git/walker.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

355 lines
7.8 KiB
C

#include "git-compat-util.h"
#include "gettext.h"
#include "hex.h"
#include "walker.h"
#include "repository.h"
#include "object-store-ll.h"
#include "commit.h"
#include "strbuf.h"
#include "tree.h"
#include "tree-walk.h"
#include "tag.h"
#include "blob.h"
#include "refs.h"
#include "progress.h"
static struct object_id current_commit_oid;
void walker_say(struct walker *walker, const char *fmt, ...)
{
if (walker->get_verbosely) {
va_list ap;
va_start(ap, fmt);
vfprintf(stderr, fmt, ap);
va_end(ap);
}
}
static void report_missing(const struct object *obj)
{
fprintf(stderr, "Cannot obtain needed %s %s\n",
obj->type ? type_name(obj->type): "object",
oid_to_hex(&obj->oid));
if (!is_null_oid(&current_commit_oid))
fprintf(stderr, "while processing commit %s.\n",
oid_to_hex(&current_commit_oid));
}
static int process(struct walker *walker, struct object *obj);
static int process_tree(struct walker *walker, struct tree *tree)
{
struct tree_desc desc;
struct name_entry entry;
if (parse_tree(tree))
return -1;
init_tree_desc(&desc, &tree->object.oid, tree->buffer, tree->size);
while (tree_entry(&desc, &entry)) {
struct object *obj = NULL;
/* submodule commits are not stored in the superproject */
if (S_ISGITLINK(entry.mode))
continue;
if (S_ISDIR(entry.mode)) {
struct tree *tree = lookup_tree(the_repository,
&entry.oid);
if (tree)
obj = &tree->object;
}
else {
struct blob *blob = lookup_blob(the_repository,
&entry.oid);
if (blob)
obj = &blob->object;
}
if (!obj || process(walker, obj))
return -1;
}
free_tree_buffer(tree);
return 0;
}
/* Remember to update object flag allocation in object.h */
#define COMPLETE (1U << 0)
#define SEEN (1U << 1)
#define TO_SCAN (1U << 2)
static struct commit_list *complete = NULL;
static int process_commit(struct walker *walker, struct commit *commit)
{
struct commit_list *parents;
if (repo_parse_commit(the_repository, commit))
return -1;
while (complete && complete->item->date >= commit->date) {
pop_most_recent_commit(&complete, COMPLETE);
}
if (commit->object.flags & COMPLETE)
return 0;
oidcpy(&current_commit_oid, &commit->object.oid);
walker_say(walker, "walk %s\n", oid_to_hex(&commit->object.oid));
if (process(walker, &repo_get_commit_tree(the_repository, commit)->object))
return -1;
for (parents = commit->parents; parents; parents = parents->next) {
if (process(walker, &parents->item->object))
return -1;
}
return 0;
}
static int process_tag(struct walker *walker, struct tag *tag)
{
if (parse_tag(tag))
return -1;
return process(walker, tag->tagged);
}
static struct object_list *process_queue = NULL;
static struct object_list **process_queue_end = &process_queue;
static int process_object(struct walker *walker, struct object *obj)
{
if (obj->type == OBJ_COMMIT) {
if (process_commit(walker, (struct commit *)obj))
return -1;
return 0;
}
if (obj->type == OBJ_TREE) {
if (process_tree(walker, (struct tree *)obj))
return -1;
return 0;
}
if (obj->type == OBJ_BLOB) {
return 0;
}
if (obj->type == OBJ_TAG) {
if (process_tag(walker, (struct tag *)obj))
return -1;
return 0;
}
return error("Unable to determine requirements "
"of type %s for %s",
type_name(obj->type), oid_to_hex(&obj->oid));
}
static int process(struct walker *walker, struct object *obj)
{
if (obj->flags & SEEN)
return 0;
obj->flags |= SEEN;
if (repo_has_object_file(the_repository, &obj->oid)) {
/* We already have it, so we should scan it now. */
obj->flags |= TO_SCAN;
}
else {
if (obj->flags & COMPLETE)
return 0;
walker->prefetch(walker, obj->oid.hash);
}
object_list_insert(obj, process_queue_end);
process_queue_end = &(*process_queue_end)->next;
return 0;
}
static int loop(struct walker *walker)
{
struct object_list *elem;
struct progress *progress = NULL;
uint64_t nr = 0;
if (walker->get_progress)
progress = start_delayed_progress(_("Fetching objects"), 0);
while (process_queue) {
struct object *obj = process_queue->item;
elem = process_queue;
process_queue = elem->next;
free(elem);
if (!process_queue)
process_queue_end = &process_queue;
/* If we are not scanning this object, we placed it in
* the queue because we needed to fetch it first.
