git/reflog.c

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#include "cache.h"
#include "object-store.h"
#include "reflog.h"
#include "refs.h"
#include "revision.h"
#include "worktree.h"
/* Remember to update object flag allocation in object.h */
#define INCOMPLETE (1u<<10)
#define STUDYING (1u<<11)
#define REACHABLE (1u<<12)
static int tree_is_complete(const struct object_id *oid)
{
struct tree_desc desc;
struct name_entry entry;
int complete;
struct tree *tree;
tree = lookup_tree(the_repository, oid);
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_object_file(oid, &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_object_file(&entry.oid) ||
(S_ISDIR(entry.mode) && !tree_is_complete(&entry.oid))) {
tree->object.flags |= INCOMPLETE;
complete = 0;
}
}
free_tree_buffer(tree);
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 *)object_array_pop(&study);
if (!c->object.parsed && !parse_object(the_repository, &c->object.oid))
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(get_commit_tree_oid(c))) {
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 */
object_array_clear(&study);
object_array_clear(&found);
return !is_incomplete;
}
static int keep_entry(struct commit **it, struct object_id *oid)
{
struct commit *commit;
if (is_null_oid(oid))
return 1;
commit = lookup_commit_reference_gently(the_repository, oid, 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;
}
/*
* Starting from commits in the cb->mark_list, mark commits that are
* reachable from them. Stop the traversal at commits older than
* the expire_limit and queue them back, so that the caller can call
* us again to restart the traversal with longer expire_limit.
*/
static void mark_reachable(struct expire_reflog_policy_cb *cb)
{
struct commit_list *pending;
timestamp_t expire_limit = cb->mark_limit;
struct commit_list *leftover = NULL;
for (pending = cb->mark_list; pending; pending = pending->next)
pending->item->object.flags &= ~REACHABLE;
pending = cb->mark_list;
while (pending) {
struct commit_list *parent;
struct commit *commit = pop_commit(&pending);
if (commit->object.flags & REACHABLE)
continue;
if (parse_commit(commit))
continue;
commit->object.flags |= REACHABLE;
if (commit->date < expire_limit) {
commit_list_insert(commit, &leftover);
continue;
}
parent = commit->parents;
while (parent) {
commit = parent->item;
parent = parent->next;
if (commit->object.flags & REACHABLE)
continue;
commit_list_insert(commit, &pending);
}
}
cb->mark_list = leftover;
}
static int unreachable(struct expire_reflog_policy_cb *cb, struct commit *commit, struct object_id *oid)
{
/*
* We may or may not have the commit yet - if not, look it
* up using the supplied sha1.
*/
if (!commit) {
if (is_null_oid(oid))
return 0;
commit = lookup_commit_reference_gently(the_repository, oid,
1);
/* Not a commit -- keep it */
if (!commit)
return 0;
}
/* Reachable from the current ref? Don't prune. */
if (commit->object.flags & REACHABLE)
return 0;
if (cb->mark_list && cb->mark_limit) {
cb->mark_limit = 0; /* dig down to the root */
mark_reachable(cb);
}
return !(commit->object.flags & REACHABLE);
}
/*
* Return true iff the specified reflog entry should be expired.
