var);
default_reflog_expire = approxidate(value);
return 0;
}
if (!strcmp(var, "gc.reflogexpireunreachable")) {
if (!value)
config_error_nonbool(var);
default_reflog_expire_unreachable = approxidate(value);
return 0;
}
return git_default_config(var, value);
}
static int cmd_reflog_expire(int argc, const char **argv, const char *prefix)
{
struct cmd_reflog_expire_cb cb;
unsigned long now = time(NULL);
int i, status, do_all;
git_config(reflog_expire_config);
save_commit_buffer = 0;
do_all = status = 0;
memset(&cb, 0, sizeof(cb));
if (!default_reflog_expire_unreachable)
default_reflog_expire_unreachable = now - 30 * 24 * 3600;
if (!default_reflog_expire)
default_reflog_expire = now - 90 * 24 * 3600;
cb.expire_total = default_reflog_expire;
cb.expire_unreachable = default_reflog_expire_unreachable;
/*
* We can trust the commits and objects reachable from refs
* even in older repository. We cannot trust what's reachable
* from reflog if the repository was pruned with older git.
*/
for (i = 1; i < argc; i++) {
const char *arg = argv[i];
if (!strcmp(arg, "--dry-run") || !strcmp(arg, "-n"))
cb.dry_run = 1;
else if (!prefixcmp(arg, "--expire="))
cb.expire_total = approxidate(arg + 9);
else if (!prefixcmp(arg, "--expire-unreachable="))
cb.expire_unreachable = approxidate(arg + 21);
else if (!strcmp(arg, "--stale-fix"))
cb.stalefix = 1;
else if (!strcmp(arg, "--rewrite"))
cb.rewrite = 1;
else if (!strcmp(arg, "--updateref"))
cb.updateref = 1;
else if (!strcmp(arg, "--all"))
do_all = 1;
else if (!strcmp(arg, "--verbose"))
cb.verbose = 1;
else if (!strcmp(arg, "--")) {
i++;
break;
}
else if (arg[0] == '-')
usage(reflog_expire_usage);
else
break;
}
if (cb.stalefix) {
init_revisions(&cb.revs, prefix);
if (cb.verbose)
printf("Marking reachable objects...");
mark_reachable_objects(&cb.revs, 0);
if (cb.verbose)
putchar('\n');
}
if (do_all) {
struct collect_reflog_cb collected;
int i;
memset(&collected, 0, sizeof(collected));
for_each_reflog(collect_reflog, &collected);
for (i = 0; i < collected.nr; i++) {
struct collected_reflog *e = collected.e[i];
status |= expire_reflog(e->reflog, e->sha1, 0, &cb);
free(e);
}
free(collected.e);
}
while (i < argc) {
const char *ref = argv[i++];
unsigned char sha1[20];
if (!resolve_ref(ref, sha1, 1, NULL)) {
status |= error("%s points nowhere!", ref);
continue;
}
status |= expire_reflog(ref, sha1, 0, &cb);
}
return status;
}
static int count_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
const char *email, unsigned long timestamp, int tz,
const char *message, void *cb_data)
{
struct cmd_reflog_expire_cb *cb = cb_data;
if (!cb->expire_total || timestamp < cb->expire_total)
cb->recno++;
return 0;
}
static int cmd_reflog_delete(int argc, const char **argv, const char *prefix)
{
struct cmd_reflog_expire_cb cb;
int i, status = 0;
memset(&cb, 0, sizeof(cb));
for (i = 1; i < argc; i++) {
const char *arg = argv[i];
if (!strcmp(arg, "--dry-run") || !strcmp(arg, "-n"))
cb.dry_run = 1;
else if (!strcmp(arg, "--rewrite"))
cb.rewrite = 1;
else if (!strcmp(arg, "--updateref"))
cb.updateref = 1;
else if (!strcmp(arg, "--verbose"))
cb.verbose = 1;
else if (!strcmp(arg, "--")) {
i++;
break;
}
else if (arg[0] == '-')
usage(reflog_delete_usage);
else
break;
}
if (argc - i < 1)
return error("Nothing to delete?");
for ( ; i < argc; i++) {
const char *spec = strstr(argv[i], "@{");
unsigned char sha1[20];
char *ep, *ref;
int recno;
if (!spec) {
status |= error("Not a reflog: %s", argv[i]);
continue;
}
if (!dwim_ref(argv[i], spec - argv[i], sha1, &ref)) {
status |= error("%s points nowhere!", argv[i]);
continue;
}
recno = strtoul(spec + 2, &ep, 10);
if (*ep == '}') {
cb.recno = -recno;
for_each_reflog_ent(ref, count_reflog_ent, &cb);
} else {
cb.expire_total = approxidate(spec + 2);
for_each_reflog_ent(ref, count_reflog_ent, &cb);
cb.expire_total = 0;
}
status |= expire_reflog(ref, sha1, 0, &cb);
free(ref);
}
return status;
}
/*
* main "reflog"
*/
static const char reflog_usage[] =
"git-reflog (expire | ...)";
int cmd_reflog(int argc, const char **argv, const char *prefix)
{
/* With no command, we default to showing it. */
if (argc < 2 || *argv[1] == '-')
return cmd_log_reflog(argc, argv, prefix);
if (!strcmp(argv[1], "show"))
return cmd_log_reflog(argc - 1, argv + 1, prefix);
if (!strcmp(argv[1], "expire"))
return cmd_reflog_expire(argc - 1, argv + 1, prefix);
if (!strcmp(argv[1], "delete"))
return cmd_reflog_delete(argc - 1, argv + 1, prefix);
/* Not a recognized reflog command..*/
usage(reflog_usage);
}