*/
if (! (obj->flags & TO_SCAN)) {
if (walker->fetch(walker, obj->oid.hash)) {
stop_progress(&progress);
report_missing(obj);
return -1;
}
}
if (!obj->type)
parse_object(the_repository, &obj->oid);
if (process_object(walker, obj)) {
stop_progress(&progress);
return -1;
}
display_progress(progress, ++nr);
}
stop_progress(&progress);
return 0;
}
static int interpret_target(struct walker *walker, char *target, struct object_id *oid)
{
if (!get_oid_hex(target, oid))
return 0;
if (!check_refname_format(target, 0)) {
struct ref *ref = alloc_ref(target);
if (!walker->fetch_ref(walker, ref)) {
oidcpy(oid, &ref->old_oid);
free(ref);
return 0;
}
free(ref);
}
return -1;
}
static int mark_complete(const char *path UNUSED,
const struct object_id *oid,
int flag UNUSED,
void *cb_data UNUSED)
{
struct commit *commit = lookup_commit_reference_gently(the_repository,
oid, 1);
if (commit) {
commit->object.flags |= COMPLETE;
commit_list_insert(commit, &complete);
}
return 0;
}
int walker_targets_stdin(char ***target, const char ***write_ref)
{
int targets = 0, targets_alloc = 0;
struct strbuf buf = STRBUF_INIT;
*target = NULL; *write_ref = NULL;
while (1) {
char *rf_one = NULL;
char *tg_one;
if (strbuf_getline_lf(&buf, stdin) == EOF)
break;
tg_one = buf.buf;
rf_one = strchr(tg_one, '\t');
if (rf_one)
*rf_one++ = 0;
if (targets >= targets_alloc) {
targets_alloc = targets_alloc ? targets_alloc * 2 : 64;
REALLOC_ARRAY(*target, targets_alloc);
REALLOC_ARRAY(*write_ref, targets_alloc);
}
(*target)[targets] = xstrdup(tg_one);
(*write_ref)[targets] = xstrdup_or_null(rf_one);
targets++;
}
strbuf_release(&buf);
return targets;
}
void walker_targets_free(int targets, char **target, const char **write_ref)
{
while (targets--) {
free(target[targets]);
if (write_ref)
free((char *) write_ref[targets]);
}
}
int walker_fetch(struct walker *walker, int targets, char **target,
const char **write_ref, const char *write_ref_log_details)
{
struct strbuf refname = STRBUF_INIT;
struct strbuf err = STRBUF_INIT;
struct ref_transaction *transaction = NULL;
struct object_id *oids;
char *msg = NULL;
int i, ret = -1;
save_commit_buffer = 0;
ALLOC_ARRAY(oids, targets);
if (write_ref) {
transaction = ref_transaction_begin(&err);
if (!transaction) {
error("%s", err.buf);
goto done;
}
}
if (!walker->get_recover) {
for_each_ref(mark_complete, NULL);
commit_list_sort_by_date(&complete);
}
for (i = 0; i < targets; i++) {
if (interpret_target(walker, target[i], oids + i)) {
error("Could not interpret response from server '%s' as something to pull", target[i]);
goto done;
}
if (process(walker, lookup_unknown_object(the_repository, &oids[i])))
goto done;
}
if (loop(walker))
goto done;
if (!write_ref) {
ret = 0;
goto done;
}
if (write_ref_log_details) {
msg = xstrfmt("fetch from %s", write_ref_log_details);
} else {
msg = NULL;
}
for (i = 0; i < targets; i++) {
if (!write_ref[i])
continue;
strbuf_reset(&refname);
strbuf_addf(&refname, "refs/%s", write_ref[i]);
if (ref_transaction_update(transaction, refname.buf,
oids + i, NULL, 0,
msg ? msg : "fetch (unknown)",
&err)) {
error("%s", err.buf);
goto done;
}
}
if (ref_transaction_commit(transaction, &err)) {
error("%s", err.buf);
goto done;
}
ret = 0;
done:
ref_transaction_free(transaction);
free(msg);
free(oids);
strbuf_release(&err);
strbuf_release(&refname);
return ret;
}
void walker_free(struct walker *walker)
{
walker->cleanup(walker);
free(walker);
}