git/reflog.c
Eric W. Biederman efed687edc tree-walk: init_tree_desc take an oid to get the hash algorithm
To make it possible for git ls-tree to display the tree encoded
in the hash algorithm of the oid specified to git ls-tree, update
init_tree_desc to take as a parameter the oid of the tree object.

Update all callers of init_tree_desc and init_tree_desc_gently
to pass the oid of the tree object.

Use the oid of the tree object to discover the hash algorithm
of the oid and store that hash algorithm in struct tree_desc.

Use the hash algorithm in decode_tree_entry and
update_tree_entry_internal to handle reading a tree object encoded in
a hash algorithm that differs from the repositories hash algorithm.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-10-02 14:57:40 -07:00

437 lines
11 KiB
C

#include "git-compat-util.h"
#include "gettext.h"
#include "object-store-ll.h"
#include "reflog.h"
#include "refs.h"
#include "revision.h"
#include "tree.h"
#include "tree-walk.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 = repo_read_object_file(the_repository, oid, &type,
&size);
if (!data) {
tree->object.flags |= INCOMPLETE;
return 0;
}
tree->buffer = data;
tree->size = size;
}
init_tree_desc(&desc, &tree->object.oid, tree->buffer, tree->size);
complete = 1;
while (tree_entry(&desc, &entry)) {
if (!repo_has_object_file(the_repository, &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 (repo_parse_commit(the_repository, 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;
}