git/walker.c
Jeff King f33206992d walker_fetch: fix minor memory leak
We sometimes allocate "msg" on the heap, but will fail to
free it if we hit the failure code path. We can instead keep
a separate variable that is safe to be freed no matter how
we get to the failure code path.

While we're here, we can also do two readability
improvements:

  1. Use xstrfmt instead of a manual malloc/sprintf

  2. Due to the "maybe we allocate msg, maybe we don't"
     strategy, the logic for deciding which message to show
     was split into two parts. Since the deallocation is now
     pushed onto a separate variable, this is no longer a
     concern, and we can keep all of the logic in the same
     place.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-06-19 15:20:56 -07:00

319 lines
7.2 KiB
C

#include "cache.h"
#include "walker.h"
#include "commit.h"
#include "tree.h"
#include "tree-walk.h"
#include "tag.h"
#include "blob.h"
#include "refs.h"
static unsigned char current_commit_sha1[20];
void walker_say(struct walker *walker, const char *fmt, const char *hex)
{
if (walker->get_verbosely)
fprintf(stderr, fmt, hex);
}
static void report_missing(const struct object *obj)
{
char missing_hex[41];
strcpy(missing_hex, sha1_to_hex(obj->sha1));
fprintf(stderr, "Cannot obtain needed %s %s\n",
obj->type ? typename(obj->type): "object", missing_hex);
if (!is_null_sha1(current_commit_sha1))
fprintf(stderr, "while processing commit %s.\n",
sha1_to_hex(current_commit_sha1));
}
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->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(entry.sha1);
if (tree)
obj = &tree->object;
}
else {
struct blob *blob = lookup_blob(entry.sha1);
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)
{
if (parse_commit(commit))
return -1;
while (complete && complete->item->date >= commit->date) {
pop_most_recent_commit(&complete, COMPLETE);
}
if (commit->object.flags & COMPLETE)
return 0;
hashcpy(current_commit_sha1, commit->object.sha1);
walker_say(walker, "walk %s\n", sha1_to_hex(commit->object.sha1));
if (walker->get_tree) {
if (process(walker, &commit->tree->object))
return -1;
if (!walker->get_all)
walker->get_tree = 0;
}
if (walker->get_history) {
struct commit_list *parents = commit->parents;
for (; 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",
typename(obj->type), sha1_to_hex(obj->sha1));
}
static int process(struct walker *walker, struct object *obj)
{
if (obj->flags & SEEN)
return 0;
obj->flags |= SEEN;
if (has_sha1_file(obj->sha1)) {
/* 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->sha1);
}
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;
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->sha1)) {
report_missing(obj);
return -1;
}
}
if (!obj->type)
parse_object(obj->sha1);
if (process_object(walker, obj))
return -1;
}
return 0;
}
static int interpret_target(struct walker *walker, char *target, unsigned char *sha1)
{
if (!get_sha1_hex(target, sha1))
return 0;
if (!check_refname_format(target, 0)) {
struct ref *ref = alloc_ref(target);
if (!walker->fetch_ref(walker, ref)) {
hashcpy(sha1, ref->old_sha1);
free(ref);
return 0;
}
free(ref);
}
return -1;
}
static int mark_complete(const char *path, const unsigned char *sha1, int flag, void *cb_data)
{
struct commit *commit = lookup_commit_reference_gently(sha1, 1);
if (commit) {
commit->object.flags |= COMPLETE;
commit_list_insert_by_date(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(&buf, stdin, '\n') == 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;
*target = xrealloc(*target, targets_alloc * sizeof(**target));
*write_ref = xrealloc(*write_ref, targets_alloc * sizeof(**write_ref));
}
(*target)[targets] = xstrdup(tg_one);
(*write_ref)[targets] = rf_one ? xstrdup(rf_one) : NULL;
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 ref_lock **lock = xcalloc(targets, sizeof(struct ref_lock *));
unsigned char *sha1 = xmalloc(targets * 20);
const char *msg;
char *to_free = NULL;
int ret;
int i;
save_commit_buffer = 0;
for (i = 0; i < targets; i++) {
if (!write_ref || !write_ref[i])
continue;
lock[i] = lock_ref_sha1(write_ref[i], NULL);
if (!lock[i]) {
error("Can't lock ref %s", write_ref[i]);
goto unlock_and_fail;
}
}
if (!walker->get_recover)
for_each_ref(mark_complete, NULL);
for (i = 0; i < targets; i++) {
if (interpret_target(walker, target[i], &sha1[20 * i])) {
error("Could not interpret response from server '%s' as something to pull", target[i]);
goto unlock_and_fail;
}
if (process(walker, lookup_unknown_object(&sha1[20 * i])))
goto unlock_and_fail;
}
if (loop(walker))
goto unlock_and_fail;
if (write_ref_log_details)
msg = to_free = xstrfmt("fetch from %s", write_ref_log_details);
else
msg = "fetch (unknown)";
for (i = 0; i < targets; i++) {
if (!write_ref || !write_ref[i])
continue;
ret = write_ref_sha1(lock[i], &sha1[20 * i], msg);
lock[i] = NULL;
if (ret)
goto unlock_and_fail;
}
free(to_free);
return 0;
unlock_and_fail:
for (i = 0; i < targets; i++)
if (lock[i])
unlock_ref(lock[i]);
free(to_free);
return -1;
}
void walker_free(struct walker *walker)
{
walker->cleanup(walker);
free(walker);
}