*/
int should_expire_reflog_ent(struct object_id *ooid, struct object_id *noid,
const char *email UNUSED,
timestamp_t timestamp, int tz UNUSED,
const char *message UNUSED, void *cb_data)
{
struct expire_reflog_policy_cb *cb = cb_data;
struct commit *old_commit, *new_commit;
if (timestamp < cb->cmd.expire_total)
return 1;
old_commit = new_commit = NULL;
if (cb->cmd.stalefix &&
(!keep_entry(&old_commit, ooid) || !keep_entry(&new_commit, noid)))
return 1;
if (timestamp < cb->cmd.expire_unreachable) {
switch (cb->unreachable_expire_kind) {
case UE_ALWAYS:
return 1;
case UE_NORMAL:
case UE_HEAD:
if (unreachable(cb, old_commit, ooid) || unreachable(cb, new_commit, noid))
return 1;
break;
}
}
if (cb->cmd.recno && --(cb->cmd.recno) == 0)
return 1;
return 0;
}
int should_expire_reflog_ent_verbose(struct object_id *ooid,
struct object_id *noid,
const char *email,
timestamp_t timestamp, int tz,
const char *message, void *cb_data)
{
struct expire_reflog_policy_cb *cb = cb_data;
int expire;
expire = should_expire_reflog_ent(ooid, noid, email, timestamp, tz,
message, cb);
if (!expire)
printf("keep %s", message);
else if (cb->dry_run)
printf("would prune %s", message);
else
printf("prune %s", message);
return expire;
}
static int push_tip_to_list(const char *refname UNUSED,
const struct object_id *oid,
int flags, void *cb_data)
{
struct commit_list **list = cb_data;
struct commit *tip_commit;
if (flags & REF_ISSYMREF)
return 0;
tip_commit = lookup_commit_reference_gently(the_repository, oid, 1);
if (!tip_commit)
return 0;
commit_list_insert(tip_commit, list);
return 0;
}
static int is_head(const char *refname)
{
const char *stripped_refname;
parse_worktree_ref(refname, NULL, NULL, &stripped_refname);
return !strcmp(stripped_refname, "HEAD");
}
void reflog_expiry_prepare(const char *refname,
const struct object_id *oid,
void *cb_data)
{
struct expire_reflog_policy_cb *cb = cb_data;
struct commit_list *elem;
struct commit *commit = NULL;
if (!cb->cmd.expire_unreachable || is_head(refname)) {
cb->unreachable_expire_kind = UE_HEAD;
} else {
commit = lookup_commit(the_repository, oid);
if (commit && is_null_oid(&commit->object.oid))
commit = NULL;
cb->unreachable_expire_kind = commit ? UE_NORMAL : UE_ALWAYS;
}
if (cb->cmd.expire_unreachable <= cb->cmd.expire_total)
cb->unreachable_expire_kind = UE_ALWAYS;
switch (cb->unreachable_expire_kind) {
case UE_ALWAYS:
return;
case UE_HEAD:
for_each_ref(push_tip_to_list, &cb->tips);
for (elem = cb->tips; elem; elem = elem->next)
commit_list_insert(elem->item, &cb->mark_list);
break;
case UE_NORMAL:
commit_list_insert(commit, &cb->mark_list);
/* For reflog_expiry_cleanup() below */
cb->tip_commit = commit;
}
cb->mark_limit = cb->cmd.expire_total;
mark_reachable(cb);
}
void reflog_expiry_cleanup(void *cb_data)
{
struct expire_reflog_policy_cb *cb = cb_data;
struct commit_list *elem;
switch (cb->unreachable_expire_kind) {
case UE_ALWAYS:
return;
case UE_HEAD:
for (elem = cb->tips; elem; elem = elem->next)
clear_commit_marks(elem->item, REACHABLE);
free_commit_list(cb->tips);
break;
case UE_NORMAL:
clear_commit_marks(cb->tip_commit, REACHABLE);
break;
}
for (elem = cb->mark_list; elem; elem = elem->next)
clear_commit_marks(elem->item, REACHABLE);
free_commit_list(cb->mark_list);
}
int count_reflog_ent(struct object_id *ooid UNUSED,
struct object_id *noid UNUSED,
const char *email UNUSED,
timestamp_t timestamp, int tz UNUSED,
const char *message UNUSED, void *cb_data)
{
struct cmd_reflog_expire_cb *cb = cb_data;
if (!cb->expire_total || timestamp < cb->expire_total)
cb->recno++;
return 0;
}
int reflog_delete(const char *rev, enum expire_reflog_flags flags, int verbose)
{
struct cmd_reflog_expire_cb cmd = { 0 };
int status = 0;
reflog_expiry_should_prune_fn *should_prune_fn = should_expire_reflog_ent;
const char *spec = strstr(rev, "@{");
char *ep, *ref;
int recno;
struct expire_reflog_policy_cb cb = {
.dry_run = !!(flags & EXPIRE_REFLOGS_DRY_RUN),
};
if (verbose)
should_prune_fn = should_expire_reflog_ent_verbose;
if (!spec)
return error(_("not a reflog: %s"), rev);
if (!dwim_log(rev, spec - rev, NULL, &ref)) {
status |= error(_("no reflog for '%s'"), rev);
goto cleanup;
}
recno = strtoul(spec + 2, &ep, 10);
if (*ep == '}') {
cmd.recno = -recno;
for_each_reflog_ent(ref, count_reflog_ent, &cmd);
} else {
cmd.expire_total = approxidate(spec + 2);
for_each_reflog_ent(ref, count_reflog_ent, &cmd);
cmd.expire_total = 0;
}
cb.cmd = cmd;
status |= reflog_expire(ref, flags,
reflog_expiry_prepare,
should_prune_fn,
reflog_expiry_cleanup,
&cb);
cleanup:
free(ref);
return status;
}